/*
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * This file is generated from kinto.js - do not modify directly.
 */

/*
 * Version 13.0.0 - 7fbf95d
 */

/**
 * Base db adapter.
 *
 * @abstract
 */
class BaseAdapter {
    /**
     * Deletes every records present in the database.
     *
     * @abstract
     * @return {Promise}
     */
    clear() {
        throw new Error("Not Implemented.");
    }
    /**
     * Executes a batch of operations within a single transaction.
     *
     * @abstract
     * @param  {Function} callback The operation callback.
     * @param  {Object}   options  The options object.
     * @return {Promise}
     */
    execute(callback, options = { preload: [] }) {
        throw new Error("Not Implemented.");
    }
    /**
     * Retrieve a record by its primary key from the database.
     *
     * @abstract
     * @param  {String} id The record id.
     * @return {Promise}
     */
    get(id) {
        throw new Error("Not Implemented.");
    }
    /**
     * Lists all records from the database.
     *
     * @abstract
     * @param  {Object} params  The filters and order to apply to the results.
     * @return {Promise}
     */
    list(params = { filters: {}, order: "" }) {
        throw new Error("Not Implemented.");
    }
    /**
     * Store the lastModified value.
     *
     * @abstract
     * @param  {Number}  lastModified
     * @return {Promise}
     */
    saveLastModified(lastModified) {
        throw new Error("Not Implemented.");
    }
    /**
     * Retrieve saved lastModified value.
     *
     * @abstract
     * @return {Promise}
     */
    getLastModified() {
        throw new Error("Not Implemented.");
    }
    /**
     * Load records in bulk that were exported from a server.
     *
     * @abstract
     * @param  {Array} records The records to load.
     * @return {Promise}
     */
    importBulk(records) {
        throw new Error("Not Implemented.");
    }
    /**
     * Load a dump of records exported from a server.
     *
     * @deprecated Use {@link importBulk} instead.
     * @abstract
     * @param  {Array} records The records to load.
     * @return {Promise}
     */
    loadDump(records) {
        throw new Error("Not Implemented.");
    }
    saveMetadata(metadata) {
        throw new Error("Not Implemented.");
    }
    getMetadata() {
        throw new Error("Not Implemented.");
    }
}

const RE_RECORD_ID = /^[a-zA-Z0-9][a-zA-Z0-9_-]*$/;
/**
 * Checks if a value is undefined.
 * @param  {Any}  value
 * @return {Boolean}
 */
function _isUndefined(value) {
    return typeof value === "undefined";
}
/**
 * Sorts records in a list according to a given ordering.
 *
 * @param  {String} order The ordering, eg. `-last_modified`.
 * @param  {Array}  list  The collection to order.
 * @return {Array}
 */
function sortObjects(order, list) {
    const hasDash = order[0] === "-";
    const field = hasDash ? order.slice(1) : order;
    const direction = hasDash ? -1 : 1;
    return list.slice().sort((a, b) => {
        if (a[field] && _isUndefined(b[field])) {
            return direction;
        }
        if (b[field] && _isUndefined(a[field])) {
            return -direction;
        }
        if (_isUndefined(a[field]) && _isUndefined(b[field])) {
            return 0;
        }
        return a[field] > b[field] ? direction : -direction;
    });
}
/**
 * Test if a single object matches all given filters.
 *
 * @param  {Object} filters  The filters object.
 * @param  {Object} entry    The object to filter.
 * @return {Boolean}
 */
function filterObject(filters, entry) {
    return Object.keys(filters).every(filter => {
        const value = filters[filter];
        if (Array.isArray(value)) {
            return value.some(candidate => candidate === entry[filter]);
        }
        else if (typeof value === "object") {
            return filterObject(value, entry[filter]);
        }
        else if (!Object.prototype.hasOwnProperty.call(entry, filter)) {
            console.error(`The property ${filter} does not exist`);
            return false;
        }
        return entry[filter] === value;
    });
}
/**
 * Resolves a list of functions sequentially, which can be sync or async; in
 * case of async, functions must return a promise.
 *
 * @param  {Array} fns  The list of functions.
 * @param  {Any}   init The initial value.
 * @return {Promise}
 */
function waterfall(fns, init) {
    if (!fns.length) {
        return Promise.resolve(init);
    }
    return fns.reduce((promise, nextFn) => {
        return promise.then(nextFn);
    }, Promise.resolve(init));
}
/**
 * Simple deep object comparison function. This only supports comparison of
 * serializable JavaScript objects.
 *
 * @param  {Object} a The source object.
 * @param  {Object} b The compared object.
 * @return {Boolean}
 */
function deepEqual(a, b) {
    if (a === b) {
        return true;
    }
    if (typeof a !== typeof b) {
        return false;
    }
    if (!(a && typeof a == "object") || !(b && typeof b == "object")) {
        return false;
    }
    if (Object.keys(a).length !== Object.keys(b).length) {
        return false;
    }
    for (const k in a) {
        if (!deepEqual(a[k], b[k])) {
            return false;
        }
    }
    return true;
}
/**
 * Return an object without the specified keys.
 *
 * @param  {Object} obj        The original object.
 * @param  {Array}  keys       The list of keys to exclude.
 * @return {Object}            A copy without the specified keys.
 */
function omitKeys(obj, keys = []) {
    const result = Object.assign({}, obj);
    for (const key of keys) {
        delete result[key];
    }
    return result;
}
function arrayEqual(a, b) {
    if (a.length !== b.length) {
        return false;
    }
    for (let i = a.length; i--;) {
        if (a[i] !== b[i]) {
            return false;
        }
    }
    return true;
}
function makeNestedObjectFromArr(arr, val, nestedFiltersObj) {
    const last = arr.length - 1;
    return arr.reduce((acc, cv, i) => {
        if (i === last) {
            return (acc[cv] = val);
        }
        else if (Object.prototype.hasOwnProperty.call(acc, cv)) {
            return acc[cv];
        }
        else {
            return (acc[cv] = {});
        }
    }, nestedFiltersObj);
}
function transformSubObjectFilters(filtersObj) {
    const transformedFilters = {};
    for (const key in filtersObj) {
        const keysArr = key.split(".");
        const val = filtersObj[key];
        makeNestedObjectFromArr(keysArr, val, transformedFilters);
    }
    return transformedFilters;
}

const INDEXED_FIELDS = ["id", "_status", "last_modified"];
/**
 * Small helper that wraps the opening of an IndexedDB into a Promise.
 *
 * @param dbname          {String}   The database name.
 * @param version         {Integer}  Schema version
 * @param onupgradeneeded {Function} The callback to execute if schema is
 *                                   missing or different.
 * @return {Promise<IDBDatabase>}
 */
async function open(dbname, { version, onupgradeneeded }) {
    return new Promise((resolve, reject) => {
        const request = indexedDB.open(dbname, version);
        request.onupgradeneeded = event => {
            const db = event.target.result;
            db.onerror = event => reject(event.target.error);
            // When an upgrade is needed, a transaction is started.
            const transaction = event.target.transaction;
            transaction.onabort = event => {
                const error = event.target.error ||
                    transaction.error ||
                    new DOMException("The operation has been aborted", "AbortError");
                reject(error);
            };
            // Callback for store creation etc.
            return onupgradeneeded(event);
        };
        request.onerror = event => {
            reject(event.target.error);
        };
        request.onsuccess = event => {
            const db = event.target.result;
            resolve(db);
        };
    });
}
/**
 * Helper to run the specified callback in a single transaction on the
 * specified store.
 * The helper focuses on transaction wrapping into a promise.
 *
 * @param db           {IDBDatabase} The database instance.
 * @param name         {String}      The store name.
 * @param callback     {Function}    The piece of code to execute in the transaction.
 * @param options      {Object}      Options.
 * @param options.mode {String}      Transaction mode (default: read).
 * @return {Promise} any value returned by the callback.
 */
async function execute(db, name, callback, options = {}) {
    const { mode } = options;
    return new Promise((resolve, reject) => {
        // On Safari, calling IDBDatabase.transaction with mode == undefined raises
        // a TypeError.
        const transaction = mode
            ? db.transaction([name], mode)
            : db.transaction([name]);
        const store = transaction.objectStore(name);
        // Let the callback abort this transaction.
        const abort = e => {
            transaction.abort();
            reject(e);
        };
        // Execute the specified callback **synchronously**.
        let result;
        try {
            result = callback(store, abort);
        }
        catch (e) {
            abort(e);
        }
        transaction.onerror = event => reject(event.target.error);
        transaction.oncomplete = event => resolve(result);
        transaction.onabort = event => {
            const error = event.target.error ||
                transaction.error ||
                new DOMException("The operation has been aborted", "AbortError");
            reject(error);
        };
    });
}
/**
 * Helper to wrap the deletion of an IndexedDB database into a promise.
 *
 * @param dbName {String} the database to delete
 * @return {Promise}
 */
async function deleteDatabase(dbName) {
    return new Promise((resolve, reject) => {
        const request = indexedDB.deleteDatabase(dbName);
        request.onsuccess = event => resolve(event.target);
        request.onerror = event => reject(event.target.error);
    });
}
/**
 * IDB cursor handlers.
 * @type {Object}
 */
const cursorHandlers = {
    all(filters, done) {
        const results = [];
        return event => {
            const cursor = event.target.result;
            if (cursor) {
                const { value } = cursor;
                if (filterObject(filters, value)) {
                    results.push(value);
                }
                cursor.continue();
            }
            else {
                done(results);
            }
        };
    },
    in(values, filters, done) {
        const results = [];
        let i = 0;
        return function (event) {
            const cursor = event.target.result;
            if (!cursor) {
                done(results);
                return;
            }
            const { key, value } = cursor;
            // `key` can be an array of two values (see `keyPath` in indices definitions).
            // `values` can be an array of arrays if we filter using an index whose key path
            // is an array (eg. `cursorHandlers.in([["bid/cid", 42], ["bid/cid", 43]], ...)`)
            while (key > values[i]) {
                // The cursor has passed beyond this key. Check next.
