import sys
import pygame
from bullet import *
from alien import *
from time import sleep


def check_keydown_events(event, ai_settings, screen, ship, bullets):
    """响应按键"""
    if event.key == pygame.K_RIGHT:
        ship.moving_right = True
    elif event.key == pygame.K_LEFT:
        ship.moving_left = True
    elif event.key == pygame.K_UP:
        ship.moving_up = True
    elif event.key == pygame.K_DOWN:
        ship.moving_down = True
    elif event.key == pygame.K_SPACE:
        fire_bullet(ai_settings, screen, ship, bullets)
    elif event.key == pygame.K_q:
        sys.exit()


def fire_bullet(ai_settings, screen, ship, bullets):
    """如果还没有到达限制，就发射一颗子弹"""
    # 创建一颗子弹，并将其加入到编组bullets中
    if len(bullets) < ai_settings.bullets_allowed:
        new_bullet = Bullet(ai_settings, screen, ship)
        bullets.add(new_bullet)
        # 增加：添加发射音效
        pygame.mixer.init()
        sound = pygame.mixer.Sound('sounds/firebullets.wav')
        sound.play()


def bossalien_fire_bullet(ai_settings, screen, bossalien, bossbullet, ship):
    """增加：BOSS发射子弹"""
    # 创建一颗子弹
    bossbullet = BossBullet(ai_settings, screen, bossalien)


def check_bossbullet_bottom(ai_settings, screen, stats, sb, ship, aliens, bossalien, bullets, bossbullet):
    """当子弹飞出屏幕底部时，重置BOSS子弹位置"""
    screen_rect = screen.get_rect()
    if bossbullet.y >= screen_rect.bottom:
        bossbullet.reset_position(bossalien)


def check_keyup_events(event, ship):
    """响应松开"""
    if event.key == pygame.K_RIGHT:
        ship.moving_right = False
    elif event.key == pygame.K_LEFT:
        ship.moving_left = False
    elif event.key == pygame.K_UP:
        ship.moving_up = False
    elif event.key == pygame.K_DOWN:
        ship.moving_down = False


def check_events(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets):
    """响应按键和鼠标事件"""
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        elif event.type == pygame.KEYDOWN:
            check_keydown_events(event, ai_settings, screen, ship, bullets)
        elif event.type == pygame.KEYUP:
            check_keyup_events(event, ship)
        elif event.type == pygame.MOUSEBUTTONDOWN:
            mouse_x, mouse_y = pygame.mouse.get_pos()

            check_play_button(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets, mouse_x, mouse_y)


def update_screen(ai_settings, screen, stats, sb, ship, aliens, bossalien, bullets, bossbullet, play_button):
    screen.fill(ai_settings.bg_color)
    ship.blitme()

    # 在飞船和外星人后面重绘所有子弹
    for bullet in bullets.sprites():
        bullet.draw_bullet()

    # 增加：如果进入BOSS关，则绘制BOSS外星人，其他关卡绘制普通外星人
    if stats.level == stats.bosslevel:
        bossalien.blitme()
        bossalien.draw_health_bar(screen)

        bossbullet.draw_bullet()
        bossalien_fire_bullet(ai_settings, screen, bossalien, bossbullet, ship)

        check_bossbullet_bottom(ai_settings, screen, stats, sb, ship, aliens, bossalien, bullets, bossbullet)
    else:
        aliens.draw(screen)

    # 显示得分
    sb.show_score()

    # 如果游戏处于非活动状态，就绘制Play按钮
    if not stats.game_active:
        play_button.draw_button()

    # 让最近绘制的屏幕可见
    pygame.display.flip()


def update_bullets(ai_settings, screen, stats, sb, ship, aliens, bullets, bossalien, bossbullet):
    """更新子弹的位置，并删除已消失的子弹"""
    # 更新子弹的位置
    bullets.update()

    if stats.level == stats.bosslevel:
        bossbullet.update()

