"""SMTP email provider. Points at Mailpit in local dev (see docker-compose.yml)
and any real SMTP server in production - same code path either way. Uses
stdlib `smtplib` off the event loop via `asyncio.to_thread` rather than
adding an async SMTP dependency.
"""

from __future__ import annotations

import asyncio
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

from app.core.config import Settings
from app.core.logging import get_logger
from app.notifications.base import DeliveryResult, NotificationMessage

logger = get_logger(__name__)


class SmtpEmailProvider:
    provider_name = "smtp"

    def __init__(self, settings: Settings) -> None:
        self._settings = settings

    async def send(self, message: NotificationMessage) -> DeliveryResult:
        try:
            await asyncio.to_thread(self._send_sync, message)
            return DeliveryResult(success=True)
        except Exception as exc:  # pragma: no cover - network/SMTP failure path
            logger.error("smtp_send_failed", error=str(exc))
            return DeliveryResult(success=False, error=str(exc))

    def _send_sync(self, message: NotificationMessage) -> None:
        mime_message = MIMEMultipart("alternative")
        mime_message["Subject"] = message.subject
        mime_message["From"] = self._settings.smtp_from_email
        mime_message["To"] = message.destination_value
        mime_message.attach(MIMEText(message.body_text, "plain"))
        if message.body_html:
            mime_message.attach(MIMEText(message.body_html, "html"))

        with smtplib.SMTP(self._settings.smtp_host, self._settings.smtp_port, timeout=10) as server:
            if self._settings.smtp_use_tls:
                server.starttls()
            if self._settings.smtp_username:
                server.login(self._settings.smtp_username, self._settings.smtp_password)
            server.sendmail(
                self._settings.smtp_from_email,
                [message.destination_value],
                mime_message.as_string(),
            )