                ++i;
                if (i === values.length) {
                    done(results); // There is no next. Stop searching.
                    return;
                }
            }
            const isEqual = Array.isArray(key)
                ? arrayEqual(key, values[i])
                : key === values[i];
            if (isEqual) {
                if (filterObject(filters, value)) {
                    results.push(value);
                }
                cursor.continue();
            }
            else {
                cursor.continue(values[i]);
            }
        };
    },
};
/**
 * Creates an IDB request and attach it the appropriate cursor event handler to
 * perform a list query.
 *
 * Multiple matching values are handled by passing an array.
 *
 * @param  {String}           cid        The collection id (ie. `{bid}/{cid}`)
 * @param  {IDBStore}         store      The IDB store.
 * @param  {Object}           filters    Filter the records by field.
 * @param  {Function}         done       The operation completion handler.
 * @return {IDBRequest}
 */
function createListRequest(cid, store, filters, done) {
    const filterFields = Object.keys(filters);
    // If no filters, get all results in one bulk.
    if (filterFields.length == 0) {
        const request = store.index("cid").getAll(IDBKeyRange.only(cid));
        request.onsuccess = event => done(event.target.result);
        return request;
    }
    // Introspect filters and check if they leverage an indexed field.
    const indexField = filterFields.find(field => {
        return INDEXED_FIELDS.includes(field);
    });
    if (!indexField) {
        // Iterate on all records for this collection (ie. cid)
        const isSubQuery = Object.keys(filters).some(key => key.includes(".")); // (ie. filters: {"article.title": "hello"})
        if (isSubQuery) {
            const newFilter = transformSubObjectFilters(filters);
            const request = store.index("cid").openCursor(IDBKeyRange.only(cid));
            request.onsuccess = cursorHandlers.all(newFilter, done);
            return request;
        }
        const request = store.index("cid").openCursor(IDBKeyRange.only(cid));
        request.onsuccess = cursorHandlers.all(filters, done);
        return request;
    }
    // If `indexField` was used already, don't filter again.
    const remainingFilters = omitKeys(filters, [indexField]);
    // value specified in the filter (eg. `filters: { _status: ["created", "updated"] }`)
    const value = filters[indexField];
    // For the "id" field, use the primary key.
    const indexStore = indexField == "id" ? store : store.index(indexField);
    // WHERE IN equivalent clause
    if (Array.isArray(value)) {
        if (value.length === 0) {
            return done([]);
        }
        const values = value.map(i => [cid, i]).sort();
        const range = IDBKeyRange.bound(values[0], values[values.length - 1]);
        const request = indexStore.openCursor(range);
        request.onsuccess = cursorHandlers.in(values, remainingFilters, done);
        return request;
    }
    // If no filters on custom attribute, get all results in one bulk.
    if (remainingFilters.length == 0) {
        const request = indexStore.getAll(IDBKeyRange.only([cid, value]));
        request.onsuccess = event => done(event.target.result);
        return request;
    }
    // WHERE field = value clause
    const request = indexStore.openCursor(IDBKeyRange.only([cid, value]));
    request.onsuccess = cursorHandlers.all(remainingFilters, done);
    return request;
}
class IDBError extends Error {
    constructor(method, err) {
        super(`IndexedDB ${method}() ${err.message}`);
        this.name = err.name;
        this.stack = err.stack;
    }
}
/**
 * IndexedDB adapter.
 *
 * This adapter doesn't support any options.
 */
class IDB extends BaseAdapter {
    /* Expose the IDBError class publicly */
    static get IDBError() {
        return IDBError;
    }
    /**
     * Constructor.
     *
     * @param  {String} cid  The key base for this collection (eg. `bid/cid`)
     * @param  {Object} options
     * @param  {String} options.dbName         The IndexedDB name (default: `"KintoDB"`)
     * @param  {String} options.migrateOldData Whether old database data should be migrated (default: `false`)
     */
    constructor(cid, options = {}) {
        super();
        this.cid = cid;
        this.dbName = options.dbName || "KintoDB";
        this._options = options;
        this._db = null;
    }
    _handleError(method, err) {
        throw new IDBError(method, err);
    }
    /**
     * Ensures a connection to the IndexedDB database has been opened.
     *
     * @override
     * @return {Promise}
     */
    async open() {
        if (this._db) {
            return this;
        }
        // In previous versions, we used to have a database with name `${bid}/${cid}`.
        // Check if it exists, and migrate data once new schema is in place.
        // Note: the built-in migrations from IndexedDB can only be used if the
        // database name does not change.
        const dataToMigrate = this._options.migrateOldData
            ? await migrationRequired(this.cid)
            : null;
        this._db = await open(this.dbName, {
            version: 2,
            onupgradeneeded: event => {
                const db = event.target.result;
                if (event.oldVersion < 1) {
                    // Records store
                    const recordsStore = db.createObjectStore("records", {
                        keyPath: ["_cid", "id"],
                    });
                    // An index to obtain all the records in a collection.
                    recordsStore.createIndex("cid", "_cid");
                    // Here we create indices for every known field in records by collection.
                    // Local record status ("synced", "created", "updated", "deleted")
                    recordsStore.createIndex("_status", ["_cid", "_status"]);
                    // Last modified field
                    recordsStore.createIndex("last_modified", ["_cid", "last_modified"]);
                    // Timestamps store
                    db.createObjectStore("timestamps", {
                        keyPath: "cid",
                    });
                }
                if (event.oldVersion < 2) {
                    // Collections store
                    db.createObjectStore("collections", {
                        keyPath: "cid",
                    });
                }
            },
        });
        if (dataToMigrate) {
            const { records, timestamp } = dataToMigrate;
            await this.importBulk(records);
            await this.saveLastModified(timestamp);
            console.log(`${this.cid}: data was migrated successfully.`);
            // Delete the old database.
            await deleteDatabase(this.cid);
            console.warn(`${this.cid}: old database was deleted.`);
        }
        return this;
    }
    /**
     * Closes current connection to the database.
     *
     * @override
     * @return {Promise}
     */
    close() {
        if (this._db) {
            this._db.close(); // indexedDB.close is synchronous
            this._db = null;
        }
        return Promise.resolve();
    }
    /**
     * Returns a transaction and an object store for a store name.
     *
     * To determine if a transaction has completed successfully, we should rather
     * listen to the transaction’s complete event rather than the IDBObjectStore
     * request’s success event, because the transaction may still fail after the
     * success event fires.
     *
     * @param  {String}      name  Store name
     * @param  {Function}    callback to execute
     * @param  {Object}      options Options
     * @param  {String}      options.mode  Transaction mode ("readwrite" or undefined)
     * @return {Object}
     */
    async prepare(name, callback, options) {
        await this.open();
        await execute(this._db, name, callback, options);
    }
    /**
     * Deletes every records in the current collection.
     *
     * @override
     * @return {Promise}
     */
    async clear() {
        try {
            await this.prepare("records", store => {
                const range = IDBKeyRange.only(this.cid);
                const request = store.index("cid").openKeyCursor(range);
                request.onsuccess = event => {
                    const cursor = event.target.result;
                    if (cursor) {
                        store.delete(cursor.primaryKey);
                        cursor.continue();
                    }
                };
                return request;
            }, { mode: "readwrite" });
        }
        catch (e) {
            this._handleError("clear", e);
        }
    }
    /**
     * Executes the set of synchronous CRUD operations described in the provided
     * callback within an IndexedDB transaction, for current db store.
     *
     * The callback will be provided an object exposing the following synchronous
     * CRUD operation methods: get, create, update, delete.
     *
     * Important note: because limitations in IndexedDB implementations, no
     * asynchronous code should be performed within the provided callback; the
     * promise will therefore be rejected if the callback returns a Promise.
     *
     * Options:
     * - {Array} preload: The list of record IDs to fetch and make available to
     *   the transaction object get() method (default: [])
     *
     * @example
     * const db = new IDB("example");
     * const result = await db.execute(transaction => {
     *   transaction.create({id: 1, title: "foo"});
     *   transaction.update({id: 2, title: "bar"});
     *   transaction.delete(3);
     *   return "foo";
     * });
     *
     * @override
     * @param  {Function} callback The operation description callback.
     * @param  {Object}   options  The options object.
     * @return {Promise}
     */
    async execute(callback, options = { preload: [] }) {
        // Transactions in IndexedDB are autocommited when a callback does not
        // perform any additional operation.
        // The way Promises are implemented in Firefox (see https://bugzilla.mozilla.org/show_bug.cgi?id=1193394)
        // prevents using within an opened transaction.
        // To avoid managing asynchronocity in the specified `callback`, we preload
        // a list of record in order to execute the `callback` synchronously.
        // See also:
        // - http://stackoverflow.com/a/28388805/330911
        // - http://stackoverflow.com/a/10405196
        // - https://jakearchibald.com/2015/tasks-microtasks-queues-and-schedules/
        let result;
        await this.prepare("records", (store, abort) => {
            const runCallback = (preloaded = []) => {
                // Expose a consistent API for every adapter instead of raw store methods.
                const proxy = transactionProxy(this, store, preloaded);
                // The callback is executed synchronously within the same transaction.
                try {
                    const returned = callback(proxy);
                    if (returned instanceof Promise) {
                        // XXX: investigate how to provide documentation details in error.
                        throw new Error("execute() callback should not return a Promise.");
                    }
                    // Bring to scope that will be returned (once promise awaited).
                    result = returned;
                }
                catch (e) {
                    // The callback has thrown an error explicitly. Abort transaction cleanly.
                    abort(e);
                }
            };
            // No option to preload records, go straight to `callback`.
            if (!options.preload.length) {
                return runCallback();
            }
            // Preload specified records using a list request.
            const filters = { id: options.preload };
            createListRequest(this.cid, store, filters, records => {
                // Store obtained records by id.
                const preloaded = {};
                for (const record of records) {
                    delete record["_cid"];
                    preloaded[record.id] = record;
                }
                runCallback(preloaded);
            });
        }, { mode: "readwrite" });
        return result;
    }
    /**
     * Retrieve a record by its primary key from the IndexedDB database.
