#!/usr/bin/env python3
"""Fetch box art for the library and attach it to each game.

Two sources, tried in order, neither needing an account:

  1. libretro-thumbnails (https://thumbnails.libretro.com) — scanned retail
     boxes named to the No-Intro / Redump conventions. Best art where it has
     any, but its coverage is the retro consoles.
  2. English Wikipedia — a cover on essentially every notable game article,
     which is what fills the Xbox 360 shelf.

Images are pushed through the app's own POST /api/images endpoint, so they get
the same validation, WebP re-encoding and per-user filing as a manual upload.

Standard library only, so it runs without a virtualenv.

    python3 fetch_art.py --password '...' --dry-run   # report, change nothing
    python3 fetch_art.py --password '...'             # download and attach
"""

from __future__ import annotations

import argparse
import difflib
import json
import re
import sys
import time
import unicodedata
import urllib.error
import urllib.parse
import urllib.request
from dataclasses import dataclass
from pathlib import Path

THUMBNAIL_HOST = "https://thumbnails.libretro.com"

# Our system codes to libretro's DAT-derived directory names.
# Several directories may back one system code. Our "GB" covers both Game Boy
# and Game Boy Color titles — Pokemon Trading Card Game, for instance, is only in
# the Color set — so both are searched and the better match wins.
SYSTEM_DIRS = {
    "NES": ["Nintendo - Nintendo Entertainment System"],
    "SNES": ["Nintendo - Super Nintendo Entertainment System"],
    "N64": ["Nintendo - Nintendo 64"],
    "GB": ["Nintendo - Game Boy", "Nintendo - Game Boy Color"],
    "GBA": ["Nintendo - Game Boy Advance"],
    "DS": ["Nintendo - Nintendo DS"],
    "GC": ["Nintendo - GameCube"],
    "WII": ["Nintendo - Wii"],
    "PS1": ["Sony - PlayStation"],
    "PS2": ["Sony - PlayStation 2"],
    "PSP": ["Sony - PlayStation Portable"],
    # libretro does publish a "Microsoft - Xbox 360" set, but it is a stub of
    # about a dozen entries. It is searched anyway in case it fills out later;
    # in practice these titles fall through to the Wikipedia pass.
    "360": ["Microsoft - Xbox 360"],
}

# Preferred release region, best first. The library is a US collection, so a USA
# release wins; a European box is better than nothing.
REGION_RANK = ["usa", "world", "usa, europe", "europe", "japan, usa", "japan"]

# Tags that mark a variant we would rather not pick when a plain release exists.
UNDESIRABLE_TAGS = (
    "beta", "proto", "demo", "sample", "virtual console", "switch online",
    "classic mini", "rev ", "alt", "unl", "aftermarket", "competition",
)

ROMAN = {
    "i": 1, "ii": 2, "iii": 3, "iv": 4, "v": 5, "vi": 6, "vii": 7, "viii": 8,
    "ix": 9, "x": 10, "xi": 11, "xii": 12, "xiii": 13, "xiv": 14, "xv": 15,
}


# --------------------------------------------------------------------------
# Title normalisation
# --------------------------------------------------------------------------

def strip_accents(text: str) -> str:
    """'Pokémon' -> 'Pokemon', so our un-accented rows still match."""
    return "".join(
        c for c in unicodedata.normalize("NFKD", text) if not unicodedata.combining(c)
    )


def normalise(title: str) -> str:
    """Reduce a title to a comparable form.

    Roman numerals become digits, which is what makes our SNES 'Final Fantasy 2'
    line up with the catalogued 'Final Fantasy II', and the PS1 'Final Fantasy V'
    with 'Final Fantasy V' rather than drifting to a different entry.
    """
    text = strip_accents(title).lower()
    text = text.replace("&", " and ")
    # The catalogue moves a leading article to the end: "Sims 2, The",
    # "Legend of Zelda, The - Ocarina of Time". Drop it before anything else,
    # while the comma that marks it is still there to find.
    text = re.sub(r",\s*(the|a|an)\b", " ", text)
    # libretro renders a subtitle colon as " - "; flatten both to a space.
    text = re.sub(r"\s+-\s+", " ", text)
    text = re.sub(r"[^a-z0-9]+", " ", text)

    words = [str(ROMAN.get(w, w)) for w in text.split()]
    # Leading articles carry no signal and differ between catalogues.
    while words and words[0] in ("the", "a", "an"):
        words.pop(0)
    return " ".join(words).strip()


