## Nathan Hinton
## Main entry point for the game. Sets up the world and holds the main loop


require 'gosu'
require 'yaml'

require './producer.rb'
require './consumer.rb'

# Viewport resolution
WIDTH = 640*2
HEIGHT = 480*2

# Default game settings
GAME_SAVE_DIRECTORY = 'game_save_data'
GAME_WIDTH = 10000
GAME_HEIGHT = 10000
GAME_PRODUCER_CHANCE = 0.005
GAME_PRODUCER_VALUE_MULT = 0.1
GAME_PRODUCER_BASE_SPEED = 1

# Camera settings
CAMERA_MOVE_RANGE = 10
CAMERA_MOVE_SPEED = 1
CAMERA_MOVE_MAX_SPEED = (CAMERA_MOVE_RANGE * CAMERA_MOVE_SPEED / 2).to_i
CAMERA_MIN_ZOOM = 0.7
CAMERA_MAX_ZOOM = 5

class NumFactory < Gosu::Window
  def initialize
    super WIDTH, HEIGHT, :fullscreen => true
    self.caption = "Number factory"

    @background_color = Gosu::Color::BLUE

    ### CAMERA ###
    # camera_x [Integer] Used to know the x position of the camera
    # camera_y [Integer] Used to know the y position of the camera
    # camera_zoom [Float] Used to know the zoom of the camera
    @camera_x = 0
    @camera_y = 0
    @camera_zoom = 1.0

    begin
      game_save_data = YAML.load_file("#{GAME_SAVE_DIRECTORY}/positions.yaml")
      puts game_save_data
      # Load from file OR generate new save file
      @producers = [
        Producer.new(0, 0, 1, 1),
        Producer.new(1000, 1000, 1, 1),
        Producer.new(2000, 2000, 1, 1),
      ]
      @consumers = []
      @belts = []
      
    rescue Errno::ENOENT # File does not exist
      puts "Generating new game..."
      @game_width = GAME_WIDTH
      @game_height = GAME_HEIGHT

      @producers = []
      @consumers = [] # Consumer in center
      @belts = []
      

      # Loop through and place producers
      center_x = (@game_width / 60).to_i
      center_y = (@game_height / 60).to_i

      # Move the camera to the center of the map:
      @camera_x = center_x * 30 - WIDTH / 2
      @camera_y = center_y * 30 - HEIGHT / 2
      
      @consumers.append(
        Consumer.new(center_x * 30, center_y * 30),
      )

      # The value of the producer is proportional to the distance from the center
      ((@game_width / 30).to_i).times do |xx|
        (@game_height / 30).to_i.times do |yy|
          if rand < GAME_PRODUCER_CHANCE
            # Place a producer:
            @producers.append(
              Producer.new(
                xx * 30,
                yy * 30,
                (Math.sqrt((xx - center_x)**2 + (yy - center_y) ** 2) * GAME_PRODUCER_VALUE_MULT).to_i,
                GAME_PRODUCER_BASE_SPEED)
            )
          end
        end
      end
    end # End file loading

    @background = Gosu.render(@game_width, @game_height) {
      im = Gosu::Image.new('assets/images/background_square.png', {:tileable => true})
      (@game_width / 30).to_i.times do |ww|
        (@game_height / 30).to_i.times do |hh|
          im.draw(ww * 30, hh * 30)
        end
      end
    }

    @tick_time = Time.now()
    @delta_time = 0

  end


  def button_down(id)
    if id == Gosu::KB_ESCAPE
      close
    elsif id == Gosu::MS_WHEEL_UP
      @camera_zoom *= 1.1
      if @camera_zoom > CAMERA_MAX_ZOOM
        @camera_zoom = CAMERA_MAX_ZOOM
      else
        @camera_x *= 1.0125
        @camera_y *= 1.0125
      end
    elsif id == Gosu::MS_WHEEL_DOWN
      @camera_zoom *= 0.9
      if @camera_zoom < CAMERA_MIN_ZOOM
        @camera_zoom = CAMERA_MIN_ZOOM
      else
        @camera_x *= 0.985
        @camera_y *= 0.985
      end
    elsif id == Gosu::KB_SPACE
      @camera_zoom = 1.0
    else
      super
    end
  end


  ## Called every frame
  def update
    @delta_time = Time.now() - @tick_time
    delta_mult = @delta_time * 30
    #puts "Time: #{@delta_time}, Mult: #{delta_mult}" # Timing debug
    @tick_time = Time.now()

