#!/usr/bin/env python3
"""
Import Einsätze from FF-Agent CSV export and write JSON in the same format
as fetch_einsaetze.py (for use by the ticker backend).
CSV format: semicolon-delimited, quoted fields, header row.
"""

import argparse
import csv
import json
import logging
import sys
from datetime import datetime, timezone
from pathlib import Path
from typing import List

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s %(levelname)s %(message)s",
    datefmt="%Y-%m-%d %H:%M:%S",
)
logger = logging.getLogger(__name__)

ENCODINGS = ("utf-8-sig", "utf-8", "cp1252")


def detect_encoding(path: Path) -> str:
    """Try to read first bytes and return encoding that works for the header."""
    raw = path.read_bytes()
    for enc in ENCODINGS:
        try:
            raw.decode(enc)
            return enc
        except UnicodeDecodeError:
            continue
    return "utf-8"


def parse_csv(path: str) -> List[dict]:
    """
    Parse semicolon-delimited CSV with quoted fields.
    Returns list of row dicts; keys are header names (quotes stripped).
    """
    p = Path(path)
    if not p.is_file():
        raise FileNotFoundError(f"CSV file not found: {path}")

    encoding = detect_encoding(p)
    logger.info("Using encoding: %s", encoding)

    with open(p, "r", encoding=encoding, newline="") as f:
        reader = csv.reader(f, delimiter=";", quotechar='"')
        rows = list(reader)

    if not rows:
        raise ValueError("CSV file is empty")

    header = [cell.strip('"') for cell in rows[0]]
    einsaetze = []
    for row in rows[1:]:
        # Pad row to header length so we don't lose columns
        while len(row) < len(header):
            row.append("")
        record = {}
        for i, key in enumerate(header):
            value = row[i].strip('"') if i < len(row) else ""
            record[key] = value
        # Skip completely empty rows
        if any(v for v in record.values()):
            einsaetze.append(record)

    return einsaetze


def write_json(einsaetze: List[dict], output_path: str) -> None:
    """Write einsaetze to JSON with updated timestamp. Creates parent dir if needed."""
    out = Path(output_path)
    out.parent.mkdir(parents=True, exist_ok=True)
    payload = {
        "einsaetze": einsaetze,
        "updated": datetime.now(timezone.utc).isoformat(),
    }
    with open(out, "w", encoding="utf-8") as f:
        json.dump(payload, f, ensure_ascii=False, indent=2)
    logger.info("Wrote %d Einsätze to %s", len(einsaetze), output_path)


def main() -> int:
    parser = argparse.ArgumentParser(
        description="Import FF-Agent CSV export and output JSON for ticker backend."
    )
    parser.add_argument(
        "input",
        nargs="?",
        default=None,
        help="Input CSV file path",
    )
    parser.add_argument(
        "--output",
        "-o",
        default="data/einsaetze.json",
        help="Output JSON path (default: data/einsaetze.json)",
    )
    args = parser.parse_args()

    if not args.input:
        parser.error("Input CSV path required (or pass as positional argument)")
        return 1

    try:
        einsaetze = parse_csv(args.input)
        write_json(einsaetze, args.output)
        return 0
    except (FileNotFoundError, ValueError) as e:
        logger.error("%s", e)
        return 1


if __name__ == "__main__":
    sys.exit(main())