// Copyright (c) 2012 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.

/**
 * This view displays options for exporting the captured data.
 */
var ExportView = (function() {
  'use strict';

  // We inherit from DivView.
  var superClass = DivView;

  /**
   * @constructor
   */
  function ExportView() {
    assertFirstConstructorCall(ExportView);

    // Call superclass's constructor.
    superClass.call(this, ExportView.MAIN_BOX_ID);

    var privacyStrippingCheckbox = $(ExportView.PRIVACY_STRIPPING_CHECKBOX_ID);
    privacyStrippingCheckbox.onclick =
        this.onSetPrivacyStripping_.bind(this, privacyStrippingCheckbox);

    this.saveFileButton_ = $(ExportView.SAVE_FILE_BUTTON_ID);
    this.saveFileButton_.onclick = this.onSaveFile_.bind(this);
    this.saveStatusText_ = $(ExportView.SAVE_STATUS_TEXT_ID);

    this.userCommentsTextArea_ = $(ExportView.USER_COMMENTS_TEXT_AREA_ID);

    // Track blob for previous log dump so it can be revoked when a new dump is
    // saved.
    this.lastBlobURL_ = null;

    // Cached copy of the last loaded log dump, for use when exporting.
    this.loadedLogDump_ = null;
  }

  // ID for special HTML element in category_tabs.html
  ExportView.TAB_HANDLE_ID = 'tab-handle-export';

  // IDs for special HTML elements in export_view.html
  ExportView.MAIN_BOX_ID = 'export-view-tab-content';
  ExportView.DOWNLOAD_ANCHOR_ID = 'export-view-download-anchor';
  ExportView.SAVE_FILE_BUTTON_ID = 'export-view-save-log-file';
  ExportView.SAVE_STATUS_TEXT_ID = 'export-view-save-status-text';
  ExportView.PRIVACY_STRIPPING_CHECKBOX_ID =
      'export-view-privacy-stripping-checkbox';
  ExportView.USER_COMMENTS_TEXT_AREA_ID = 'export-view-user-comments';
  ExportView.PRIVACY_WARNING_ID = 'export-view-privacy-warning';

  cr.addSingletonGetter(ExportView);

  ExportView.prototype = {
    // Inherit the superclass's methods.
    __proto__: superClass.prototype,

    /**
     * Depending on the value of the checkbox, enables or disables stripping
     * cookies and passwords from log dumps and displayed events.
     */
    onSetPrivacyStripping_: function(privacyStrippingCheckbox) {
      SourceTracker.getInstance().setPrivacyStripping(
          privacyStrippingCheckbox.checked);
    },

    /**
     * When loading a log dump, cache it for future export and continue showing
     * the ExportView.
     */
    onLoadLogFinish: function(polledData, tabData, logDump) {
      this.loadedLogDump_ = logDump;
      this.setUserComments_(logDump.userComments);
      return true;
    },

    /**
     * Sets the save to file status text, displayed below the save to file
     * button, to |text|.  Also enables or disables the save button based on the
     * value of |isSaving|, which must be true if the save process is still
     * ongoing, and false when the operation has stopped, regardless of success
     * of failure.
     */
    setSaveFileStatus: function(text, isSaving) {
      this.enableSaveFileButton_(!isSaving);
      this.saveStatusText_.textContent = text;
    },

    enableSaveFileButton_: function(enabled) {
      this.saveFileButton_.disabled = !enabled;
    },

    showPrivacyWarning: function() {
      setNodeDisplay($(ExportView.PRIVACY_WARNING_ID), true);
      $(ExportView.PRIVACY_STRIPPING_CHECKBOX_ID).checked = false;
      $(ExportView.PRIVACY_STRIPPING_CHECKBOX_ID).disabled = true;

      // Updating the checkbox doesn't actually disable privacy stripping, since
      // the onclick function will not be called.
      this.onSetPrivacyStripping_($(ExportView.PRIVACY_STRIPPING_CHECKBOX_ID));
    },

    /**
     * If not already busy saving a log dump, triggers asynchronous
     * generation of log dump and starts waiting for it to complete.
     */
    onSaveFile_: function() {
      if (this.saveFileButton_.disabled)
        return;

      // Clean up previous blob, if any, to reduce resource usage.
      if (this.lastBlobURL_) {
        window.webkitURL.revokeObjectURL(this.lastBlobURL_);
        this.lastBlobURL_ = null;
      }
      this.createLogDump_(this.onLogDumpCreated_.bind(this));
    },

    /**
     * Creates a log dump, and either synchronously or asynchronously calls
     * |callback| if it succeeds.  Separate from onSaveFile_ for unit tests.
     */
    createLogDump_: function(callback) {
      // Get an explanation for the dump file (this is mandatory!)
      var userComments = this.getNonEmptyUserComments_();
      if (userComments == undefined) {
        return;
      }

      this.setSaveFileStatus('Preparing data...', true);

      var privacyStripping = SourceTracker.getInstance().getPrivacyStripping();

      // If we have a cached log dump, update it synchronously.
      if (this.loadedLogDump_) {
        var dumpText = log_util.createUpdatedLogDump(userComments,
                                                     this.loadedLogDump_,
                                                     privacyStripping);
        callback(dumpText);
        return;
      }

      // Otherwise, poll information from the browser before creating one.
      log_util.createLogDumpAsync(userComments,
                                  callback,
                                  privacyStripping);
    },

    /**
     * Sets the user comments.
     */
    setUserComments_: function(userComments) {
      this.userCommentsTextArea_.value = userComments;
    },

    /**
     * Fetches the user comments for this dump. If none were entered, warns the
     * user and returns undefined. Otherwise returns the comments text.
     */
    getNonEmptyUserComments_: function() {
      var value = this.userCommentsTextArea_.value;

      // Reset the class name in case we had hilighted it earlier.
      this.userCommentsTextArea_.className = '';

      // We don't accept empty explanations. We don't care what is entered, as
      // long as there is something (a single whitespace would work).
      if (value == '') {
        // Put a big obnoxious red border around the text area.
        this.userCommentsTextArea_.className =
            'export-view-explanation-warning';
        alert('Please fill in the text field!');
        return undefined;
      }

      return value;
    },

    /**
     * Creates a blob url and starts downloading it.
     */
    onLogDumpCreated_: function(dumpText) {
      var textBlob = new Blob([dumpText], {type: 'octet/stream'});
      this.lastBlobURL_ = window.webkitURL.createObjectURL(textBlob);

      // Update the anchor tag and simulate a click on it to start the
      // download.
      var downloadAnchor = $(ExportView.DOWNLOAD_ANCHOR_ID);
      downloadAnchor.href = this.lastBlobURL_;
      downloadAnchor.click();

      this.setSaveFileStatus('Dump successful', false);
    }
  };

  return ExportView;
})();