#!/usr/bin/env python3
"""Two strips showing different patterns at the same time."""

import argparse
import sys
import time

from leds import LedStrips, board_family, board_model, default_dual_strip_configs, pi5_setup_hint


def _describe(cfg) -> str:
    if cfg.backend == "pio":
        return f"GPIO {cfg.pin} → {cfg.device}"
    if cfg.backend == "ws281x":
        return f"GPIO {cfg.pin} (channel {cfg.channel})"
    return f"/dev/spidev{cfg.spi_bus}.{cfg.spi_device}"


def _wheel(pos: int) -> tuple[int, int, int]:
    pos = pos % 256
    if pos < 85:
        return (255 - pos * 3, pos * 3, 0)
    if pos < 170:
        pos -= 85
        return (0, 255 - pos * 3, pos * 3)
    pos -= 170
    return (pos * 3, 0, 255 - pos * 3)


def chase(strip, color: tuple[int, int, int], step: int) -> None:
    count = len(strip)
    strip.fill((0, 0, 0))
    strip[step % count] = color


def rainbow(strip, offset: int) -> None:
    for i in range(len(strip)):
        strip[i] = _wheel(offset + i * 256 // max(len(strip), 1))


def main() -> int:
    parser = argparse.ArgumentParser(description="WS2812 dual-strip demo")
    parser.add_argument(
        "-n",
        "--count",
        type=int,
        nargs=2,
        default=[200, 200],
        metavar=("STRIP0", "STRIP1"),
        help="LED count per strip (default: 10 10)",
    )
    parser.add_argument(
        "--brightness",
        type=float,
        default=0.25,
        help="brightness 0.0-1.0 (default: 0.25)",
    )
    args = parser.parse_args()

    print(f"Board: {board_model()}")
    cfg0, cfg1 = default_dual_strip_configs(
        args.count[0], args.count[1], brightness=args.brightness
    )
    print(f"Strip 0: {cfg0.backend} → {_describe(cfg0)}  (red chase)")
    print(f"Strip 1: {cfg1.backend} → {_describe(cfg1)}  (rainbow)")

    step = 0
    try:
        with LedStrips(args.count[0], args.count[1], brightness=args.brightness) as strips:
            while True:
                # strip 0: red dot chasing along the strip
                chase(strips[0], (255, 0, 0), step)

                # strip 1: rainbow scroll — completely independent
                rainbow(strips[1], step * 4)

                strips.show()
                step += 1
                time.sleep(0.05)
    except KeyboardInterrupt:
        print("\nStopped.")
        return 0
    except FileNotFoundError as exc:
        print(f"Error: {exc}", file=sys.stderr)
        if board_family() == "pi5":
            print("\n" + pi5_setup_hint(args.count[0], args.count[1]), file=sys.stderr)
        return 1
    except OSError as exc:
        print(f"Error: {exc}", file=sys.stderr)
        if board_family() == "pi5" and "No such file" in str(exc):
            print("\n" + pi5_setup_hint(args.count[0], args.count[1]), file=sys.stderr)
        return 1
    except Exception as exc:
        print(f"Error: {exc}", file=sys.stderr)
        return 1


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