import re
import sqlite3
import time
import logging
import asyncio
import urllib.request
import json
from concurrent.futures import ThreadPoolExecutor
from urllib.parse import quote_plus
import tmdb as _tmdb

logger = logging.getLogger(__name__)

CACHE_TTL = 6 * 3600
DB_PATH = "data/arte_dl.db"
_cache: dict = {"data": [], "ts": 0}
_fetch_lock: asyncio.Lock | None = None
_refresh_task: asyncio.Task | None = None


def _get_fetch_lock() -> asyncio.Lock:
    global _fetch_lock
    if _fetch_lock is None:
        _fetch_lock = asyncio.Lock()
    return _fetch_lock


import os as _os
_os.makedirs("data", exist_ok=True)


def _db():
    conn = sqlite3.connect(DB_PATH)
    conn.row_factory = sqlite3.Row
    return conn


def _init_concerts_cache_table():
    with _db() as conn:
        conn.execute("""
            CREATE TABLE IF NOT EXISTS concerts_cache (
                id      INTEGER PRIMARY KEY CHECK (id = 1),
                data    TEXT NOT NULL,
                ts      REAL NOT NULL
            )
        """)


_init_concerts_cache_table()


def _load_db_cache() -> tuple[list, float]:
    try:
        with _db() as conn:
            row = conn.execute("SELECT data, ts FROM concerts_cache WHERE id=1").fetchone()
        if row:
            return json.loads(row["data"]), row["ts"]
    except Exception:
        pass
    return [], 0.0


def _save_db_cache(data: list, ts: float):
    try:
        with _db() as conn:
            conn.execute(
                "INSERT OR REPLACE INTO concerts_cache (id, data, ts) VALUES (1, ?, ?)",
                (json.dumps(data), ts),
            )
    except Exception as e:
        logger.warning("Failed to save concerts cache: %s", e)

PLAYER_API = "https://api.arte.tv/api/player/v2/config/fr/{pid}"
SEARCH_URL = "https://www.arte.tv/fr/search/?q={q}"

GENRE_PAGES = [
    ("Pop & Rock",       "https://www.arte.tv/fr/p/pop-rock/"),
    ("Classique",        "https://www.arte.tv/fr/p/classique/"),
    ("Electro",          "https://www.arte.tv/fr/p/musiques-electroniques/"),
    ("Jazz",             "https://www.arte.tv/fr/p/jazz"),
    ("Arts de la scène", "https://www.arte.tv/fr/p/arts-de-la-scene"),
    ("Hip-hop",          "https://www.arte.tv/fr/p/hip-hop"),
    ("Metal",            "https://www.arte.tv/fr/p/metal"),
    ("Opéra",            "https://www.arte.tv/fr/p/opera"),
    ("World",            "https://www.arte.tv/fr/p/world"),
    ("Baroque",          "https://www.arte.tv/fr/p/musique-baroque/"),
]

EXTRA_PAGES = [
    "https://www.arte.tv/fr/arte-concert/agenda/",
    "https://www.arte.tv/fr/arte-concert/",
]

CATEGORIES = [name for name, _ in GENRE_PAGES]

_HEADERS = {
    "User-Agent": (
        "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 "
        "Chrome/120.0.0.0 Safari/537.36"
    ),
    "RSC": "1",
}

_PROG_RE = re.compile(r"\b(\d{6}-\d{3}-[A-Z])\b")


def _fetch_url(url: str, headers: dict | None = None) -> str:
    req = urllib.request.Request(url, headers=headers or _HEADERS)
    with urllib.request.urlopen(req, timeout=15) as r:
        return r.read().decode("utf-8", errors="replace")


EMAC_ZONE_API = "https://api.arte.tv/api/emac/v4/fr/web/zones/{zone_id}/content?page={page}"
_EMAC_HEADERS = {"User-Agent": _HEADERS["User-Agent"], "Origin": "https://www.arte.tv"}
_ZONE_RE = re.compile(r"/api/emac/v4/fr/web/zones/([a-f0-9-]+)/content\?page=1")


def _zone_ids_from_page(url: str) -> list[str]:
    try:
        html = _fetch_url(url)
        return _ZONE_RE.findall(html)
    except Exception as ex:
        logger.warning("Failed to fetch %s: %s", url, ex)
        return []


