if (!(typeof window.google === 'object' && window.google.maps)) {
  throw 'Google Maps API is required. Please register the following JavaScript library http://maps.google.com/maps/api/js?sensor=true.'
}

var extend_object = function(obj, new_obj) {
  var name;

  if (obj === new_obj) {
    return obj;
  }

  for (name in new_obj) {
    obj[name] = new_obj[name];
  }

  return obj;
};

var replace_object = function(obj, replace) {
  var name;

  if (obj === replace) {
    return obj;
  }

  for (name in replace) {
    if (obj[name] != undefined) {
      obj[name] = replace[name];
    }
  }

  return obj;
};

var array_map = function(array, callback) {
  var original_callback_params = Array.prototype.slice.call(arguments, 2),
      array_return = [],
      array_length = array.length,
      i;

  if (Array.prototype.map && array.map === Array.prototype.map) {
    array_return = Array.prototype.map.call(array, function(item) {
      callback_params = original_callback_params;
      callback_params.splice(0, 0, item);

      return callback.apply(this, callback_params);
    });
  }
  else {
    for (i = 0; i < array_length; i++) {
      callback_params = original_callback_params;
      callback_params.splice(0, 0, array[i]);
      array_return.push(callback.apply(this, callback_params));
    }
  }

  return array_return;
};

var array_flat = function(array) {
  var new_array = [],
      i;

  for (i = 0; i < array.length; i++) {
    new_array = new_array.concat(array[i]);
  }

  return new_array;
};

var coordsToLatLngs = function(coords, useGeoJSON) {
  var first_coord = coords[0],
      second_coord = coords[1];

  if (useGeoJSON) {
    first_coord = coords[1];
    second_coord = coords[0];
  }

  return new google.maps.LatLng(first_coord, second_coord);
};

var arrayToLatLng = function(coords, useGeoJSON) {
  var i;

  for (i = 0; i < coords.length; i++) {
    if (coords[i].length > 0 && typeof(coords[i][0]) == "object") {
      coords[i] = arrayToLatLng(coords[i], useGeoJSON);
    }
    else {
      coords[i] = coordsToLatLngs(coords[i], useGeoJSON);
    }
  }

  return coords;
};

var getElementById = function(id, context) {
  var element,
  id = id.replace('#', '');

  if ('jQuery' in this && context) {
    element = $("#" + id, context)[0];
  } else {
    element = document.getElementById(id);
  };

  return element;
};

var findAbsolutePosition = function(obj)  {
  var curleft = 0,
      curtop = 0;

  if (obj.offsetParent) {
    do {
      curleft += obj.offsetLeft;
      curtop += obj.offsetTop;
    } while (obj = obj.offsetParent);
  }

  return [curleft, curtop];
};

var GMaps = (function(global) {
  "use strict";

  var doc = document;

  var GMaps = function(options) {
    if (!this) return new GMaps(options);

    options.zoom = options.zoom || 15;
    options.mapType = options.mapType || 'roadmap';

    var self = this,
        i,
        events_that_hide_context_menu = ['bounds_changed', 'center_changed', 'click', 'dblclick', 'drag', 'dragend', 'dragstart', 'idle', 'maptypeid_changed', 'projection_changed', 'resize', 'tilesloaded', 'zoom_changed'],
        events_that_doesnt_hide_context_menu = ['mousemove', 'mouseout', 'mouseover'],
        options_to_be_deleted = ['el', 'lat', 'lng', 'mapType', 'width', 'height', 'markerClusterer', 'enableNewStyle'],
        container_id = options.el || options.div,
        markerClustererFunction = options.markerClusterer,
        mapType = google.maps.MapTypeId[options.mapType.toUpperCase()],
        map_center = new google.maps.LatLng(options.lat, options.lng),
        zoomControl = options.zoomControl || true,
        zoomControlOpt = options.zoomControlOpt || {
          style: 'DEFAULT',
          position: 'TOP_LEFT'
        },
        zoomControlStyle = zoomControlOpt.style || 'DEFAULT',
        zoomControlPosition = zoomControlOpt.position || 'TOP_LEFT',
        panControl = options.panControl || true,
        mapTypeControl = options.mapTypeControl || true,
        scaleControl = options.scaleControl || true,
        streetViewControl = options.streetViewControl || true,
        overviewMapControl = overviewMapControl || true,
        map_options = {},
        map_base_options = {
          zoom: this.zoom,
          center: map_center,
          mapTypeId: mapType
        },
        map_controls_options = {
          panControl: panControl,
          zoomControl: zoomControl,
          zoomControlOptions: {
            style: google.maps.ZoomControlStyle[zoomControlStyle],
            position: google.maps.ControlPosition[zoomControlPosition]
          },
          mapTypeControl: mapTypeControl,
          scaleControl: scaleControl,
          streetViewControl: streetViewControl,
          overviewMapControl: overviewMapControl
        };

