(function (global, factory) {
    if (typeof define === "function" && define.amd) {
        define('asyncStorage', ['module', 'exports', '../utils/isIndexedDBValid', '../utils/createBlob', '../utils/idb', '../utils/promise', '../utils/executeCallback', '../utils/executeTwoCallbacks', '../utils/normalizeKey', '../utils/getCallback'], factory);
    } else if (typeof exports !== "undefined") {
        factory(module, exports, require('../utils/isIndexedDBValid'), require('../utils/createBlob'), require('../utils/idb'), require('../utils/promise'), require('../utils/executeCallback'), require('../utils/executeTwoCallbacks'), require('../utils/normalizeKey'), require('../utils/getCallback'));
    } else {
        var mod = {
            exports: {}
        };
        factory(mod, mod.exports, global.isIndexedDBValid, global.createBlob, global.idb, global.promise, global.executeCallback, global.executeTwoCallbacks, global.normalizeKey, global.getCallback);
        global.asyncStorage = mod.exports;
    }
})(this, function (module, exports, _isIndexedDBValid, _createBlob, _idb, _promise, _executeCallback, _executeTwoCallbacks, _normalizeKey, _getCallback) {
    'use strict';

    Object.defineProperty(exports, "__esModule", {
        value: true
    });

    var _isIndexedDBValid2 = _interopRequireDefault(_isIndexedDBValid);

    var _createBlob2 = _interopRequireDefault(_createBlob);

    var _idb2 = _interopRequireDefault(_idb);

    var _promise2 = _interopRequireDefault(_promise);

    var _executeCallback2 = _interopRequireDefault(_executeCallback);

    var _executeTwoCallbacks2 = _interopRequireDefault(_executeTwoCallbacks);

    var _normalizeKey2 = _interopRequireDefault(_normalizeKey);

    var _getCallback2 = _interopRequireDefault(_getCallback);

    function _interopRequireDefault(obj) {
        return obj && obj.__esModule ? obj : {
            default: obj
        };
    }

    // Some code originally from async_storage.js in
    // [Gaia](https://github.com/mozilla-b2g/gaia).

    var DETECT_BLOB_SUPPORT_STORE = 'local-forage-detect-blob-support';
    var supportsBlobs = void 0;
    var dbContexts = {};
    var toString = Object.prototype.toString;

    // Transaction Modes
    var READ_ONLY = 'readonly';
    var READ_WRITE = 'readwrite';

    // Transform a binary string to an array buffer, because otherwise
    // weird stuff happens when you try to work with the binary string directly.
    // It is known.
    // From http://stackoverflow.com/questions/14967647/ (continues on next line)
    // encode-decode-image-with-base64-breaks-image (2013-04-21)
    function _binStringToArrayBuffer(bin) {
        var length = bin.length;
        var buf = new ArrayBuffer(length);
        var arr = new Uint8Array(buf);
        for (var i = 0; i < length; i++) {
            arr[i] = bin.charCodeAt(i);
        }
        return buf;
    }

    //
    // Blobs are not supported in all versions of IndexedDB, notably
    // Chrome <37 and Android <5. In those versions, storing a blob will throw.
    //
    // Various other blob bugs exist in Chrome v37-42 (inclusive).
    // Detecting them is expensive and confusing to users, and Chrome 37-42
    // is at very low usage worldwide, so we do a hacky userAgent check instead.
    //
    // content-type bug: https://code.google.com/p/chromium/issues/detail?id=408120
    // 404 bug: https://code.google.com/p/chromium/issues/detail?id=447916
    // FileReader bug: https://code.google.com/p/chromium/issues/detail?id=447836
    //
    // Code borrowed from PouchDB. See:
    // https://github.com/pouchdb/pouchdb/blob/master/packages/node_modules/pouchdb-adapter-idb/src/blobSupport.js
    //
    function _checkBlobSupportWithoutCaching(idb) {
        return new _promise2.default(function (resolve) {
            var txn = idb.transaction(DETECT_BLOB_SUPPORT_STORE, READ_WRITE);
            var blob = (0, _createBlob2.default)(['']);
            txn.objectStore(DETECT_BLOB_SUPPORT_STORE).put(blob, 'key');

