var Display = {
  scrolled: false,

  add_message: function(text, className, time) {
    var time_html = '<span class="time">\#{time}</span>'.interpolate({ time: TextHelper.dateText(time) });
    $('messages').insert({ bottom: '<li class="' + className + '">' + time_html + ' ' + text + '</li>' });
    this.scrollMessagesToTop();
  },

  addImageOnLoads: function() {
    $$('#messages li').last().select('img').each(function(element) {
        element.observe('load', this.scrollMessagesToTop);
    }.bind(this));
  },

  message: function(message, time) {
    var name = JsChat.user.name;
    var user_class = name == message['user'] ? 'user active' : 'user';
    var text = '<span class="\#{user_class}">\#{user}</span> <span class="\#{message_class}">\#{message}</span>';
    var blurred_mention = '';

    if (message['message'].match(new RegExp(name, 'i')) && name != message['user']) {
      user_class = 'user mentioned';
      blurred_mention = '*';
    }

    Display.clearIdleState(message['user']);

    text = text.interpolate({
      user_class: user_class,
      room: message['room'],
      user: TextHelper.truncateName(message['user']),
      message: TextHelper.decorateMessage(message['message']),
      message_class: 'message'
    });

    this.add_message(text, 'message', time);
    this.addImageOnLoads();

    if (this.show_unread) {
      this.unread++;
      document.title = 'JsChat: (' + this.unread + blurred_mention + ') new messages';
    }
  },

  messages: function(messages) {
    $('messages').innerHTML = '';
    this.ignore_notices = true;

    $A(messages).each(function(json) {
      try {
        if (json['change']) {
          Change[json['change']](json[json['change']]);
        } else {
          this[json['display']](json[json['display']]);
        }
      } catch (exception) {
      }
    }.bind(this));

    this.ignore_notices = false;
    this.scrollMessagesToTop();
    /* This is assumed to be the point at which displaying /lastlog completes */
    $('loading').hide();
  },

  scrollMessagesToTop: function() {
    if (!this.scrolled) {
      $('messages').scrollTop = $('messages').scrollHeight;
    }
  },

  clearIdleState: function(user_name) {
    $$('#names li').each(function(element) {
      if (element.innerHTML == user_name && element.hasClassName('idle')) {
        element.lastIdle = (new Date());
        element.removeClassName('idle');
      }
    });
  },

  isIdle: function(dateValue) {
    try {
      var d = typeof dateValue == 'string' ? new Date(Date.parse(dateValue)) : dateValue,
          now = new Date();
      if (((now - d) / 1000) > (60 * 5)) {
        return true;
      }
    } catch (exception) {
      console.log(exception);
    }
    return false;
  },

  names: function(users) {
    $('names').innerHTML = '';
    users.each(function(user) {
      var name = user['name'],
          list_class = this.isIdle(user['last_activity']) ? 'idle' : '',
          element = $(document.createElement('li'));

      element.addClassName(list_class);
      element.innerHTML = TextHelper.truncateName(name);
      $('names').insert({ bottom: element });

      try {
        // Record the last idle time so the idle state can be dynamically updated
        element.lastIdle = new Date(Date.parse(user['last_activity']));
      } catch (exception) {
        element.lastIdle = null;
      }
    }.bind(this));
  },

  join: function(join) {
    $('room-name').innerHTML = TextHelper.truncateRoomName(join['room']);
    $('room-name').title = PageHelper.currentRoom();
  },

  join_notice: function(join, time) {
    this.add_user(join['user']);
    this.add_message(join['user'] + ' has joined the room', 'server', time);
  },

  add_user: function(name) {
    if (!this.ignore_notices) {
      $('names').insert({ bottom: '<li>' + TextHelper.truncateName(name) + '</li>' });
    }
  },

  remove_user: function(name) {
    if (!this.ignore_notices) {
      $$('#names li').each(function(element) { if (element.innerHTML == name) element.remove(); });
    }
  },

  part_notice: function(part, time) {
    this.remove_user(part['user']);
    this.add_message(part['user'] + ' has left the room', 'server', time);
  },

  quit_notice: function(quit, time) {
    this.remove_user(quit['user']);
    this.add_message(quit['user'] + ' has quit', 'server', time);
  },

  notice: function(notice) {
    this.add_message(notice, 'server');
  },

  error: function(error) {
    this.add_message(error['message'], 'error');
  }
};