import logging
from typing import Dict, Any, List, Optional
import httpx
from .config import settings

logger = logging.getLogger(__name__)

STATUS_MAP = {
    0: "일시정지됨",
    1: "검사 대기",
    2: "검사 중",
    3: "다운로드 대기",
    4: "다운로드 중",
    5: "시딩 대기",
    6: "시딩 중 (완료)",
}

class TransmissionClient:
    def __init__(self):
        self.session_id: str = ""
        self.base_url = settings.rpc_url
        self.auth = None
        if settings.TRANSMISSION_USER and settings.TRANSMISSION_PASSWORD:
            self.auth = (settings.TRANSMISSION_USER, settings.TRANSMISSION_PASSWORD)

    async def _request(self, method: str, arguments: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
        """Transmission RPC 요청 전송 (세션 ID 자동 획득 및 409 처리)"""
        payload = {"method": method}
        if arguments:
            payload["arguments"] = arguments

        async with httpx.AsyncClient(timeout=10.0, auth=self.auth) as client:
            headers = {}
            if self.session_id:
                headers["X-Transmission-Session-Id"] = self.session_id

            # 첫 번째 요청
            response = await client.post(self.base_url, json=payload, headers=headers)

            # 409 Conflict: 세션 ID 갱신 후 재시도
            if response.status_code == 409:
                new_session_id = response.headers.get("X-Transmission-Session-Id")
                if not new_session_id:
                    raise Exception("Transmission에서 X-Transmission-Session-Id 헤더를 받지 못했습니다.")
                self.session_id = new_session_id
                headers["X-Transmission-Session-Id"] = self.session_id
                response = await client.post(self.base_url, json=payload, headers=headers)

            if response.status_code != 200:
                raise Exception(f"Transmission RPC 오류: HTTP {response.status_code} - {response.text}")

            res_data = response.json()
            if res_data.get("result") != "success":
                raise Exception(f"Transmission 요청 실패: {res_data.get('result')}")

            return res_data

    async def add_torrent(self, magnet_or_url: str, download_dir: Optional[str] = None, paused: bool = False) -> Dict[str, Any]:
        """마그넷 또는 토렌트 URL 추가"""
        arguments: Dict[str, Any] = {
            "filename": magnet_or_url.strip(),
            "paused": paused
        }
        if download_dir and download_dir.strip():
            arguments["download-dir"] = download_dir.strip()

        data = await self._request("torrent-add", arguments)
        args = data.get("arguments", {})
        
        # 'torrent-added' or 'torrent-duplicate'
        if "torrent-added" in args:
            return {"status": "added", "torrent": args["torrent-added"]}
        elif "torrent-duplicate" in args:
            return {"status": "duplicate", "torrent": args["torrent-duplicate"]}
        else:
            return {"status": "unknown", "arguments": args}

    async def get_torrents(self) -> List[Dict[str, Any]]:
        """토렌트 목록 조회"""
        fields = [
            "id", "name", "status", "percentDone", "rateDownload",
            "rateUpload", "totalSize", "eta", "downloadDir",
            "errorString", "isFinished", "addedDate"
        ]
        data = await self._request("torrent-get", {"fields": fields})
        torrents = data.get("arguments", {}).get("torrents", [])
        
        # 가공 및 상태 레이블 추가
        result = []
        for t in torrents:
            status_code = t.get("status", 0)
            result.append({
                "id": t.get("id"),
                "name": t.get("name", "알 수 없음"),
                "status": status_code,
                "status_label": STATUS_MAP.get(status_code, "알 수 없음"),
                "percent_done": round(t.get("percentDone", 0) * 100, 2),
                "rate_download": t.get("rateDownload", 0),
                "rate_upload": t.get("rateUpload", 0),
                "total_size": t.get("totalSize", 0),
                "eta": t.get("eta"),
                "download_dir": t.get("downloadDir"),
                "error_string": t.get("errorString"),
                "is_finished": t.get("isFinished", False),
            })
        return result

    async def remove_torrent(self, torrent_id: int, delete_local_data: bool = False) -> None:
        """토렌트 삭제"""
        arguments = {
            "ids": [torrent_id],
            "delete-local-data": delete_local_data
        }
        await self._request("torrent-remove", arguments)

    async def start_torrent(self, torrent_id: int) -> None:
        """토렌트 시작/재개"""
        await self._request("torrent-start", {"ids": [torrent_id]})

    async def stop_torrent(self, torrent_id: int) -> None:
        """토렌트 일시정지"""
        await self._request("torrent-stop", {"ids": [torrent_id]})

    async def get_session_stats(self) -> Dict[str, Any]:
        """세션 정보 및 통계 확인"""
        session_data = await self._request("session-get")
        return session_data.get("arguments", {})

transmission_client = TransmissionClient()