/**
 * The map object, null until script loads in.
 * @type {GMap2}
 */
var map = null;  

/**
 * The bounds of the markers once loaded in.
 * @type {GLatLngBounds}
 */
var bounds = null;

/**
 * The marker with currently opened info window.
 * @type {GMarker}
 */
var currentMarker = null;

/**
 * The dom element that the map is loaded into
 * @type {Element}
 */
var mapDiv = null;

/**
 * The dom element that everything is a child of.
 * @type {Element}
 */
var containerDiv = null;

/**
 * Position of mouse click (clientX) on map div when in static mode.
 * @type {Number}
 */
var clickedX = 0;

/**
 * Position of mouse click (clientY) on map div when in static mode.
 * @type {Number}
 */
var clickedY = 0;

/**
 * Indicates whether we've created a script tag with Maps API yet
 * @type {Boolean}
 */
var isLoaded = false;


/**
 * Called after script is asynchronously loaded in.
 * Creates the GMap2, GMarker objects and performs actions according to 
 * what the user did to trigger the map load (search, zoom, click etc).
 */
function loadMap() {
  if (GBrowserIsCompatible()) {
    mapDiv.style.background = '#fff';
    mapDiv.style.cursor = '';
    map = new GMap2(mapDiv, {logoPassive: true});
    map.addControl(new GLargeMapControl());
	map.enableScrollWheelZoom();
    bounds = new GLatLngBounds();
    for (var i = 0; i < businesses.length; i++) {
      bounds.extend(new GLatLng(businesses[i].lat, businesses[i].lng));
    }
    var latSpan = bounds.toSpan().lat();
    map.setCenter(bounds.getCenter(), map.getBoundsZoomLevel(bounds));

    // The static map server gives markers more space when calculating
    // bounds and zoom level, so sometimes the API will give a higher
    // zoom level than was used by the static map server.
    // The .98 value is just a guess right now, may need tweaking.
    var newBounds = map.getBounds();
    var newLatSpan = newBounds.toSpan().lat();
    if (latSpan/newLatSpan > .90) { map.zoomOut(); }

    for (var i = 0; i < businesses.length; i++) {
      var marker = createMarker(i);
      var latlng = marker.getLatLng();
      var pixel = map.fromLatLngToDivPixel(latlng);
      if (Math.abs(pixel.x - clickedX) < 12 && Math.abs(pixel.y - clickedY) < 20) {
        //GEvent.trigger(marker, 'click');
      }
      map.addOverlay(marker);
    }
  }
}

/**
 * Zooms to the viewport that fits all the markers.
 */
function zoomToAll() {
  map.setCenter(bounds.getCenter(), map.getBoundsZoomLevel(bounds));
}

/**
 * Creates a marker for the given business.
 * @param {Number} ind
 * @return {GMarker}
 */
function createMarker(ind) {
  var business = businesses[ind];
  var marker = new GMarker(new GLatLng(business.lat, business.lng));
  GEvent.addListener(marker, 'click', function() {
    marker.html = [
        '<div class="baloon-text">'
    ,   '<b>' + business.name + '</b><br />'
    ,   business.address + '<br />'
    ,   business.price || business.stars ? '<center><div class="price-stars">' : ''
    ,   business.price ? '<b class="baloon-price">' + business.price + '</b>' : ''
    ,   business.stars ? '<div class="graphic stars baloon-stars number' + business.stars + '"></div>' : ''
    ,   business.price || business.stars ? '</div></center>' : ''
    ,   business.link ? '<div class="hotel-info">' + business.link + '</div>' : ''   
    ,   '</div>'
    ].join('');
    currentMarker = marker;
    marker.openInfoWindowHtml(marker.html);
  });
  return marker;
}

/**
 * Convenience function for creating an element and assigning an id to it.
 * @param {String} elementType
 * @param {String} id
 * @return {Element} 
 */
function _cel(elementType, id) {
  var element = document.createElement(elementType);
  element.id = id;
  return element;
}

/**
 * Loads in the Maps API script. This is called after some sort of user interaction.
 * The script loads asynchronously and calls loadMap once it's in.
 */
function loadScript(key, hotels, reloadMap) {
    
  businesses = hotels;
  containerDiv = document.getElementById('container_map');
  mapDiv = document.getElementById('map');
  
  if (!isLoaded || reloadMap) {
    isLoaded = true;
    var div = document.createElement('div');
    div.className = 'message';
    div.innerHTML = 'Loading...';
    div.style.left = '10px';
    div.style.top = '10px'; 
    mapDiv.appendChild(div);
    var script = document.createElement('script');
    script.type = 'text/javascript';
    script.src = 'http://maps.google.com/maps?file=api&v=2&async=2&callback=loadMap&key=' + key;
    document.body.appendChild(script);
  }
}

/**
 * Sets up the gadget by setting CSS and click events.
 */
function loadMapGadget(key, hotels) {
    
  businesses = hotels;
  containerDiv = document.getElementById('container_map');
  mapDiv = document.getElementById('map');
  
  mapDiv.onclick = function (e) {
    clickedX = (window.event && window.event.offsetX) || e.clientX;
    clickedY = (window.event && window.event.offsetY) || e.clientY;
    loadScript(key, hotels); 
  };

  mapDiv.style.cursor = 'pointer';

  var urlString = ['http://maps.google.com/staticmap?markers='];
  var markerString = [];
  for (var i = 0; i < businesses.length; i++) {
    markerString.push(businesses[i].lat + ',' + businesses[i].lng + ',red');
  }
  urlString.push(markerString.join('|'));
  urlString.push('&size=375x285');
  urlString.push('&key=' + key);
  mapDiv.style.background = 'url(\'' + urlString.join('') + '\')';

}