"""SendGrid 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 SendGridEmailProvider(EmailProvider):
    """SendGrid API-based email provider implementation."""

    # Configuration keys
    SENDGRID_API_KEY = "SENDGRID_API_KEY"
    SENDGRID_FROM_EMAIL = "SENDGRID_FROM_EMAIL"
    FROM_ADDRESS = "FROM_ADDRESS"

    API_URL = "https://api.sendgrid.com/v3/mail/send"

    def send(self, message: EmailMessage) -> bool:
        """Send an email via SendGrid 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.SENDGRID_API_KEY)
        default_from = current_app.config.get(self.SENDGRID_FROM_EMAIL)
        fallback_from = current_app.config.get(self.FROM_ADDRESS)

        if not api_key:
            logger.error(
                f"[SENDGRID] Cannot send — missing SENDGRID_API_KEY config. "
                f"Would have sent to: {message.to} | Subject: {message.subject}"
            )
            return False

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

        payload = {
            "personalizations": [
                {
                    "to": [{"email": message.to}]
                }
            ],
            "from": {"email": from_address},
            "subject": message.subject,
            "content": [
                {
                    "type": "text/plain",
                    "value": message.body
                }
            ]
        }

        if message.html_body:
            payload["content"].append({
                "type": "text/html",
                "value": message.html_body
            })

        try:
            response = requests.post(
                self.API_URL,
                json=payload,
                headers={
                    "Authorization": f"Bearer {api_key}",
                    "Content-Type": "application/json"
                }
            )

            if response.status_code == 202:
                logger.info(f"[SENDGRID] Sent to {message.to} | Subject: {message.subject}")
                return True
            else:
                logger.error(
                    f"[SENDGRID] Failed to send to {message.to}: "
                    f"status={response.status_code} body={response.text}"
                )
                return False

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