class IMICFPS
  class CameraController
    include CommonMethods
    
    def initialize(mode: :fpv, camera:, entity:)
      # :fpv - First Person View
      # :tpv - Third Person View
      @mode = mode
      @camera = camera
      @entity = entity
      
      @distance = 4
      @origin_distance = @distance
      @constant_pitch = 0
      
      window.mouse_x, window.mouse_y = window.width / 2, window.height / 2
      
      @true_mouse = Point.new(window.width / 2, window.height / 2)
      @mouse_sensitivity = 20.0 # Less is faster, more is slower
      @mouse_captured = true
      @mouse_checked = 0
    end
    
    def distance_from_object
      @distance
    end

    def horizontal_distance_from_object
      distance_from_object * Math.cos(@constant_pitch)
    end

    def vertical_distance_from_object
      distance_from_object * Math.sin(@constant_pitch)
    end
    
    def position_camera
      if defined?(@entity.first_person_view)
        if @entity.first_person_view
          @distance = 0
        else
          @distance = @origin_distance
        end
      end

      x_offset = horizontal_distance_from_object * Math.sin(@entity.orientation.y.degrees_to_radians)
      z_offset = horizontal_distance_from_object * Math.cos(@entity.orientation.y.degrees_to_radians)

      eye_height = @entity.bounding_box.max.y

      @camera.position.x = @entity.position.x - x_offset
      @camera.position.y = @entity.position.y + eye_height
      @camera.position.z = @entity.position.z - z_offset

      @camera.orientation.y = 180 - @entity.orientation.y
    end
    
    def update
      position_camera
      
      if @mouse_captured
        delta = Float(@true_mouse.x - self.mouse_x) / (@mouse_sensitivity * @camera.field_of_view) * 70
        @camera.orientation.y -= delta
        @camera.orientation.y %= 360.0

        @camera.orientation.x -= Float(@true_mouse.y - window.mouse_y) / (@mouse_sensitivity * @camera.field_of_view) * 70
        @camera.orientation.x = @camera.orientation.x.clamp(-90.0, 90.0)

        @entity.orientation.y += delta
        @entity.orientation.y %= 360.0

        window.mouse_x = window.width  / 2 if window.mouse_x <= 1 || window.mouse_x >= window.width-1
        window.mouse_y = window.height / 2 if window.mouse_y <= 1 || window.mouse_y >= window.height-1
        @true_mouse.x, @true_mouse.y = window.mouse_x, window.mouse_y
      end
    end
    
    def button_down(id)
      case id
      when Gosu::KB_LEFT_ALT, Gosu::KB_RIGHT_ALT
        @mouse_captured = false
        window.needs_cursor = true
      when Gosu::MS_LEFT, Gosu::MS_MIDDLE, Gosu::MS_RIGHT
        @mouse_captured = true
        window.needs_cursor = false
      end
    end
    
    def button_up(id); end
  end
end