"""upstream.py — the only module that talks to anidb.app.

anidb.app sits behind Cloudflare: plain curl gets 403. All requests use
curl_cffi Chrome TLS impersonation (verified to pass the challenge).
Parsers are regex against live markup — keep them here so the layout
breaks in one place, not across the app.
"""
import re
import sys

from curl_cffi import requests

BASE = "https://anidb.app"
H = dict(impersonate="chrome", timeout=20)

_ANIME_LINK = re.compile(r'anime/([a-z0-9-]+)-(\d+)"[^>]*title="([^"]*)"')


def _get(url, **kw):
    r = requests.get(url, **H, **kw)
    if r.status_code in (403, 503) or "Just a moment" in r.text[:500]:
        raise RuntimeError(f"blocked by cloudflare: {url}")
    r.raise_for_status()
    return r


def search(q):
    """Step 1: browse page -> [{id, slug_id, name, poster}]"""
    html = _get(f"{BASE}/browse", params={"q": q}).text
    out, seen = [], set()
    for m in re.finditer(
        r'<a href="https://anidb\.app/anime/([a-z0-9-]+-\d+)"[^>]*title="([^"]*)"[^>]*>(.*?)</a>',
        html, re.S):
        slug_id, name, block = m.group(1), m.group(2), m.group(3)
        if slug_id in seen:
            continue
        seen.add(slug_id)
        img = re.search(r'<img src="([^"]+)"', block)
        out.append({"id": int(slug_id.rsplit("-", 1)[1]), "slug_id": slug_id,
                    "name": name, "poster": img.group(1) if img else None})
    return out


def details(slug_id):
    """Step 2: details page -> {name, synopsis, mal_id, seasons}"""
    p = _get(f"{BASE}/anime/{slug_id}").text
    mal = re.search(r'myanimelist\.net/anime/(\d+)', p)
    syn = re.search(r'>Synopsis</h2>.*?<p[^>]*>(.*?)</p>', p, re.S)
    h1 = re.search(r'<h1[^>]*>(.*?)</h1>', p, re.S)
    seasons, seen = [], set()
    i = p.find(">Seasons<")
    if i > 0:
        cnt = re.search(r">(\d+) entries in this series<", p[i:i + 400])
        n = int(cnt.group(1)) if cnt else 10  # fall back to cap if count markup changes
        for m in _ANIME_LINK.finditer(p[i:i + 20000]):
            sid = f"{m.group(1)}-{m.group(2)}"
            if sid in seen:
                continue
            seen.add(sid)
            seasons.append({"slug_id": sid, "name": m.group(3), "id": int(m.group(2))})
            if len(seasons) == n:
                break
    return {"id": int(slug_id.rsplit("-", 1)[1]),
            "name": h1.group(1).strip() if h1 else None,
            "synopsis": re.sub(r"<[^>]+>", "", syn.group(1)).strip() if syn else None,
            "mal_id": int(mal.group(1)) if mal else None,
            "seasons": seasons}


def episodes(anime_id):
    """Step 3: JSON API -> [{id, number, filler}]"""
    d = _get(f"{BASE}/api/frontend/anime/{anime_id}/episodes").json()
    return [{"id": e["id"], "number": e["number"], "filler": bool(e.get("filler"))}
            for e in d["episodes"]]


def languages(ep_id):
    """Step 4: JSON API -> [{code, name, embed_url}] (jpn=sub, eng=dub)"""
    return _get(f"{BASE}/api/frontend/episode/{ep_id}/languages").json()["languages"]


def master_m3u8(ep_id, lang="eng"):
    """Steps 5+6: embed page -> 'file: <master m3u8>' URL (None if unavailable)"""
    for l in languages(ep_id):
        if l["code"] == lang:
            m = re.search(r"file: '([^']*)'", _get(l["embed_url"]).text)
            if m:
                return m.group(1)
    return None


def master_variants(master_url):
    """Step 7: parse #EXT-X-STREAM-INF lines -> ['1920x1080', ...] (for display)"""
    text = _get(master_url).text
    return re.findall(r"RESOLUTION=(\d+x\d+)", text)


if __name__ == "__main__":
    # ponytail: assert self-check instead of a test framework
    results = search("chainsaw man")
    assert results and any(x["name"] == "Chainsaw Man" for x in results), results
    top = next(x for x in results if x["name"] == "Chainsaw Man")
    d = details(top["slug_id"])
    assert d["mal_id"] == 44511 and d["synopsis"], d
    assert [s["id"] for s in d["seasons"]] == [922, 923], d["seasons"]
    eps = episodes(top["id"])
    assert eps and eps[0]["number"] == 1, eps
    m = master_m3u8(eps[0]["id"], "eng")
    assert m and "EXT-X-STREAM" in _get(m).text, m
    print(f"OK: {top['name']} (MAL {d['mal_id']}, {len(d['seasons'])} seasons, "
          f"{len(eps)} eps) -> ep1 dub: {m[:70]}...")
    sys.exit(0)