@dataclass
class Candidate:
    filename: str
    base: str        # title with all parenthetical tags removed
    tags: str        # the tags, lowercased, for region and variant ranking
    directory: str   # libretro set it came from, needed to build the download URL

    @property
    def region_rank(self) -> int:
        for i, region in enumerate(REGION_RANK):
            if region in self.tags:
                return i
        return len(REGION_RANK)

    @property
    def variant_penalty(self) -> int:
        return sum(1 for tag in UNDESIRABLE_TAGS if tag in self.tags)


def parse_candidate(filename: str, directory: str) -> Candidate:
    stem = filename[:-4] if filename.lower().endswith(".png") else filename
    tags = " ".join(re.findall(r"\(([^)]*)\)", stem)).lower()
    base = re.sub(r"\s*\([^)]*\)", "", stem).strip()
    return Candidate(filename=filename, base=base, tags=tags, directory=directory)


# --------------------------------------------------------------------------
# HTTP
# --------------------------------------------------------------------------

def http(url: str, *, data=None, headers=None, method=None, timeout=90) -> bytes:
    request = urllib.request.Request(url, data=data, method=method)
    for key, value in (headers or {}).items():
        request.add_header(key, value)
    last_error: Exception | None = None

    for attempt in range(4):
        try:
            with urllib.request.urlopen(request, timeout=timeout) as response:
                return response.read()
        except urllib.error.HTTPError as exc:
            # 429 means we asked too fast, so back off hard and try again.
            if exc.code == 429:
                last_error = exc
                time.sleep(5 * (attempt + 1))
                continue
            # Other 4xx will not improve on retry; surface immediately.
            if exc.code < 500:
                raise
            last_error = exc
        except (urllib.error.URLError, TimeoutError) as exc:
            last_error = exc
        time.sleep(1.5 * (attempt + 1))

    raise RuntimeError(f"GET {url} failed after 4 attempts: {last_error}")


def api_json(base: str, path: str, token: str | None = None, *, data=None, method=None):
    headers = {"Accept": "application/json"}
    if token:
        headers["Authorization"] = f"Bearer {token}"
    body = None
    if data is not None:
        body = json.dumps(data).encode()
        headers["Content-Type"] = "application/json"
    raw = http(base + path, data=body, headers=headers, method=method)
    return json.loads(raw) if raw else None


def upload_image(base: str, token: str, filename: str, blob: bytes) -> dict:
    """multipart/form-data POST, hand-rolled to avoid a requests dependency."""
    boundary = "----LudosArt" + str(int(time.time() * 1000))
    body = b"".join([
        f'--{boundary}\r\n'.encode(),
        f'Content-Disposition: form-data; name="file"; filename="{filename}"\r\n'.encode(),
        b"Content-Type: image/png\r\n\r\n",
        blob,
        f"\r\n--{boundary}--\r\n".encode(),
    ])
    raw = http(
        base + "/api/images",
        data=body,
        headers={
            "Authorization": f"Bearer {token}",
            "Content-Type": f"multipart/form-data; boundary={boundary}",
        },
    )
    return json.loads(raw)


# --------------------------------------------------------------------------
# Wikipedia fallback
# --------------------------------------------------------------------------
#
# libretro's coverage stops at the retro consoles — its "Microsoft - Xbox 360"
# set exists but holds only a dozen entries, none of them ours. English
# Wikipedia carries a cover image on essentially every notable game article and
# needs no account.
#
# The image is read from the article's infobox rather than guessed from file
# names: filtering names for "box" also matches "Xbox-360-Pro-wController.png".

