import smtplib
from email.mime.base import MIMEBase
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email import encoders
from typing import Optional, List, Tuple
import httpx

from app.settings.config import settings


class EmailClient:
    def send(self, to_email: str, subject: Optional[str], body: str, file_bytes: Optional[bytes], file_name: Optional[str], content_type: Optional[str]) -> dict:
        if not settings.SMTP_HOST or not settings.SMTP_PORT or not settings.SMTP_FROM:
            raise RuntimeError("SMTP 未配置")

        msg = MIMEMultipart()
        msg["From"] = settings.SMTP_FROM
        msg["To"] = to_email
        msg["Subject"] = subject or "估值服务通知"
        msg.attach(MIMEText(body, "plain", "utf-8"))

        if file_bytes and file_name:
            part = MIMEBase("application", "octet-stream")
            part.set_payload(file_bytes)
            encoders.encode_base64(part)
            part.add_header("Content-Disposition", f"attachment; filename=\"{file_name}\"")
            msg.attach(part)

        if hasattr(self, "_extra_attachments") and isinstance(self._extra_attachments, list):
            for fb, fn in self._extra_attachments:
                part = MIMEBase("application", "octet-stream")
                part.set_payload(fb)
                encoders.encode_base64(part)
                part.add_header("Content-Disposition", f"attachment; filename=\"{fn}\"")
                msg.attach(part)

        if settings.SMTP_TLS:
            server = smtplib.SMTP(settings.SMTP_HOST, settings.SMTP_PORT, timeout=30)
            server.starttls()
        else:
            server = smtplib.SMTP_SSL(settings.SMTP_HOST, settings.SMTP_PORT, timeout=30)
        try:
            if settings.SMTP_USERNAME and settings.SMTP_PASSWORD:
                server.login(settings.SMTP_USERNAME, settings.SMTP_PASSWORD)
            server.sendmail(settings.SMTP_FROM, [to_email], msg.as_string())
            server.quit()
            return {"status": "OK"}
        except Exception as e:
            try:
                server.quit()
            except Exception:
                pass
            if isinstance(e, smtplib.SMTPRecipientsRefused):
                return {"status": "FAIL", "error": "收件方地址不存在或暂时不可用"}
            return {"status": "FAIL", "error": str(e)}

    def send_many(self, to_email: str, subject: Optional[str], body: str, attachments: Optional[List[Tuple[bytes, str]]] = None) -> dict:
        self._extra_attachments = attachments or []
        try:
            return self.send(to_email, subject, body, None, None, None)
        finally:
            self._extra_attachments = []


email_client = EmailClient()