function _slicedToArray(arr, i) { return _arrayWithHoles(arr) || _iterableToArrayLimit(arr, i) || _unsupportedIterableToArray(arr, i) || _nonIterableRest(); }

function _nonIterableRest() { throw new TypeError("Invalid attempt to destructure non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); }

function _unsupportedIterableToArray(o, minLen) { if (!o) return; if (typeof o === "string") return _arrayLikeToArray(o, minLen); var n = Object.prototype.toString.call(o).slice(8, -1); if (n === "Object" && o.constructor) n = o.constructor.name; if (n === "Map" || n === "Set") return Array.from(o); if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray(o, minLen); }

function _arrayLikeToArray(arr, len) { if (len == null || len > arr.length) len = arr.length; for (var i = 0, arr2 = new Array(len); i < len; i++) { arr2[i] = arr[i]; } return arr2; }

function _iterableToArrayLimit(arr, i) { var _i = arr == null ? null : typeof Symbol !== "undefined" && arr[Symbol.iterator] || arr["@@iterator"]; if (_i == null) return; var _arr = []; var _n = true; var _d = false; var _s, _e; try { for (_i = _i.call(arr); !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"] != null) _i["return"](); } finally { if (_d) throw _e; } } return _arr; }

function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; }

function promisifyRequest(request) {
  return new Promise(function (resolve, reject) {
    // @ts-ignore - file size hacks
    request.oncomplete = request.onsuccess = function () {
      return resolve(request.result);
    }; // @ts-ignore - file size hacks


    request.onabort = request.onerror = function () {
      return reject(request.error);
    };
  });
}

function createStore(dbName, storeName) {
  var request = indexedDB.open(dbName);

  request.onupgradeneeded = function () {
    return request.result.createObjectStore(storeName);
  };

  var dbp = promisifyRequest(request);
  return function (txMode, callback) {
    return dbp.then(function (db) {
      return callback(db.transaction(storeName, txMode).objectStore(storeName));
    });
  };
}

var defaultGetStoreFunc;

function defaultGetStore() {
  if (!defaultGetStoreFunc) {
    defaultGetStoreFunc = createStore('keyval-store', 'keyval');
  }

  return defaultGetStoreFunc;
}
/**
 * Get a value by its key.
 *
 * @param key
 * @param customStore Method to get a custom store. Use with caution (see the docs).
 */


function get(key) {
  var customStore = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : defaultGetStore();
  return customStore('readonly', function (store) {
    return promisifyRequest(store.get(key));
  });
}
/**
 * Set a value with a key.
 *
 * @param key
 * @param value
 * @param customStore Method to get a custom store. Use with caution (see the docs).
 */


function set(key, value) {
  var customStore = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : defaultGetStore();
  return customStore('readwrite', function (store) {
    store.put(value, key);
    return promisifyRequest(store.transaction);
  });
}
/**
 * Set multiple values at once. This is faster than calling set() multiple times.
 * It's also atomic – if one of the pairs can't be added, none will be added.
 *
 * @param entries Array of entries, where each entry is an array of `[key, value]`.
 * @param customStore Method to get a custom store. Use with caution (see the docs).
 */


function setMany(entries) {
  var customStore = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : defaultGetStore();
  return customStore('readwrite', function (store) {
    entries.forEach(function (entry) {
      return store.put(entry[1], entry[0]);
    });
    return promisifyRequest(store.transaction);
  });
}
/**
 * Get multiple values by their keys
 *
 * @param keys
 * @param customStore Method to get a custom store. Use with caution (see the docs).
 */


function getMany(keys) {
  var customStore = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : defaultGetStore();
  return customStore('readonly', function (store) {
    return Promise.all(keys.map(function (key) {
      return promisifyRequest(store.get(key));
    }));
  });
}
/**
 * Update a value. This lets you see the old value and update it as an atomic operation.
 *
 * @param key
 * @param updater A callback that takes the old value and returns a new value.
 * @param customStore Method to get a custom store. Use with caution (see the docs).
 */


function update(key, updater) {
  var customStore = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : defaultGetStore();
  return customStore('readwrite', function (store) {
    return (// Need to create the promise manually.
      // If I try to chain promises, the transaction closes in browsers
      // that use a promise polyfill (IE10/11).
      new Promise(function (resolve, reject) {
        store.get(key).onsuccess = function () {
          try {
            store.put(updater(this.result), key);
            resolve(promisifyRequest(store.transaction));
          } catch (err) {
            reject(err);
          }
        };
      })
    );
  });
}
/**
 * Delete a particular key from the store.
 *
 * @param key
 * @param customStore Method to get a custom store. Use with caution (see the docs).
 */


function del(key) {
  var customStore = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : defaultGetStore();
  return customStore('readwrite', function (store) {
    store.delete(key);
    return promisifyRequest(store.transaction);
  });
}
/**
 * Delete multiple keys at once.
 *
 * @param keys List of keys to delete.
 * @param customStore Method to get a custom store. Use with caution (see the docs).
 */


function delMany(keys) {
  var customStore = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : defaultGetStore();
  return customStore('readwrite', function (store) {
    keys.forEach(function (key) {
      return store.delete(key);
    });
    return promisifyRequest(store.transaction);
  });
}
/**
 * Clear all values in the store.
 *
 * @param customStore Method to get a custom store. Use with caution (see the docs).
 */


function clear() {
  var customStore = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : defaultGetStore();
  return customStore('readwrite', function (store) {
    store.clear();
    return promisifyRequest(store.transaction);
  });
}

function eachCursor(store, callback) {
  store.openCursor().onsuccess = function () {
    if (!this.result) return;
    callback(this.result);
    this.result.continue();
  };

  return promisifyRequest(store.transaction);
}
/**
 * Get all keys in the store.
 *
 * @param customStore Method to get a custom store. Use with caution (see the docs).
 */


function keys() {
  var customStore = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : defaultGetStore();
  return customStore('readonly', function (store) {
    // Fast path for modern browsers
    if (store.getAllKeys) {
      return promisifyRequest(store.getAllKeys());
    }

    var items = [];
    return eachCursor(store, function (cursor) {
      return items.push(cursor.key);
    }).then(function () {
      return items;
    });
  });
}
/**
 * Get all values in the store.
 *
 * @param customStore Method to get a custom store. Use with caution (see the docs).
 */


function values() {
  var customStore = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : defaultGetStore();
  return customStore('readonly', function (store) {
    // Fast path for modern browsers
    if (store.getAll) {
      return promisifyRequest(store.getAll());
    }

    var items = [];
    return eachCursor(store, function (cursor) {
      return items.push(cursor.value);
    }).then(function () {
      return items;
    });
  });
}
/**
 * Get all entries in the store. Each entry is an array of `[key, value]`.
 *
 * @param customStore Method to get a custom store. Use with caution (see the docs).
 */


function entries() {
  var customStore = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : defaultGetStore();
  return customStore('readonly', function (store) {
    // Fast path for modern browsers
    // (although, hopefully we'll get a simpler path some day)
    if (store.getAll && store.getAllKeys) {
      return Promise.all([promisifyRequest(store.getAllKeys()), promisifyRequest(store.getAll())]).then(function (_ref) {
        var _ref2 = _slicedToArray(_ref, 2),
            keys = _ref2[0],
            values = _ref2[1];

        return keys.map(function (key, i) {
          return [key, values[i]];
        });
      });
    }

    var items = [];
    return customStore('readonly', function (store) {
      return eachCursor(store, function (cursor) {
        return items.push([cursor.key, cursor.value]);
      }).then(function () {
        return items;
      });
    });
  });
}

export { clear, createStore, del, delMany, entries, get, getMany, keys, promisifyRequest, set, setMany, update, values };