"""Verify train/val/test seed split JSON files (disjointness, counts, checksums)."""

from __future__ import annotations

import json
import sys
from pathlib import Path

ROOT = Path(__file__).resolve().parent.parent
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))

import splits  # noqa: E402


_EXPECTED_TOTAL = {"train": 2100, "val": 450, "test": 450}
_EXPECTED_PER_ARCH = {"train": 700, "val": 150, "test": 150}


def _fail(msg: str) -> None:
    print(msg, file=sys.stderr)
    sys.exit(1)


def main() -> None:
    docs: dict[str, dict] = {}
    sets_by_split: dict[str, set[int]] = {}

    for name in splits._SPLIT_NAMES:
        path = splits._split_path(name)
        if not path.is_file():
            _fail(f"missing split file: {path}")

        data = json.loads(path.read_text(encoding="utf-8"))
        docs[name] = data

        if data.get("split") != name:
            _fail(f"{path}: expected split={name!r}, got {data.get('split')!r}")
        if data.get("version") != splits.SPLIT_VERSION:
            _fail(
                f"{path}: expected version={splits.SPLIT_VERSION!r}, got {data.get('version')!r}"
            )
        if data.get("master_seed") != splits.MASTER_SEED:
            _fail(
                f"{path}: expected master_seed={splits.MASTER_SEED!r}, got {data.get('master_seed')!r}"
            )

        sb = data["seeds_by_archetype"]
        actual = splits._checksum_seeds_only(sb)
        expected = data["checksum"]
        if actual != expected:
            _fail(
                f"{path}: checksum mismatch: expected {expected!r}, got {actual!r}"
            )

        for arch in ("easy", "medium", "hard"):
            n = len(sb[arch])
            want = _EXPECTED_PER_ARCH[name]
            if n != want:
                _fail(
                    f"{path}: {arch}: expected {want} seeds, got {n}"
                )

        flat = [*sb["easy"], *sb["medium"], *sb["hard"]]
        if len(flat) != _EXPECTED_TOTAL[name]:
            _fail(
                f"{path}: expected {_EXPECTED_TOTAL[name]} total seeds, got {len(flat)}"
            )
        if len(set(flat)) != len(flat):
            _fail(f"{path}: duplicate seed within split")

        sets_by_split[name] = set(flat)

    if (
        sets_by_split["train"] & sets_by_split["val"]
        or sets_by_split["train"] & sets_by_split["test"]
        or sets_by_split["val"] & sets_by_split["test"]
    ):
        _fail("splits overlap: same seed appears in more than one split")

    union_size = len(
        sets_by_split["train"] | sets_by_split["val"] | sets_by_split["test"]
    )
    if union_size != 3000:
        _fail(f"expected 3000 globally unique seeds, got {union_size}")

    print(
        "verify_splits: OK (checksums, per-archetype counts, global disjointness)"
    )


if __name__ == "__main__":
    main()