     *
     * @override
     * @param  {String} id The record id.
     * @return {Promise}
     */
    async get(id) {
        try {
            let record;
            await this.prepare("records", store => {
                store.get([this.cid, id]).onsuccess = e => (record = e.target.result);
            });
            return record;
        }
        catch (e) {
            this._handleError("get", e);
        }
    }
    /**
     * Lists all records from the IndexedDB database.
     *
     * @override
     * @param  {Object} params  The filters and order to apply to the results.
     * @return {Promise}
     */
    async list(params = { filters: {} }) {
        const { filters } = params;
        try {
            let results = [];
            await this.prepare("records", store => {
                createListRequest(this.cid, store, filters, _results => {
                    // we have received all requested records that match the filters,
                    // we now park them within current scope and hide the `_cid` attribute.
                    for (const result of _results) {
                        delete result["_cid"];
                    }
                    results = _results;
                });
            });
            // The resulting list of records is sorted.
            // XXX: with some efforts, this could be fully implemented using IDB API.
            return params.order ? sortObjects(params.order, results) : results;
        }
        catch (e) {
            this._handleError("list", e);
        }
    }
    /**
     * Store the lastModified value into metadata store.
     *
     * @override
     * @param  {Number}  lastModified
     * @return {Promise}
     */
    async saveLastModified(lastModified) {
        const value = parseInt(lastModified, 10) || null;
        try {
            await this.prepare("timestamps", store => {
                if (value === null) {
                    store.delete(this.cid);
                }
                else {
                    store.put({ cid: this.cid, value });
                }
            }, { mode: "readwrite" });
            return value;
        }
        catch (e) {
            this._handleError("saveLastModified", e);
        }
    }
    /**
     * Retrieve saved lastModified value.
     *
     * @override
     * @return {Promise}
     */
    async getLastModified() {
        try {
            let entry = null;
            await this.prepare("timestamps", store => {
                store.get(this.cid).onsuccess = e => (entry = e.target.result);
            });
            return entry ? entry.value : null;
        }
        catch (e) {
            this._handleError("getLastModified", e);
        }
    }
    /**
     * Load a dump of records exported from a server.
     *
     * @deprecated Use {@link importBulk} instead.
     * @abstract
     * @param  {Array} records The records to load.
     * @return {Promise}
     */
    async loadDump(records) {
        return this.importBulk(records);
    }
    /**
     * Load records in bulk that were exported from a server.
     *
     * @abstract
     * @param  {Array} records The records to load.
     * @return {Promise}
     */
    async importBulk(records) {
        try {
            await this.execute(transaction => {
                // Since the put operations are asynchronous, we chain
                // them together. The last one will be waited for the
                // `transaction.oncomplete` callback. (see #execute())
                let i = 0;
                putNext();
                function putNext() {
                    if (i == records.length) {
                        return;
                    }
                    // On error, `transaction.onerror` is called.
                    transaction.update(records[i]).onsuccess = putNext;
                    ++i;
                }
            });
            const previousLastModified = await this.getLastModified();
            const lastModified = Math.max(...records.map(record => record.last_modified));
            if (lastModified > previousLastModified) {
                await this.saveLastModified(lastModified);
            }
            return records;
        }
        catch (e) {
            this._handleError("importBulk", e);
        }
    }
    async saveMetadata(metadata) {
        try {
            await this.prepare("collections", store => store.put({ cid: this.cid, metadata }), { mode: "readwrite" });
            return metadata;
        }
        catch (e) {
            this._handleError("saveMetadata", e);
        }
    }
    async getMetadata() {
        try {
            let entry = null;
            await this.prepare("collections", store => {
                store.get(this.cid).onsuccess = e => (entry = e.target.result);
            });
            return entry ? entry.metadata : null;
        }
        catch (e) {
            this._handleError("getMetadata", e);
        }
    }
}
/**
 * IDB transaction proxy.
 *
 * @param  {IDB} adapter        The call IDB adapter
 * @param  {IDBStore} store     The IndexedDB database store.
 * @param  {Array}    preloaded The list of records to make available to
 *                              get() (default: []).
 * @return {Object}
 */
function transactionProxy(adapter, store, preloaded = []) {
    const _cid = adapter.cid;
    return {
        create(record) {
            store.add(Object.assign(Object.assign({}, record), { _cid }));
        },
        update(record) {
            return store.put(Object.assign(Object.assign({}, record), { _cid }));
        },
        delete(id) {
            store.delete([_cid, id]);
        },
        get(id) {
            return preloaded[id];
        },
    };
}
/**
 * Up to version 10.X of kinto.js, each collection had its own collection.
 * The database name was `${bid}/${cid}` (eg. `"blocklists/certificates"`)
 * and contained only one store with the same name.
 */
async function migrationRequired(dbName) {
    let exists = true;
    const db = await open(dbName, {
        version: 1,
        onupgradeneeded: event => {
            exists = false;
        },
    });
    // Check that the DB we're looking at is really a legacy one,
    // and not some remainder of the open() operation above.
    exists &=
        db.objectStoreNames.contains("__meta__") &&
            db.objectStoreNames.contains(dbName);
    if (!exists) {
        db.close();
        // Testing the existence creates it, so delete it :)
        await deleteDatabase(dbName);
        return null;
    }
    console.warn(`${dbName}: old IndexedDB database found.`);
    try {
        // Scan all records.
        let records;
        await execute(db, dbName, store => {
            store.openCursor().onsuccess = cursorHandlers.all({}, res => (records = res));
        });
        console.log(`${dbName}: found ${records.length} records.`);
        // Check if there's a entry for this.
        let timestamp = null;
        await execute(db, "__meta__", store => {
            store.get(`${dbName}-lastModified`).onsuccess = e => {
                timestamp = e.target.result ? e.target.result.value : null;
            };
        });
        // Some previous versions, also used to store the timestamps without prefix.
        if (!timestamp) {
            await execute(db, "__meta__", store => {
                store.get("lastModified").onsuccess = e => {
                    timestamp = e.target.result ? e.target.result.value : null;
                };
            });
        }
        console.log(`${dbName}: ${timestamp ? "found" : "no"} timestamp.`);
        // Those will be inserted in the new database/schema.
        return { records, timestamp };
    }
    catch (e) {
        console.error("Error occured during migration", e);
        return null;
    }
    finally {
        db.close();
    }
}

var uuid4 = {};

const RECORD_FIELDS_TO_CLEAN = ["_status"];
const AVAILABLE_HOOKS = ["incoming-changes"];
const IMPORT_CHUNK_SIZE = 200;
/**
 * Compare two records omitting local fields and synchronization
 * attributes (like _status and last_modified)
 * @param {Object} a    A record to compare.
 * @param {Object} b    A record to compare.
 * @param {Array} localFields Additional fields to ignore during the comparison
 * @return {boolean}
 */
function recordsEqual(a, b, localFields = []) {
    const fieldsToClean = RECORD_FIELDS_TO_CLEAN.concat(["last_modified"]).concat(localFields);
    const cleanLocal = r => omitKeys(r, fieldsToClean);
    return deepEqual(cleanLocal(a), cleanLocal(b));
}
/**
 * Synchronization result object.
 */
class SyncResultObject {
    /**
     * Public constructor.
     */
    constructor() {
        /**
         * Current synchronization result status; becomes `false` when conflicts or
         * errors are registered.
         * @type {Boolean}
         */
        this.lastModified = null;
        this._lists = {};
        [
            "errors",
            "created",
            "updated",
            "deleted",
            "published",
            "conflicts",
            "skipped",
            "resolved",
            "void",
        ].forEach(l => (this._lists[l] = []));
        this._cached = {};
    }
    /**
     * Adds entries for a given result type.
     *
     * @param {String} type    The result type.
     * @param {Array}  entries The result entries.
     * @return {SyncResultObject}
     */
    add(type, entries) {
        if (!Array.isArray(this._lists[type])) {
            console.warn(`Unknown type "${type}"`);
            return;
        }
        if (!Array.isArray(entries)) {
            entries = [entries];
        }
        this._lists[type] = this._lists[type].concat(entries);
        delete this._cached[type];
        return this;
    }
    get ok() {
        return this.errors.length + this.conflicts.length === 0;
    }
    get errors() {
        return this._lists["errors"];
    }
    get conflicts() {
        return this._lists["conflicts"];
    }
    get skipped() {
        return this._deduplicate("skipped");
    }
    get resolved() {
        return this._deduplicate("resolved");
    }
    get created() {
        return this._deduplicate("created");
    }
    get updated() {
        return this._deduplicate("updated");
    }
    get deleted() {
        return this._deduplicate("deleted");
    }
    get published() {
        return this._deduplicate("published");
    }
    _deduplicate(list) {
        if (!(list in this._cached)) {
            // Deduplicate entries by id. If the values don't have `id` attribute, just
            // keep all.
            const recordsWithoutId = new Set();
            const recordsById = new Map();
            this._lists[list].forEach(record => {
                if (!record.id) {
                    recordsWithoutId.add(record);
                }
                else {
                    recordsById.set(record.id, record);
                }
            });
            this._cached[list] = Array.from(recordsById.values()).concat(Array.from(recordsWithoutId));
        }
        return this._cached[list];
    }
    /**
     * Reinitializes result entries for a given result type.
     *
     * @param  {String} type The result type.
     * @return {SyncResultObject}
     */
    reset(type) {
        this._lists[type] = [];
        delete this._cached[type];
        return this;
    }
    toObject() {
        // Only used in tests.
        return {
            ok: this.ok,
            lastModified: this.lastModified,
            errors: this.errors,
            created: this.created,
            updated: this.updated,
            deleted: this.deleted,
            skipped: this.skipped,
            published: this.published,
            conflicts: this.conflicts,
            resolved: this.resolved,
        };
    }
}
class ServerWasFlushedError extends Error {
    constructor(clientTimestamp, serverTimestamp, message) {
        super(message);
        if (Error.captureStackTrace) {
            Error.captureStackTrace(this, ServerWasFlushedError);
        }
        this.clientTimestamp = clientTimestamp;
        this.serverTimestamp = serverTimestamp;
    }
}
function createUUIDSchema() {
    return {
        generate() {
            return uuid4();
        },
        validate(id) {
            return typeof id == "string" && RE_RECORD_ID.test(id);
        },
    };
}
function markStatus(record, status) {
    return Object.assign(Object.assign({}, record), { _status: status });
}
function markDeleted(record) {
    return markStatus(record, "deleted");
}
function markSynced(record) {
    return markStatus(record, "synced");
}
/**
 * Import a remote change into the local database.
