# app/services/mailer.py
import smtplib
import ssl
from email.message import EmailMessage

from app.core.config import get_app_settings


def send_email(to_email: str, subject: str, html: str) -> None:
    """
    发送邮件：
    - 端口为 465 时使用 SSL 直连（SMTP_SSL）
    - 其他端口：按配置 smtp_tls 决定是否 STARTTLS
    """
    s = get_app_settings()

    host = s.smtp_host
    port = int(s.smtp_port)
    use_starttls = bool(s.smtp_tls)

    # SecretStr / Optional 兼容处理
    smtp_user = s.smtp_user.get_secret_value() if getattr(s, "smtp_user", None) else None
    smtp_pass = s.smtp_password.get_secret_value() if getattr(s, "smtp_password", None) else None

    msg = EmailMessage()
    msg["From"] = str(s.mail_from)  # EmailStr -> str
    msg["To"] = to_email
    msg["Subject"] = subject
    # 纯文本 + HTML（多部件）
    msg.set_content("Your mail client does not support HTML.")
    msg.add_alternative(html, subtype="html")

    ctx = ssl.create_default_context()

    # === 建立连接 ===
    if port == 465:
        server = smtplib.SMTP_SSL(host, port, context=ctx, timeout=20)
    else:
        server = smtplib.SMTP(host, port, timeout=20)
        server.ehlo()
        if use_starttls:
            server.starttls(context=ctx)
            server.ehlo()

    try:
        # 如配置了用户名/密码，则登录
        if smtp_user and smtp_pass:
            server.login(smtp_user, smtp_pass)

        server.send_message(msg)
    finally:
        try:
            server.quit()
        except Exception:
            # 连接已断开也无妨，忽略
            pass