#!/usr/bin/env python3
"""Explicit TRL SFT entrypoint for small/scale profiles."""

from __future__ import annotations

import argparse
import json
from pathlib import Path

import sys

ROOT = Path(__file__).resolve().parents[1]
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))

from app.training.sft_trl import SFTRunConfig, run_sft_trl


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Train SFT adapter with TRL + Unsloth.")
    parser.add_argument("--model-id", default="Qwen/Qwen2.5-1.5B-Instruct")
    parser.add_argument("--dataset-path", default="data/processed/sft_examples.json")
    parser.add_argument("--output-dir", default="checkpoints")
    parser.add_argument("--report-path", default="outputs/reports/sft_trl_run.json")
    parser.add_argument("--epochs", type=int, default=1)
    parser.add_argument("--batch-size", type=int, default=2)
    parser.add_argument("--max-steps", type=int, default=30)
    parser.add_argument("--max-seq-len", type=int, default=1024)
    parser.add_argument("--learning-rate", type=float, default=2e-5)
    parser.add_argument("--use-unsloth", action="store_true")
    parser.add_argument("--allow-fallback", action="store_true")
    return parser.parse_args()


def main() -> None:
    args = parse_args()
    root = Path(__file__).resolve().parents[1]
    cfg = SFTRunConfig(
        model_id=args.model_id,
        output_dir=root / args.output_dir,
        dataset_path=root / args.dataset_path,
        epochs=args.epochs,
        batch_size=args.batch_size,
        max_steps=args.max_steps,
        max_seq_len=args.max_seq_len,
        learning_rate=args.learning_rate,
        use_unsloth=args.use_unsloth,
        allow_fallback=args.allow_fallback,
    )
    result = run_sft_trl(cfg)
    report_path = root / args.report_path
    report_path.parent.mkdir(parents=True, exist_ok=True)
    report_path.write_text(json.dumps(result, ensure_ascii=True, indent=2), encoding="utf-8")
    print("sft_trl_done")


if __name__ == "__main__":
    main()