"""Mailgun email provider implementation."""
import logging

import requests
from flask import current_app

from gatehouse_app.services.email_provider import EmailMessage, EmailProvider

logger = logging.getLogger(__name__)


class MailgunEmailProvider(EmailProvider):
    """Mailgun API-based email provider implementation."""

    # Configuration keys
    MAILGUN_API_KEY = "MAILGUN_API_KEY"
    MAILGUN_DOMAIN = "MAILGUN_DOMAIN"
    MAILGUN_API_URL = "MAILGUN_API_URL"
    FROM_ADDRESS = "FROM_ADDRESS"

    DEFAULT_API_URL = "https://api.mailgun.net/v3"

    def send(self, message: EmailMessage) -> bool:
        """Send an email via Mailgun API.

        Args:
            message: EmailMessage instance containing email details

        Returns:
            bool: True if email was sent successfully, False otherwise
        """
        api_key = current_app.config.get(self.MAILGUN_API_KEY)
        domain = current_app.config.get(self.MAILGUN_DOMAIN)
        api_url = current_app.config.get(self.MAILGUN_API_URL, self.DEFAULT_API_URL)
        default_from = current_app.config.get(self.FROM_ADDRESS)

        missing = [k for k, v in [("MAILGUN_API_KEY", api_key), ("MAILGUN_DOMAIN", domain)] if not v]
        if missing:
            logger.error(
                f"[MAILGUN] Cannot send — missing config: {', '.join(missing)}. "
                f"Would have sent to: {message.to} | Subject: {message.subject}"
            )
            return False

        from_address = message.from_address or default_from
        if not from_address:
            logger.error(
                f"[MAILGUN] Cannot send — missing FROM_ADDRESS. "
                f"Would have sent to: {message.to} | Subject: {message.subject}"
            )
            return False

        url = f"{api_url}/{domain}/messages"

        data = {
            "to": message.to,
            "subject": message.subject,
            "text": message.body,
            "from": from_address,
        }
        if message.html_body:
            data["html"] = message.html_body

        try:
            response = requests.post(
                url,
                auth=("api", api_key),
                data=data,
            )

            if response.status_code == 200:
                logger.info(f"[MAILGUN] Sent to {message.to} | Subject: {message.subject}")
                return True
            else:
                logger.error(
                    f"[MAILGUN] Failed to send to {message.to}: from {from_address}"
                    f"status={response.status_code} body={response.text}"
                )
                return False

        except Exception as e:
            logger.error(f"[MAILGUN] Exception while sending to {message.to}: {e}")
            return False