def _fetch_zone_concerts(zone_id: str, category: str) -> list[dict]:
    """Fetch all concerts from a single EMAC zone (paginated)."""
    concerts = []
    page = 1
    while True:
        url = EMAC_ZONE_API.format(zone_id=zone_id, page=page)
        try:
            raw = _fetch_url(url, headers=_EMAC_HEADERS)
            data = json.loads(raw)
        except Exception as ex:
            logger.warning("EMAC zone %s page %d failed: %s", zone_id, page, ex)
            break
        for item in data.get("data", []):
            pid = item.get("programId") or ""
            if not pid:
                continue
            img = item.get("mainImage") or {}
            avail = item.get("availability") or {}
            concerts.append({
                "id": pid,
                "title": item.get("title") or "",
                "subtitle": item.get("subtitle") or "",
                "url": item.get("url") or f"https://www.arte.tv/fr/videos/{pid}/",
                "thumbnail": img.get("url") or "",
                "duration": item.get("duration"),
                "description": item.get("shortDescription") or item.get("teaserText") or "",
                "expiry": avail.get("end") or "",
            })
        pagination = data.get("pagination", {})
        if page >= pagination.get("pages", 1):
            break
        page += 1
    logger.info("  %s (zone %s…) → %d concerts", category, zone_id[:8], len(concerts))
    return concerts


def _metadata_for_pid(pid: str) -> dict | None:
    try:
        raw = _fetch_url(
            PLAYER_API.format(pid=pid),
            headers={"User-Agent": _HEADERS["User-Agent"], "Accept": "application/json"},
        )
        data = json.loads(raw)
        attrs = data["data"]["attributes"]
        meta = attrs["metadata"]

        url = (meta.get("link") or {}).get("url") or f"https://www.arte.tv/fr/videos/{pid}/"
        imgs = meta.get("images") or []
        thumbnail = imgs[0]["url"] if imgs else ""
        duration_s = (meta.get("duration") or {}).get("seconds")
        rights = attrs.get("rights") or {}

        return {
            "id": pid,
            "title": meta.get("title") or "",
            "subtitle": meta.get("subtitle") or "",
            "url": url,
            "thumbnail": thumbnail,
            "duration": duration_s,
            "description": meta.get("description") or "",
            "expiry": rights.get("end") or "",
        }
    except Exception as ex:
        logger.debug("Failed to get metadata for %s: %s", pid, ex)
        return None


def _fetch_all_sync() -> list[dict]:
    by_id: dict[str, dict] = {}
    id_cats: dict[str, list[str]] = {}

    # Genre pages: use EMAC zone API (paginated) — gets ALL concerts, not just initial HTML
    for name, url in GENRE_PAGES:
        zone_ids = _zone_ids_from_page(url)
        if not zone_ids:
            logger.warning("No zone IDs found for %s (%s)", name, url)
            continue
        # All zones on a page are identical copies; use the first one
        concerts = _fetch_zone_concerts(zone_ids[0], name)
        for c in concerts:
            pid = c["id"]
            id_cats.setdefault(pid, []).append(name)
            if pid not in by_id:
                by_id[pid] = c

    # Extra pages: fall back to regex (no EMAC zones)
    for url in EXTRA_PAGES:
        try:
            extra_ids = set(_PROG_RE.findall(_fetch_url(url)))
        except Exception as ex:
            logger.warning("Failed to fetch %s: %s", url, ex)
            extra_ids = set()
        new_ids = extra_ids - set(by_id)
        logger.info("  %s → %d new IDs", url.split("/fr/")[1], len(new_ids))
        if new_ids:
            with ThreadPoolExecutor(max_workers=10) as pool:
                results = list(pool.map(_metadata_for_pid, sorted(new_ids)))
            for meta in results:
                if meta and meta.get("title"):
                    by_id[meta["id"]] = meta

    logger.info("Total unique programme IDs: %d", len(by_id))
    concerts = list(by_id.values())
    for c in concerts:
        c["categories"] = id_cats.get(c["id"], [])

    # TMDB enrichment (concurrent, results cached in SQLite)
    def _enrich(c: dict) -> dict:
        t = _tmdb.lookup(c["id"], c.get("title", ""), c.get("subtitle", ""))
        if t:
            c.update(t)
        return c

    with ThreadPoolExecutor(max_workers=5) as pool:
        concerts = list(pool.map(_enrich, concerts))

    concerts.sort(key=lambda c: c.get("expiry") or "", reverse=True)
    return concerts


def _resolve_ids(ids: set[str], exclude: set[str] | None = None) -> list[dict]:
    to_fetch = ids - (exclude or set())
    with ThreadPoolExecutor(max_workers=10) as pool:
        results = list(pool.map(_metadata_for_pid, sorted(to_fetch)))
    return [c for c in results if c and c.get("title")]


def _search_sync(query: str) -> set[str]:
    url = SEARCH_URL.format(q=quote_plus(query))
    try:
        html = _fetch_url(url)
        return set(_PROG_RE.findall(html))
    except Exception as ex:
        logger.warning("Search failed for %r: %s", query, ex)
        return set()


