#!/usr/bin/env python3
"""Provenance manifest of the 40250 client assets the tests and the runtime read (docs/PORT-PLAN.md 2D step 3).

Records path (relative to the Client directory) + size + sha256 for pack/Index, every .eix/.epk in pack/ and the
loose Eternexus/root/*.msm race specs. `verify` fails on a missing, changed or untracked file, so a strict
run proves it read exactly the bytes the manifest names.

  tools/asset_manifest.py generate <Client dir> [-o audit/assets/40250-client.json]
  tools/asset_manifest.py verify   <Client dir> [-m audit/assets/40250-client.json]
"""
import argparse
import hashlib
import json
import os
import sys

DEFAULT = os.path.join(os.path.dirname(__file__), "..", "audit", "assets", "40250-client.json")


def sha256(path):
    h = hashlib.sha256()
    with open(path, "rb") as f:
        for block in iter(lambda: f.read(1 << 20), b""):
            h.update(block)
    return h.hexdigest()


def tracked(client):
    files = ["pack/Index"]
    pack = os.path.join(client, "pack")
    files += sorted("pack/" + n for n in os.listdir(pack) if n.lower().endswith((".eix", ".epk")))
    root = os.path.join(client, "Eternexus", "root")
    if os.path.isdir(root):
        files += sorted("Eternexus/root/" + n for n in os.listdir(root) if n.lower().endswith(".msm"))
    return files


def entry(client, rel):
    p = os.path.join(client, rel)
    return {"path": rel, "size": os.path.getsize(p), "sha256": sha256(p)}


def generate(args):
    files = [entry(args.client, rel) for rel in tracked(args.client)]
    out = {
        "schema": 1,
        "source": "40250 Server Client TMP4/Client",
        "note": "path relative to the Client directory; regenerate with tools/asset_manifest.py generate",
        "files": files,
    }
    os.makedirs(os.path.dirname(os.path.abspath(args.output)), exist_ok=True)
    with open(args.output, "w") as f:
        json.dump(out, f, indent=1)
        f.write("\n")
    print("%d files, %d bytes -> %s" % (len(files), sum(e["size"] for e in files), args.output))
    return 0


def verify(args):
    try:
        with open(args.manifest) as f:
            want = json.load(f)["files"]
    except (OSError, ValueError, KeyError) as e:
        print("asset_manifest: cannot read manifest %s: %s" % (args.manifest, e), file=sys.stderr)
        return 1
    if not os.path.isfile(os.path.join(args.client, "pack", "Index")):
        print("asset_manifest: no pack/Index under %s" % args.client, file=sys.stderr)
        return 1
    bad = 0
    for e in want:
        p = os.path.join(args.client, e["path"])
        if not os.path.isfile(p):
            print("missing  %s" % e["path"], file=sys.stderr)
            bad += 1
        elif os.path.getsize(p) != e["size"] or sha256(p) != e["sha256"]:
            print("changed  %s" % e["path"], file=sys.stderr)
            bad += 1
    extra = sorted(set(tracked(args.client)) - {e["path"] for e in want})
    for rel in extra:
        print("untracked %s" % rel, file=sys.stderr)
    bad += len(extra)
    print("%d files checked, %d mismatch(es)" % (len(want), bad))
    return 1 if bad else 0


def main():
    ap = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
    sub = ap.add_subparsers(dest="cmd", required=True)
    g = sub.add_parser("generate")
    g.add_argument("client")
    g.add_argument("-o", "--output", default=DEFAULT)
    v = sub.add_parser("verify")
    v.add_argument("client")
    v.add_argument("-m", "--manifest", default=DEFAULT)
    args = ap.parse_args()
    return generate(args) if args.cmd == "generate" else verify(args)


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