/** @const */
var CLIENT_ID = '125643747010-9s9n1ne2fnnuh5v967licfkt83r4vba5.apps.googleusercontent.com';
/** @const */
var SCOPES = 'https://www.googleapis.com/auth/drive';
/** @const */
var DEVELOPER_KEY = 'AIzaSyBbKO_v9p-G9StQjYmtUYLP6Px4MkGions';

/**
 * 
 * @constructor
 */
ascii.DriveController = function(state) {
  /** @type {ascii.State} */
  this.state = state;
  // This is a file resource, as defined by the Drive API.
  /** @type {Object} */
  this.file = null;

  $('#save-button').click(function(e) {
      this.save();
  }.bind(this));
};

/**
 * Check if the current user has authorized the application.
 */
ascii.DriveController.prototype.checkAuth = function(callback) {
  window['gapi']['auth']['authorize']({
      'client_id': CLIENT_ID,
      'scope': SCOPES,
      'immediate': true},
      function(result) {
        if (result && !result.error) {
          callback(true);
        } else {
          window['gapi']['auth']['authorize']({
              'client_id': CLIENT_ID,
              'scope': SCOPES,
              'immediate': false},
              function(result) {
                callback(result && !result.error);
              });
        }
      });
};

/**
 * Handles a file resource being returned from Drive.
 */
ascii.DriveController.prototype.handleFile = function(file) {
  this.file = file;
  $('#drive-filename').text(file['title']);
  $('#drive-filename')['editable'](function(value, settings) {
      this.file['title'] = value;
      this.save();
      // Remove the event handler.
      $('#drive-filename').off();
      return value;
    }.bind(this),
    { 
      type    : 'text',
      submit  : 'OK',
    });
};


/**
 * Loads the picker.
 * TODO: Implement this...
 */
ascii.DriveController.prototype.load = function() {
/*
  window['gapi']['client']['load']('picker',
     {'callback': function() {
    var picker = new window['google']['picker']['PickerBuilder']().
              addView(google.picker.ViewId.PHOTOS).
              setOAuthToken(oauthToken).
              setDeveloperKey(developerKey).
              setCallback(pickerCallback).
              build();
          picker.setVisible(true);
}});
*/
};

/**
 * Saves the current diagram to drive.
 */
ascii.DriveController.prototype.save = function() {
  window['gapi']['client']['load']('drive', 'v2', function() {
      this.checkAuth(function(authed) {
          if (authed) {
            this.getSaveRequest().execute(function(result) {
                this.handleFile(result);
            }.bind(this));
          }
      }.bind(this))
  }.bind(this));
};

ascii.DriveController.prototype.getSaveRequest = function() {
  var text = this.state.outputText();

  var boundary = '-------314159265358979323846';
  var delimiter = "\r\n--" + boundary + "\r\n";
  var close_delim = "\r\n--" + boundary + "--";

  var title = this.file == null ? 'Untitled ASCII Diagram' : this.file['title'];

  var metadata = {
      'title': title,
      'mimeType': 'text/plain'
  };

  var multipartRequestBody =
      delimiter +
      'Content-Type: application/json\r\n\r\n' +
      JSON.stringify(metadata) +
      delimiter +
      'Content-Type: ' + 'text/plain' + '\r\n' +
      '\r\n' +
      text +
      close_delim;

  // Choose upload path and method depending on whether we have create a file already.
  var fileId = this.file == null ? '' : '/' + this.file['id'];
  var method = this.file == null ? 'POST' : 'PUT';

  return window['gapi']['client']['request']({
      'path': '/upload/drive/v2/files' + fileId,
      'method': method,
      'params': {'uploadType': 'multipart'},
      'headers': {
        'Content-Type': 'multipart/mixed; boundary="' + boundary + '"'
      },
      'body': multipartRequestBody});
};