# ── public API ────────────────────────────────────────────────────────────────

async def _ensure_cache() -> list[dict]:
    return await get_all_concerts()


async def get_concerts_by_category(category: str) -> list[dict]:
    data = await _ensure_cache()
    return [c for c in data if category in (c.get("categories") or [])]


async def _do_refresh():
    """Full scrape under lock; updates in-memory + DB cache."""
    global _refresh_task
    async with _get_fetch_lock():
        if _cache["data"] and time.time() - _cache["ts"] < CACHE_TTL:
            return
        loop = asyncio.get_event_loop()
        data = await loop.run_in_executor(None, _fetch_all_sync)
        if data:
            ts = time.time()
            _cache["data"] = data
            _cache["ts"] = ts
            _save_db_cache(data, ts)
            logger.info("Cache refreshed: %d concerts", len(data))
    _refresh_task = None


async def get_all_concerts() -> list[dict]:
    global _refresh_task
    now = time.time()

    # In-memory cache hit
    if _cache["data"] and now - _cache["ts"] < CACHE_TTL:
        return _cache["data"]

    # Try DB cache — return immediately even if stale, refresh in background
    db_data, db_ts = _load_db_cache()
    if db_data:
        _cache["data"] = db_data
        _cache["ts"] = db_ts
        logger.info("Concerts loaded from DB cache (%d concerts)", len(db_data))
        if now - db_ts >= CACHE_TTL:
            # Stale — serve now, refresh silently in background
            if _refresh_task is None or _refresh_task.done():
                _refresh_task = asyncio.create_task(_do_refresh())
        return _cache["data"]

    # No cache at all — must scrape synchronously (first run or cleared DB)
    await _do_refresh()
    return _cache["data"]


async def fetch_concerts(page: int = 1, search: str = "", page_size: int = 24, category: str = "") -> dict:
    all_c = await get_all_concerts()

    if category:
        all_c = [c for c in all_c if category in (c.get("categories") or [])]

    cached_ids = {c["id"] for c in all_c}

    if search:
        q = search.lower()
        local = [
            c for c in all_c
            if q in (c.get("title") or "").lower()
            or q in (c.get("subtitle") or "").lower()
            or q in (c.get("description") or "").lower()
        ]
        # Remote search only when no category filter (results have no category info)
        if not category:
            loop = asyncio.get_event_loop()
            remote_ids = await loop.run_in_executor(None, _search_sync, search)
            new_ids = remote_ids - cached_ids
            if new_ids:
                extra = await loop.run_in_executor(None, _resolve_ids, new_ids, None)
                local_ids = {c["id"] for c in local}
                for c in extra:
                    if c["id"] not in local_ids:
                        local.append(c)
        filtered = local
    else:
        filtered = all_c

    start = (page - 1) * page_size
    return {
        "concerts": filtered[start : start + page_size],
        "total": len(filtered),
        "page": page,
        "page_size": page_size,
        "pages": max(1, (len(filtered) + page_size - 1) // page_size),
    }


def get_versions(pid: str) -> list[dict]:
    """Fetch available stream versions from Arte Player API for a programme ID."""
    try:
        raw = _fetch_url(
            PLAYER_API.format(pid=pid),
            headers={"User-Agent": _HEADERS["User-Agent"], "Accept": "application/json"},
        )
        data = json.loads(raw)
        streams = data["data"]["attributes"].get("streams") or []
        return streams[0].get("versions") or [] if streams else []
    except Exception as ex:
        logger.debug("Failed to get versions for %s: %s", pid, ex)
        return []


def select_lang_tag(versions: list[dict]) -> str:
    """
    Determine UNFR language tag from stream versions.
    FR audio → FRENCH, non-FR + FR subs → VOSTFR, otherwise → VO.
    """
    if not versions:
        return "VO"
    if any(v.get("audioLanguage") == "fr" for v in versions):
        return "FRENCH"
    if any(v.get("subtitleLanguage") == "fr" for v in versions):
        return "VOSTFR"
    return "VO"


async def invalidate_cache() -> int:
    _cache["ts"] = 0
    try:
        with _db() as conn:
            conn.execute("DELETE FROM concerts_cache")
    except Exception:
        pass
    data = await get_all_concerts()
    return len(data)