import pygame
from random import randrange

from display import Scaling
from text import Fonts

class EnemySprite(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.position = (0, 0)
        self.movement = (0, 0)
    
    def set_position(self, position: tuple):
        self.position = position
        self.update()
        
    def set_movement(self, movement: tuple):
        self.movement = movement

    def update(self, dt = 0, **kwargs):
        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())
                
    def force_right(self):
        self.movement = (abs(self.movement[0]), self.movement[1])

    def force_left(self):
        self.movement = (-abs(self.movement[0]), self.movement[1])

    def force_down(self):
        self.movement = (self.movement[0], abs(self.movement[1]))

    def force_up(self):
        self.movement = (self.movement[0], -abs(self.movement[1]))

class EnemyBall(EnemySprite):
    def __init__(self):
        super().__init__()
        letter = Fonts.fonts['8x8'].get(randrange(1,3)).subsurface((0,0,8,8))
        colored = letter.fill( "black", special_flags = pygame.BLEND_RGBA_MULT)
        self.image = pygame.transform.scale_by(letter, 1_000 * Scaling.factor)
        self.update()
    

class Enemies(pygame.sprite.Group):
    def __init__(self, field = None, count = 0):
        super().__init__()
        for _ in range(count):
            enemy = EnemyBall()
            enemy.set_position( (randrange(0,300_000), randrange(0,200_000)) )
            enemy.set_movement( (randrange(0,200)-100, randrange(0,200)-100) )
            self.add(enemy)
        self.field = field

    def update(self, field_rects = [], **kwargs):
        super().update(**kwargs)
        """ Do actions on enemies that are only partly on the fields """
        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):
                        self.wall_hit(field_rect, enemy)

    def wall_hit(self, field, enemy):
        if enemy.rect.x < field.x:
            enemy.force_right()
        if enemy.rect.y < field.y:
            enemy.force_down()
        if ( enemy.rect.x + enemy.rect.w >= field.x + field.w ):
            enemy.force_left()
        if ( enemy.rect.y + enemy.rect.h >= field.y + field.h ):
            enemy.force_up()