from celery import shared_task
from django.core.mail import EmailMultiAlternatives
from django.template.loader import render_to_string

FROM_EMAIL = '可乐平台 <cs10086086@qq.com>'

EMAIL_CONFIG = {
    'register': {
        'subject': '【可乐平台】账号注册验证码',
        'title': '欢迎注册可乐平台',
        'greeting': '欢迎使用可乐平台！',
        'description': '感谢您的注册，您正在完成账号注册操作，请在注册页面输入以下验证码完成验证。',
    },
    'login': {
        'subject': '【可乐平台】登录验证验证码',
        'title': '登录安全验证',
        'greeting': '感谢您的信任！',
        'description': '您正在进行邮箱登录操作，请在登录页面输入以下验证码完成验证。',
    },
    'reset_password': {
        'subject': '【可乐平台】重置密码验证码',
        'title': '重置您的密码',
        'greeting': '您好！',
        'description': '您正在进行重置密码操作，请在重置密码页面输入以下验证码完成验证，以重新设置您的账号密码。',
    },
    'change_email_old': {
        'subject': '【可乐平台】验证当前邮箱',
        'title': '邮箱修改验证',
        'greeting': '您好！',
        'description': '您正在进行邮箱修改操作，请先验证当前绑定的邮箱。请输入以下验证码完成验证。',
    },
    'change_email_new': {
        'subject': '【可乐平台】验证新邮箱',
        'title': '绑定新邮箱',
        'greeting': '您好！',
        'description': '您正在将可乐平台账号绑定到此新邮箱，请输入以下验证码完成新邮箱的绑定操作。',
    },
}


def _send_html_email(to_email, code, config_key):
    config = EMAIL_CONFIG[config_key]

    context = {
        'code': code,
        'title': config['title'],
        'greeting': config['greeting'],
        'description': config['description'],
    }

    html_content = render_to_string('email/verification_code.html', context)

    text_content = (
        f'{config["subject"]}\n'
        f'{config["description"]}\n'
        f'您的验证码：{code}\n'
        f'验证码10分钟内有效，请勿泄露给他人。\n'
        f'如非本人操作，请忽略此邮件。\n'
        f'— 可乐平台 ChunYu.dev'
    )

    email = EmailMultiAlternatives(
        subject=config['subject'],
        body=text_content,
        from_email=FROM_EMAIL,
        to=[to_email],
    )
    email.attach_alternative(html_content, 'text/html')

    try:
        email.send()
    except Exception as e:
        import logging
        logger = logging.getLogger(__name__)
        logger.error(
            f'[Email] SMTP send failed: to={to_email}, type={config_key}, error={str(e)}',
            exc_info=True
        )
        raise


@shared_task
def send_verification_email_task(to_email, code, email_type='register'):
    _send_html_email(to_email, code, email_type)
    return {'email': to_email, 'type': email_type, 'status': 'sent'}


@shared_task
def send_reset_password_email_task(to_email, code):
    _send_html_email(to_email, code, 'reset_password')
    return {'email': to_email, 'type': 'reset_password', 'status': 'sent'}


@shared_task
def send_change_email_task(to_email, code, target='old'):
    config_key = 'change_email_old' if target == 'old' else 'change_email_new'
    _send_html_email(to_email, code, config_key)
    return {'email': to_email, 'target': target, 'status': 'sent'}