 *
 * @param  {IDBTransactionProxy} transaction The transaction handler.
 * @param  {Object}              remote      The remote change object to import.
 * @param  {Array<String>}       localFields The list of fields that remain local.
 * @param  {String}              strategy    The {@link Collection.strategy}.
 * @return {Object}
 */
function importChange(transaction, remote, localFields, strategy) {
    const local = transaction.get(remote.id);
    if (!local) {
        // Not found locally but remote change is marked as deleted; skip to
        // avoid recreation.
        if (remote.deleted) {
            return { type: "skipped", data: remote };
        }
        const synced = markSynced(remote);
        transaction.create(synced);
        return { type: "created", data: synced };
    }
    // Apply remote changes on local record.
    const synced = Object.assign(Object.assign({}, local), markSynced(remote));
    // With pull only, we don't need to compare records since we override them.
    if (strategy === Collection.strategy.PULL_ONLY) {
        if (remote.deleted) {
            transaction.delete(remote.id);
            return { type: "deleted", data: local };
        }
        transaction.update(synced);
        return { type: "updated", data: { old: local, new: synced } };
    }
    // With other sync strategies, we detect conflicts,
    // by comparing local and remote, ignoring local fields.
    const isIdentical = recordsEqual(local, remote, localFields);
    // Detect or ignore conflicts if record has also been modified locally.
    if (local._status !== "synced") {
        // Locally deleted, unsynced: scheduled for remote deletion.
        if (local._status === "deleted") {
            return { type: "skipped", data: local };
        }
        if (isIdentical) {
            // If records are identical, import anyway, so we bump the
            // local last_modified value from the server and set record
            // status to "synced".
            transaction.update(synced);
            return { type: "updated", data: { old: local, new: synced } };
        }
        if (local.last_modified !== undefined &&
            local.last_modified === remote.last_modified) {
            // If our local version has the same last_modified as the remote
            // one, this represents an object that corresponds to a resolved
            // conflict. Our local version represents the final output, so
            // we keep that one. (No transaction operation to do.)
            // But if our last_modified is undefined,
            // that means we've created the same object locally as one on
            // the server, which *must* be a conflict.
            return { type: "void" };
        }
        return {
            type: "conflicts",
            data: { type: "incoming", local: local, remote: remote },
        };
    }
    // Local record was synced.
    if (remote.deleted) {
        transaction.delete(remote.id);
        return { type: "deleted", data: local };
    }
    // Import locally.
    transaction.update(synced);
    // if identical, simply exclude it from all SyncResultObject lists
    const type = isIdentical ? "void" : "updated";
    return { type, data: { old: local, new: synced } };
}
/**
 * Abstracts a collection of records stored in the local database, providing
 * CRUD operations and synchronization helpers.
 */
class Collection {
    /**
     * Constructor.
     *
     * Options:
     * - `{BaseAdapter} adapter` The DB adapter (default: `IDB`)
     *
     * @param  {String}    bucket  The bucket identifier.
     * @param  {String}    name    The collection name.
     * @param  {KintoBase} kinto   The Kinto instance.
     * @param  {Object}    options The options object.
     */
    constructor(bucket, name, kinto, options = {}) {
        this._bucket = bucket;
        this._name = name;
        this._lastModified = null;
        const DBAdapter = options.adapter || IDB;
        if (!DBAdapter) {
            throw new Error("No adapter provided");
        }
        const db = new DBAdapter(`${bucket}/${name}`, options.adapterOptions);
        if (!(db instanceof BaseAdapter)) {
            throw new Error("Unsupported adapter.");
        }
        // public properties
        /**
         * The db adapter instance
         * @type {BaseAdapter}
         */
        this.db = db;
        /**
         * The KintoBase instance.
         * @type {KintoBase}
         */
        this.kinto = kinto;
        /**
         * The event emitter instance.
         * @type {EventEmitter}
         */
        this.events = options.events;
        /**
         * The IdSchema instance.
         * @type {Object}
         */
        this.idSchema = this._validateIdSchema(options.idSchema);
        /**
         * The list of remote transformers.
         * @type {Array}
         */
        this.remoteTransformers = this._validateRemoteTransformers(options.remoteTransformers);
        /**
         * The list of hooks.
         * @type {Object}
         */
        this.hooks = this._validateHooks(options.hooks);
        /**
         * The list of fields names that will remain local.
         * @type {Array}
         */
        this.localFields = options.localFields || [];
    }
    /**
     * The HTTP client.
     * @type {KintoClient}
     */
    get api() {
        return this.kinto.api;
    }
    /**
     * The collection name.
     * @type {String}
     */
    get name() {
        return this._name;
    }
    /**
     * The bucket name.
     * @type {String}
     */
    get bucket() {
        return this._bucket;
    }
    /**
     * The last modified timestamp.
     * @type {Number}
     */
    get lastModified() {
        return this._lastModified;
    }
    /**
     * Synchronization strategies. Available strategies are:
     *
     * - `MANUAL`: Conflicts will be reported in a dedicated array.
     * - `SERVER_WINS`: Conflicts are resolved using remote data.
     * - `CLIENT_WINS`: Conflicts are resolved using local data.
     *
     * @type {Object}
     */
    static get strategy() {
        return {
            CLIENT_WINS: "client_wins",
            SERVER_WINS: "server_wins",
            PULL_ONLY: "pull_only",
            MANUAL: "manual",
        };
    }
    /**
     * Validates an idSchema.
     *
     * @param  {Object|undefined} idSchema
     * @return {Object}
     */
    _validateIdSchema(idSchema) {
        if (typeof idSchema === "undefined") {
            return createUUIDSchema();
        }
        if (typeof idSchema !== "object") {
            throw new Error("idSchema must be an object.");
        }
        else if (typeof idSchema.generate !== "function") {
            throw new Error("idSchema must provide a generate function.");
        }
        else if (typeof idSchema.validate !== "function") {
            throw new Error("idSchema must provide a validate function.");
        }
        return idSchema;
    }
    /**
     * Validates a list of remote transformers.
     *
     * @param  {Array|undefined} remoteTransformers
     * @return {Array}
     */
    _validateRemoteTransformers(remoteTransformers) {
        if (typeof remoteTransformers === "undefined") {
            return [];
        }
        if (!Array.isArray(remoteTransformers)) {
            throw new Error("remoteTransformers should be an array.");
        }
        return remoteTransformers.map(transformer => {
            if (typeof transformer !== "object") {
                throw new Error("A transformer must be an object.");
            }
            else if (typeof transformer.encode !== "function") {
                throw new Error("A transformer must provide an encode function.");
            }
            else if (typeof transformer.decode !== "function") {
                throw new Error("A transformer must provide a decode function.");
            }
            return transformer;
        });
    }
    /**
     * Validate the passed hook is correct.
     *
     * @param {Array|undefined} hook.
     * @return {Array}
     **/
    _validateHook(hook) {
        if (!Array.isArray(hook)) {
            throw new Error("A hook definition should be an array of functions.");
        }
        return hook.map(fn => {
            if (typeof fn !== "function") {
                throw new Error("A hook definition should be an array of functions.");
            }
            return fn;
        });
    }
    /**
     * Validates a list of hooks.
     *
     * @param  {Object|undefined} hooks
     * @return {Object}
     */
    _validateHooks(hooks) {
        if (typeof hooks === "undefined") {
            return {};
        }
        if (Array.isArray(hooks)) {
            throw new Error("hooks should be an object, not an array.");
        }
        if (typeof hooks !== "object") {
            throw new Error("hooks should be an object.");
        }
        const validatedHooks = {};
        for (const hook in hooks) {
            if (!AVAILABLE_HOOKS.includes(hook)) {
                throw new Error("The hook should be one of " + AVAILABLE_HOOKS.join(", "));
            }
            validatedHooks[hook] = this._validateHook(hooks[hook]);
        }
        return validatedHooks;
    }
    /**
     * Deletes every records in the current collection and marks the collection as
     * never synced.
     *
     * @return {Promise}
     */
    async clear() {
        await this.db.clear();
        await this.db.saveMetadata(null);
        await this.db.saveLastModified(null);
        return { data: [], permissions: {} };
    }
    /**
     * Encodes a record.
     *
     * @param  {String} type   Either "remote" or "local".
     * @param  {Object} record The record object to encode.
     * @return {Promise}
     */
    _encodeRecord(type, record) {
        if (!this[`${type}Transformers`].length) {
            return Promise.resolve(record);
        }
        return waterfall(this[`${type}Transformers`].map(transformer => {
            return record => transformer.encode(record);
        }), record);
    }
    /**
     * Decodes a record.
     *
     * @param  {String} type   Either "remote" or "local".
     * @param  {Object} record The record object to decode.
     * @return {Promise}
     */
    _decodeRecord(type, record) {
        if (!this[`${type}Transformers`].length) {
            return Promise.resolve(record);
        }
        return waterfall(this[`${type}Transformers`].reverse().map(transformer => {
            return record => transformer.decode(record);
        }), record);
    }
    /**
     * Adds a record to the local database, asserting that none
     * already exist with this ID.
     *
     * Note: If either the `useRecordId` or `synced` options are true, then the
     * record object must contain the id field to be validated. If none of these
     * options are true, an id is generated using the current IdSchema; in this
     * case, the record passed must not have an id.
     *
     * Options:
     * - {Boolean} synced       Sets record status to "synced" (default: `false`).
     * - {Boolean} useRecordId  Forces the `id` field from the record to be used,
     *                          instead of one that is generated automatically
     *                          (default: `false`).
