import logging
import resend
from config import settings

logger = logging.getLogger(__name__)


def _get_client() -> resend.Resend:
    return resend.Resend(api_key=settings.resend_api_key)


def send_email(to: str, subject: str, html: str) -> None:
    """Send a transactional email via Resend. Logs errors but does not raise."""
    try:
        client = _get_client()
        client.emails.send({
            "from": settings.email_from,
            "to": to,
            "subject": subject,
            "html": html,
        })
        logger.info("Email sent to %s — subject: %s", to, subject)
    except Exception as exc:
        logger.error("Failed to send email to %s: %s", to, exc)
        raise


def send_device_assignment_invite(
    customer_email: str,
    serial_number: str,
    customer_name: str | None = None,
) -> None:
    """Notify a customer that a Vesper device has been assigned to them."""
    greeting = f"Hi {customer_name}," if customer_name else "Hello,"
    html = f"""
    <div style="font-family: sans-serif; max-width: 600px; margin: 0 auto;">
      <h2 style="color: #111827;">Your Vesper device is ready</h2>
      <p>{greeting}</p>
      <p>A Vesper bell automation device has been registered and assigned to you.</p>
      <p>
        <strong>Serial Number:</strong>
        <code style="background: #f3f4f6; padding: 2px 6px; border-radius: 4px; font-size: 14px;">{serial_number}</code>
      </p>
      <p>Open the Vesper app and enter this serial number to get started.</p>
      <hr style="border: none; border-top: 1px solid #e5e7eb; margin: 24px 0;" />
      <p style="color: #6b7280; font-size: 12px;">
        If you did not expect this email, please contact your system administrator.
      </p>
    </div>
    """
    send_email(
        to=customer_email,
        subject=f"Your Vesper device is ready — {serial_number}",
        html=html,
    )


def send_device_provisioned_alert(
    admin_email: str,
    serial_number: str,
    hw_type: str,
) -> None:
    """Internal alert sent to an admin when a device reaches provisioned status."""
    html = f"""
    <div style="font-family: sans-serif; max-width: 600px; margin: 0 auto;">
      <h2 style="color: #111827;">Device Provisioned</h2>
      <p>A Vesper device has successfully provisioned and is ready to ship.</p>
      <table style="border-collapse: collapse; width: 100%; margin-top: 16px;">
        <tr>
          <td style="padding: 6px 12px; font-weight: bold; background: #f9fafb;">Serial Number</td>
          <td style="padding: 6px 12px; font-family: monospace;">{serial_number}</td>
        </tr>
        <tr>
          <td style="padding: 6px 12px; font-weight: bold; background: #f9fafb;">Board Type</td>
          <td style="padding: 6px 12px;">{hw_type.upper()}</td>
        </tr>
      </table>
      <p style="margin-top: 24px;">
        <a href="#" style="color: #2563eb;">View in Admin Console</a>
      </p>
    </div>
    """
    send_email(
        to=admin_email,
        subject=f"[Vesper] Device provisioned — {serial_number}",
        html=html,
    )