#!/usr/bin/env python3
"""Print or install Pi 5 ws2812-pio overlay lines for two strips."""

from __future__ import annotations

import argparse
import sys
from pathlib import Path

CONFIG = Path("/boot/firmware/config.txt")
MARKER = "# portal ws2812 strips"


def overlay_lines(count0: int, count1: int, gpio0: int, gpio1: int) -> list[str]:
    return [
        MARKER,
        f"dtoverlay=ws2812-pio,gpio={gpio0},num_leds={count0}",
        f"dtoverlay=ws2812-pio,gpio={gpio1},num_leds={count1}",
    ]


def main() -> int:
    parser = argparse.ArgumentParser(
        description="Configure Pi 5 ws2812-pio overlays for two LED strips"
    )
    parser.add_argument("-n", type=int, nargs=2, default=[10, 10], metavar=("STRIP0", "STRIP1"))
    parser.add_argument("--gpio0", type=int, default=18, help="strip 0 data pin (default 18)")
    parser.add_argument("--gpio1", type=int, default=13, help="strip 1 data pin (default 13)")
    parser.add_argument(
        "--install",
        action="store_true",
        help="append overlay lines to /boot/firmware/config.txt (requires sudo)",
    )
    args = parser.parse_args()

    lines = overlay_lines(args.n[0], args.n[1], args.gpio0, args.gpio1)

    print("Add these lines to /boot/firmware/config.txt under [all], then reboot:\n")
    for line in lines:
        print(line)
    print(
        f"\nWiring: strip 0 DIN → GPIO {args.gpio0}, strip 1 DIN → GPIO {args.gpio1}, "
        "GND → Pi GND, 5V from external supply for long strips."
    )
    print("\nAfter reboot you should see /dev/leds0 and /dev/leds1.")

    if not args.install:
        return 0

    if not CONFIG.exists():
        print(f"Error: {CONFIG} not found", file=sys.stderr)
        return 1

    text = CONFIG.read_text()
    if MARKER in text:
        print("\nOverlay lines already present in config.txt.")
        return 0

    with CONFIG.open("a") as f:
        f.write("\n")
        for line in lines:
            f.write(line + "\n")

    print(f"\nAppended to {CONFIG}. Reboot to apply.")
    return 0


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