    if (typeof(options.el) === 'string' || typeof(options.div) === 'string') {
      this.el = getElementById(container_id, options.context);
    } else {
      this.el = container_id;
    }

    if (typeof(this.el) === 'undefined' || this.el === null) {
      throw 'No element defined.';
    }

    window.context_menu = window.context_menu || {};
    window.context_menu[self.el.id] = {};

    this.controls = [];
    this.overlays = [];
    this.layers = []; // array with kml/georss and fusiontables layers, can be as many
    this.singleLayers = {}; // object with the other layers, only one per layer
    this.markers = [];
    this.polylines = [];
    this.routes = [];
    this.polygons = [];
    this.infoWindow = null;
    this.overlay_el = null;
    this.zoom = options.zoom;
    this.registered_events = {};

    this.el.style.width = options.width || this.el.scrollWidth || this.el.offsetWidth;
    this.el.style.height = options.height || this.el.scrollHeight || this.el.offsetHeight;

    google.maps.visualRefresh = options.enableNewStyle;

    for (i = 0; i < options_to_be_deleted.length; i++) {
      delete options[options_to_be_deleted[i]];
    }

    if(options.disableDefaultUI != true) {
      map_base_options = extend_object(map_base_options, map_controls_options);
    }

    map_options = extend_object(map_base_options, options);

    for (i = 0; i < events_that_hide_context_menu.length; i++) {
      delete map_options[events_that_hide_context_menu[i]];
    }

    for (i = 0; i < events_that_doesnt_hide_context_menu.length; i++) {
      delete map_options[events_that_doesnt_hide_context_menu[i]];
    }

    this.map = new google.maps.Map(this.el, map_options);

    if (markerClustererFunction) {
      this.markerClusterer = markerClustererFunction.apply(this, [this.map]);
    }

    var buildContextMenuHTML = function(control, e) {
      var html = '',
          options = window.context_menu[self.el.id][control];

      for (var i in options){
        if (options.hasOwnProperty(i)) {
          var option = options[i];

          html += '<li><a id="' + control + '_' + i + '" href="#">' + option.title + '</a></li>';
        }
      }

      if (!getElementById('gmaps_context_menu')) return;

      var context_menu_element = getElementById('gmaps_context_menu');
      
      context_menu_element.innerHTML = html;

      var context_menu_items = context_menu_element.getElementsByTagName('a'),
          context_menu_items_count = context_menu_items.length
          i;

      for (i = 0; i < context_menu_items_count; i++) {
        var context_menu_item = context_menu_items[i];

        var assign_menu_item_action = function(ev){
          ev.preventDefault();

          options[this.id.replace(control + '_', '')].action.apply(self, [e]);
          self.hideContextMenu();
        };

        google.maps.event.clearListeners(context_menu_item, 'click');
        google.maps.event.addDomListenerOnce(context_menu_item, 'click', assign_menu_item_action, false);
      }

      var position = findAbsolutePosition.apply(this, [self.el]),
          left = position[0] + e.pixel.x - 15,
          top = position[1] + e.pixel.y- 15;

      context_menu_element.style.left = left + "px";
      context_menu_element.style.top = top + "px";

      context_menu_element.style.display = 'block';
    };

    this.buildContextMenu = function(control, e) {
      if (control === 'marker') {
        e.pixel = {};

        var overlay = new google.maps.OverlayView();
        overlay.setMap(self.map);
        
