import pygame
import random
import math
from pygame import mixer

# Initialize Pygame / Initialisation de Pygame

pygame.init()

# The screen / L'écran
screen = pygame.display.set_mode((800,600))

# Background / Fond d'écran
background = pygame.image.load("background.png")
mixer.music.load('backgroundz.wav')
mixer.music.play(-1)

# Title and icon / Titre et icone pour la fenetre
pygame.display.set_caption("Space Invaders")
icon = pygame.image.load("ufo.png")
pygame.display.set_icon(icon)

# Player / Joueur
playerImg = pygame.image.load("player.png")
playerX = 370
playerY = 480
playerX_change = 0
playerY_change = 0

# enemies / enemis
enemyImg = []
enemyX = []
enemyY = []
enemyX_change = []
enemyY_change = []
num_of_enemies = 10

# Plusieurs images différentes d'ennemis
for i in range(num_of_enemies):
    num_img = random.randint(0, 4)
    image_monster = "en4.png"
    if num_img == 0 :
        image_monster = "en3.png"
    elif num_img == 1 :
        image_monster = "en2.png"
    else:
        image_monster == "en4.png"

    enemyImg.append(pygame.image.load(image_monster))
    enemyX.append(random.randint(0, 735 ))
    enemyY.append(random.randint(0, 150 ))
    enemyX_change.append(4)
    enemyY_change.append(40)

# bullet / missile
bulletImg = pygame.image.load("bullet.png")
bulletX = 0
bulletY = 480
bulletX_change = 0
bulletY_change = 10
# ready bullet fire bullet moving
bullet_state = "ready"

# Score
score_value = 0
font = pygame.font.Font("freesansbold.ttf", 32)

textX = 10
textY = 10

# Game over text
over_font = pygame.font.Font("freesansbold.ttf", 80 )

#############################    les fonctions    #################################################
def game_over_text():
    over_text = over_font.render("GAME OVER", True, (255, 255, 255))
    screen.blit(over_text, (180, 230))


def show_score(x,y):
    score = font.render("Score : " + str(score_value), True, (255, 255, 255))
    screen.blit(score, (x, y))


def player(x, y):
    screen.blit(playerImg, (x, y))


def enemy(x, y, i):
    screen.blit(enemyImg[i], (x, y))


def fire_bullet(x,y):
    global bullet_state
    bullet_state = "fire"
    screen.blit(bulletImg, (x+16, y+10))


def isCollision(enemyX, enemyY, bulletX, bulletY):
    distance = math.sqrt(math.pow(enemyX-bulletX, 2)) + (math.pow(enemyY-bulletY, 2))
    if distance < 27:
        return True
    else:
        return False


# game loop
running = True
while running:

    # color screen / couleur de l'ecran
    screen.fill((0, 0, 0))

    # background image
    screen.blit(background, (0, 0))

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

        # left or right / mouvements de droite à gauche
        # touche enfoncée
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                playerX_change = -5
            if event.key == pygame.K_RIGHT:
                playerX_change = 5
            if event.key == pygame.K_SPACE:
                if bullet_state is "ready":
                    bullet_sound = mixer.Sound('laserz.wav')
                    bullet_sound.play()
                    bulletX = playerX
                    fire_bullet(bulletX, bulletY)
        # touche relâchée
        if event.type == pygame.KEYUP:
            if event.key == pygame.K_LEFT or event.key == pygame.K_RIGHT:
                playerX_change = 0

    playerX += playerX_change

    #  limits in the screen / limites de l'ecran
    if playerX <= 0:
        playerX = 0
    elif playerX >= 736:
        playerX = 736

    # enemy moves / les ennemis se déplacent
    for i in range(num_of_enemies):

        # Game over
        if enemyY[i] > 440:
            for j in range(num_of_enemies):
                enemyY[j] = 2000
            game_over_text()
            break

        enemyX[i] += enemyX_change[i]
        if enemyX[i] <= 0:
            enemyX_change[i] = 3
            enemyY[i] += enemyY_change[i]
        elif enemyX[i] >= 736:
            enemyX_change[i] = -3
            enemyY[i] += enemyY_change[i]

        # collision
        collision = isCollision(enemyX[i], enemyY[i], bulletX, bulletY)
        if collision:
            explosion_sound = mixer.Sound('explosionz.wav')
            explosion_sound.play()
            bulletY = 480
            bullet_state = "ready"
            score_value += 1
            enemyX[i] = random.randint(0, 735)
            enemyY[i] = random.randint(0, 150)

        enemy(enemyX[i], enemyY[i], i)

    # bullet moves / missiles se déplacent
    if bulletY <= 0:
        bulletY = 480
        bullet_state = "ready"

    if bullet_state is "fire":
        fire_bullet(bulletX, bulletY)
        bulletY -= bulletY_change

    player(playerX, playerY)
    show_score(textX, textY)
    pygame.display.update()