"""
One-shot migration: import all NewBellCurve CSV candle files into data/candles.db.

Usage:
    python -m shared.import_csv
    python -m shared.import_csv --csv-dir /path/to/other/csvs
    python -m shared.import_csv --dry-run
"""
import argparse
import logging
import re
import sys
from pathlib import Path

import pandas as pd

# Allow running from repo root or any subdirectory
sys.path.insert(0, str(Path(__file__).parent.parent))
from shared.db import upsert_candles, list_available, DB_PATH

logger = logging.getLogger(__name__)

DEFAULT_CSV_DIR = Path(__file__).parent.parent / "NewBellCurve" / "simulation" / "data"
_FILENAME_RE = re.compile(r"^([A-Z]+)_([A-Z0-9]+)\.csv$")


def import_directory(csv_dir: Path, dry_run: bool = False) -> dict[str, int]:
    csv_files = sorted(csv_dir.glob("*.csv"))
    if not csv_files:
        logger.warning("No CSV files found in %s", csv_dir)
        return {}

    results = {}
    for path in csv_files:
        m = _FILENAME_RE.match(path.name)
        if not m:
            logger.warning("Skipping unrecognised filename: %s", path.name)
            continue

        symbol, timeframe = m.group(1), m.group(2)
        df = pd.read_csv(path, parse_dates=["time"])

        if dry_run:
            logger.info("DRY RUN  %-10s %-5s  %d candles", symbol, timeframe, len(df))
            results[path.name] = len(df)
            continue

        n = upsert_candles(symbol, timeframe, df)
        logger.info("%-10s %-5s  %d candles written", symbol, timeframe, n)
        results[path.name] = n

    return results


def main():
    logging.basicConfig(level=logging.INFO, format="%(asctime)s %(message)s")
    parser = argparse.ArgumentParser(description="Import CSV candle files into shared candles.db")
    parser.add_argument("--csv-dir", default=str(DEFAULT_CSV_DIR), help="Directory of CSV files")
    parser.add_argument("--dry-run", action="store_true", help="Parse only, do not write to DB")
    args = parser.parse_args()

    csv_dir = Path(args.csv_dir)
    if not csv_dir.exists():
        logger.error("CSV directory not found: %s", csv_dir)
        sys.exit(1)

    logger.info("Importing from: %s", csv_dir)
    logger.info("Database:       %s", DB_PATH)

    results = import_directory(csv_dir, dry_run=args.dry_run)
    total = sum(results.values())
    logger.info("Done — %d files, %d candles total", len(results), total)

    if not args.dry_run:
        print("\nAvailable data in candles.db:")
        print(list_available().to_string(index=False))


if __name__ == "__main__":
    main()