#!/usr/bin/env python3
"""Subtitle fetcher v2 — direct OpenSubtitles REST API.

Bypasses the Jellyfin OpenSubtitles plugin to dodge season/episode numbering
mismatches. Looks each library episode up by its per-episode IMDB id, picks
the best English match, downloads via the REST endpoint, and writes the
sidecar straight onto nullstone next to the media file (via SSH).

Why v2 exists: see ../CHANGELOG.md "Known break" — American Dad library
uses Hulu season numbering, OS catalogues by Fox airing order; the plugin
queries by (parent_imdb_id, season, episode) so library S02E01 → OS S01E08
returned 0 hits even though the per-episode IMDB id (tt0511631) is real.

Picker: highest download_count among non-HI, non-MT, non-AI, non-Forced
candidates; 23.976fps preferred. Falls back to all candidates if every match
is HI/MT/AI/Forced.

Usage:
    sub-rest-fetch.py <series-id> --season <N> [--start <ep>] [--end <ep>]
    sub-rest-fetch.py <series-id> --all

Env (required):
    JELLYFIN_TOKEN         X-Emby-Token for nullstone Jellyfin
    OPENSUBTITLES_API_KEY  Path to file holding the API key
    OPENSUBTITLES_USER     OS account username
    OPENSUBTITLES_PASS     OS account password

Env (optional):
    NULLSTONE              SSH target, default user@192.168.0.100
    DRY_RUN=1              search + pick only, no download
"""
from __future__ import annotations

import argparse
import json
import os
import shlex
import subprocess
import sys
import time
import urllib.parse

OS_BASE = "https://api.opensubtitles.com/api/v1"
USER_AGENT = "arrflix v1.0.0"
JF_BASE = "http://localhost:8096"
NULLSTONE = os.environ.get("NULLSTONE", "user@192.168.0.100")


def die(msg: str, code: int = 1) -> None:
    print(f"ERROR: {msg}", file=sys.stderr)
    sys.exit(code)


def env_or_die(name: str) -> str:
    v = os.environ.get(name)
    if not v:
        die(f"{name} not set")
    return v


def load_api_key() -> str:
    path = env_or_die("OPENSUBTITLES_API_KEY")
    with open(path) as f:
        return f.read().strip()


def _curl(url: str, method: str = "GET", headers: dict | None = None,
          body: dict | None = None, binary: bool = False) -> bytes:
    """OpenSubtitles' frontend rejects urllib (consistent 503 on /download).
    curl works against the same endpoint and headers. Use curl uniformly."""
    cmd = ["curl", "-sSf", "-X", method, url]
    for k, v in (headers or {}).items():
        cmd += ["-H", f"{k}: {v}"]
    if body is not None:
        cmd += ["--data", json.dumps(body)]
    return subprocess.check_output(cmd)


def http_json(url: str, method: str = "GET", headers: dict | None = None,
              body: dict | None = None) -> dict:
    raw = _curl(url, method, headers, body)
    return json.loads(raw.decode())


def http_get_bytes(url: str) -> bytes:
    return _curl(url, "GET", headers={"User-Agent": USER_AGENT})


def jellyfin(path: str, params: dict | None = None) -> dict:
    """Run Jellyfin API call inside the container on nullstone via SSH."""
    tok = env_or_die("JELLYFIN_TOKEN")
    qs = ""
    if params:
        qs = "?" + urllib.parse.urlencode(params, safe=",")
    url = JF_BASE + path + qs
    cmd = ["ssh", NULLSTONE,
           f"docker exec jellyfin curl -s -H 'X-Emby-Token: {tok}' {shlex.quote(url)}"]
    out = subprocess.check_output(cmd, text=True)
    return json.loads(out)


def list_episodes(series_id: str) -> list[dict]:
    d = jellyfin(f"/Items", {
        "ParentId": series_id,
        "IncludeItemTypes": "Episode",
        "Recursive": "true",
        "Fields": "Path,ParentIndexNumber,IndexNumber,ProviderIds",
        "SortBy": "ParentIndexNumber,IndexNumber",
    })
    return d["Items"]


def os_login(api_key: str, user: str, password: str) -> str:
    res = http_json(f"{OS_BASE}/login", "POST", headers={
        "Api-Key": api_key,
        "Content-Type": "application/json",
        "User-Agent": USER_AGENT,
    }, body={"username": user, "password": password})
    return res["token"]


def os_user_info(api_key: str, bearer: str) -> dict:
    return http_json(f"{OS_BASE}/infos/user", headers={
        "Api-Key": api_key,
        "Authorization": f"Bearer {bearer}",
        "User-Agent": USER_AGENT,
    })["data"]


def os_search(api_key: str, imdb_id: str) -> list[dict]:
    """imdb_id without the 'tt' prefix per OS convention."""
    res = http_json(
        f"{OS_BASE}/subtitles?imdb_id={imdb_id}&languages=en",
        headers={"Api-Key": api_key, "User-Agent": USER_AGENT})
    return res.get("data", [])


def pick_best(hits: list[dict]) -> dict | None:
    """Filter HI/MT/AI/Forced, prefer 23.976fps, sort by download_count desc."""
    def attr(h, k):
        return h["attributes"].get(k)