    # 删除已消失的子弹
    for bullet in bullets.copy():
        if bullet.rect.bottom <= 0:
            bullets.remove(bullet)

    check_bullet_collisions(ai_settings, screen, stats, sb, ship, aliens, bossalien, bullets, bossbullet)


def check_bullet_collisions(ai_settings, screen, stats, sb, ship, aliens, bossalien, bullets, bossbullet):
    """响应子弹和外星人的碰撞，以及外星人子弹和船的碰撞"""
    # 增加：只有在非BOSS关才启用
    if stats.level != stats.bosslevel:

        # 删除发生碰撞的子弹和外星人
        collisions = pygame.sprite.groupcollide(bullets, aliens, True, True)

        if collisions:
            for aliens in collisions.values():
                stats.score += ai_settings.alien_points * len(aliens)
                sb.prep_score()
            check_high_score(stats, sb)

        if len(aliens) == 0:
            # 如果整群外星人都被消灭，就提高一个等级
            bullets.empty()
            ai_settings.increase_speed()

            # 增加：播放音效
            pygame.mixer.init()
            sound = pygame.mixer.Sound('sounds/levelup.wav')
            sound.play()

            # 提高等级
            stats.level += 1
            sb.prep_level()

            # 如果当前关卡下一关是BOSS关就不要再生成舰队
            if stats.level != stats.bosslevel - 1:
                create_fleet(ai_settings, screen, ship, aliens)
            else:
                pass
    # 增加：只有在BOSS关才启用
    elif stats.level == stats.bosslevel:

        # 子弹击中BOSS外星人，BOSS外星人失去一定血量
        for bullet in bullets:
            if pygame.Rect.colliderect(bullet.rect, bossalien.rect):
                bossalien.health -= 100
                bullets.remove(bullet)

        # 生命值为0时删除该BOSS
        if bossalien.health <= 0:
            # 提高等级，加分
            stats.level += 1
            sb.prep_level()
            stats.score += ai_settings.bossalien_points
            sb.prep_score()
            check_high_score(stats, sb)

            create_fleet(ai_settings, screen, ship, aliens)

        # BOSS发射子弹和船碰撞

        if pygame.Rect.colliderect(bossbullet.rect, ship.rect):
            ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets, bossalien, bossbullet)


def create_fleet(ai_settings, screen, ship, aliens):
    """创建外星人群"""
    # 创建一个外星人，并计算一行可容纳多少个外星人
    alien = Alien(ai_settings, screen)
    number_aliens_x = get_number_aliens_x(ai_settings, alien.rect.width)
    number_rows = get_number_rows(ai_settings, ship.rect.height, alien.rect.height)

    # 创建外星人群
    for row_number in range(number_rows):
        for alien_number in range(number_aliens_x):
            create_alien(ai_settings, screen, aliens, alien_number, row_number)


def get_number_aliens_x(ai_settings, alien_width):
    """计算每行可容纳多少个外星人"""
    available_space_x = ai_settings.screen_width - 3 * alien_width
    number_aliens_x = int(available_space_x / (3 * alien_width))
    return number_aliens_x


def create_alien(ai_settings, screen, aliens, alien_number, row_number):
    """创建一个外星人并将其放在当前行"""
    alien = Alien(ai_settings, screen)
    alien_width = alien.rect.width
    alien.x = alien_width + 4 * alien_width * alien_number
    alien.rect.x = alien.x
    alien.rect.y = alien.rect.height + 2 * alien.rect.height * row_number
    aliens.add(alien)


def get_number_rows(ai_settings, ship_height, alien_height):
    """计算屏幕可容纳多少行外星人"""
    available_space_y = (ai_settings.screen_height - (5 * alien_height) - ship_height)
    number_rows = int(available_space_y / (2 * alien_height))
    return number_rows


def update_aliens(ai_settings, screen, stats, sb, ship, aliens, bullets, bossalien, bossbullet):
    """
    检查是否有外星人位于屏幕边缘，并更新整群外星人的位置
    """
    # 增加：在非BOSS关卡时检查
    if stats.level != stats.bosslevel:
        check_fleet_edges(ai_settings, aliens)
        aliens.update()