WIKI_API = "https://en.wikipedia.org/w/api.php"
WIKI_UA = "LudosData/1.0 (personal game library; https://github.com/)"
WIKI_MIN_INTERVAL = 1.0  # seconds between calls; the API 429s if pushed

_wiki_last_call = 0.0


def wiki_api(**params):
    """Throttled Wikipedia API call."""
    global _wiki_last_call

    wait = WIKI_MIN_INTERVAL - (time.monotonic() - _wiki_last_call)
    if wait > 0:
        time.sleep(wait)

    params.setdefault("action", "query")
    params.setdefault("format", "json")
    raw = http(f"{WIKI_API}?{urllib.parse.urlencode(params)}", headers={"User-Agent": WIKI_UA})
    _wiki_last_call = time.monotonic()
    return json.loads(raw)


def is_game_article(wikitext: str) -> bool:
    """True for an article about a single game.

    A substring test for "Infobox video game" also matches "Infobox video game
    series", which would resolve Banjo-Kazooie to the series overview rather
    than the 1998 game — and give the wrong cover and the wrong summary.
    """
    return re.search(r"\{\{\s*Infobox video game\b(?!\s*series)", wikitext, re.I) is not None


def wiki_article(title: str, cache_dir: Path) -> tuple[str, str] | None:
    """(resolved title, wikitext) for a page, or None when it does not exist."""
    safe = re.sub(r"[^A-Za-z0-9._ -]", "_", title)[:120]
    cache = cache_dir / "wiki" / f"{safe}.json"

    if cache.exists():
        blob = json.loads(cache.read_text())
        return (blob["title"], blob["text"]) if blob else None

    data = wiki_api(prop="revisions", rvprop="content", rvslots="main",
                    titles=title, redirects=1)
    page = next(iter(data["query"]["pages"].values()))

    result = None
    if "missing" not in page and page.get("revisions"):
        result = (page["title"], page["revisions"][0]["slots"]["main"]["*"])

    cache.parent.mkdir(parents=True, exist_ok=True)
    cache.write_text(json.dumps({"title": result[0], "text": result[1]} if result else None))
    return result


def wiki_cover_url(game: dict, cache_dir: str | Path) -> tuple[str, str] | None:
    """(image URL, source description) for a game's cover, or None."""
    cache_dir = Path(cache_dir)
    title, year, system = game["title"], game.get("year"), game.get("system")

    # Bare title first, then the disambiguated forms Wikipedia actually uses.
    attempts = [title, f"{title} (video game)"]
    if year:
        attempts.append(f"{title} ({year} video game)")

    article = None
    for candidate in attempts:
        found = wiki_article(candidate, cache_dir)
        if found and is_game_article(found[1]):
            article = found
            break

    if not article:
        return None

    page_title, text = article

    # Guard against landing on the film/book of the same name, or a different
    # entry in the series: the article should mention the platform we hold.
    if system == "360" and "Xbox 360" not in text:
        return None

    match = re.search(r"\|\s*image\s*=\s*([^\n|]+)", text)
    if not match:
        return None

    filename = match.group(1).strip()
    filename = re.sub(r"<!--.*?-->", "", filename).strip()
    filename = filename.strip("[]| ")
    # The field is written both ways: bare ("Halo 3 final boxshot.JPG") and
    # prefixed ("File:Lost-Planet-New.jpg"), with or without [[ ]] around it.
    # Strip any prefix so exactly one is added back below.
    filename = re.sub(r"^\s*(?:File|Image)\s*:\s*", "", filename, flags=re.I).strip()
    if not filename:
        return None

    info = wiki_api(prop="imageinfo", titles=f"File:{filename}",
                    iiprop="url|mime", iiurlwidth=600)
    page = next(iter(info["query"]["pages"].values()))
    image_info = (page.get("imageinfo") or [{}])[0]
    url = image_info.get("thumburl") or image_info.get("url")

    return (url, f"wikipedia:{page_title}") if url else None


# --------------------------------------------------------------------------
# Listings
# --------------------------------------------------------------------------

def load_listing(system: str, cache_dir: Path) -> list[Candidate]:
    """Every candidate for a system, across all of its libretro sets.