     *
     * @param  {Object} record
     * @param  {Object} options
     * @return {Promise}
     */
    create(record, options = { useRecordId: false, synced: false }) {
        // Validate the record and its ID (if any), even though this
        // validation is also done in the CollectionTransaction method,
        // because we need to pass the ID to preloadIds.
        const reject = msg => Promise.reject(new Error(msg));
        if (typeof record !== "object") {
            return reject("Record is not an object.");
        }
        if ((options.synced || options.useRecordId) &&
            !Object.prototype.hasOwnProperty.call(record, "id")) {
            return reject("Missing required Id; synced and useRecordId options require one");
        }
        if (!options.synced &&
            !options.useRecordId &&
            Object.prototype.hasOwnProperty.call(record, "id")) {
            return reject("Extraneous Id; can't create a record having one set.");
        }
        const newRecord = Object.assign(Object.assign({}, record), { id: options.synced || options.useRecordId
                ? record.id
                : this.idSchema.generate(record), _status: options.synced ? "synced" : "created" });
        if (!this.idSchema.validate(newRecord.id)) {
            return reject(`Invalid Id: ${newRecord.id}`);
        }
        return this.execute(txn => txn.create(newRecord), {
            preloadIds: [newRecord.id],
        }).catch(err => {
            if (options.useRecordId) {
                throw new Error("Couldn't create record. It may have been virtually deleted.");
            }
            throw err;
        });
    }
    /**
     * Like {@link CollectionTransaction#update}, but wrapped in its own transaction.
     *
     * Options:
     * - {Boolean} synced: Sets record status to "synced" (default: false)
     * - {Boolean} patch:  Extends the existing record instead of overwriting it
     *   (default: false)
     *
     * @param  {Object} record
     * @param  {Object} options
     * @return {Promise}
     */
    update(record, options = { synced: false, patch: false }) {
        // Validate the record and its ID, even though this validation is
        // also done in the CollectionTransaction method, because we need
        // to pass the ID to preloadIds.
        if (typeof record !== "object") {
            return Promise.reject(new Error("Record is not an object."));
        }
        if (!Object.prototype.hasOwnProperty.call(record, "id")) {
            return Promise.reject(new Error("Cannot update a record missing id."));
        }
        if (!this.idSchema.validate(record.id)) {
            return Promise.reject(new Error(`Invalid Id: ${record.id}`));
        }
        return this.execute(txn => txn.update(record, options), {
            preloadIds: [record.id],
        });
    }
    /**
     * Like {@link CollectionTransaction#upsert}, but wrapped in its own transaction.
     *
     * @param  {Object} record
     * @return {Promise}
     */
    upsert(record) {
        // Validate the record and its ID, even though this validation is
        // also done in the CollectionTransaction method, because we need
        // to pass the ID to preloadIds.
        if (typeof record !== "object") {
            return Promise.reject(new Error("Record is not an object."));
        }
        if (!Object.prototype.hasOwnProperty.call(record, "id")) {
            return Promise.reject(new Error("Cannot update a record missing id."));
        }
        if (!this.idSchema.validate(record.id)) {
            return Promise.reject(new Error(`Invalid Id: ${record.id}`));
        }
        return this.execute(txn => txn.upsert(record), { preloadIds: [record.id] });
    }
    /**
     * Like {@link CollectionTransaction#get}, but wrapped in its own transaction.
     *
     * Options:
     * - {Boolean} includeDeleted: Include virtually deleted records.
     *
     * @param  {String} id
     * @param  {Object} options
     * @return {Promise}
     */
    get(id, options = { includeDeleted: false }) {
        return this.execute(txn => txn.get(id, options), { preloadIds: [id] });
    }
    /**
     * Like {@link CollectionTransaction#getAny}, but wrapped in its own transaction.
     *
     * @param  {String} id
     * @return {Promise}
     */
    getAny(id) {
        return this.execute(txn => txn.getAny(id), { preloadIds: [id] });
    }
    /**
     * Same as {@link Collection#delete}, but wrapped in its own transaction.
     *
     * Options:
     * - {Boolean} virtual: When set to `true`, doesn't actually delete the record,
     *   update its `_status` attribute to `deleted` instead (default: true)
     *
     * @param  {String} id       The record's Id.
     * @param  {Object} options  The options object.
     * @return {Promise}
     */
    delete(id, options = { virtual: true }) {
        return this.execute(transaction => {
            return transaction.delete(id, options);
        }, { preloadIds: [id] });
    }
    /**
     * Same as {@link Collection#deleteAll}, but wrapped in its own transaction, execulding the parameter.
     *
     * @return {Promise}
     */
    async deleteAll() {
        const { data } = await this.list({}, { includeDeleted: false });
        const recordIds = data.map(record => record.id);
        return this.execute(transaction => {
            return transaction.deleteAll(recordIds);
        }, { preloadIds: recordIds });
    }
    /**
     * The same as {@link CollectionTransaction#deleteAny}, but wrapped
     * in its own transaction.
     *
     * @param  {String} id       The record's Id.
     * @return {Promise}
     */
    deleteAny(id) {
        return this.execute(txn => txn.deleteAny(id), { preloadIds: [id] });
    }
    /**
     * Lists records from the local database.
     *
     * Params:
     * - {Object} filters Filter the results (default: `{}`).
     * - {String} order   The order to apply   (default: `-last_modified`).
     *
     * Options:
     * - {Boolean} includeDeleted: Include virtually deleted records.
     *
     * @param  {Object} params  The filters and order to apply to the results.
     * @param  {Object} options The options object.
     * @return {Promise}
     */
    async list(params = {}, options = { includeDeleted: false }) {
        params = Object.assign({ order: "-last_modified", filters: {} }, params);
        const results = await this.db.list(params);
        let data = results;
        if (!options.includeDeleted) {
            data = results.filter(record => record._status !== "deleted");
        }
        return { data, permissions: {} };
    }
    /**
     * Imports remote changes into the local database.
     * This method is in charge of detecting the conflicts, and resolve them
     * according to the specified strategy.
     * @param  {SyncResultObject} syncResultObject The sync result object.
     * @param  {Array}            decodedChanges   The list of changes to import in the local database.
     * @param  {String}           strategy         The {@link Collection.strategy} (default: MANUAL)
     * @return {Promise}
     */
    async importChanges(syncResultObject, decodedChanges, strategy = Collection.strategy.MANUAL) {
        // Retrieve records matching change ids.
        try {
            for (let i = 0; i < decodedChanges.length; i += IMPORT_CHUNK_SIZE) {
                const slice = decodedChanges.slice(i, i + IMPORT_CHUNK_SIZE);
                const { imports, resolved } = await this.db.execute(transaction => {
                    const imports = slice.map(remote => {
                        // Store remote change into local database.
                        return importChange(transaction, remote, this.localFields, strategy);
                    });
                    const conflicts = imports
                        .filter(i => i.type === "conflicts")
                        .map(i => i.data);
                    const resolved = this._handleConflicts(transaction, conflicts, strategy);
                    return { imports, resolved };
                }, { preload: slice.map(record => record.id) });
                // Lists of created/updated/deleted records
                imports.forEach(({ type, data }) => syncResultObject.add(type, data));
                // Automatically resolved conflicts (if not manual)
                if (resolved.length > 0) {
                    syncResultObject.reset("conflicts").add("resolved", resolved);
                }
            }
        }
        catch (err) {
            const data = {
                type: "incoming",
                message: err.message,
                stack: err.stack,
            };
            // XXX one error of the whole transaction instead of per atomic op
            syncResultObject.add("errors", data);
        }
        return syncResultObject;
    }
    /**
     * Imports the responses of pushed changes into the local database.
     * Basically it stores the timestamp assigned by the server into the local
     * database.
     * @param  {SyncResultObject} syncResultObject The sync result object.
     * @param  {Array}            toApplyLocally   The list of changes to import in the local database.
     * @param  {Array}            conflicts        The list of conflicts that have to be resolved.
     * @param  {String}           strategy         The {@link Collection.strategy}.
     * @return {Promise}
     */
    async _applyPushedResults(syncResultObject, toApplyLocally, conflicts, strategy = Collection.strategy.MANUAL) {
        const toDeleteLocally = toApplyLocally.filter(r => r.deleted);
        const toUpdateLocally = toApplyLocally.filter(r => !r.deleted);
        const { published, resolved } = await this.db.execute(transaction => {
            const updated = toUpdateLocally.map(record => {
                const synced = markSynced(record);
                transaction.update(synced);
                return synced;
            });
            const deleted = toDeleteLocally.map(record => {
                transaction.delete(record.id);
                // Amend result data with the deleted attribute set
                return { id: record.id, deleted: true };
            });
            const published = updated.concat(deleted);
            // Handle conflicts, if any
            const resolved = this._handleConflicts(transaction, conflicts, strategy);
            return { published, resolved };
        });
        syncResultObject.add("published", published);
        if (resolved.length > 0) {
            syncResultObject
                .reset("conflicts")
                .reset("resolved")
                .add("resolved", resolved);
        }
        return syncResultObject;
    }
    /**
     * Handles synchronization conflicts according to specified strategy.
     *
     * @param  {SyncResultObject} result    The sync result object.
     * @param  {String}           strategy  The {@link Collection.strategy}.
     * @return {Promise<Array<Object>>} The resolved conflicts, as an
     *    array of {accepted, rejected} objects
     */
    _handleConflicts(transaction, conflicts, strategy) {
        if (strategy === Collection.strategy.MANUAL) {
            return [];
        }
        return conflicts.map(conflict => {
            const resolution = strategy === Collection.strategy.CLIENT_WINS
                ? conflict.local
                : conflict.remote;
            const rejected = strategy === Collection.strategy.CLIENT_WINS
                ? conflict.remote
                : conflict.local;
            let accepted, status, id;
            if (resolution === null) {
                // We "resolved" with the server-side deletion. Delete locally.
                // This only happens during SERVER_WINS because the local
                // version of a record can never be null.