        # 检查是否有外星人到达屏幕底端
        check_aliens_bottom(ai_settings, screen, stats, sb, ship, aliens, bullets)

        # 检测外星人和飞船之间的碰撞
        if pygame.sprite.spritecollideany(ship, aliens):
            ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets, bossalien, bossbullet)

    else:
        check_bossalien_edges(ai_settings, bossalien)
        bossalien.update()


def check_fleet_edges(ai_settings, aliens):
    """有外星人到达边缘时采取相应的措施"""
    for alien in aliens.sprites():
        if alien.check_edges():
            change_fleet_direction(ai_settings, aliens)
            break


def check_bossalien_edges(ai_settings, bossalien):
    """检查BOSS外星人是否碰到边缘"""
    if bossalien.check_edges():
        change_bossalien_direction(ai_settings, bossalien)


def change_fleet_direction(ai_settings, aliens):
    """将整群外星人下移，并改变它们的方向"""
    for alien in aliens.sprites():
        alien.rect.y += ai_settings.fleet_drop_speed
    ai_settings.fleet_direction *= -1


def change_bossalien_direction(ai_settings, bossalien):
    """改变BOSS外星人的方向"""
    ai_settings.bossalien_direction *= -1


def ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets, bossalien, bossbullet):
    """响应被外星人撞到的飞船"""
    if stats.ships_left > 0:
        # 增加：播放失去生命值音效
        pygame.mixer.init()
        sound = pygame.mixer.Sound('sounds/loselifes.wav')
        sound.play()

        # 将ships_left减1
        stats.ships_left -= 1

        # 更新记分牌
        sb.prep_ships()

        # 清空外星人列表和子弹列表
        aliens.empty()
        bullets.empty()

        # 增加：如果不是BOSS关，就创建一群新的外星人，并将飞船放到屏幕底端中央
        if stats.level != stats.bosslevel:
            create_fleet(ai_settings, screen, ship, aliens)
            ship.center_ship()
        # 增加：如果是BOSS关，直接创建一个飞船继续，并且重置撞击到飞船的子弹的位置
        else:
            ship.center_ship()
            bossbullet.reset_position(bossalien)

        # 暂停
        sleep(0.5)

    else:
        stats.game_active = False
        pygame.mouse.set_visible(True)

        # 增加：播放游戏结束音效
        pygame.mixer.music.stop()
        pygame.mixer.init()
        sound = pygame.mixer.Sound('sounds/gameover.wav')
        sound.play()


def check_aliens_bottom(ai_settings, screen, stats, sb, ship, aliens, bullets):
    """检查是否有外星人到达了屏幕底端"""
    screen_rect = screen.get_rect()
    for alien in aliens.sprites():
        if alien.rect.bottom >= screen_rect.bottom:
            # 像飞船被撞到一样进行处理
            ship_hit(ai_settings, screen, stats, sb, ship, aliens, bossalien, bullets)
            break


def check_play_button(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets, mouse_x, mouse_y):
    """在玩家单击Play按钮时开始新游戏"""
    button_clicked = play_button.rect.collidepoint(mouse_x, mouse_y)
    if button_clicked and not stats.game_active:
        # 增加：播放音效
        pygame.mixer.init()
        sound = pygame.mixer.Sound('sounds/clickbuttons.wav')
        sound.play()

        # 重置游戏设置
        ai_settings.initialize_dynamic_settings()
        # 隐藏光标
        pygame.mouse.set_visible(False)
        # 重置游戏统计信息
        stats.reset_stats()
        stats.game_active = True

        # 重置记分牌图像
        sb.prep_score()
        sb.prep_high_score()
        sb.prep_level()
        sb.prep_ships()

        # 清空外星人列表和子弹列表
        aliens.empty()
        bullets.empty()

        # 创建一群新的外星人，并让飞船居中
        create_fleet(ai_settings, screen, ship, aliens)
        ship.center_ship()


def check_high_score(stats, sb):
    """检查是否诞生了新的最高得分"""
    if stats.score > stats.high_score:
        stats.high_score = stats.score
        sb.prep_high_score()