var travelMode, unitSystem;

GMaps.prototype.getRoutes = function(options) {
  switch (options.travelMode) {
    case 'bicycling':
      travelMode = google.maps.TravelMode.BICYCLING;
      break;
    case 'transit':
      travelMode = google.maps.TravelMode.TRANSIT;
      break;
    case 'driving':
      travelMode = google.maps.TravelMode.DRIVING;
      break;
    default:
      travelMode = google.maps.TravelMode.WALKING;
      break;
  }

  if (options.unitSystem === 'imperial') {
    unitSystem = google.maps.UnitSystem.IMPERIAL;
  }
  else {
    unitSystem = google.maps.UnitSystem.METRIC;
  }

  var base_options = {
        avoidHighways: false,
        avoidTolls: false,
        optimizeWaypoints: false,
        waypoints: []
      },
      request_options =  extend_object(base_options, options);

  request_options.origin = /string/.test(typeof options.origin) ? options.origin : new google.maps.LatLng(options.origin[0], options.origin[1]);
  request_options.destination = /string/.test(typeof options.destination) ? options.destination : new google.maps.LatLng(options.destination[0], options.destination[1]);
  request_options.travelMode = travelMode;
  request_options.unitSystem = unitSystem;

  delete request_options.callback;

  var self = this,
      service = new google.maps.DirectionsService();

  service.route(request_options, function(result, status) {
    if (status === google.maps.DirectionsStatus.OK) {
      for (var r in result.routes) {
        if (result.routes.hasOwnProperty(r)) {
          self.routes.push(result.routes[r]);
        }
      }
    }

    if (options.callback) {
      options.callback(self.routes);
    }
  });
};

GMaps.prototype.removeRoutes = function() {
  this.routes = [];
};

GMaps.prototype.getElevations = function(options) {
  options = extend_object({
    locations: [],
    path : false,
    samples : 256
  }, options);

  if (options.locations.length > 0) {
    if (options.locations[0].length > 0) {
      options.locations = array_flat(array_map([options.locations], arrayToLatLng,  false));
    }
  }

  var callback = options.callback;
  delete options.callback;

  var service = new google.maps.ElevationService();

  //location request
  if (!options.path) {
    delete options.path;
    delete options.samples;

    service.getElevationForLocations(options, function(result, status) {
      if (callback && typeof(callback) === "function") {
        callback(result, status);
      }
    });
  //path request
  } else {
    var pathRequest = {
      path : options.locations,
      samples : options.samples
    };

    service.getElevationAlongPath(pathRequest, function(result, status) {
     if (callback && typeof(callback) === "function") {
        callback(result, status);
      }
    });
  }
};

GMaps.prototype.cleanRoute = GMaps.prototype.removePolylines;

GMaps.prototype.drawRoute = function(options) {
  var self = this;

  this.getRoutes({
    origin: options.origin,
    destination: options.destination,
    travelMode: options.travelMode,
    waypoints: options.waypoints,
    unitSystem: options.unitSystem,
    callback: function(e) {
      if (e.length > 0) {
        self.drawPolyline({
          path: e[e.length - 1].overview_path,
          strokeColor: options.strokeColor,
          strokeOpacity: options.strokeOpacity,
          strokeWeight: options.strokeWeight
        });
        
        if (options.callback) {
          options.callback(e[e.length - 1]);
        }
      }
    }
  });
};

GMaps.prototype.travelRoute = function(options) {
  if (options.origin && options.destination) {
    this.getRoutes({
      origin: options.origin,
      destination: options.destination,
      travelMode: options.travelMode,
      waypoints : options.waypoints,
      callback: function(e) {
        //start callback
        if (e.length > 0 && options.start) {
          options.start(e[e.length - 1]);
        }

        //step callback
        if (e.length > 0 && options.step) {
          var route = e[e.length - 1];
          if (route.legs.length > 0) {
            var steps = route.legs[0].steps;
            for (var i=0, step; step=steps[i]; i++) {
              step.step_number = i;
              options.step(step, (route.legs[0].steps.length - 1));
            }
          }
        }

        //end callback
        if (e.length > 0 && options.end) {
           options.end(e[e.length - 1]);
        }
      }
    });
  }
  else if (options.route) {
    if (options.route.legs.length > 0) {
      var steps = options.route.legs[0].steps;
      for (var i=0, step; step=steps[i]; i++) {
        step.step_number = i;
        options.step(step);
      }
    }
  }
};

GMaps.prototype.drawSteppedRoute = function(options) {
  var self = this;
  
  if (options.origin && options.destination) {
    this.getRoutes({
      origin: options.origin,
      destination: options.destination,
      travelMode: options.travelMode,
      waypoints : options.waypoints,
      callback: function(e) {
        //start callback
        if (e.length > 0 && options.start) {
          options.start(e[e.length - 1]);
        }

        //step callback
        if (e.length > 0 && options.step) {
          var route = e[e.length - 1];
          if (route.legs.length > 0) {
            var steps = route.legs[0].steps;
            for (var i=0, step; step=steps[i]; i++) {
              step.step_number = i;
              self.drawPolyline({
                path: step.path,
                strokeColor: options.strokeColor,
                strokeOpacity: options.strokeOpacity,
                strokeWeight: options.strokeWeight
              });
              options.step(step, (route.legs[0].steps.length - 1));
            }
          }
        }

        //end callback
        if (e.length > 0 && options.end) {
           options.end(e[e.length - 1]);
        }
      }
    });
  }
  else if (options.route) {
    if (options.route.legs.length > 0) {
      var steps = options.route.legs[0].steps;
      for (var i=0, step; step=steps[i]; i++) {
        step.step_number = i;
        self.drawPolyline({
          path: step.path,
          strokeColor: options.strokeColor,
          strokeOpacity: options.strokeOpacity,
          strokeWeight: options.strokeWeight
        });
        options.step(step);
      }
    }
  }
};

GMaps.Route = function(options) {
  this.origin = options.origin;
  this.destination = options.destination;
  this.waypoints = options.waypoints;

  this.map = options.map;
  this.route = options.route;
  this.step_count = 0;
  this.steps = this.route.legs[0].steps;
  this.steps_length = this.steps.length;

  this.polyline = this.map.drawPolyline({
    path: new google.maps.MVCArray(),
    strokeColor: options.strokeColor,
    strokeOpacity: options.strokeOpacity,
    strokeWeight: options.strokeWeight
  }).getPath();
};

GMaps.Route.prototype.getRoute = function(options) {
  var self = this;

  this.map.getRoutes({
    origin : this.origin,
    destination : this.destination,
    travelMode : options.travelMode,
    waypoints : this.waypoints || [],
    callback : function() {
      self.route = e[0];

      if (options.callback) {
        options.callback.call(self);
      }
    }
  });
};

GMaps.Route.prototype.back = function() {
  if (this.step_count > 0) {
    this.step_count--;
    var path = this.route.legs[0].steps[this.step_count].path;

    for (var p in path){
      if (path.hasOwnProperty(p)){
        this.polyline.pop();
      }
    }
  }
};

GMaps.Route.prototype.forward = function() {
  if (this.step_count < this.steps_length) {
    var path = this.route.legs[0].steps[this.step_count].path;

    for (var p in path){
      if (path.hasOwnProperty(p)){
        this.polyline.push(path[p]);
      }
    }
    this.step_count++;
  }
};