    Listings are cached on disk, so reruns and dry-runs cost nothing.
    """
    candidates: list[Candidate] = []

    for directory in SYSTEM_DIRS[system]:
        cache = cache_dir / f"{directory}.json"
        if cache.exists():
            names = json.loads(cache.read_text())
        else:
            quoted = urllib.parse.quote(directory)
            html = http(f"{THUMBNAIL_HOST}/{quoted}/Named_Boxarts/").decode(
                "utf-8", errors="replace"
            )
            names = sorted(
                {urllib.parse.unquote(m) for m in re.findall(r'href="([^"]+\.png)"', html)}
            )
            cache.parent.mkdir(parents=True, exist_ok=True)
            cache.write_text(json.dumps(names, indent=0))

        candidates.extend(parse_candidate(n, directory) for n in names)

    return candidates


def contains_tokens(haystack: list[str], needle: list[str]) -> bool:
    """True when `needle` appears as a contiguous run inside `haystack`."""
    if not needle or len(needle) > len(haystack):
        return False
    return any(
        haystack[i:i + len(needle)] == needle
        for i in range(len(haystack) - len(needle) + 1)
    )


def best_match(title: str, candidates: list[Candidate]) -> tuple[Candidate | None, float]:
    """Highest-scoring candidate, with region and variant used as tie-breakers."""
    target = normalise(title)
    if not target:
        return None, 0.0
    target_tokens = target.split()

    scored: list[tuple[float, int, int, int, Candidate]] = []
    for candidate in candidates:
        base = normalise(candidate.base)
        score = difflib.SequenceMatcher(None, target, base).ratio()
        base_tokens = base.split()
        extra = len(base_tokens) - len(target_tokens)

        # Subtitles go missing in both directions. Our rows sometimes omit what
        # the catalogue carries ("Wave Race 64" vs "Wave Race 64 - Kawasaki Jet
        # Ski") and sometimes carry what it omits (our "Donkey Kong Country 2:
        # Diddy's Kong Quest" vs the GBA set's "Donkey Kong Country 2"). Either
        # way a clean token-run containment is a strong signal, so compare
        # whichever is shorter against whichever is longer.
        #
        # Capped below 0.95 so a genuine exact title always outranks it, and
        # scaled by coverage so the closest-length candidate wins among several
        # ("Donkey Kong Country 3" beats a bare "Donkey Kong Country").
        #
        # Guard against collapsing a sequel onto its base game. If we are asking
        # for a number the candidate does not have — "Donkey Kong Country 2"
        # against a plain "Donkey Kong Country" — containment would happily match
        # the wrong box. Extra numbers on the candidate side are fine, since that
        # is just a series prefix ("Super Mario World 2 - Yoshi's Island").
        target_numbers = {t for t in target_tokens if t.isdigit()}
        base_numbers = {t for t in base_tokens if t.isdigit()}
        sequel_mismatch = bool(target_numbers - base_numbers)

        shorter, longer = sorted((target_tokens, base_tokens), key=len)
        if extra != 0 and not sequel_mismatch and contains_tokens(longer, shorter):
            coverage = len(shorter) / len(longer)
            score = max(score, 0.88 + 0.06 * coverage)

        if score >= 0.80:
            scored.append(
                (score, -candidate.region_rank, -abs(extra), -candidate.variant_penalty, candidate)
            )

    if not scored:
        return None, 0.0

    # Similarity first, then the US release, the closest-length title, and the
    # plain variant over a revision or re-release.
    scored.sort(key=lambda t: (round(t[0], 3), t[1], t[2], t[3]), reverse=True)
    score, _, _, _, candidate = scored[0]
    return candidate, score


# --------------------------------------------------------------------------
# Main
# --------------------------------------------------------------------------

def main() -> int:
    parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument("--api", default="http://localhost:8080", help="API base URL")
    parser.add_argument("--user", default="ckoch")
    parser.add_argument("--password", required=True)
    parser.add_argument("--dry-run", action="store_true", help="report matches, change nothing")
    parser.add_argument("--overwrite", action="store_true", help="replace art that is already set")
    parser.add_argument("--min-score", type=float, default=0.80,
                        help="similarity below which a match is not applied (0-1)")
    parser.add_argument("--no-wikipedia", action="store_true",
                        help="skip the Wikipedia fallback; use libretro only")
    parser.add_argument("--cache", default=str(Path(__file__).parent / ".cache"))
    args = parser.parse_args()

    base = args.api.rstrip("/")
    cache_dir = Path(args.cache)

    print("Signing in…")
    auth = api_json(base, "/api/auth/login", data={"userName": args.user, "password": args.password})
    token = auth["token"]

