"""Synology DSM 7.x API 클라이언트.

각 호출 = login → 작업 → logout (세션 풀링은 v1.1+에서). 단일 컨테이너 + 동시성 낮음 가정.

- create_share_link(file_path, expires_in_sec) -> share URL
"""
import logging
import os
from datetime import datetime, timedelta, timezone

import httpx

logger = logging.getLogger("packs-lab.dsm")

DSM_HOST = os.getenv("DSM_HOST", "")  # 예: https://gahusb.synology.me:5001
DSM_USER = os.getenv("DSM_USER", "")
DSM_PASS = os.getenv("DSM_PASS", "")
# LAN IP로 DSM 접근 시 self-signed cert가 IP에 매칭 안 되어 검증 실패. LAN 내부 통신이라 false 허용.
# 운영에서 LAN IP + self-signed면 DSM_VERIFY_SSL=false. 도메인 + 정상 cert면 기본값(true) 유지.
DSM_VERIFY_SSL = os.getenv("DSM_VERIFY_SSL", "true").strip().lower() != "false"

API_AUTH = "/webapi/auth.cgi"
API_SHARE = "/webapi/entry.cgi"


class DSMError(RuntimeError):
    pass


async def _login(client: httpx.AsyncClient) -> str:
    """DSM 세션 sid 반환."""
    if not all([DSM_HOST, DSM_USER, DSM_PASS]):
        raise DSMError("DSM 환경변수 미설정")
    r = await client.get(
        f"{DSM_HOST}{API_AUTH}",
        params={
            "api": "SYNO.API.Auth",
            "version": "7",
            "method": "login",
            "account": DSM_USER,
            "passwd": DSM_PASS,
            "session": "FileStation",
            "format": "sid",
        },
        timeout=15.0,
    )
    r.raise_for_status()
    data = r.json()
    if not data.get("success"):
        raise DSMError(f"DSM login 실패: {data.get('error')}")
    return data["data"]["sid"]


async def _logout(client: httpx.AsyncClient, sid: str) -> None:
    try:
        await client.get(
            f"{DSM_HOST}{API_AUTH}",
            params={
                "api": "SYNO.API.Auth",
                "version": "7",
                "method": "logout",
                "session": "FileStation",
                "_sid": sid,
            },
            timeout=10.0,
        )
    except Exception as e:
        logger.warning("DSM logout 실패: %s", e)


async def create_share_link(file_path: str, expires_in_sec: int = 14400) -> tuple[str, datetime]:
    """파일 공유 링크 생성. 반환: (URL, expires_at).

    file_path: NAS 절대경로 (예: /volume1/docker/webpage/media/packs/master/x.mp4)
    expires_in_sec: 만료 (기본 4시간)
    """
    expires_at = datetime.now(timezone.utc) + timedelta(seconds=expires_in_sec)
    expire_time_ms = int(expires_at.timestamp() * 1000)

    async with httpx.AsyncClient(verify=DSM_VERIFY_SSL) as client:
        sid = await _login(client)
        try:
            r = await client.get(
                f"{DSM_HOST}{API_SHARE}",
                params={
                    "api": "SYNO.FileStation.Sharing",
                    "version": "3",
                    "method": "create",
                    "path": file_path,
                    "date_expired": expire_time_ms,
                    "_sid": sid,
                },
                timeout=15.0,
            )
            r.raise_for_status()
            data = r.json()
            if not data.get("success"):
                raise DSMError(f"DSM Sharing.create 실패: {data.get('error')}")
            links = data["data"]["links"]
            if not links:
                raise DSMError("Sharing 응답에 링크 없음")
            url = links[0]["url"]
            return url, expires_at
        finally:
            await _logout(client, sid)