import pygame
from bullet import Bullet

class Enemy:
    def __init__(self, game, screen):
        self.pos = [0,0]
        self.size = 20
        self.health = 200
        self.speed = 3

        self.screen = screen
        self.game = game

        self.color = (255,0,0)


    def target(self, obj):
        self.target_obj = obj

    def draw(self):
        pygame.draw.rect(self.screen, self.color, pygame.rect.Rect(self.pos, (self.size, self.size)))

    def move(self, x, y):
        self.pos[0] += x * self.speed
        self.pos[1] += y * self.speed

    def get_pos(self):
        return self.pos

    def get_center_pos(self):
        return [self.pos[0] + 0.5*self.size, self.pos[1] + 0.5*self.size]

    def set_pos(self, x,y):
        self.pos = [x,y]

    def update(self):
        dx = self.target_obj.pos[0] - self.pos[0]
        dy = self.target_obj.pos[1] - self.pos[1]

        length = (dx**2+dy**2)**(0.5)

        x = dx/length
        y = dy/length

        self.move(x,y)
        self.check_collisions()

        if self.health <= 0:
            self.game.remove_object(self)
            self.game.add_score(1)

    def check_collisions(self):
        for obj in self.game.get_objects():
            if not isinstance(obj, Bullet): continue
            
            bullet = obj
            bullet_pos = bullet.get_pos()
            if self.pos[0] <= bullet_pos[0] <= self.pos[0]+self.size and self.pos[1] <= bullet_pos[1] <= self.pos[1]+self.size:
                self.health -= 20
                self.game.remove_object(bullet)