            txn.onabort = function (e) {
                // If the transaction aborts now its due to not being able to
                // write to the database, likely due to the disk being full
                e.preventDefault();
                e.stopPropagation();
                resolve(false);
            };

            txn.oncomplete = function () {
                var matchedChrome = navigator.userAgent.match(/Chrome\/(\d+)/);
                var matchedEdge = navigator.userAgent.match(/Edge\//);
                // MS Edge pretends to be Chrome 42:
                // https://msdn.microsoft.com/en-us/library/hh869301%28v=vs.85%29.aspx
                resolve(matchedEdge || !matchedChrome || parseInt(matchedChrome[1], 10) >= 43);
            };
        }).catch(function () {
            return false; // error, so assume unsupported
        });
    }

    function _checkBlobSupport(idb) {
        if (typeof supportsBlobs === 'boolean') {
            return _promise2.default.resolve(supportsBlobs);
        }
        return _checkBlobSupportWithoutCaching(idb).then(function (value) {
            supportsBlobs = value;
            return supportsBlobs;
        });
    }

    function _deferReadiness(dbInfo) {
        var dbContext = dbContexts[dbInfo.name];

        // Create a deferred object representing the current database operation.
        var deferredOperation = {};

        deferredOperation.promise = new _promise2.default(function (resolve, reject) {
            deferredOperation.resolve = resolve;
            deferredOperation.reject = reject;
        });

        // Enqueue the deferred operation.
        dbContext.deferredOperations.push(deferredOperation);

        // Chain its promise to the database readiness.
        if (!dbContext.dbReady) {
            dbContext.dbReady = deferredOperation.promise;
        } else {
            dbContext.dbReady = dbContext.dbReady.then(function () {
                return deferredOperation.promise;
            });
        }
    }

    function _advanceReadiness(dbInfo) {
        var dbContext = dbContexts[dbInfo.name];

        // Dequeue a deferred operation.
        var deferredOperation = dbContext.deferredOperations.pop();

        // Resolve its promise (which is part of the database readiness
        // chain of promises).
        if (deferredOperation) {
            deferredOperation.resolve();
            return deferredOperation.promise;
        }
    }

    function _rejectReadiness(dbInfo, err) {
        var dbContext = dbContexts[dbInfo.name];

        // Dequeue a deferred operation.
        var deferredOperation = dbContext.deferredOperations.pop();

        // Reject its promise (which is part of the database readiness
        // chain of promises).
        if (deferredOperation) {
            deferredOperation.reject(err);
            return deferredOperation.promise;
        }
    }

    function _getConnection(dbInfo, upgradeNeeded) {
        return new _promise2.default(function (resolve, reject) {
            dbContexts[dbInfo.name] = dbContexts[dbInfo.name] || createDbContext();

            if (dbInfo.db) {
                if (upgradeNeeded) {
                    _deferReadiness(dbInfo);
                    dbInfo.db.close();
                } else {
                    return resolve(dbInfo.db);
                }
            }

            var dbArgs = [dbInfo.name];

            if (upgradeNeeded) {
                dbArgs.push(dbInfo.version);
            }

            var openreq = _idb2.default.open.apply(_idb2.default, dbArgs);

            if (upgradeNeeded) {
                openreq.onupgradeneeded = function (e) {
                    var db = openreq.result;
                    try {
                        db.createObjectStore(dbInfo.storeName);
                        if (e.oldVersion <= 1) {
                            // Added when support for blob shims was added
                            db.createObjectStore(DETECT_BLOB_SUPPORT_STORE);
                        }
                    } catch (ex) {
                        if (ex.name === 'ConstraintError') {
                            console.warn('The database "' + dbInfo.name + '"' + ' has been upgraded from version ' + e.oldVersion + ' to version ' + e.newVersion + ', but the storage "' + dbInfo.storeName + '" already exists.');
                        } else {
                            throw ex;
                        }
                    }
                };
            }

            openreq.onerror = function (e) {
                e.preventDefault();
                reject(openreq.error);
            };

            openreq.onsuccess = function () {
                resolve(openreq.result);
                _advanceReadiness(dbInfo);
            };
        });
    }

