from __future__ import annotations

import argparse
import json
from pathlib import Path

from inferscale.measurements import calibrate_measurements


def main() -> None:
    parser = argparse.ArgumentParser(description="Fit timing scale factors and validate on held-out serving measurements.")
    parser.add_argument("cases", type=Path, help="Normalized measurement_cases.json or a raw list of InferScale cases.")
    parser.add_argument("--holdout", type=float, default=0.33)
    parser.add_argument("--seed", type=int, default=7)
    parser.add_argument("--output", type=Path, default=Path("calibration_result.json"))
    args = parser.parse_args()

    payload = json.loads(args.cases.read_text())
    cases = payload.get("cases", payload) if isinstance(payload, dict) else payload
    result = calibrate_measurements(cases, args.holdout, args.seed)
    args.output.write_text(json.dumps(result, indent=2) + "\n")
    print(f"Validation mode: {result['validation_mode']}")
    print(f"Baseline MAPE: {result['baseline']['mape_pct']:.2f}%")
    print(f"Calibrated MAPE: {result['calibrated']['mape_pct']:.2f}%")
    print(f"Wrote {args.output}")


if __name__ == "__main__":
    main()