import logging
from email.message import EmailMessage

import aiosmtplib

from app.config.settings import settings

logger = logging.getLogger(__name__)


class EmailDeliveryError(Exception):
    pass


class EmailService:
    async def send_verification_email(self, email: str, token: str) -> None:
        verify_link = f"{settings.frontend_base_url}/verify-email?token={token}"
        subject = "Verify your BenyaMessenger account"
        text = (
            "Welcome to BenyaMessenger.\n\n"
            f"Verify your email by opening this link:\n{verify_link}\n\n"
            "If you did not create this account, ignore this email."
        )
        html = (
            "<p>Welcome to <b>BenyaMessenger</b>.</p>"
            f"<p>Verify your email by opening this link:<br><a href='{verify_link}'>{verify_link}</a></p>"
            "<p>If you did not create this account, ignore this email.</p>"
        )
        await self._send_email(email, subject, text, html)

    async def send_password_reset_email(self, email: str, token: str) -> None:
        reset_link = f"{settings.frontend_base_url}/reset-password?token={token}"
        subject = "Reset your BenyaMessenger password"
        text = (
            "Password reset request.\n\n"
            f"Open this link to reset your password:\n{reset_link}\n\n"
            "If you did not request this, ignore this email."
        )
        html = (
            "<p>Password reset request.</p>"
            f"<p>Open this link to reset your password:<br><a href='{reset_link}'>{reset_link}</a></p>"
            "<p>If you did not request this, ignore this email.</p>"
        )
        await self._send_email(email, subject, text, html)

    async def _send_email(self, recipient: str, subject: str, text: str, html: str) -> None:
        if settings.email_provider.lower() != "smtp":
            logger.info("EMAIL to=%s subject=%s body=%s", recipient, subject, text)
            return

        message = EmailMessage()
        message["From"] = settings.smtp_from_email
        message["To"] = recipient
        message["Subject"] = subject
        message.set_content(text)
        message.add_alternative(html, subtype="html")

        try:
            await aiosmtplib.send(
                message,
                hostname=settings.smtp_host,
                port=settings.smtp_port,
                username=settings.smtp_username or None,
                password=settings.smtp_password or None,
                start_tls=settings.smtp_use_tls,
                use_tls=settings.smtp_use_ssl,
                timeout=settings.smtp_timeout_seconds,
            )
        except Exception as exc:
            logger.exception("SMTP delivery failed to=%s subject=%s", recipient, subject)
            raise EmailDeliveryError("Email delivery failed") from exc


def get_email_service() -> EmailService:
    return EmailService()