if RUBY_PLATFORM == 'opal'
  require 'native'
end

module GoogleMaps
  class MainController < Volt::ModelController
    attr_accessor :section

    def index_ready
      @markers = []

      `this.geocoder = new google.maps.Geocoder();`

      node = section.container_node

      if attrs.respond_to?(:center)
        @center_watch = proc do
          attrs.center.then do |center|
            if center
              geocode(center) do |latlng|
                setup_map(node, latlng.to_n)
              end
            end
          end
        end.watch!
      else
        setup_map(node, {lat: -34.397, lng: 150.644}.to_n)
      end
    end


    def before_index_remove
      @center_watch.stop if @center_watch
      %x{
        delete this.map;
        delete this.geocoder;
      }

      @add_listener.remove if @add_listener
      @remove_listener.remove if @remove_listener
    end

    def set_markers
      -> do
        # clear existing markers on full re-render
        if @markers
          @markers.each do |marker|
            remove_marker(marker.to_n)
          end
        end
        @markers = []

        markers = attrs.markers

        markers.then do |markers|
          markers.each do |marker|
            add_marker(marker) do |result|
              @markers << result
            end
          end

          @add_listener.remove if @add_listener
          @remove_listener.remove if @remove_listener

          if markers.respond_to?(:on)
            @add_listener = markers.on('added') do |index|
              marker = markers[index]

              add_marker(marker) do |result|
                @markers[index] = result
              end
            end

            @remove_listener = markers.on('removed') do |index|
              marker = @markers.delete_at(index)
              remove_marker(marker.to_n)
            end
          end
        end

      end.watch!
    end

    def setup_zoom
      `google.maps.event.addListener(self.map, 'zoom_changed', function() {
          var zoomLevel = self.map.getZoom();`

          @changing_zoom = true
          new_zoom = Native(`zoomLevel`)
          if attrs.zoom != new_zoom && attrs.respond_to?(:zoom=)
            attrs.zoom = new_zoom
          end

          # Setup listener again
          set_zoom

          @changing_zoom = false

      `});`

    end

    def set_zoom
      -> do
        attrs.zoom
        unless @changing_zoom
          level = attrs.zoom
          if level.blank?
            level = 8
          else
            level = (level || 8).to_i
          end

          level_n = level.to_n
          `if (self.map.getZoom() != level_n) {`
            `self.map.setZoom(level_n);`
          `}`
        end
      end.watch!
    end

    def setup_map(node, latlng)
      %x{
        var mapOptions = {
          center: latlng,
          zoom: 8
        };
        this.map = new google.maps.Map($(node).find('.google-map-instance').get(0), mapOptions);
        this.map.addListener('click', function(e) {
          self.$trigger('click', e.latLng.lat(), e.latLng.lng());
        });
      }

      if attrs.respond_to?(:center)
        @first = true
        -> { set_center(attrs.center) }.watch!
      end


      set_zoom if attrs.respond_to?(:zoom)

      set_markers if attrs.respond_to?(:markers)

      setup_zoom if attrs.respond_to?(:zoom=)
    end

    def set_center(address)
      if @first
        @first = false
      else
        geocode(address) do |latlng|
          latlng_n = latlng.to_n
          if (`!!self.map`)
            `self.map.setCenter(latlng_n);`
          end
        end
      end
    end

    def geocode(address)
      unless address.is_a?(String)
        yield({lat: -34.397, lng: 150.644})
        return
      end

      `this.geocoder.geocode( { 'address': address}, function(results, status) {`
        `if (status == google.maps.GeocoderStatus.OK) {`
          `var latlng = results[0].geometry.location;`
          yield(Native(`latlng`))
        `} else {`
          yield({lat: -34.397, lng: 150.644})
        `}`
      `}.bind(this));`

    end

    def add_marker(marker_data)
      if marker_data.is_a?(String)
        address = marker_data
        content = marker_data
      else
        address = (marker_data._address || '').to_n
        content = (marker_data._content || address || '').to_n
      end

      geocode(address) do |latlng|
        latlng_n = latlng.to_n
        marker = nil

        %x{
          marker = new google.maps.Marker({
            position: latlng_n,
            map: self.map,
            title: content
          });
        }

        yield Native(marker)
      end
    end

    def remove_marker(marker)
      `marker.setMap(null);`
    end
  end
end