    ### CAMERA ###
    # Move the camera if needed
    if self.mouse_x < CAMERA_MOVE_RANGE
      @camera_x -= ([(CAMERA_MOVE_SPEED * ((CAMERA_MOVE_RANGE - self.mouse_x ) / 2)).to_i, CAMERA_MOVE_MAX_SPEED].min * delta_mult * @camera_zoom)
    elsif self.mouse_x > WIDTH - CAMERA_MOVE_RANGE
      @camera_x += ([(CAMERA_MOVE_SPEED * ((CAMERA_MOVE_RANGE - (WIDTH - self.mouse_x) ) / 2)).to_i, CAMERA_MOVE_MAX_SPEED].min * delta_mult * @camera_zoom)
    end
    
    if self.mouse_y < CAMERA_MOVE_RANGE
      @camera_y -= ([(CAMERA_MOVE_SPEED * ((CAMERA_MOVE_RANGE - self.mouse_y ) / 2)).to_i, CAMERA_MOVE_MAX_SPEED].min * delta_mult)
    elsif self.mouse_y > HEIGHT - CAMERA_MOVE_RANGE
      @camera_y += ([(CAMERA_MOVE_SPEED * ((CAMERA_MOVE_RANGE - (HEIGHT - (self.mouse_y + 1)) ) / 2)).to_i, CAMERA_MOVE_MAX_SPEED].min * delta_mult)
    end

    # Prevent camera from leaving the screen
    @camera_x = [@camera_x, -10].max
    @camera_x = [@camera_x, @game_width - (WIDTH / @camera_zoom) + 10].min
    @camera_y = [@camera_y, -10].max
    @camera_y = [@camera_y, @game_height - (HEIGHT / @camera_zoom) + 10].min

    # Setup variables used to know what portions of the screen need to be rendered
    @camera_max_x = [@game_width, @camera_x + (WIDTH / @camera_zoom)].min
    @camera_min_x = [0, @camera_x].max
    @camera_max_y = [@game_height, @camera_y + (WIDTH / @camera_zoom)].min
    @camera_min_y = [0, @camera_y].max
    
    ### ITEMS ###
    @producers.each do |producer|
      producer.update(delta_mult)
    end

    @belts.each do |belt|
      belt.update(delta_mult)
    end

    @consumers.each do |consumer|
      consumer.update(delta_mult)
    end
  end

  ## Called when OS wants to update window.
  def draw
    # Draw mouse coords:
    onscreen_items = 0
    Gosu.draw_rect(
      [(@camera_min_x - @camera_x) * @camera_zoom, self.width].min,
      [(@camera_min_y - @camera_y) * @camera_zoom, self.width].min,
      [self.width, (@camera_max_x - @camera_x) * @camera_zoom].min,
      [self.height, (@camera_max_y - @camera_y) * @camera_zoom].min,
      @background_color, 0)
    @background.draw(0, 0, 0, @camera_zoom, @camera_zoom)
    @producers.each do |producer|
      if producer.x <= @camera_max_x && producer.x >= @camera_min_x
        if producer.y <= @camera_max_y && producer.y >= @camera_min_y
          producer.draw(@camera_x, @camera_y, @camera_zoom)
          onscreen_items += 1
        end
      end
    end
    @consumers.each do |consumer|
      if consumer.x <= (@camera_x + WIDTH) && consumer.x >= (@camera_x)
        if consumer.y <= (@camera_y + WIDTH) && consumer.y >= (@camera_y)
          consumer.draw(@camera_x, @camera_y, @camera_zoom)
          onscreen_items += 1
        end
      end
    end
    Gosu::Image.from_text("#{mouse_x}, #{mouse_y}", 20).draw(0, 100, 1)
    Gosu::Image.from_text("Tick time: #{((Time.now() - @tick_time).to_f * 1000).to_i}", 20).draw(0, 25, 1)
    Gosu::Image.from_text("FPS: #{Gosu.fps}", 20).draw(0, 50, 1)
    Gosu::Image.from_text("items on screen: #{onscreen_items}", 20).draw(0, 75, 1)
    Gosu::Image.from_text("#{width}, #{height}", 20).draw(0, 0, 1)
    Gosu::Image.from_text("Camera location: #{@camera_x}, #{@camera_y}", 20).draw(0, 200, 1)
    Gosu::Image.from_text("Camera zoom: #{@camera_zoom}", 20).draw(0, 225, 1)
    Gosu::Image.from_text("Camera viewport: (#{@camera_min_x}, #{@camera_min_y}) to  (#{@camera_max_x}, #{@camera_max_y})", 20).draw(0, 250, 1)
  end
end

NumFactory.new.show