                // We can get "null" from the remote side if we got a conflict
                // and there is no remote version available; see kinto-http.js
                // batch.js:aggregate.
                transaction.delete(conflict.local.id);
                accepted = null;
                // The record was deleted, but that status is "synced" with
                // the server, so we don't need to push the change.
                status = "synced";
                id = conflict.local.id;
            }
            else {
                const updated = this._resolveRaw(conflict, resolution);
                transaction.update(updated);
                accepted = updated;
                status = updated._status;
                id = updated.id;
            }
            return { rejected, accepted, id, _status: status };
        });
    }
    /**
     * Execute a bunch of operations in a transaction.
     *
     * This transaction should be atomic -- either all of its operations
     * will succeed, or none will.
     *
     * The argument to this function is itself a function which will be
     * called with a {@link CollectionTransaction}. Collection methods
     * are available on this transaction, but instead of returning
     * promises, they are synchronous. execute() returns a Promise whose
     * value will be the return value of the provided function.
     *
     * Most operations will require access to the record itself, which
     * must be preloaded by passing its ID in the preloadIds option.
     *
     * Options:
     * - {Array} preloadIds: list of IDs to fetch at the beginning of
     *   the transaction
     *
     * @return {Promise} Resolves with the result of the given function
     *    when the transaction commits.
     */
    execute(doOperations, { preloadIds = [] } = {}) {
        for (const id of preloadIds) {
            if (!this.idSchema.validate(id)) {
                return Promise.reject(Error(`Invalid Id: ${id}`));
            }
        }
        return this.db.execute(transaction => {
            const txn = new CollectionTransaction(this, transaction);
            const result = doOperations(txn);
            txn.emitEvents();
            return result;
        }, { preload: preloadIds });
    }
    /**
     * Resets the local records as if they were never synced; existing records are
     * marked as newly created, deleted records are dropped.
     *
     * A next call to {@link Collection.sync} will thus republish the whole
     * content of the local collection to the server.
     *
     * @return {Promise} Resolves with the number of processed records.
     */
    async resetSyncStatus() {
        const unsynced = await this.list({ filters: { _status: ["deleted", "synced"] }, order: "" }, { includeDeleted: true });
        await this.db.execute(transaction => {
            unsynced.data.forEach(record => {
                if (record._status === "deleted") {
                    // Garbage collect deleted records.
                    transaction.delete(record.id);
                }
                else {
                    // Records that were synced become «created».
                    transaction.update(Object.assign(Object.assign({}, record), { last_modified: undefined, _status: "created" }));
                }
            });
        });
        this._lastModified = null;
        await this.db.saveLastModified(null);
        return unsynced.data.length;
    }
    /**
     * Returns an object containing two lists:
     *
     * - `toDelete`: unsynced deleted records we can safely delete;
     * - `toSync`: local updates to send to the server.
     *
     * @return {Promise}
     */
    async gatherLocalChanges() {
        const unsynced = await this.list({
            filters: { _status: ["created", "updated"] },
            order: "",
        });
        const deleted = await this.list({ filters: { _status: "deleted" }, order: "" }, { includeDeleted: true });
        return await Promise.all(unsynced.data
            .concat(deleted.data)
            .map(this._encodeRecord.bind(this, "remote")));
    }
    /**
     * Fetch remote changes, import them to the local database, and handle
     * conflicts according to `options.strategy`. Then, updates the passed
     * {@link SyncResultObject} with import results.
     *
     * Options:
     * - {String} strategy: The selected sync strategy.
     * - {String} expectedTimestamp: A timestamp to use as a "cache busting" query parameter.
     * - {Array<String>} exclude: A list of record ids to exclude from pull.
     * - {Object} headers: The HTTP headers to use in the request.
     * - {int} retry: The number of retries to do if the HTTP request fails.
     * - {int} lastModified: The timestamp to use in `?_since` query.
     *
     * @param  {KintoClient.Collection} client           Kinto client Collection instance.
     * @param  {SyncResultObject}       syncResultObject The sync result object.
     * @param  {Object}                 options          The options object.
     * @return {Promise}
     */
    async pullChanges(client, syncResultObject, options = {}) {
        if (!syncResultObject.ok) {
            return syncResultObject;
        }
        const since = this.lastModified
            ? this.lastModified
            : await this.db.getLastModified();
        options = Object.assign({ strategy: Collection.strategy.MANUAL, lastModified: since, headers: {} }, options);
        // Optionally ignore some records when pulling for changes.
        // (avoid redownloading our own changes on last step of #sync())
        let filters;
        if (options.exclude) {
            // Limit the list of excluded records to the first 50 records in order
            // to remain under de-facto URL size limit (~2000 chars).
            // http://stackoverflow.com/questions/417142/what-is-the-maximum-length-of-a-url-in-different-browsers/417184#417184
            const exclude_id = options.exclude
                .slice(0, 50)
                .map(r => r.id)
                .join(",");
            filters = { exclude_id };
        }
        if (options.expectedTimestamp) {
            filters = Object.assign(Object.assign({}, filters), { _expected: options.expectedTimestamp });
        }
        // First fetch remote changes from the server
        const { data, last_modified } = await client.listRecords({
            // Since should be ETag (see https://github.com/Kinto/kinto.js/issues/356)
            since: options.lastModified ? `${options.lastModified}` : undefined,
            headers: options.headers,
            retry: options.retry,
            // Fetch every page by default (FIXME: option to limit pages, see #277)
            pages: Infinity,
            filters,
        });
        // last_modified is the ETag header value (string).
        // For retro-compatibility with first kinto.js versions
        // parse it to integer.
        const unquoted = last_modified ? parseInt(last_modified, 10) : undefined;
        // Check if server was flushed.
        // This is relevant for the Kinto demo server
        // (and thus for many new comers).
        const localSynced = options.lastModified;
        const serverChanged = unquoted > options.lastModified;
        const emptyCollection = data.length === 0;
        if (!options.exclude && localSynced && serverChanged && emptyCollection) {
            const e = new ServerWasFlushedError(localSynced, unquoted, "Server has been flushed. Client Side Timestamp: " +
                localSynced +
                " Server Side Timestamp: " +
                unquoted);
            throw e;
        }
        // Atomic updates are not sensible here because unquoted is not
        // computed as a function of syncResultObject.lastModified.
        // eslint-disable-next-line require-atomic-updates
        syncResultObject.lastModified = unquoted;
        // Decode incoming changes.
        const decodedChanges = await Promise.all(data.map(change => {
            return this._decodeRecord("remote", change);
        }));
        // Hook receives decoded records.
        const payload = { lastModified: unquoted, changes: decodedChanges };
        const afterHooks = await this.applyHook("incoming-changes", payload);
        // No change, nothing to import.
        if (afterHooks.changes.length > 0) {
            // Reflect these changes locally
            await this.importChanges(syncResultObject, afterHooks.changes, options.strategy);
        }
        return syncResultObject;
    }
    applyHook(hookName, payload) {
        if (typeof this.hooks[hookName] == "undefined") {
            return Promise.resolve(payload);
        }
        return waterfall(this.hooks[hookName].map(hook => {
            return record => {
                const result = hook(payload, this);
                const resultThenable = result && typeof result.then === "function";
                const resultChanges = result && Object.prototype.hasOwnProperty.call(result, "changes");
                if (!(resultThenable || resultChanges)) {
                    throw new Error(`Invalid return value for hook: ${JSON.stringify(result)} has no 'then()' or 'changes' properties`);
                }
                return result;
            };
        }), payload);
    }
    /**
     * Publish local changes to the remote server and updates the passed
     * {@link SyncResultObject} with publication results.
     *
     * Options:
     * - {String} strategy: The selected sync strategy.
     * - {Object} headers: The HTTP headers to use in the request.
     * - {int} retry: The number of retries to do if the HTTP request fails.
     *
     * @param  {KintoClient.Collection} client           Kinto client Collection instance.
     * @param  {SyncResultObject}       syncResultObject The sync result object.
     * @param  {Object}                 changes          The change object.
     * @param  {Array}                  changes.toDelete The list of records to delete.
     * @param  {Array}                  changes.toSync   The list of records to create/update.
     * @param  {Object}                 options          The options object.
     * @return {Promise}
     */
    async pushChanges(client, changes, syncResultObject, options = {}) {
        if (!syncResultObject.ok) {
            return syncResultObject;
        }
        const safe = !options.strategy || options.strategy !== Collection.CLIENT_WINS;
        const toDelete = changes.filter(r => r._status == "deleted");
        const toSync = changes.filter(r => r._status != "deleted");
        // Perform a batch request with every changes.
        const synced = await client.batch(batch => {
            toDelete.forEach(r => {
                // never published locally deleted records should not be pusblished
                if (r.last_modified) {
                    batch.deleteRecord(r);
                }
            });
            toSync.forEach(r => {
                // Clean local fields (like _status) before sending to server.
                const published = this.cleanLocalFields(r);
                if (r._status === "created") {
                    batch.createRecord(published);
                }
                else {
                    batch.updateRecord(published);
                }
            });
        }, {
            headers: options.headers,
            retry: options.retry,
            safe,
            aggregate: true,
        });
        // Store outgoing errors into sync result object
        syncResultObject.add("errors", synced.errors.map(e => (Object.assign(Object.assign({}, e), { type: "outgoing" }))));
        // Store outgoing conflicts into sync result object
        const conflicts = [];
        for (const { type, local, remote } of synced.conflicts) {
            // Note: we ensure that local data are actually available, as they may
            // be missing in the case of a published deletion.
            const safeLocal = (local && local.data) || { id: remote.id };
            const realLocal = await this._decodeRecord("remote", safeLocal);
            // We can get "null" from the remote side if we got a conflict
            // and there is no remote version available; see kinto-http.js
            // batch.js:aggregate.
            const realRemote = remote && (await this._decodeRecord("remote", remote));
            const conflict = { type, local: realLocal, remote: realRemote };
            conflicts.push(conflict);
        }
        syncResultObject.add("conflicts", conflicts);
        // Records that must be deleted are either deletions that were pushed
        // to server (published) or deleted records that were never pushed (skipped).
        const missingRemotely = synced.skipped.map(r => (Object.assign(Object.assign({}, r), { deleted: true })));
        // For created and updated records, the last_modified coming from server
        // will be stored locally.