        overlay.draw = function() {
          var projection = overlay.getProjection(),
              position = e.marker.getPosition();
          
          e.pixel = projection.fromLatLngToContainerPixel(position);

          buildContextMenuHTML(control, e);
        };
      }
      else {
        buildContextMenuHTML(control, e);
      }
    };

    this.setContextMenu = function(options) {
      window.context_menu[self.el.id][options.control] = {};

      var i,
          ul = doc.createElement('ul');

      for (i in options.options) {
        if (options.options.hasOwnProperty(i)) {
          var option = options.options[i];

          window.context_menu[self.el.id][options.control][option.name] = {
            title: option.title,
            action: option.action
          };
        }
      }

      ul.id = 'gmaps_context_menu';
      ul.style.display = 'none';
      ul.style.position = 'absolute';
      ul.style.minWidth = '100px';
      ul.style.background = 'white';
      ul.style.listStyle = 'none';
      ul.style.padding = '8px';
      ul.style.boxShadow = '2px 2px 6px #ccc';

      doc.body.appendChild(ul);

      var context_menu_element = getElementById('gmaps_context_menu')

      google.maps.event.addDomListener(context_menu_element, 'mouseout', function(ev) {
        if (!ev.relatedTarget || !this.contains(ev.relatedTarget)) {
          window.setTimeout(function(){
            context_menu_element.style.display = 'none';
          }, 400);
        }
      }, false);
    };

    this.hideContextMenu = function() {
      var context_menu_element = getElementById('gmaps_context_menu');

      if (context_menu_element) {
        context_menu_element.style.display = 'none';
      }
    };

    var setupListener = function(object, name) {
      google.maps.event.addListener(object, name, function(e){
        if (e == undefined) {
          e = this;
        }

        options[name].apply(this, [e]);

        self.hideContextMenu();
      });
    };

    for (var ev = 0; ev < events_that_hide_context_menu.length; ev++) {
      var name = events_that_hide_context_menu[ev];

      if (name in options) {
        setupListener(this.map, name);
      }
    }

    for (var ev = 0; ev < events_that_doesnt_hide_context_menu.length; ev++) {
      var name = events_that_doesnt_hide_context_menu[ev];

      if (name in options) {
        setupListener(this.map, name);
      }
    }

    google.maps.event.addListener(this.map, 'rightclick', function(e) {
      if (options.rightclick) {
        options.rightclick.apply(this, [e]);
      }

      if(window.context_menu[self.el.id]['map'] != undefined) {
        self.buildContextMenu('map', e);
      }
    });

    this.refresh = function() {
      google.maps.event.trigger(this.map, 'resize');
    };

    this.fitZoom = function() {
      var latLngs = [],
          markers_length = this.markers.length,
          i;

      for (i = 0; i < markers_length; i++) {
        latLngs.push(this.markers[i].getPosition());
      }

      this.fitLatLngBounds(latLngs);
    };

    this.fitLatLngBounds = function(latLngs) {
      var total = latLngs.length;
      var bounds = new google.maps.LatLngBounds();

      for(var i=0; i < total; i++) {
        bounds.extend(latLngs[i]);
      }

      this.map.fitBounds(bounds);
    };

    this.setCenter = function(lat, lng, callback) {
      this.map.panTo(new google.maps.LatLng(lat, lng));

      if (callback) {
        callback();
      }
    };

    this.getElement = function() {
      return this.el;
    };

    this.zoomIn = function(value) {
      value = value || 1;

      this.zoom = this.map.getZoom() + value;
      this.map.setZoom(this.zoom);
    };

    this.zoomOut = function(value) {
      value = value || 1;

      this.zoom = this.map.getZoom() - value;
      this.map.setZoom(this.zoom);
    };

    var native_methods = [],
        method;

    for (method in this.map) {
      if (typeof(this.map[method]) == 'function' && !this[method]) {
        native_methods.push(method);
      }
    }

    for (i=0; i < native_methods.length; i++) {
      (function(gmaps, scope, method_name) {
        gmaps[method_name] = function(){
          return scope[method_name].apply(scope, arguments);
        };
      })(this, this.map, native_methods[i]);
    }
  };

  return GMaps;
})(this);