const dgram = require('dgram');

const DEFAULT_PORT = 4210;
const DEFAULT_WIDTH = 16;
const DEFAULT_HEIGHT = 16;
const DEFAULT_INTERVAL_MS = 60;
const DEFAULT_BLOB_COUNT = 6;
const SERPENTINE_WIRING = true;
const BASE_BLOB_SPEED = 0.18;
const PHASE_SPEED_MIN = 0.6;
const PHASE_SPEED_MAX = 1.2;

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);
const blobCount = parseInt(process.argv[7] || String(DEFAULT_BLOB_COUNT), 10);

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

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

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

if (blobCount <= 0) {
  console.error('Blob count must be a positive integer.');
  process.exit(1);
}

const totalPixels = width * height;
const socket = dgram.createSocket('udp4');
const isBroadcast = host === '255.255.255.255' || host.endsWith('.255');

const maxAxis = