import pygame
from random import randrange

from display import Scaling
from text import get_letter_surface

BALL_SPAWN_AREA = (0, 0, 300_000, 200_000)
BALL_MOVEMENT = (100, 100)

class EnemyBall(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.position = (
                randrange(BALL_SPAWN_AREA[0], BALL_SPAWN_AREA[2]),
                randrange(BALL_SPAWN_AREA[1], BALL_SPAWN_AREA[3]))
        self.movement = (
                randrange(0, BALL_MOVEMENT[0]*2) - BALL_MOVEMENT[0],
                randrange(0, BALL_MOVEMENT[1]*2) - BALL_MOVEMENT[1])
        self.image = get_letter_surface(
                ('8x8', 8_000, 0),
                randrange(1,3)).subsurface(
                        (0,0,8_000*Scaling.factor,8_000*Scaling.factor))
        self.update()
        self.rect = None

    def update(self, dt = 0, wall_hit = None, **kwargs):
        if wall_hit:
            if self.rect.x < wall_hit.x:
                self.movement = (abs(self.movement[0]), self.movement[1])
            if self.rect.y < wall_hit.y:
                self.movement = (self.movement[0], abs(self.movement[1]))
            if self.rect.x + self.rect.w >= wall_hit.x + wall_hit.w:
                self.movement = (-abs(self.movement[0]), self.movement[1])
            if self.rect.y + self.rect.h >= wall_hit.y + wall_hit.h:
                self.movement = (self.movement[0], -abs(self.movement[1]))
            return
        if dt:
            self.position = (
                    self.position[0] + self.movement[0] * dt,
                    self.position[1] + self.movement[1] * dt)
        self.rect = pygame.Rect(
                Scaling.scale_to_display(self.position),
                self.image.get_size())

class Enemies(pygame.sprite.Group):
    def __init__(self, field = None, count = 0):
        super().__init__()
        for _ in range(count):
            self.add(EnemyBall())
        self.field = field

    def update(self, field_rects = [], **kwargs):
        """ Do actions on enemies that are only partly on the fields """
        super().update(**kwargs)
        for enemy in self.sprites():
            for field_rect in field_rects:
                # if enemy is completely inside any field do next enemy
                if field_rect.contains(enemy):
                    break
            else:
                # now find field that enemy is partly on
                for field_rect in field_rects:
                    if field_rect.colliderect(enemy):
                        enemy.update(wall_hit = field_rect)