// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.


/**
 * An item in the model. Represents a single providing extension.
 *
 * @param {string} providerId
 * @param {!chrome.fileManagerPrivate.IconSet} iconSet
 * @param {string} name
 * @param {boolean} configurable
 * @param {boolean} watchable
 * @param {boolean} multipleMounts
 * @param {string} source
 * @constructor
 * @struct
 */
function ProvidersModelItem(
    providerId, iconSet, name, configurable, watchable, multipleMounts,
    source) {
  /**
   * @private {string}
   * @const
   */
  this.providerId_ = providerId;

  /**
   * @private {!chrome.fileManagerPrivate.IconSet}
   * @const
   */
  this.iconSet_ = iconSet;

  /**
   * @private {string}
   * @const
   */
  this.name_ = name;

  /**
   * @private {boolean}
   * @const
   */
  this.configurable_ = configurable;

  /**
   * @private {boolean}
   * @const
   */
  this.watchable_ = watchable;

  /**
   * @private {boolean}
   * @const
   */
  this.multipleMounts_ = multipleMounts;

  /**
   * @private {string}
   * @const
   */
  this.source_ = source;
}

ProvidersModelItem.prototype = {
  /**
   * @return {string}
   */
  get providerId() {
    return this.providerId_;
  },

  /**
   * @return {!chrome.fileManagerPrivate.IconSet}
   */
  get iconSet() {
    return this.iconSet_;
  },

  /**
   * @return {string}
   */
  get name() {
    return this.name_;
  },

  /**
   * @return {boolean}
   */
  get configurable() {
    return this.configurable_;
  },

  /**
   * @return {boolean}
   */
  get watchable() {
    return this.watchable_;
  },

  /**
   * @return {boolean}
   */
  get multipleMounts() {
    return this.multipleMounts_;
  },

  /**
   * @return {string}
   */
  get source() {
    return this.source_;
  }
};

/**
 * Model for providing extensions. Providers methods for fetching lists of
 * providing extensions as well as performing operations on them, such as
 * requesting a new mount point.
 *
 * @param {!VolumeManager} volumeManager
 * @constructor
 * @struct
 */
function ProvidersModel(volumeManager) {
  /**
   * @private {!VolumeManager}
   * @const
   */
  this.volumeManager_ = volumeManager;
}

/**
 * @return {!Promise<Array<ProvidersModelItem>>}
 */
ProvidersModel.prototype.getInstalledProviders = () => {
  return new Promise((fulfill, reject) => {
    chrome.fileManagerPrivate.getProviders(providers => {
      if (chrome.runtime.lastError) {
        reject(chrome.runtime.lastError.message);
        return;
      }
      const results = [];
      providers.forEach(provider => {
        results.push(new ProvidersModelItem(
            provider.providerId, provider.iconSet, provider.name,
            provider.configurable, provider.watchable, provider.multipleMounts,
            provider.source));
      });
      fulfill(results);
    });
  });
};

/**
 * @return {!Promise<Array<ProvidersModelItem>>}
 */
ProvidersModel.prototype.getMountableProviders = function() {
  return this.getInstalledProviders().then(providers => {
    const mountedProviders = {};
    for (let i = 0; i < this.volumeManager_.volumeInfoList.length; i++) {
      const volumeInfo = this.volumeManager_.volumeInfoList.item(i);
      if (volumeInfo.volumeType === VolumeManagerCommon.VolumeType.PROVIDED) {
        mountedProviders[volumeInfo.providerId] = true;
      }
    }
    return providers.filter(item => {
      // File systems handling files are mounted via file handlers. Device
      // handlers are mounted when a device is inserted. Only network file
      // systems are mounted manually by user via a menu.
      return item.source === 'network' &&
          (!mountedProviders[item.providerId] || item.multipleMounts);
    });
  });
};

/**
 * @param {string} providerId
 */
ProvidersModel.prototype.requestMount = providerId => {
  chrome.fileManagerPrivate.addProvidedFileSystem(
      assert(providerId), () => {
        if (chrome.runtime.lastError) {
          console.error(chrome.runtime.lastError.message);
        }
      });
};