    clean = [h for h in hits
             if not attr(h, "hearing_impaired")
             and not attr(h, "machine_translated")
             and not attr(h, "ai_translated")
             and not attr(h, "foreign_parts_only")]
    if not clean:
        clean = hits
    fps2398 = [h for h in clean if abs((attr(h, "fps") or 0) - 23.976) < 0.01]
    pool = fps2398 if fps2398 else clean
    pool.sort(key=lambda h: -(attr(h, "download_count") or 0))
    return pool[0] if pool else None


def os_download(api_key: str, bearer: str, file_id: int) -> dict:
    return http_json(f"{OS_BASE}/download", "POST", headers={
        "Api-Key": api_key,
        "Authorization": f"Bearer {bearer}",
        "Content-Type": "application/json",
        "User-Agent": USER_AGENT,
    }, body={"file_id": file_id})


def write_sidecar_remote(content: bytes, remote_path: str) -> None:
    """ssh redirect file content to nullstone."""
    cmd = ["ssh", NULLSTONE, f"cat > {shlex.quote(remote_path)}"]
    p = subprocess.Popen(cmd, stdin=subprocess.PIPE)
    p.communicate(content)
    if p.returncode != 0:
        die(f"failed writing {remote_path}")


def imdb_strip(s: str | None) -> str | None:
    if not s:
        return None
    return s[2:] if s.startswith("tt") else s


def episode_to_paths(ep: dict) -> tuple[str, str]:
    """Return (remote_dir, base_filename) for sidecar placement."""
    container_path = ep["Path"]  # /media/tv/Show/Season XX/Show - SxxExx - Title.mkv
    host_path = container_path.replace("/media/", "/home/user/media/")
    remote_dir = os.path.dirname(host_path)
    base = os.path.splitext(os.path.basename(host_path))[0]
    return remote_dir, base


def main() -> int:
    ap = argparse.ArgumentParser()
    ap.add_argument("series_id")
    ap.add_argument("--season", type=int, default=None)
    ap.add_argument("--start", type=int, default=1)
    ap.add_argument("--end", type=int, default=10**6)
    ap.add_argument("--all", action="store_true")
    args = ap.parse_args()

    if args.season is None and not args.all:
        die("pass --season N or --all")

    api_key = load_api_key()
    user = env_or_die("OPENSUBTITLES_USER")
    pw = env_or_die("OPENSUBTITLES_PASS")
    dry = os.environ.get("DRY_RUN") == "1"

    bearer = os_login(api_key, user, pw)
    info = os_user_info(api_key, bearer)
    print(f"[quota] remaining={info['remaining_downloads']}/{info['allowed_downloads']}, "
          f"resets in {info['reset_time']}", file=sys.stderr)

    eps = list_episodes(args.series_id)
    work = []
    for ep in eps:
        s = ep["ParentIndexNumber"]
        n = ep["IndexNumber"]
        if not args.all and s != args.season:
            continue
        if not (args.start <= n <= args.end):
            continue
        work.append(ep)
    if not work:
        die("no episodes selected")

    print(f"[plan] {len(work)} episodes selected", file=sys.stderr)
    if not dry and len(work) > info["remaining_downloads"]:
        print(f"[warn] {len(work)} > quota {info['remaining_downloads']}; "
              f"will halt mid-run", file=sys.stderr)

    ok = 0
    fail = []
    for ep in work:
        s, n = ep["ParentIndexNumber"], ep["IndexNumber"]
        label = f"S{s:02}E{n:02} {ep['Name']}"
        imdb = imdb_strip(ep.get("ProviderIds", {}).get("Imdb"))
        if not imdb:
            print(f"[skip] {label} — no IMDB id", file=sys.stderr)
            fail.append((label, "no-imdb"))
            continue

        hits = os_search(api_key, imdb)
        pick = pick_best(hits)
        if not pick:
            print(f"[skip] {label} — 0 hits for imdb={imdb}", file=sys.stderr)
            fail.append((label, "no-hits"))
            continue

        a = pick["attributes"]
        f = a["files"][0]
        print(f"[pick] {label} imdb={imdb} fid={f['file_id']} dl={a.get('download_count')} "
              f"fps={a.get('fps')} fname={f.get('file_name')}", file=sys.stderr)

        if dry:
            ok += 1
            continue

        try:
            dl = os_download(api_key, bearer, f["file_id"])
        except subprocess.CalledProcessError as e:
            print(f"[fail] {label} download (curl exit {e.returncode})", file=sys.stderr)
            fail.append((label, f"dl-curl-{e.returncode}"))
            break  # may be quota; stop run

        link = dl.get("link")
        if not link:
            print(f"[fail] {label} no download link in response: {dl}", file=sys.stderr)
            fail.append((label, "no-link"))
            break

        content = http_get_bytes(link)
        remote_dir, base = episode_to_paths(ep)
        dest = f"{remote_dir}/{base}.eng.srt"
        write_sidecar_remote(content, dest)
        print(f"[ok]  {label} -> {dest} (remaining={dl.get('remaining')})",
              file=sys.stderr)
        ok += 1
        time.sleep(0.5)  # be polite

    print(f"\n[done] ok={ok}/{len(work)} failures={len(fail)}", file=sys.stderr)
    for lab, why in fail:
        print(f"  - {lab}: {why}", file=sys.stderr)
    if ok:
        try:
            subprocess.run([os.path.join(os.path.dirname(__file__),
                                         "audit-coverage.py")],
                           check=False)
        except Exception as e:
            print(f"[warn] coverage refresh skipped: {e}", file=sys.stderr)
    return 0 if ok else 2


if __name__ == "__main__":
    sys.exit(main())