osclient.py

#!/usr/bin/env python3
"""OSRS Official client auto-update launcher for rs3tk.

Uses Jagex Direct6 CDN with piece-based download.
"""

import base64
import gzip
import json
import os
import shutil
import sys
import urllib.request
from pathlib import Path

DIRECT6_URL = "https://jagex.akamaized.net/direct6/"
META_PATH = "osrs-win"
UA = "OSRS-client/1.0"


def fetch(url: str) -> bytes:
    req = urllib.request.Request(url, headers={"User-Agent": UA})
    with urllib.request.urlopen(req, timeout=30) as r:
        data: bytes = r.read()
        return data


def fetch_jwt(url: str) -> dict[str, object]:
    raw = fetch(url).decode("ascii").strip()
    b64 = raw.split(".")[1]
    pad = 4 - len(b64) % 4
    if pad != 4:
        b64 += "=" * pad
    result: dict[str, object] = json.loads(base64.urlsafe_b64decode(b64))
    return result


def download_client(target: Path, version_file: Path) -> None:
    meta = fetch_jwt(f"{DIRECT6_URL}{META_PATH}/{META_PATH}.json")
    prod = meta.get("environments", {}).get("production", {})
    meta_id = prod.get("id", "")
    version = prod.get("version", "")
    if not meta_id:
        print("Could not determine latest version", file=sys.stderr)
        sys.exit(1)

    if target.exists() and version_file.exists() and version_file.read_text().strip() == version:
        print(f"OSRS {version} \u2014 up to date")
        return

    print(f"New version: {version}, downloading...")

    catalog = fetch_jwt(f"{DIRECT6_URL}{META_PATH}/catalog/{meta_id}/catalog.json")
    mf_url = catalog.get("metafile") or catalog.get("metaFile", "")
    if not mf_url.startswith("http"):
        mf_url = f"{DIRECT6_URL}{META_PATH}/{mf_url.lstrip('/')}"

    metafile = fetch_jwt(mf_url)
    exe = next((f for f in metafile.get("files", []) if f["name"].endswith(".exe")), None)
    if not exe:
        print("No executable found in metafile", file=sys.stderr)
        sys.exit(1)

    base = catalog.get("config", {}).get("remote", {}).get("baseUrl", "")
    fmt = catalog.get("config", {}).get("remote", {}).get("pieceFormat", "{TargetDigest}")
    pieces = metafile.get("pieces", metafile.get("chunks", {}))
    if isinstance(pieces, dict) and "digests" in pieces:
        digests = pieces["digests"]
    elif isinstance(pieces, list):
        digests = pieces
    else:
        digests = []

    exe_off = sum(f.get("size", 0) for f in metafile.get("files", []) if not f["name"].endswith(".exe"))

    assembled = b""
    for d in digests:
        ds = d.get("digest", "") if isinstance(d, dict) else str(d)
        if not ds or len(ds) < 2:
            continue
        try:
            hd = base64.b64decode(ds).hex()
        except Exception:
            hd = ds
        url = base + fmt.replace("{SubString:0,2,{TargetDigest}}", hd[:2]).replace("{TargetDigest}", hd)
        raw = fetch(url)
        try:
            assembled += gzip.decompress(raw[6:])
        except Exception:
            assembled += raw

    exe_bytes = assembled[exe_off : exe_off + exe.get("size", 0)] if exe.get("size") else assembled

    tmp = target.with_suffix(".exe.tmp")
    tmp.write_bytes(exe_bytes)
    tmp.rename(target)
    target.chmod(0o755)
    version_file.write_text(version)
    print(f"OSRS {version} installed")


def main() -> None:
    d = Path(__file__).resolve().parent
    exe = d / "osclient.exe"
    version_file = d / ".version"

    download_client(exe, version_file)

    wine = shutil.which("umu-run") or shutil.which("wine")
    if not wine:
        print("wine or umu-run not found in PATH", file=sys.stderr)
        sys.exit(1)

    env = os.environ.copy()
    env.setdefault("WINEPREFIX", str(d / "prefix"))
    env["GAMEID"] = "1343370"
    env["PROTONPATH"] = "GE-Latest"
    env["PROTON_VERB"] = "runinprefix"

    os.execve(wine, [wine, str(exe), *sys.argv[1:]], env)


if __name__ == "__main__":
    main()