// Copyright 2016 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.

/**
 * @fileoverview Fake implementation of chrome.system.display for testing.
 */
cr.define('settings', function() {
  /**
   * Fake of the chrome.settings.display API.
   * @constructor
   * @implements {SystemDisplay}
   */
  function FakeSystemDisplay() {
    /** @type {!Array<!chrome.system.display.DisplayUnitInfo>} */
    this.fakeDisplays = [];
    this.fakeLayouts = [];
    this.getInfoCalled = new PromiseResolver();
    this.getLayoutCalled = new PromiseResolver();
  }

  FakeSystemDisplay.prototype = {
    // Public testing methods.
    /**
     * @param {!chrome.system.display.DisplayUnitInfo>} display
     */
    addDisplayForTest: function(display) {
      this.fakeDisplays.push(display);
      this.updateLayouts_();
    },

    // SystemDisplay overrides.
    /** @override */
    getInfo: function(flags, callback) {
      setTimeout(function() {
        // Create a shallow copy to trigger Polymer data binding updates.
        let displays;
        if (this.fakeDisplays.length > 0 &&
            this.fakeDisplays[0].mirroringSourceId) {
          // When mirroring is enabled, send only the info for the display
          // being mirrored.
          const display =
              this.getFakeDisplay_(this.fakeDisplays[0].mirroringSourceId);
          assert(!!display);
          displays = [display];
        } else {
          displays = this.fakeDisplays.slice();
        }
        callback(displays);
        this.getInfoCalled.resolve();
        // Reset the promise resolver.
        this.getInfoCalled = new PromiseResolver();
      }.bind(this));
    },

    /** @override */
    setDisplayProperties: function(id, info, callback) {
      const display = this.getFakeDisplay_(id);
      if (!display) {
        chrome.runtime.lastError = 'Display not found.';
        callback();
      }

      if (info.mirroringSourceId != undefined) {
        for (let d of this.fakeDisplays)
          d.mirroringSourceId = info.mirroringSourceId;
      }

      if (info.isPrimary != undefined) {
        let havePrimary = info.isPrimary;
        for (let d of this.fakeDisplays) {
          if (d.id == id) {
            d.isPrimary = info.isPrimary;
          } else if (havePrimary) {
            d.isPrimary = false;
          } else {
            d.isPrimary = true;
            havePrimary = true;
          }
        }
        this.updateLayouts_();
      }
      if (info.rotation != undefined)
        display.rotation = info.rotation;
    },

    /** @override */
    getDisplayLayout(callback) {
      setTimeout(function() {
        // Create a shallow copy to trigger Polymer data binding updates.
        callback(this.fakeLayouts.slice());
        this.getLayoutCalled.resolve();
        // Reset the promise resolver.
        this.getLayoutCalled = new PromiseResolver();
      }.bind(this));
    },

    /** @override */
    setDisplayLayout(layouts, callback) {
      this.fakeLayouts = layouts;
      callback();
    },

    /** @override */
    onDisplayChanged: new FakeChromeEvent(),

    /** @private */
    getFakeDisplay_(id) {
      const idx = this.fakeDisplays.findIndex(function(display) {
        return display.id == id;
      });
      if (idx >= 0)
        return this.fakeDisplays[idx];
      return undefined;
    },

    /** @private */
    updateLayouts_() {
      this.fakeLayouts = [];
      let primaryId = '';
      for (let d of this.fakeDisplays) {
        if (d.isPrimary) {
          primaryId = d.id;
          break;
        }
      }
      for (let d of this.fakeDisplays) {
        this.fakeLayouts.push({
          id: d.id,
          parentId: d.isPrimary ? '' : primaryId,
          position: chrome.system.display.LayoutPosition.RIGHT,
          offset: 0
        });
      }
    }
  };

  return {FakeSystemDisplay: FakeSystemDisplay};
});