        // Reflect publication results locally using the response from
        // the batch request.
        const published = synced.published.map(c => c.data);
        const toApplyLocally = published.concat(missingRemotely);
        // Apply the decode transformers, if any
        const decoded = await Promise.all(toApplyLocally.map(record => {
            return this._decodeRecord("remote", record);
        }));
        // We have to update the local records with the responses of the server
        // (eg. last_modified values etc.).
        if (decoded.length > 0 || conflicts.length > 0) {
            await this._applyPushedResults(syncResultObject, decoded, conflicts, options.strategy);
        }
        return syncResultObject;
    }
    /**
     * Return a copy of the specified record without the local fields.
     *
     * @param  {Object} record  A record with potential local fields.
     * @return {Object}
     */
    cleanLocalFields(record) {
        const localKeys = RECORD_FIELDS_TO_CLEAN.concat(this.localFields);
        return omitKeys(record, localKeys);
    }
    /**
     * Resolves a conflict, updating local record according to proposed
     * resolution — keeping remote record `last_modified` value as a reference for
     * further batch sending.
     *
     * @param  {Object} conflict   The conflict object.
     * @param  {Object} resolution The proposed record.
     * @return {Promise}
     */
    resolve(conflict, resolution) {
        return this.db.execute(transaction => {
            const updated = this._resolveRaw(conflict, resolution);
            transaction.update(updated);
            return { data: updated, permissions: {} };
        });
    }
    /**
     * @private
     */
    _resolveRaw(conflict, resolution) {
        const resolved = Object.assign(Object.assign({}, resolution), {
            // Ensure local record has the latest authoritative timestamp
            last_modified: conflict.remote && conflict.remote.last_modified });
        // If the resolution object is strictly equal to the
        // remote record, then we can mark it as synced locally.
        // Otherwise, mark it as updated (so that the resolution is pushed).
        const synced = deepEqual(resolved, conflict.remote);
        return markStatus(resolved, synced ? "synced" : "updated");
    }
    /**
     * Synchronize remote and local data. The promise will resolve with a
     * {@link SyncResultObject}, though will reject:
     *
     * - if the server is currently backed off;
     * - if the server has been detected flushed.
     *
     * Options:
     * - {Object} headers: HTTP headers to attach to outgoing requests.
     * - {String} expectedTimestamp: A timestamp to use as a "cache busting" query parameter.
     * - {Number} retry: Number of retries when server fails to process the request (default: 1).
     * - {Collection.strategy} strategy: See {@link Collection.strategy}.
     * - {Boolean} ignoreBackoff: Force synchronization even if server is currently
     *   backed off.
     * - {String} bucket: The remove bucket id to use (default: null)
     * - {String} collection: The remove collection id to use (default: null)
     * - {String} remote The remote Kinto server endpoint to use (default: null).
     *
     * @param  {Object} options Options.
     * @return {Promise}
     * @throws {Error} If an invalid remote option is passed.
     */
    async sync(options = {
        strategy: Collection.strategy.MANUAL,
        headers: {},
        retry: 1,
        ignoreBackoff: false,
        bucket: null,
        collection: null,
        remote: null,
        expectedTimestamp: null,
    }) {
        options = Object.assign(Object.assign({}, options), { bucket: options.bucket || this.bucket, collection: options.collection || this.name });
        const previousRemote = this.api.remote;
        if (options.remote) {
            // Note: setting the remote ensures it's valid, throws when invalid.
            this.api.remote = options.remote;
        }
        if (!options.ignoreBackoff && this.api.backoff > 0) {
            const seconds = Math.ceil(this.api.backoff / 1000);
            return Promise.reject(new Error(`Server is asking clients to back off; retry in ${seconds}s or use the ignoreBackoff option.`));
        }
        const client = this.api
            .bucket(options.bucket)
            .collection(options.collection);
        const result = new SyncResultObject();
        try {
            // Fetch collection metadata.
            await this.pullMetadata(client, options);
            // Fetch last changes from the server.
            await this.pullChanges(client, result, options);
            const { lastModified } = result;
            if (options.strategy != Collection.strategy.PULL_ONLY) {
                // Fetch local changes
                const toSync = await this.gatherLocalChanges();
                // Publish local changes and pull local resolutions
                await this.pushChanges(client, toSync, result, options);
                // Publish local resolution of push conflicts to server (on CLIENT_WINS)
                const resolvedUnsynced = result.resolved.filter(r => r._status !== "synced");
                if (resolvedUnsynced.length > 0) {
                    const resolvedEncoded = await Promise.all(resolvedUnsynced.map(resolution => {
                        let record = resolution.accepted;
                        if (record === null) {
                            record = { id: resolution.id, _status: resolution._status };
                        }
                        return this._encodeRecord("remote", record);
                    }));
                    await this.pushChanges(client, resolvedEncoded, result, options);
                }
                // Perform a last pull to catch changes that occured after the last pull,
                // while local changes were pushed. Do not do it nothing was pushed.
                if (result.published.length > 0) {
                    // Avoid redownloading our own changes during the last pull.
                    const pullOpts = Object.assign(Object.assign({}, options), { lastModified, exclude: result.published });
                    await this.pullChanges(client, result, pullOpts);
                }
            }
            // Don't persist lastModified value if any conflict or error occured
            if (result.ok) {
                // No conflict occured, persist collection's lastModified value
                this._lastModified = await this.db.saveLastModified(result.lastModified);
            }
        }
        catch (e) {
            this.events.emit("sync:error", Object.assign(Object.assign({}, options), { error: e }));
            throw e;
        }
        finally {
            // Ensure API default remote is reverted if a custom one's been used
            this.api.remote = previousRemote;
        }
        this.events.emit("sync:success", Object.assign(Object.assign({}, options), { result }));
        return result;
    }
    /**
     * Load a list of records already synced with the remote server.
     *
     * The local records which are unsynced or whose timestamp is either missing
     * or superior to those being loaded will be ignored.
     *
     * @deprecated Use {@link importBulk} instead.
     * @param  {Array} records The previously exported list of records to load.
     * @return {Promise} with the effectively imported records.
     */
    async loadDump(records) {
        return this.importBulk(records);
    }
    /**
     * Load a list of records already synced with the remote server.
     *
     * The local records which are unsynced or whose timestamp is either missing
     * or superior to those being loaded will be ignored.
     *
     * @param  {Array} records The previously exported list of records to load.
     * @return {Promise} with the effectively imported records.
     */
    async importBulk(records) {
        if (!Array.isArray(records)) {
            throw new Error("Records is not an array.");
        }
        for (const record of records) {
            if (!Object.prototype.hasOwnProperty.call(record, "id") ||
                !this.idSchema.validate(record.id)) {
                throw new Error("Record has invalid ID: " + JSON.stringify(record));
            }
            if (!record.last_modified) {
                throw new Error("Record has no last_modified value: " + JSON.stringify(record));
            }
        }
        // Fetch all existing records from local database,
        // and skip those who are newer or not marked as synced.
        // XXX filter by status / ids in records
        const { data } = await this.list({}, { includeDeleted: true });
        const existingById = data.reduce((acc, record) => {
            acc[record.id] = record;
            return acc;
        }, {});
        const newRecords = records.filter(record => {
            const localRecord = existingById[record.id];
            const shouldKeep =
            // No local record with this id.
            localRecord === undefined ||
                // Or local record is synced
                (localRecord._status === "synced" &&
                    // And was synced from server
                    localRecord.last_modified !== undefined &&
                    // And is older than imported one.
                    record.last_modified > localRecord.last_modified);
            return shouldKeep;
        });
        return await this.db.importBulk(newRecords.map(markSynced));
    }
    async pullMetadata(client, options = {}) {
        const { expectedTimestamp, headers } = options;
        const query = expectedTimestamp
            ? { query: { _expected: expectedTimestamp } }
            : undefined;
        const metadata = await client.getData(Object.assign(Object.assign({}, query), { headers }));
        return this.db.saveMetadata(metadata);
    }
    async metadata() {
        return this.db.getMetadata();
    }
}
/**
 * A Collection-oriented wrapper for an adapter's transaction.
 *
 * This defines the high-level functions available on a collection.
 * The collection itself offers functions of the same name. These will
 * perform just one operation in its own transaction.
 */
class CollectionTransaction {
    constructor(collection, adapterTransaction) {
        this.collection = collection;
        this.adapterTransaction = adapterTransaction;
        this._events = [];
    }
    _queueEvent(action, payload) {
        this._events.push({ action, payload });
    }
    /**
     * Emit queued events, to be called once every transaction operations have
     * been executed successfully.
     */
    emitEvents() {
        for (const { action, payload } of this._events) {
            this.collection.events.emit(action, payload);
        }
        if (this._events.length > 0) {
            const targets = this._events.map(({ action, payload }) => (Object.assign({ action }, payload)));
            this.collection.events.emit("change", { targets });
        }
        this._events = [];
    }
    /**
     * Retrieve a record by its id from the local database, or
     * undefined if none exists.
     *
     * This will also return virtually deleted records.
     *
     * @param  {String} id
     * @return {Object}
     */
    getAny(id) {
        const record = this.adapterTransaction.get(id);
        return { data: record, permissions: {} };
    }
    /**
     * Retrieve a record by its id from the local database.
     *
     * Options:
     * - {Boolean} includeDeleted: Include virtually deleted records.
     *
     * @param  {String} id
     * @param  {Object} options
     * @return {Object}
     */
    get(id, options = { includeDeleted: false }) {
        const res = this.getAny(id);
        if (!res.data ||
            (!options.includeDeleted && res.data._status === "deleted")) {
            throw new Error(`Record with id=${id} not found.`);
        }
        return res;
    }
    /**
     * Deletes a record from the local database.
     *
     * Options:
     * - {Boolean} virtual: When set to `true`, doesn't actually delete the record,
     *   update its `_status` attribute to `deleted` instead (default: true)
     *
     * @param  {String} id       The record's Id.
     * @param  {Object} options  The options object.
