from __future__ import annotations

import argparse
from decimal import Decimal
from pathlib import Path

from . import _io


def _money(value: str | int | float) -> str:
    return f"{Decimal(str(value)):.2f}"


def import_usage(export: dict, fx_usd_eur: str = "0.92") -> dict:
    rate = Decimal(str(fx_usd_eur))
    records = []
    for index, row in enumerate(export.get("usage", export.get("records", [])), start=1):
        cost_usd = Decimal(str(row.get("cost_usd") or row.get("cost", "0")))
        cost_eur = (cost_usd * rate).quantize(Decimal("0.01"))
        records.append(
            {
                "id": row.get("id") or f"usage-{row['period']}-{index}",
                "period": row["period"],
                "member_id": row.get("member_id") or row.get("user_id"),
                "model": row["model"],
                "tokens": row.get("tokens", 0),
                "cost_usd": _money(cost_usd),
                "cost_eur": _money(cost_eur),
                "source": "openrouter",
            }
        )
    return {
        "version": 1,
        "fx_usd_eur": str(rate),
        "records": sorted(records, key=lambda item: (item["period"], item["id"])),
    }


def main(argv: list[str] | None = None) -> int:
    parser = argparse.ArgumentParser(description="Import OpenRouter usage export")
    parser.add_argument("--input", type=Path, required=True, help="OpenRouter JSON export")
    parser.add_argument(
        "--output",
        type=Path,
        default=Path(__file__).resolve().parent.parent.parent / "data" / "usage_records.json",
    )
    parser.add_argument("--fx-usd-eur", default="0.92")
    args = parser.parse_args(argv)

    payload = import_usage(_io.read_export(args.input), args.fx_usd_eur)
    _io.write_registry(args.output, payload)
    print(f"Wrote {len(payload['records'])} usage records → {args.output}")
    return 0


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