import pygame
from random import randrange

from display import Scaling
from images import Images
from stats import Stats

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, move = 0):
        if move:
            self.position = (
                    self.position[0] + self.movement[0] * move,
                    self.position[1] + self.movement[1] * move)
        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__()
        self.image = Images.surfaces['ball']
        self.update()
    

class Enemies():
    def __init__(self, field = None):
        self.sprites = pygame.sprite.Group()
        self.emerge_enemies()
        self.field = field

    def emerge_enemies(self):
        for _ in range(3 + (Stats.level-1) * 2):
            enemy = EnemyBall()
            enemy.set_position( (randrange(0,380_000), randrange(0,260_000)) )
            enemy.set_movement( (randrange(0,200)-100, randrange(0,200)-100) )
            self.sprites.add(enemy)
        
    def wall_hit(self, field, enemy):
        if enemy.rect.x < field.rect.x:
            enemy.force_right()
        if enemy.rect.y < field.rect.y:
            enemy.force_down()
        if ( enemy.rect.x + enemy.rect.w >= field.rect.x + field.rect.w ):
            enemy.force_left()
        if ( enemy.rect.y + enemy.rect.h >= field.rect.y + field.rect.h ):
            enemy.force_up()

    def update(self, dt):
        """ Update sprites basis of dt. dt = milliseconds from last update """
        self.sprites.update(move=dt)
        for enemy in self.sprites:
            for field in self.field.sprites:
                if field.rect.contains(enemy):
                    break
            else:
                for field in self.field.sprites:
                    if field.rect.colliderect(enemy):
                        self.wall_hit(field, enemy)