"""Interactive zone mapper: lights one LED slot at a time in white (all others
off) and records which keys you see lit. Results go to tools/zone_map.json.

    .venv\\Scripts\\python tools\\zone_walk.py            # slots 0..19
    .venv\\Scripts\\python tools\\zone_walk.py --start 5  # resume from slot 5
"""
import argparse
import json
import pathlib
import threading
import time

import eve

OUT = pathlib.Path(__file__).with_name("zone_map.json")


class Streamer(threading.Thread):
    """Keeps re-sending the current frame so the keyboard never times out."""

    def __init__(self, total, fps=10):
        super().__init__(daemon=True)
        self.colors = [(0, 0, 0)] * total
        self.fps = fps
        self.lock = threading.Lock()
        self.running = True

    def set(self, colors):
        with self.lock:
            self.colors = list(colors)

    def run(self):
        dev = eve.open_device()
        dev.set_nonblocking(True)
        try:
            while self.running:
                with self.lock:
                    packets = eve.build_packets(self.colors)
                for p in packets:
                    dev.write(p)
                while dev.read(eve.REPORT_LEN):
                    pass
                time.sleep(1 / self.fps)
        finally:
            dev.close()


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--start", type=int, default=0)
    ap.add_argument("--total", type=int, default=20)
    args = ap.parse_args()

    results = json.loads(OUT.read_text()) if OUT.exists() else {}
    streamer = Streamer(args.total)
    streamer.start()

    print("For each slot, type the keys that are lit (e.g. 'Esc, F1-F4, ~ 1 2 Tab Q')")
    print("Just press Enter if NOTHING is lit.  Type q to stop.\n")
    try:
        for slot in range(args.start, args.total):
            colors = [(0, 0, 0)] * args.total
            colors[slot] = (255, 255, 255)
            streamer.set(colors)
            answer = input(f"Slot {slot:2} lit white -> which keys? ").strip()
            if answer.lower() == "q":
                break
            results[str(slot)] = answer or "(nothing)"
            OUT.write_text(json.dumps(results, indent=2))
    finally:
        streamer.running = False
        streamer.join(timeout=2)

    print(f"\nSaved to {OUT}")


if __name__ == "__main__":
    main()