    function _getOriginalConnection(dbInfo) {
        return _getConnection(dbInfo, false);
    }

    function _getUpgradedConnection(dbInfo) {
        return _getConnection(dbInfo, true);
    }

    function _isUpgradeNeeded(dbInfo, defaultVersion) {
        if (!dbInfo.db) {
            return true;
        }

        var isNewStore = !dbInfo.db.objectStoreNames.contains(dbInfo.storeName);
        var isDowngrade = dbInfo.version < dbInfo.db.version;
        var isUpgrade = dbInfo.version > dbInfo.db.version;

        if (isDowngrade) {
            // If the version is not the default one
            // then warn for impossible downgrade.
            if (dbInfo.version !== defaultVersion) {
                console.warn('The database "' + dbInfo.name + '"' + " can't be downgraded from version " + dbInfo.db.version + ' to version ' + dbInfo.version + '.');
            }
            // Align the versions to prevent errors.
            dbInfo.version = dbInfo.db.version;
        }

        if (isUpgrade || isNewStore) {
            // If the store is new then increment the version (if needed).
            // This will trigger an "upgradeneeded" event which is required
            // for creating a store.
            if (isNewStore) {
                var incVersion = dbInfo.db.version + 1;
                if (incVersion > dbInfo.version) {
                    dbInfo.version = incVersion;
                }
            }

            return true;
        }

        return false;
    }

    // encode a blob for indexeddb engines that don't support blobs
    function _encodeBlob(blob) {
        return new _promise2.default(function (resolve, reject) {
            var reader = new FileReader();
            reader.onerror = reject;
            reader.onloadend = function (e) {
                var base64 = btoa(e.target.result || '');
                resolve({
                    __local_forage_encoded_blob: true,
                    data: base64,
                    type: blob.type
                });
            };
            reader.readAsBinaryString(blob);
        });
    }

    // decode an encoded blob
    function _decodeBlob(encodedBlob) {
        var arrayBuff = _binStringToArrayBuffer(atob(encodedBlob.data));
        return (0, _createBlob2.default)([arrayBuff], { type: encodedBlob.type });
    }

    // is this one of our fancy encoded blobs?
    function _isEncodedBlob(value) {
        return value && value.__local_forage_encoded_blob;
    }

    // Specialize the default `ready()` function by making it dependent
    // on the current database operations. Thus, the driver will be actually
    // ready when it's been initialized (default) *and* there are no pending
    // operations on the database (initiated by some other instances).
    function _fullyReady(callback) {
        var self = this;

        var promise = self._initReady().then(function () {
            var dbContext = dbContexts[self._dbInfo.name];

            if (dbContext && dbContext.dbReady) {
                return dbContext.dbReady;
            }
        });

        (0, _executeTwoCallbacks2.default)(promise, callback, callback);
        return promise;
    }

    // Try to establish a new db connection to replace the
    // current one which is broken (i.e. experiencing
    // InvalidStateError while creating a transaction).
    function _tryReconnect(dbInfo) {
        _deferReadiness(dbInfo);

        var dbContext = dbContexts[dbInfo.name];
        var forages = dbContext.forages;

        for (var i = 0; i < forages.length; i++) {
            var forage = forages[i];
            if (forage._dbInfo.db) {
                forage._dbInfo.db.close();
                forage._dbInfo.db = null;
            }
        }
        dbInfo.db = null;

        return _getOriginalConnection(dbInfo).then(function (db) {
            dbInfo.db = db;
            if (_isUpgradeNeeded(dbInfo)) {
                // Reopen the database for upgrading.
                return _getUpgradedConnection(dbInfo);
            }
            return db;
        }).then(function (db) {
            // store the latest db reference
            // in case the db was upgraded
            dbInfo.db = dbContext.db = db;
            for (var i = 0; i < forages.length; i++) {
                forages[i]._dbInfo.db = db;
            }
        }).catch(function (err) {
            _rejectReadiness(dbInfo, err);
            throw err;
        });
    }