     * @return {Object}
     */
    delete(id, options = { virtual: true }) {
        // Ensure the record actually exists.
        const existing = this.adapterTransaction.get(id);
        const alreadyDeleted = existing && existing._status == "deleted";
        if (!existing || (alreadyDeleted && options.virtual)) {
            throw new Error(`Record with id=${id} not found.`);
        }
        // Virtual updates status.
        if (options.virtual) {
            this.adapterTransaction.update(markDeleted(existing));
        }
        else {
            // Delete for real.
            this.adapterTransaction.delete(id);
        }
        this._queueEvent("delete", { data: existing });
        return { data: existing, permissions: {} };
    }
    /**
     * Soft delete all records from the local database.
     *
     * @param  {Array} ids        Array of non-deleted Record Ids.
     * @return {Object}
     */
    deleteAll(ids) {
        const existingRecords = [];
        ids.forEach(id => {
            existingRecords.push(this.adapterTransaction.get(id));
            this.delete(id);
        });
        this._queueEvent("deleteAll", { data: existingRecords });
        return { data: existingRecords, permissions: {} };
    }
    /**
     * Deletes a record from the local database, if any exists.
     * Otherwise, do nothing.
     *
     * @param  {String} id       The record's Id.
     * @return {Object}
     */
    deleteAny(id) {
        const existing = this.adapterTransaction.get(id);
        if (existing) {
            this.adapterTransaction.update(markDeleted(existing));
            this._queueEvent("delete", { data: existing });
        }
        return { data: Object.assign({ id }, existing), deleted: !!existing, permissions: {} };
    }
    /**
     * Adds a record to the local database, asserting that none
     * already exist with this ID.
     *
     * @param  {Object} record, which must contain an ID
     * @return {Object}
     */
    create(record) {
        if (typeof record !== "object") {
            throw new Error("Record is not an object.");
        }
        if (!Object.prototype.hasOwnProperty.call(record, "id")) {
            throw new Error("Cannot create a record missing id");
        }
        if (!this.collection.idSchema.validate(record.id)) {
            throw new Error(`Invalid Id: ${record.id}`);
        }
        this.adapterTransaction.create(record);
        this._queueEvent("create", { data: record });
        return { data: record, permissions: {} };
    }
    /**
     * Updates a record from the local database.
     *
     * Options:
     * - {Boolean} synced: Sets record status to "synced" (default: false)
     * - {Boolean} patch:  Extends the existing record instead of overwriting it
     *   (default: false)
     *
     * @param  {Object} record
     * @param  {Object} options
     * @return {Object}
     */
    update(record, options = { synced: false, patch: false }) {
        if (typeof record !== "object") {
            throw new Error("Record is not an object.");
        }
        if (!Object.prototype.hasOwnProperty.call(record, "id")) {
            throw new Error("Cannot update a record missing id.");
        }
        if (!this.collection.idSchema.validate(record.id)) {
            throw new Error(`Invalid Id: ${record.id}`);
        }
        const oldRecord = this.adapterTransaction.get(record.id);
        if (!oldRecord) {
            throw new Error(`Record with id=${record.id} not found.`);
        }
        const newRecord = options.patch ? Object.assign(Object.assign({}, oldRecord), record) : record;
        const updated = this._updateRaw(oldRecord, newRecord, options);
        this.adapterTransaction.update(updated);
        this._queueEvent("update", { data: updated, oldRecord });
        return { data: updated, oldRecord, permissions: {} };
    }
    /**
     * Lower-level primitive for updating a record while respecting
     * _status and last_modified.
     *
     * @param  {Object} oldRecord: the record retrieved from the DB
     * @param  {Object} newRecord: the record to replace it with
     * @return {Object}
     */
    _updateRaw(oldRecord, newRecord, { synced = false } = {}) {
        const updated = Object.assign({}, newRecord);
        // Make sure to never loose the existing timestamp.
        if (oldRecord && oldRecord.last_modified && !updated.last_modified) {
            updated.last_modified = oldRecord.last_modified;
        }
        // If only local fields have changed, then keep record as synced.
        // If status is created, keep record as created.
        // If status is deleted, mark as updated.
        const isIdentical = oldRecord &&
            recordsEqual(oldRecord, updated, this.collection.localFields);
        const keepSynced = isIdentical && oldRecord._status == "synced";
        const neverSynced = !oldRecord || (oldRecord && oldRecord._status == "created");
        const newStatus = keepSynced || synced ? "synced" : neverSynced ? "created" : "updated";
        return markStatus(updated, newStatus);
    }
    /**
     * Upsert a record into the local database.
     *
     * This record must have an ID.
     *
     * If a record with this ID already exists, it will be replaced.
     * Otherwise, this record will be inserted.
     *
     * @param  {Object} record
     * @return {Object}
     */
    upsert(record) {
        if (typeof record !== "object") {
            throw new Error("Record is not an object.");
        }
        if (!Object.prototype.hasOwnProperty.call(record, "id")) {
            throw new Error("Cannot update a record missing id.");
        }
        if (!this.collection.idSchema.validate(record.id)) {
            throw new Error(`Invalid Id: ${record.id}`);
        }
        let oldRecord = this.adapterTransaction.get(record.id);
        const updated = this._updateRaw(oldRecord, record);
        this.adapterTransaction.update(updated);
        // Don't return deleted records -- pretend they are gone
        if (oldRecord && oldRecord._status == "deleted") {
            oldRecord = undefined;
        }
        if (oldRecord) {
            this._queueEvent("update", { data: updated, oldRecord });
        }
        else {
            this._queueEvent("create", { data: updated });
        }
        return { data: updated, oldRecord, permissions: {} };
    }
}

const DEFAULT_BUCKET_NAME = "default";
const DEFAULT_REMOTE = "http://localhost:8888/v1";
const DEFAULT_RETRY = 1;
/**
 * KintoBase class.
 */
class KintoBase {
    /**
     * Provides a public access to the base adapter class. Users can create a
     * custom DB adapter by extending {@link BaseAdapter}.
     *
     * @type {Object}
     */
    static get adapters() {
        return {
            BaseAdapter: BaseAdapter,
        };
    }
    /**
     * Synchronization strategies. Available strategies are:
     *
     * - `MANUAL`: Conflicts will be reported in a dedicated array.
     * - `SERVER_WINS`: Conflicts are resolved using remote data.
     * - `CLIENT_WINS`: Conflicts are resolved using local data.
     *
     * @type {Object}
     */
    static get syncStrategy() {
        return Collection.strategy;
    }
    /**
     * Constructor.
     *
     * Options:
     * - `{String}`       `remote`         The server URL to use.
     * - `{String}`       `bucket`         The collection bucket name.
     * - `{EventEmitter}` `events`         Events handler.
     * - `{BaseAdapter}`  `adapter`        The base DB adapter class.
     * - `{Object}`       `adapterOptions` Options given to the adapter.
     * - `{Object}`       `headers`        The HTTP headers to use.
     * - `{Object}`       `retry`          Number of retries when the server fails to process the request (default: `1`)
     * - `{String}`       `requestMode`    The HTTP CORS mode to use.
     * - `{Number}`       `timeout`        The requests timeout in ms (default: `5000`).
     *
     * @param  {Object} options The options object.
     */
    constructor(options = {}) {
        const defaults = {
            bucket: DEFAULT_BUCKET_NAME,
            remote: DEFAULT_REMOTE,
            retry: DEFAULT_RETRY,
        };
        this._options = Object.assign(Object.assign({}, defaults), options);
        if (!this._options.adapter) {
            throw new Error("No adapter provided");
        }
        this._api = null;
        /**
         * The event emitter instance.
         * @type {EventEmitter}
         */
        this.events = this._options.events;
    }
    /**
     * The kinto HTTP client instance.
     * @type {KintoClient}
     */
    get api() {
        const { events, headers, remote, requestMode, retry, timeout, } = this._options;
        if (!this._api) {
            this._api = new this.ApiClass(remote, {
                events,
                headers,
                requestMode,
                retry,
                timeout,
            });
        }
        return this._api;
    }
    /**
     * Creates a {@link Collection} instance. The second (optional) parameter
     * will set collection-level options like e.g. `remoteTransformers`.
     *
     * @param  {String} collName The collection name.
     * @param  {Object} [options={}]                 Extra options or override client's options.
     * @param  {Object} [options.idSchema]           IdSchema instance (default: UUID)
     * @param  {Object} [options.remoteTransformers] Array<RemoteTransformer> (default: `[]`])
     * @param  {Object} [options.hooks]              Array<Hook> (default: `[]`])
     * @param  {Object} [options.localFields]        Array<Field> (default: `[]`])
     * @return {Collection}
     */
    collection(collName, options = {}) {
        if (!collName) {
            throw new Error("missing collection name");
        }
        const { bucket, events, adapter, adapterOptions } = Object.assign(Object.assign({}, this._options), options);
        const { idSchema, remoteTransformers, hooks, localFields } = options;
        return new Collection(bucket, collName, this, {
            events,
            adapter,
            adapterOptions,
            idSchema,
            remoteTransformers,
            hooks,
            localFields,
        });
    }
}

/*
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
    EventEmitter: "resource://gre/modules/EventEmitter.sys.mjs",
    // Use standalone kinto-http module landed in FFx.
    KintoHttpClient: "resource://services-common/kinto-http-client.sys.mjs"
});
export class Kinto extends KintoBase {
    static get adapters() {
        return {
            BaseAdapter,
            IDB,
        };
    }
    get ApiClass() {
        return lazy.KintoHttpClient;
    }
    constructor(options = {}) {
        const events = {};
        lazy.EventEmitter.decorate(events);
        const defaults = {
            adapter: IDB,
            events,
        };
        super(Object.assign(Object.assign({}, defaults), options));
    }
    collection(collName, options = {}) {
        const idSchema = {
            validate(id) {
                return typeof id == "string" && RE_RECORD_ID.test(id);
            },
            generate() {
                return Services.uuid.generateUUID()
                    .toString()
                    .replace(/[{}]/g, "");
            },
        };
        return super.collection(collName, Object.assign({ idSchema }, options));
    }
}

