#!/usr/bin/env python3
"""Listen for MIDI events via UDP and display note activity on LED matrix.

Uses RPC requests (not notifications) for reliability, with rate limiting.
"""
import socket, msgpack, time, os, re

VIZ_PORT = int(os.environ.get("VIZ_PORT", "8082"))
ROUTER_SOCK = os.environ.get("ROUTER_SOCK", "/var/run/arduino-router.sock")
DECAY_FRAMES = int(os.environ.get("DECAY_FRAMES", "8"))
MIN_INTERVAL = 1 / 15

COLS = 13
ROWS = 8

def pack_frame(pixels):
    bits = 0
    for row in range(ROWS):
        for col in range(COLS):
            if pixels[row][col]:
                bits |= 1 << (row * COLS + col)
    return (bits & 0xFFFFFFFF, (bits >> 32) & 0xFFFFFFFF,
            (bits >> 64) & 0xFFFFFFFF, (bits >> 96) & 0xFFFFFFFF)

def main():
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    sock.bind(("0.0.0.0", VIZ_PORT))
    sock.setblocking(False)

    router = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
    router.settimeout(2)
    router.connect(ROUTER_SOCK)
    packer = msgpack.Packer()

    active_notes = {}
    last_frame = None
    last_send = 0
    buf = b""
    msg_id = 0

    while True:
        now = time.monotonic()

        try:
            while True:
                data, _ = sock.recvfrom(1024)
                buf += data
        except BlockingIOError:
            pass

        while b";" in buf:
            msg, buf = buf.split(b";", 1)
            msg = msg.decode().strip()
            parts = msg.split()
            if len(parts) >= 3 and parts[0] == "midi":
                status = int(parts[1])
                note = int(parts[2])
                vel = int(parts[3]) if len(parts) >= 4 else 0
                msg_type = status & 0xF0
                if msg_type == 0x90 and vel > 0:
                    active_notes[note] = DECAY_FRAMES
                elif msg_type == 0x80 or (msg_type == 0x90 and vel == 0):
                    active_notes.pop(note, None)

        if now - last_send >= MIN_INTERVAL:
            pixels = [[0] * COLS for _ in range(ROWS)]
            for note, decay in list(active_notes.items()):
                if decay <= 0:
                    del active_notes[note]
                    continue
                active_notes[note] = decay - 1
                note_min, note_max = 36, 96
                row = 7 - int((note - note_min) / (note_max - note_min) * 7)
                row = max(0, min(7, row))
                col = note % 12
                pixels[row][col] = 1

            frame = pack_frame(pixels)
            if frame != last_frame:
                msg_id = (msg_id + 1) % 65535
                params = [str(v) for v in frame]
                req = packer.pack([0, msg_id, "draw_frame", params])
                try:
                    router.sendall(req)
                    router.settimeout(0.3)
                    router.recv(128)
                    router.settimeout(2)
                except socket.timeout:
                    pass
                except OSError:
                    router.close()
                    router = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
                    router.settimeout(2)
                    router.connect(ROUTER_SOCK)
                last_frame = frame
            last_send = now

if __name__ == "__main__":
    main()