    // FF doesn't like Promises (micro-tasks) and IDDB store operations,
    // so we have to do it with callbacks
    function createTransaction(dbInfo, mode, callback, retries) {
        if (retries === undefined) {
            retries = 1;
        }

        try {
            var tx = dbInfo.db.transaction(dbInfo.storeName, mode);
            callback(null, tx);
        } catch (err) {
            if (retries > 0 && (!dbInfo.db || err.name === 'InvalidStateError' || err.name === 'NotFoundError')) {
                return _promise2.default.resolve().then(function () {
                    if (!dbInfo.db || err.name === 'NotFoundError' && !dbInfo.db.objectStoreNames.contains(dbInfo.storeName) && dbInfo.version <= dbInfo.db.version) {
                        // increase the db version, to create the new ObjectStore
                        if (dbInfo.db) {
                            dbInfo.version = dbInfo.db.version + 1;
                        }
                        // Reopen the database for upgrading.
                        return _getUpgradedConnection(dbInfo);
                    }
                }).then(function () {
                    return _tryReconnect(dbInfo).then(function () {
                        createTransaction(dbInfo, mode, callback, retries - 1);
                    });
                }).catch(callback);
            }

            callback(err);
        }
    }

    function createDbContext() {
        return {
            // Running localForages sharing a database.
            forages: [],
            // Shared database.
            db: null,
            // Database readiness (promise).
            dbReady: null,
            // Deferred operations on the database.
            deferredOperations: []
        };
    }

    // Open the IndexedDB database (automatically creates one if one didn't
    // previously exist), using any options set in the config.
    function _initStorage(options) {
        var self = this;
        var dbInfo = {
            db: null
        };

        if (options) {
            for (var i in options) {
                dbInfo[i] = options[i];
            }
        }

        // Get the current context of the database;
        var dbContext = dbContexts[dbInfo.name];

        // ...or create a new context.
        if (!dbContext) {
            dbContext = createDbContext();
            // Register the new context in the global container.
            dbContexts[dbInfo.name] = dbContext;
        }

        // Register itself as a running localForage in the current context.
        dbContext.forages.push(self);

        // Replace the default `ready()` function with the specialized one.
        if (!self._initReady) {
            self._initReady = self.ready;
            self.ready = _fullyReady;
        }

        // Create an array of initialization states of the related localForages.
        var initPromises = [];

        function ignoreErrors() {
            // Don't handle errors here,
            // just makes sure related localForages aren't pending.
            return _promise2.default.resolve();
        }

        for (var j = 0; j < dbContext.forages.length; j++) {
            var forage = dbContext.forages[j];
            if (forage !== self) {
                // Don't wait for itself...
                initPromises.push(forage._initReady().catch(ignoreErrors));
            }
        }

        // Take a snapshot of the related localForages.
        var forages = dbContext.forages.slice(0);

        // Initialize the connection process only when
        // all the related localForages aren't pending.
        return _promise2.default.all(initPromises).then(function () {
            dbInfo.db = dbContext.db;
            // Get the connection or open a new one without upgrade.
            return _getOriginalConnection(dbInfo);
        }).then(function (db) {
            dbInfo.db = db;
            if (_isUpgradeNeeded(dbInfo, self._defaultConfig.version)) {
                // Reopen the database for upgrading.
                return _getUpgradedConnection(dbInfo);
            }
            return db;
        }).then(function (db) {
            dbInfo.db = dbContext.db = db;
            self._dbInfo = dbInfo;
            // Share the final connection amongst related localForages.
            for (var k = 0; k < forages.length; k++) {
                var forage = forages[k];
                if (forage !== self) {
                    // Self is already up-to-date.
                    forage._dbInfo.db = dbInfo.db;
                    forage._dbInfo.version = dbInfo.version;
                }
            }
        });
    }

    function getItem(key, callback) {
        var self = this;

        key = (0, _normalizeKey2.default)(key);

        var promise = new _promise2.default(function (resolve, reject) {
            self.ready().then(function () {
                createTransaction(self._dbInfo, READ_ONLY, function (err, transaction) {
                    if (err) {
                        return reject(err);
                    }

                    try {
                        var store = transaction.objectStore(self._dbInfo.storeName);
                        var req = store.get(key);

                        req.onsuccess = function () {
                            var value = req.result;
                            if (value === undefined) {
                                value = null;
                            }
                            if (_isEncodedBlob(value)) {
                                value = _decodeBlob(value);
                            }
                            resolve(value);
                        };

                        req.onerror = function () {
                            reject(req.error);
                        };
                    } catch (e) {
                        reject(e);
                    }
                });
            }).catch(reject);
        });

        (0, _executeCallback2.default)(promise, callback);
        return promise;
    }

    // Iterate over all items stored in database.
    function iterate(iterator, callback) {
        var self = this;

        var promise = new _promise2.default(function (resolve, reject) {
            self.ready().then(function () {
                createTransaction(self._dbInfo, READ_ONLY, function (err, transaction) {
                    if (err) {
                        return reject(err);
                    }

                    try {
                        var store = transaction.objectStore(self._dbInfo.storeName);
                        var req = store.openCursor();
                        var iterationNumber = 1;

                        req.onsuccess = function () {
                            var cursor = req.result;

                            if (cursor) {
                                var value = cursor.value;
                                if (_isEncodedBlob(value)) {
                                    value = _decodeBlob(value);
                                }
                                var result = iterator(value, cursor.key, iterationNumber++);

                                // when the iterator callback returns any
                                // (non-`undefined`) value, then we stop
                                // the iteration immediately
                                if (result !== void 0) {
                                    resolve(result);
                                } else {
                                    cursor.continue();
                                }
                            } else {
                                resolve();
                            }
                        };

                        req.onerror = function () {
                            reject(req.error);
                        };
                    } catch (e) {
                        reject(e);
                    }
                });
            }).catch(reject);
        });

        (0, _executeCallback2.default)(promise, callback);

        return promise;
    }

    function setItem(key, value, callback) {
        var self = this;

        key = (0, _normalizeKey2.default)(key);

        var promise = new _promise2.default(function (resolve, reject) {
            var dbInfo;
            self.ready().then(function () {
                dbInfo = self._dbInfo;
                if (toString.call(value) === '[object Blob]') {
                    return _checkBlobSupport(dbInfo.db).then(function (blobSupport) {
                        if (blobSupport) {
                            return value;
                        }
                        return _encodeBlob(value);
                    });
                }
                return value;
            }).then(function (value) {
                createTransaction(self._dbInfo, READ_WRITE, function (err, transaction) {
                    if (err) {
                        return reject(err);
                    }

                    try {
                        var store = transaction.objectStore(self._dbInfo.storeName);

                        // The reason we don't _save_ null is because IE 10 does
                        // not support saving the `null` type in IndexedDB. How
                        // ironic, given the bug below!
                        // See: https://github.com/mozilla/localForage/issues/161
                        if (value === null) {
                            value = undefined;
                        }

                        var req = store.put(value, key);

                        transaction.oncomplete = function () {
                            // Cast to undefined so the value passed to
                            // callback/promise is the same as what one would get out
                            // of `getItem()` later. This leads to some weirdness
                            // (setItem('foo', undefined) will return `null`), but
                            // it's not my fault localStorage is our baseline and that
                            // it's weird.
                            if (value === undefined) {
                                value = null;
                            }

                            resolve(value);
                        };
                        transaction.onabort = transaction.onerror = function () {
                            var err = req.error ? req.error : req.transaction.error;
                            reject(err);
                        };
                    } catch (e) {
                        reject(e);
                    }
                });
            }).catch(reject);
        });

        (0, _executeCallback2.default)(promise, callback);
        return promise;
    }

    function removeItem(key, callback) {
        var self = this;

        key = (0, _normalizeKey2.default)(key);

        var promise = new _promise2.default(function (resolve, reject) {
            self.ready().then(function () {
                createTransaction(self._dbInfo, READ_WRITE, function (err, transaction) {
                    if (err) {
                        return reject(err);
                    }

                    try {
                        var store = transaction.objectStore(self._dbInfo.storeName);
                        // We use a Grunt task to make this safe for IE and some
                        // versions of Android (including those used by Cordova).
                        // Normally IE won't like `.delete()` and will insist on
                        // using `['delete']()`, but we have a build step that
                        // fixes this for us now.
                        var req = store.delete(key);
                        transaction.oncomplete = function () {
                            resolve();
                        };

                        transaction.onerror = function () {
                            reject(req.error);
                        };

                        // The request will be also be aborted if we've exceeded our storage
                        // space.
                        transaction.onabort = function () {
                            var err = req.error ? req.error : req.transaction.error;
                            reject(err);
                        };
                    } catch (e) {
                        reject(e);
                    }
                });
            }).catch(reject);
        });

        (0, _executeCallback2.default)(promise, callback);
        return promise;
    }

    function clear(callback) {
        var self = this;

        var promise = new _promise2.default(function (resolve, reject) {
            self.ready().then(function () {
                createTransaction(self._dbInfo, READ_WRITE, function (err, transaction) {
                    if (err) {
                        return reject(err);
                    }

                    try {
                        var store = transaction.objectStore(self._dbInfo.storeName);
                        var req = store.clear();

                        transaction.oncomplete = function () {
                            resolve();
                        };

                        transaction.onabort = transaction.onerror = function () {
                            var err = req.error ? req.error : req.transaction.error;
                            reject(err);
                        };
                    } catch (e) {
                        reject(e);
                    }
                });
            }).catch(reject);
        });

        (0, _executeCallback2.default)(promise, callback);
        return promise;
    }

    function length(callback) {
        var self = this;

        var promise = new _promise2.default(function (resolve, reject) {
            self.ready().then(function () {
                createTransaction(self._dbInfo, READ_ONLY, function (err, transaction) {
                    if (err) {
                        return reject(err);
                    }

                    try {
                        var store = transaction.objectStore(self._dbInfo.storeName);
                        var req = store.count();

                        req.onsuccess = function () {
                            resolve(req.result);
                        };

                        req.onerror = function () {
                            reject(req.error);
                        };
                    } catch (e) {
                        reject(e);
                    }
                });
            }).catch(reject);
        });

        (0, _executeCallback2.default)(promise, callback);
        return promise;
    }

    function key(n, callback) {
        var self = this;

        var promise = new _promise2.default(function (resolve, reject) {
            if (n < 0) {
                resolve(null);

                return;
            }

            self.ready().then(function () {
                createTransaction(self._dbInfo, READ_ONLY, function (err, transaction) {
                    if (err) {
                        return reject(err);
                    }

                    try {
                        var store = transaction.objectStore(self._dbInfo.storeName);
                        var advanced = false;
                        var req = store.openKeyCursor();

                        req.onsuccess = function () {
                            var cursor = req.result;
                            if (!cursor) {
                                // this means there weren't enough keys
                                resolve(null);

                                return;
                            }

                            if (n === 0) {
                                // We have the first key, return it if that's what they
                                // wanted.
                                resolve(cursor.key);
                            } else {
                                if (!advanced) {
                                    // Otherwise, ask the cursor to skip ahead n
                                    // records.
                                    advanced = true;
                                    cursor.advance(n);
                                } else {
                                    // When we get here, we've got the nth key.
                                    resolve(cursor.key);
                                }
                            }
                        };

                        req.onerror = function () {
                            reject(req.error);
                        };
                    } catch (e) {
                        reject(e);
                    }
                });
            }).catch(reject);
        });

        (0, _executeCallback2.default)(promise, callback);
        return promise;
    }

    function keys(callback) {
        var self = this;

        var promise = new _promise2.default(function (resolve, reject) {
            self.ready().then(function () {
                createTransaction(self._dbInfo, READ_ONLY, function (err, transaction) {
                    if (err) {
                        return reject(err);
                    }

                    try {
                        var store = transaction.objectStore(self._dbInfo.storeName);
                        var req = store.openKeyCursor();
                        var keys = [];

                        req.onsuccess = function () {
                            var cursor = req.result;

                            if (!cursor) {
                                resolve(keys);
                                return;
                            }

                            keys.push(cursor.key);
                            cursor.continue();
                        };

                        req.onerror = function () {
                            reject(req.error);
                        };
                    } catch (e) {
                        reject(e);
                    }
                });
            }).catch(reject);
        });

