"""
MailClient — 呼叫 Docker Mailserver Admin API (http://10.1.0.254:8080)
管理 mail domain 和 mailbox 的建立/查詢。
建立 domain 前必須驗證 MX DNS 設定（對 active 租戶）。
"""
import logging
from typing import Optional
import httpx
import dns.resolver

from app.core.config import settings

logger = logging.getLogger(__name__)

TIMEOUT = 10.0


class MailClient:
    def __init__(self):
        self._base = settings.MAIL_ADMIN_API_URL.rstrip("/")
        self._headers = {"X-API-Key": settings.MAIL_ADMIN_API_KEY}

    def check_mx_dns(self, domain: str) -> bool:
        """驗證 domain 的 MX record 是否指向正確的 mail server"""
        try:
            answers = dns.resolver.resolve(domain, "MX")
            for rdata in answers:
                if settings.MAIL_MX_HOST in str(rdata.exchange).rstrip("."):
                    return True
            return False
        except Exception as e:
            logger.warning(f"MX DNS check failed for {domain}: {e}")
            return False

    def domain_exists(self, domain: str) -> bool:
        try:
            resp = httpx.get(
                f"{self._base}/api/v1/domains/{domain}",
                headers=self._headers,
                timeout=TIMEOUT,
            )
            return resp.status_code == 200
        except Exception:
            return False

    def create_domain(self, domain: str) -> bool:
        try:
            resp = httpx.post(
                f"{self._base}/api/v1/domains",
                json={"domain": domain},
                headers=self._headers,
                timeout=TIMEOUT,
            )
            return resp.status_code in (200, 201, 204)
        except Exception as e:
            logger.error(f"create_domain({domain}) failed: {e}")
            return False

    def mailbox_exists(self, email: str) -> bool:
        try:
            resp = httpx.get(
                f"{self._base}/api/v1/mailboxes/{email}",
                headers=self._headers,
                timeout=TIMEOUT,
            )
            return resp.status_code == 200
        except Exception:
            return False

    def create_mailbox(self, email: str, password: Optional[str], quota_gb: int = 20) -> bool:
        try:
            resp = httpx.post(
                f"{self._base}/api/v1/mailboxes",
                json={"email": email, "password": password or "", "quota": quota_gb},
                headers=self._headers,
                timeout=TIMEOUT,
            )
            return resp.status_code in (200, 201, 204)
        except Exception as e:
            logger.error(f"create_mailbox({email}) failed: {e}")
            return False