#!/usr/bin/env python3
# classify-mods.py — seed/update mods-sides.json from jar manifests (tomllib only).
#
# Enumerates the distribution's server-required jars and, for each jar NOT already
# a key in mods-sides.json, reads META-INF/neoforge.mods.toml and derives a side
# from the minecraft/neoforge dependency `side`:
#   side == "CLIENT" -> client
#   side == "SERVER" -> server
#   "BOTH" / unspecified / no manifest / parse error -> both   (the default)
# Existing entries are PRESERVED verbatim (never clobbers human edits); only new
# jars are added. No network calls. Pure stdlib (Python 3.11+ for tomllib).
#
# Source dir resolution (first match wins):
#   1. CLI arg: classify-mods.py <forgemods-required-dir-or-dist-root>
#   2. env MODS_DIST_DIR
#   3. $DISTRIBUTION_WEB_ROOT from .env / environment
# The path may point at either the dist ROOT (…/distribution[/dist]) or directly
# at the …/servers/ulicraft-1.21.1/forgemods/required dir — both are accepted.

import glob
import json
import os
import sys
import zipfile

try:
    import tomllib
except ModuleNotFoundError:
    sys.exit("classify-mods.py requires Python 3.11+ (tomllib is stdlib)")

REPO_ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), ".."))
SIDES_JSON = os.path.join(REPO_ROOT, "mods-sides.json")
REQUIRED_SUBPATH = os.path.join("servers", "ulicraft-1.21.1", "forgemods", "required")
MANIFEST = "META-INF/neoforge.mods.toml"


def read_env_dist_root():
    """Read DISTRIBUTION_WEB_ROOT from environment, else from repo .env."""
    val = os.environ.get("DISTRIBUTION_WEB_ROOT")
    if val:
        return val
    env_path = os.path.join(REPO_ROOT, ".env")
    if os.path.isfile(env_path):
        with open(env_path, encoding="utf-8") as fh:
            for line in fh:
                line = line.strip()
                if line.startswith("DISTRIBUTION_WEB_ROOT="):
                    return line.split("=", 1)[1].strip().strip('"').strip("'")
    return None


def resolve_required_dir():
    """Resolve the forgemods/required dir from override or .env. Halt if missing."""
    src = None
    origin = None
    if len(sys.argv) > 1 and sys.argv[1]:
        src, origin = sys.argv[1], "CLI arg"
    elif os.environ.get("MODS_DIST_DIR"):
        src, origin = os.environ["MODS_DIST_DIR"], "MODS_DIST_DIR env"
    else:
        src = read_env_dist_root()
        origin = "$DISTRIBUTION_WEB_ROOT"
    if not src:
        sys.exit(
            "no source dir: pass a path, set MODS_DIST_DIR, or DISTRIBUTION_WEB_ROOT in .env"
        )
    candidates = [os.path.join(src, REQUIRED_SUBPATH), src]
    for cand in candidates:
        if os.path.isdir(cand) and os.path.basename(os.path.normpath(cand)) == "required":
            return cand, origin
    for cand in candidates:
        if os.path.isdir(cand):
            return cand, origin
    sys.exit(
        f"forgemods/required dir not found (from {origin}={src!r}). "
        f"Tried: {', '.join(candidates)}"
    )


def derive_side(jar_path):
    """Return client|server|both from the jar's minecraft/neoforge dep side."""
    try:
        with zipfile.ZipFile(jar_path) as z:
            data = z.read(MANIFEST)
        manifest = tomllib.loads(data.decode("utf-8"))
    except (KeyError, zipfile.BadZipFile, tomllib.TOMLDecodeError, OSError, UnicodeDecodeError):
        return "both"
    deps = manifest.get("dependencies", {})
    if not isinstance(deps, dict):
        return "both"
    decided = None
    for dep_list in deps.values():
        if not isinstance(dep_list, list):
            continue
        for d in dep_list:
            if not isinstance(d, dict):
                continue
            if d.get("modId") in ("minecraft", "neoforge"):
                side = d.get("side")
                if side == "CLIENT":
                    return "client"
                if side == "SERVER":
                    return "server"
                # BOTH or unspecified — keep looking; a later CLIENT/SERVER wins.
                decided = "both"
    return decided or "both"


def main():
    required_dir, origin = resolve_required_dir()
    jars = sorted(glob.glob(os.path.join(required_dir, "*.jar")))
    if not jars:
        sys.exit(f"no jars found in {required_dir} (from {origin})")

    if os.path.isfile(SIDES_JSON):
        with open(SIDES_JSON, encoding="utf-8") as fh:
            sides = json.load(fh)
        if not isinstance(sides, dict):
            sys.exit(f"{SIDES_JSON} is not a JSON object")
    else:
        sides = {}

    existing_count = len(sides)
    added = {}
    defaulted_both = []  # newly-added jars that fell back to "both"
    for jar in jars:
        name = os.path.basename(jar)
        if name in sides:
            continue
        side = derive_side(jar)
        sides[name] = side
        added[name] = side
        if side == "both":
            defaulted_both.append(name)

    # Stable, human-diffable output.
    ordered = {k: sides[k] for k in sorted(sides)}
    with open(SIDES_JSON, "w", encoding="utf-8") as fh:
        json.dump(ordered, fh, indent=2, ensure_ascii=False)
        fh.write("\n")

    # Warn about stale keys (in mods-sides.json but no jar in the dist dir).
    present = {os.path.basename(j) for j in jars}
    stale = sorted(k for k in sides if k not in present)

    counts = {"client": 0, "server": 0, "both": 0}
    for v in sides.values():
        if v in counts:
            counts[v] += 1

    print(f"source: {required_dir}  (from {origin})")
    print(f"jars in dist: {len(jars)}  |  pre-existing entries: {existing_count}  |  added: {len(added)}")
    print(f"sides totals — both: {counts['both']}  client: {counts['client']}  server: {counts['server']}")
    if added:
        print(f"\nnewly classified ({len(added)}):")
        for name, side in sorted(added.items()):
            print(f"  {side:6}  {name}")
    if defaulted_both:
        print(f"\nDEFAULTED to 'both' ({len(defaulted_both)}) — review for cosmetic-client mods:")
        for name in defaulted_both:
            print(f"  {name}")
    if stale:
        print(f"\nWARNING — {len(stale)} key(s) in mods-sides.json have no jar in the dist dir:")
        for name in stale:
            print(f"  {name}")
    print(f"\nwrote {SIDES_JSON}")


if __name__ == "__main__":
    main()