#!/usr/bin/env python3
"""
QR Code Generator

Reads a CSV/TSV file where:
  - First row is a header (skipped).
  - First column contains the data/text to encode into a QR code.
  - Second column contains the base name for the output PNG file.

Uses the `qrencode` command-line tool to generate QR codes.
"""

import argparse
import csv
import os
import subprocess
import sys


def main():
    parser = argparse.ArgumentParser(
        description="Generate QR codes from a data file using qrencode."
    )
    parser.add_argument(
        "input_file",
        help="Path to the input file (CSV or TSV). The first row is treated as a header and skipped.",
    )
    parser.add_argument(
        "-d",
        "--delimiter",
        default=None,
        help="Column delimiter (default: auto-detect — comma for .csv, tab otherwise).",
    )
    parser.add_argument(
        "-o",
        "--output-dir",
        default=".",
        help="Directory to write PNG files into (default: current directory).",
    )
    parser.add_argument(
        "--qrencode",
        default="qrencode",
        help="Path to the qrencode binary (default: qrencode).",
    )
    parser.add_argument(
        "--size",
        type=int,
        default=10,
        help="Module size in pixels (qrencode -s, default: 10).",
    )

    args = parser.parse_args()

    # --- auto-detect delimiter ---
    if args.delimiter is None:
        if args.input_file.lower().endswith(".csv"):
            args.delimiter = ","
        else:
            args.delimiter = "\t"

    # --- check qrencode ---
    try:
        subprocess.run(
            [args.qrencode, "--version"],
            capture_output=True,
            check=True,
        )
    except (FileNotFoundError, subprocess.CalledProcessError):
        print(
            f"Error: '{args.qrencode}' not found or not working. Install qrencode (e.g. apt install qrencode).",
            file=sys.stderr,
        )
        sys.exit(1)

    os.makedirs(args.output_dir, exist_ok=True)

    # --- read file and generate QR codes ---
    with open(args.input_file, "r", encoding="utf-8") as fh:
        reader = csv.reader(fh, delimiter=args.delimiter)
        header = next(reader)  # skip header row
        print(f"Skipped header: {header}")

        count = 0
        for row_num, row in enumerate(reader, start=2):  # row 2 = first data row
            if not row or len(row) < 2:
                print(f"Row {row_num}: skipping (needs at least 2 columns)", file=sys.stderr)
                continue

            data = row[0].strip()
            name = row[1].strip()

            if not data or not name:
                print(f"Row {row_num}: skipping (empty column)", file=sys.stderr)
                continue

            output_path = os.path.join(args.output_dir, f"{name}.png")

            cmd = [
                args.qrencode,
                "-s", str(args.size),
                "-o", output_path,
                data,
            ]

            print(f"Row {row_num}: encoding '{data}' -> {output_path}")
            subprocess.run(cmd, check=True)
            count += 1

    print(f"\nDone. Generated {count} QR code(s) in '{args.output_dir}'.")


if __name__ == "__main__":
    main()