    print("Fetching library…")
    games: list[dict] = []
    page = 1
    while True:
        result = api_json(base, f"/api/games?page={page}&pageSize=100", token)
        games.extend(result["items"])
        if page >= result["totalPages"] or not result["items"]:
            break
        page += 1
    print(f"  {len(games)} games\n")

    systems = sorted({g["system"] for g in games if g["system"]})
    listings: dict[str, list[Candidate]] = {}
    for system in systems:
        if system not in SYSTEM_DIRS:
            continue
        print(f"Loading {system} catalogue…", end=" ", flush=True)
        listings[system] = load_listing(system, cache_dir)
        print(f"{len(listings[system])} covers")
    print()

    applied = skipped = failed = 0
    from_wiki = 0
    weak: list[tuple[dict, str, float]] = []
    unmatched: list[dict] = []

    def attach(game: dict, blob: bytes, filename: str) -> None:
        """Upload the image and point the game at it."""
        uploaded = upload_image(base, token, filename, blob)
        payload = {k: game.get(k) for k in (
            "title", "system", "genre", "year", "developer", "publisher",
            "description", "own", "dumped", "played", "finished")}
        payload["art"] = uploaded["fileName"]
        api_json(base, f"/api/games/{game['id']}", token, data=payload, method="PUT")

    for game in sorted(games, key=lambda g: g["title"].lower()):
        title, system = game["title"], game["system"]

        if game.get("art") and not args.overwrite:
            skipped += 1
            continue

        # --- pass 1: libretro, which has the better art where it has any ----
        candidate, score = (None, 0.0)
        if system in SYSTEM_DIRS:
            candidate, score = best_match(title, listings.get(system, []))

        if candidate and score >= args.min_score:
            flag = " " if score >= 0.95 else "~"
            print(f"  {flag}  {system:4} {title[:46]:48} {score:.2f}  {candidate.filename[:50]}")
            if score < 0.95:
                weak.append((game, candidate.filename, score))

            if args.dry_run:
                applied += 1
                continue
            try:
                directory = urllib.parse.quote(candidate.directory)
                name = urllib.parse.quote(candidate.filename)
                attach(game, http(f"{THUMBNAIL_HOST}/{directory}/Named_Boxarts/{name}"),
                       candidate.filename)
                applied += 1
            except Exception as exc:  # noqa: BLE001 - report and continue
                print(f"     -> FAILED: {exc}")
                failed += 1
            continue

        # --- pass 2: Wikipedia, for anything libretro does not carry --------
        if args.no_wikipedia:
            print(f"  ?  {system:4} {title[:46]:48} no match")
            unmatched.append(game)
            failed += 1
            continue

        try:
            found = wiki_cover_url(game, cache_dir)
        except Exception as exc:  # noqa: BLE001
            print(f"  !  {system:4} {title[:46]:48} wikipedia error: {exc}")
            found = None

        if not found:
            print(f"  ?  {system:4} {title[:46]:48} no match")
            unmatched.append(game)
            failed += 1
            continue

        url, source = found
        print(f"  W  {system:4} {title[:46]:48} {source[:50]}")

        if args.dry_run:
            applied += 1
            from_wiki += 1
            continue

        try:
            attach(game, http(url, headers={"User-Agent": WIKI_UA}), url.split("/")[-1])
            applied += 1
            from_wiki += 1
        except Exception as exc:  # noqa: BLE001
            print(f"     -> FAILED: {exc}")
            failed += 1

    # ---- report ----------------------------------------------------------
    print("\n" + "=" * 72)
    verb = "would attach" if args.dry_run else "attached"
    print(f"{verb}: {applied}  (libretro {applied - from_wiki}, wikipedia {from_wiki})   "
          f"already had art: {skipped}   still missing: {failed}")

    if weak:
        print(f"\nWorth eyeballing in the UI — matched below 0.95 similarity ({len(weak)}):")
        for game, filename, score in sorted(weak, key=lambda w: w[2]):
            print(f"  {score:.2f}  {game['system']:4} {game['title'][:40]:42} -> {filename[:50]}")

    if unmatched:
        print(f"\nNo cover found from either source ({len(unmatched)}):")
        for game in unmatched:
            print(f"       {game['system'] or '-':4} {game['title']}")

    return 0


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