from __future__ import annotations

from threading import RLock
from time import time
from . import rtorrent

_VOLATILE = {"down_rate", "down_rate_h", "up_rate", "up_rate_h", "progress", "completed_bytes", "peers", "seeds", "ratio", "state", "status", "message", "down_total", "down_total_h", "up_total", "up_total_h"}


class TorrentCache:
    def __init__(self):
        self._lock = RLock()
        self._data: dict[int, dict[str, dict]] = {}
        self._errors: dict[int, str] = {}
        self._updated_at: dict[int, float] = {}

    def snapshot(self, profile_id: int) -> list[dict]:
        with self._lock:
            return list(self._data.get(profile_id, {}).values())

    def error(self, profile_id: int) -> str:
        with self._lock:
            return self._errors.get(profile_id, "")

    def refresh(self, profile: dict) -> dict:
        profile_id = int(profile["id"])
        try:
            rows = rtorrent.list_torrents(profile)
            fresh = {t["hash"]: t for t in rows}
            with self._lock:
                old = self._data.get(profile_id, {})
                added = [v for h, v in fresh.items() if h not in old]
                removed = [h for h in old.keys() if h not in fresh]
                updated = []
                for h, new in fresh.items():
                    prev = old.get(h)
                    if not prev:
                        continue
                    patch = {"hash": h}
                    for key, value in new.items():
                        if prev.get(key) != value:
                            patch[key] = value
                    if len(patch) > 1:
                        updated.append(patch)
                self._data[profile_id] = fresh
                self._errors[profile_id] = ""
                self._updated_at[profile_id] = time()
            return {"ok": True, "profile_id": profile_id, "added": added, "updated": updated, "removed": removed}
        except Exception as exc:
            with self._lock:
                self._errors[profile_id] = str(exc)
            return {"ok": False, "profile_id": profile_id, "error": str(exc), "added": [], "updated": [], "removed": []}


torrent_cache = TorrentCache()