import pygame

SCREEN_SIZE = (400, 300)
CLOCK = 60

class Directions:
  NORD = UP = 0
  SUD = DOWN = 1
  WEST = LEFT = 2
  EST = RIGHT = 3

class Entity:
  def __init__(self, x, y, w = 10, h = 10, color=(255,0,0)):
    self.x = x
    self.y = y
    self.w = w
    self.h = h
    self.color = color
    self.speed = 1

  def draw(self, surface):
    pygame.draw.rect(surface, self.color, (self.x, self.y, self.w, self.h))

  def update(self):
    pass

  def destroy(self):
    entities.remove(self)

  def move(self, direction):
    if direction == Directions.UP:
      self.y -= self.speed
    elif direction == Directions.DOWN:
      self.y += self.speed
    elif direction == Directions.LEFT and self.x > 0:
      self.x -= self.speed
    elif direction == Directions.RIGHT and self.x < SCREEN_SIZE[0] - self.w:
      self.x += self.speed



class Player(Entity):
  def __init__(self):
    w = 10
    h = 10
    x = SCREEN_SIZE[0] // 2 - w // 2
    y = SCREEN_SIZE[1] - h - 10

    Entity.__init__(self, x, y, w, h, (0, 255, 0))

    self.__fire_counter = 0

  def fire(self):
    entities.append(Bullet(self.x, self.y - self.w))

  def update(self):
    if self.__fire_counter == 0:
      self.fire()

    self.__fire_counter += 1

    if self.__fire_counter == CLOCK//2:
      self.__fire_counter = 0


class Bullet(Entity):
  def __init__(self, x, y):
    Entity.__init__(self, x, y, color = (255, 0, 0))
    self.speed = 1

  def update(self):
    self.move(Directions.UP)
    if self.y < -self.h:
      self.destroy()

    for e in entities:
      if e != self and e != player and type(e) != Bullet:
        if self.collide(e):
          self.destroy()
          e.destroy()
          break

  def collide(self, entity):
     #and (self.y >= entity.y and self.y <= entity.y + entity.h)
    return self.x >= entity.x

class Enemy(Entity):
  def __init__(self, x, y):
    Entity.__init__(self, x, y, color = (255, 0, 255))


pygame.init()
screen = pygame.display.set_mode(SCREEN_SIZE)
done = False

clock = pygame.time.Clock()
player = Player()
entities = [player, Enemy(0,0)]

while not done:
  pygame.draw.rect(screen, (0, 0, 0), (0, 0, *SCREEN_SIZE))

  for event in pygame.event.get():
    if event.type == pygame.QUIT:
      done = True

  keys = pygame.key.get_pressed()
  if keys[pygame.K_LEFT]:
    player.move(Directions.LEFT)
  elif keys[pygame.K_RIGHT]:
    player.move(Directions.RIGHT)

  for e in entities:
    e.draw(screen)
    e.update()

  pygame.display.flip()

  clock.tick(CLOCK)