// Initialize.
function init_modal() {

  // Does element exist?
  if (!$('a.modal').length) {

    // If not, exit.
    return;
  }

  // Detect IE6 (boolean).
  var $IE6 = typeof document.addEventListener !== 'function' && !window.XMLHttpRequest;

  // Do some math.
  function sizeModal() {

    // Modal dimensions.
    var $modal = $('#modal_window');
    var $modal_width = $modal.outerWidth();
    var $modal_height = $modal.outerHeight();
    var $modal_top = '-' + Math.floor($modal_height / 2) + 'px';
    var $modal_left = '-' + Math.floor($modal_width / 2) + 'px';

    // Set modal.
    $('#modal_window').css('margin-top', $modal_top).css('margin-left', $modal_left);
  }

  /* For IE6. */
  function positionModal() {

    // Force modal into place.
    $('#modal_wrapper').css('top', $(document).scrollTop() + 'px');
  }

  // Reveal the modal.
  function showModal() {

    // Bleh.
    if ($IE6) {
      positionModal();
    }

    // Unveil the wrapper.
    $('#modal_wrapper').show();

    // Size it.
    sizeModal();

    // Reveal modal window.
    $('#modal_window').css('visibility', 'visible').show();

    // Resize as images load.
    $('#modal_content img').each(function() {
      $(this).load(function() {
        $(this).removeClass('modal_placeholder').show();
        sizeModal();
      });
    });
  }

  // Insert modal at end of </body>.
  $('body').append('<div id="modal_wrapper"><!--[if IE 6]><iframe id="modal_iframe" frameborder="0"></iframe><![endif]--><div id="modal_overlay"></div><div id="modal_window"><div id="modal_bar"><strong>Modal window</strong><a href="#" id="modal_close">Close</a></div><div id="modal_content"></div></div>');

  // Look for modal links.
  $('a.modal').click(function() {

    // Check the href="..."
    var $the_link = $(this).attr('href');

    // Determine link target.
    if ($the_link.match(/^#./)) {

      // Assume #anchor content.
      $('#modal_content').html($($(this).attr('href')).html());
      showModal();

    } else if ($the_link.match(/.jpg$/) || $the_link.match(/.png$/) || $the_link.match(/.gif$/)) {

      // Assume image content.
      $('#modal_content').html('<p id="modal_image_wrapper"><img src="' + $the_link + '" class="modal_placeholder" /></p>');
      showModal();

    } else {

      // Assume external Ajax content.
      $('#modal_content').load($(this).attr('href').replace('#', ' #'), '', showModal);
    }

    // Determine modal title.
    if ($(this).attr('title')) {

      // Insert title.
      $('#modal_bar strong').html($(this).attr('title'));

    } else if ($(this).html() !== '') {

      // Insert link text.
      $('#modal_bar strong').html($(this).html());
    }

    // Nofollow.
    this.blur();
    return false;
  });

  // Hide modal elements.
  $('#modal_overlay, #modal_close').click(function() {

    // Hide the modal.
    $('#modal_wrapper').hide();

    // Hide, because images might load later.
    $('#modal_window').css('visibility', 'hidden');

    // Unbind image listeners.
    $('#modal_content img').each(function() {
      $(this).unbind();
    });

    // Destroy modal content.
    $('#modal_content').html('');

    // Reset modal title.
    $('#modal_bar strong').html('Modal window');

    // Nofollow.
    this.blur();
    return false;
  });

  // Listen for browser scroll, if IE6.
  if ($IE6) {
    $(window).scroll(function() {
      if ($('#modal_wrapper').is(':visible')) {
        positionModal();
      }
    });
  }
}

// Kick things off.
$(document).ready(function() {
  init_modal();
});