// max of 140 chars is recommended, but it really allows 160
const TWEET_MAXLEN = 140;
const TWEET_SHORT_URL_MAX_LENGTH = 17;

CmdUtils.CreateCommand({
  name: "tweet",
  icon: "http://assets3.twitter.com/images/favicon.ico",
  takes: {status: noun_arb_text},
  modifiers: {},
  description: "Sets your Twitter status to a message of at most 160 characters.",
  help: "You'll need a Twitter account, obviously.  If you're not already logged in" +
        " you'll be asked to log in.",
  preview: function(previewBlock, directObj) {
    var statusText = directObj.text;
    var statusLength = statusText.length;

    var usesUrlShortener = statusText.indexOf('isgd') != -1;
    if (usesUrlShortener) statusLength += TWEET_SHORT_URL_MAX_LENGTH - 4;

    var previewData = {
      status: statusText,
      chars: TWEET_MAXLEN - statusLength
    };

    var previewTemplate = "Updates your Twitter status to: 
${status}

Characters remaining: ${chars}";
    var truncateTemplate = "
The last ${truncate} characters will be truncated!";
    var urlWillBeShortenedText = "
The text 'isgd' will be replaced with an http://is.gd/ link to the current page."

    var previewHTML = CmdUtils.renderTemplate(previewTemplate, previewData);

    if (usesUrlShortener) previewHTML += urlWillBeShortenedText;

    if(previewData.chars < 0) {
      var truncateData = {
        truncate: 0 - previewData.chars
      };

      previewHTML += CmdUtils.renderTemplate(truncateTemplate, truncateData);
    }

    previewBlock.innerHTML = previewHTML;
  },
  execute: function(directObj) {
    var statusText = directObj.text;
    if(statusText.length < 1) {
      displayMessage("Twitter requires a status to be entered");
      return;
    }

    var usesUrlShortener = statusText.indexOf('isgd') != -1;

    var postUpdate = function( shortURL ) {
      var finalStatusText = statusText.replace('isgd', shortURL);

      var updateUrl = "https://twitter.com/statuses/update.json";
      var updateParams = {
        source: "ubiquity",
        status: statusText
      };

      jQuery.ajax({
        type: "POST",
        url: updateUrl,
        data: updateParams,
        dataType: "json",
        error: function() {
          displayMessage("Twitter error - status not updated");
        },
        success: function() {
          displayMessage("Twitter status updated");
        }
      });
    }

    if (usesUrlShortener) {
      var urlToShorten = Application.activeWindow.activeTab.document.location.href;
      jQuery.get( 'http://is.gd/api.php', { 'longurl' : urlToShorten }, postUpdate);
    } else {
      postUpdate('');
    }
  }
});