"""邮件发送工具（基于标准库 smtplib，465 端口 SSL）。

配置来自 app.config.setting.settings（SMTP_HOST/PORT/USER/PASSWORD/FROM/FROM_NAME/TLS）。
"""
from email.header import Header
from email.mime.text import MIMEText
from smtplib import SMTP_SSL, SMTPException

from app.config.setting import settings
from app.core.logger import logger


def send_email(to_addr: str, subject: str, html_body: str) -> None:
    """发送一封 HTML 邮件（同步，内部阻塞；服务层用线程池调用）。

    参数:
    - to_addr (str): 收件人邮箱
    - subject (str): 邮件主题
    - html_body (str): HTML 正文

    异常:
    - SMTPException: 发送失败时抛出，由调用方捕获并处理
    """
    if not settings.SMTP_HOST or not settings.SMTP_USER:
        raise RuntimeError("SMTP 未配置：请在 .env 中设置 SMTP_HOST/SMTP_USER/SMTP_PASSWORD")

    from_addr = settings.SMTP_FROM or settings.SMTP_USER
    display = settings.SMTP_FROM_NAME or from_addr
    # 显示名单独编码，邮箱地址保持 ASCII
    from_header = f"{Header(display, 'utf-8').encode()} <{from_addr}>"

    msg = MIMEText(html_body, "html", "utf-8")
    msg["From"] = from_header
    msg["To"] = to_addr
    msg["Subject"] = Header(subject, "utf-8").encode()

    with SMTP_SSL(settings.SMTP_HOST, settings.SMTP_PORT, timeout=10) as server:
        server.login(settings.SMTP_USER, settings.SMTP_PASSWORD)
        server.sendmail(from_addr, [to_addr], msg.as_string())


def send_reset_code_email(to_addr: str, code: str, expire_seconds: int) -> None:
    """发送找回密码验证码邮件。"""
    try:
        send_email(
            to_addr=to_addr,
            subject="【dpb】找回密码验证码",
            html_body=(
                f"<p>您好，</p>"
                f"<p>您正在申请找回密码，验证码为：</p>"
                f'<p style="font-size:24px;font-weight:bold;color:#1677ff;letter-spacing:4px;">{code}</p>'
                f"<p>验证码 {expire_seconds // 60} 分钟内有效，请勿泄露给他人。</p>"
                f"<p>若非本人操作，请忽略本邮件。</p>"
            ),
        )
    except SMTPException as e:
        logger.error(f"发送验证码邮件失败 -> {to_addr}: {e!s}")
        raise
    except Exception as e:  # noqa: BLE001
        logger.error(f"发送验证码邮件异常 -> {to_addr}: {e!s}")
        raise