#!/usr/bin/env python3
"""Generate bench/gold/poj-104.json from the fetched POJ-104 directory tree.

POJ-104's gold standard is structural: every pair of submissions inside the
same numbered folder solves the same algorithm and is therefore Type-4
equivalent. We materialize this as one gold entry per folder, with `files`
listing every submission's basename in that folder.

The scorer in bench/score.py treats a fold finding as covering a gold
entry if the finding's `kind` is `equiv` (or matches `kind` prefix) and
the finding's location files are a superset of the gold entry's files.
This is generous for fold (it doesn't need to find all C(n,2) pairs — one
proof per cluster is enough) which matches Zubkov 2022's clustering
evaluation methodology.
"""
from __future__ import annotations

import json
import sys
from pathlib import Path

ROOT = Path(__file__).resolve().parent.parent / "corpora" / "poj-104" / "dataset"
OUT = Path(__file__).resolve().parent / "poj-104.json"


def main() -> int:
    if not ROOT.is_dir():
        print(f"dataset not found at {ROOT}; run bench/corpora/poj-104/fetch.sh",
              file=sys.stderr)
        return 2
    expected = []
    for algo_dir in sorted(ROOT.iterdir()):
        if not algo_dir.is_dir():
            continue
        cpps = sorted(p.name for p in algo_dir.glob("*.cpp"))
        if len(cpps) < 2:
            continue
        # Gold entry: at least one cross-pair from this algorithm folder
        # must be reported by the tool as equiv.
        expected.append({
            "kind": "equiv",
            "files": [str(algo_dir.name + "/" + p) for p in cpps[:2]],
            "id": f"poj-104-algo-{algo_dir.name}",
            "description": f"Algorithm {algo_dir.name} cluster (~{len(cpps)} submissions)",
        })
    OUT.write_text(json.dumps({
        "name": "poj-104",
        "description": "POJ-104 C++ clone-detection benchmark. "
                       "Each gold entry is 'at least one cross-pair within "
                       "an algorithm folder must be flagged equivalent'.",
        "expected": expected,
    }, indent=2))
    print(f"wrote {len(expected)} gold entries → {OUT}")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())