        (0, _executeCallback2.default)(promise, callback);
        return promise;
    }

    function dropInstance(options, callback) {
        callback = _getCallback2.default.apply(this, arguments);

        var currentConfig = this.config();
        options = typeof options !== 'function' && options || {};
        if (!options.name) {
            options.name = options.name || currentConfig.name;
            options.storeName = options.storeName || currentConfig.storeName;
        }

        var self = this;
        var promise;
        if (!options.name) {
            promise = _promise2.default.reject('Invalid arguments');
        } else {
            var isCurrentDb = options.name === currentConfig.name && self._dbInfo.db;

            var dbPromise = isCurrentDb ? _promise2.default.resolve(self._dbInfo.db) : _getOriginalConnection(options).then(function (db) {
                var dbContext = dbContexts[options.name];
                var forages = dbContext.forages;
                dbContext.db = db;
                for (var i = 0; i < forages.length; i++) {
                    forages[i]._dbInfo.db = db;
                }
                return db;
            });

            if (!options.storeName) {
                promise = dbPromise.then(function (db) {
                    _deferReadiness(options);

                    var dbContext = dbContexts[options.name];
                    var forages = dbContext.forages;

                    db.close();
                    for (var i = 0; i < forages.length; i++) {
                        var forage = forages[i];
                        forage._dbInfo.db = null;
                    }

                    var dropDBPromise = new _promise2.default(function (resolve, reject) {
                        var req = _idb2.default.deleteDatabase(options.name);

                        req.onerror = req.onblocked = function (err) {
                            var db = req.result;
                            if (db) {
                                db.close();
                            }
                            reject(err);
                        };

                        req.onsuccess = function () {
                            var db = req.result;
                            if (db) {
                                db.close();
                            }
                            resolve(db);
                        };
                    });

                    return dropDBPromise.then(function (db) {
                        dbContext.db = db;
                        for (var i = 0; i < forages.length; i++) {
                            var _forage = forages[i];
                            _advanceReadiness(_forage._dbInfo);
                        }
                    }).catch(function (err) {
                        (_rejectReadiness(options, err) || _promise2.default.resolve()).catch(function () {});
                        throw err;
                    });
                });
            } else {
                promise = dbPromise.then(function (db) {
                    if (!db.objectStoreNames.contains(options.storeName)) {
                        return;
                    }

                    var newVersion = db.version + 1;

                    _deferReadiness(options);

                    var dbContext = dbContexts[options.name];
                    var forages = dbContext.forages;

                    db.close();
                    for (var i = 0; i < forages.length; i++) {
                        var forage = forages[i];
                        forage._dbInfo.db = null;
                        forage._dbInfo.version = newVersion;
                    }

                    var dropObjectPromise = new _promise2.default(function (resolve, reject) {
                        var req = _idb2.default.open(options.name, newVersion);

                        req.onerror = function (err) {
                            var db = req.result;
                            db.close();
                            reject(err);
                        };

                        req.onupgradeneeded = function () {
                            var db = req.result;
                            db.deleteObjectStore(options.storeName);
                        };

                        req.onsuccess = function () {
                            var db = req.result;
                            db.close();
                            resolve(db);
                        };
                    });

                    return dropObjectPromise.then(function (db) {
                        dbContext.db = db;
                        for (var j = 0; j < forages.length; j++) {
                            var _forage2 = forages[j];
                            _forage2._dbInfo.db = db;
                            _advanceReadiness(_forage2._dbInfo);
                        }
                    }).catch(function (err) {
                        (_rejectReadiness(options, err) || _promise2.default.resolve()).catch(function () {});
                        throw err;
                    });
                });
            }
        }

        (0, _executeCallback2.default)(promise, callback);
        return promise;
    }

    var asyncStorage = {
        _driver: 'asyncStorage',
        _initStorage: _initStorage,
        _support: (0, _isIndexedDBValid2.default)(),
        iterate: iterate,
        getItem: getItem,
        setItem: setItem,
        removeItem: removeItem,
        clear: clear,
        length: length,
        key: key,
        keys: keys,
        dropInstance: dropInstance
    };
    exports.default = asyncStorage;
    module.exports = exports['default'];
});