const dgram = require('dgram');

const {
  clamp,
  createFrame,
  frameToPayload,
  hexToRgb,
  samplePalette,
  toIndex,
} = require('./shared-frame-utils');

const DEFAULT_PORT = 4210;
const DEFAULT_WIDTH = 16;
const DEFAULT_HEIGHT = 16;
const DEFAULT_INTERVAL_MS = 65;
const BAND_COUNT = 5;
const WAVE_SPEED = 0.35;
const HORIZONTAL_SWAY = 0.45;

const paletteStops = [
  { stop: 0.0, color: hexToRgb('01010a') },
  { stop: 0.2, color: hexToRgb('041332') },
  { stop: 0.4, color: hexToRgb('0c3857') },
  { stop: 0.65, color: hexToRgb('1aa07a') },
  { stop: 0.85, color: hexToRgb('68d284') },
  { stop: 1.0, color: hexToRgb('f4f5c6') },
];

const host = process.argv[2];
const port = parseInt(process.argv[3] || String(DEFAULT_PORT), 10);
const width = parseInt(process.argv[4] || String(DEFAULT_WIDTH), 10);
const height = parseInt(process.argv[5] || String(DEFAULT_HEIGHT), 10);
const intervalMs = parseInt(process.argv[6] || String(DEFAULT_INTERVAL_MS), 10);

if (!host) {
  console.error('Usage: node aurora-curtains.js <device-ip> [port] [width] [height] [interval-ms]');
  process.exit(1);
}

if (Number.isNaN(port) || Number.isNaN(width) || Number.isNaN(height) || Number.isNaN(intervalMs)) {
  console.error('Invalid numeric argument. Expected integers for port, width, height, and interval-ms.');
  process.exit(1);
}

if (width <= 0 || height <= 0) {
  console.error('Matrix dimensions must be positive integers.');
  process.exit(1);
}

const socket = dgram.createSocket('udp4');
const isBroadcast = host === '255.255.255.255' || host.endsWith('.255');
const frame = createFrame(width, height);
const bands = createBands(BAND_COUNT, width);
let timeSeconds = 0;
const frameTimeSeconds = intervalMs / 1000;

if (isBroadcast) {
  socket.bind(() => {
    socket.setBroadcast(true);
  });
}

socket.on('error', (error) => {
  console.error('Socket error:', error.message);
});

function createBands(count, matrixWidth) {
  const generatedBands = [];
  for (let index = 0; index < count; ++index) {
    generatedBands.push({
      center: Math.random() * (matrixWidth - 1),
      phase: Math.random() * Math.PI * 2,
      width: 1.2 + Math.random() * 1.8,
    });
  }
  return generatedBands;
}

function generateFrame() {
  timeSeconds += frameTimeSeconds;

  for (let row = 0; row < height; ++row) {
    const verticalRatio = row / Math.max(1, height - 1);
    for (let col = 0; col < width; ++col) {
      let intensity = 0;

      bands.forEach((band, index) => {
        const sway = Math.sin(timeSeconds * WAVE_SPEED + band.phase + verticalRatio * Math.PI * 2) * HORIZONTAL_SWAY;
        const center = band.center + sway * (index % 2 === 0 ? 1 : -1);
        const distance = Math.abs(col - center);
        const blurred = Math.exp(-(distance * distance) / (2 * band.width * band.width));
        intensity += blurred * (0.8 + Math.sin(timeSeconds * 0.4 + index) * 0.2);
      });

      const normalized = clamp(intensity / bands.length, 0, 1);
      const gradientBlend = clamp((normalized * 0.7 + verticalRatio * 0.3), 0, 1);
      frame[toIndex(col, row, width)] = samplePalette(paletteStops, gradientBlend);
    }
  }

  return frameToPayload(frame);
}

function sendFrame() {
  const payload = generateFrame();
  const message = Buffer.from(payload, 'utf8');
  socket.send(message, port, host);
}

setInterval(sendFrame, intervalMs);

console.log(
  `Streaming aurora curtains to ${host}:${port} (${width}x${height}, interval=${intervalMs}ms)`
);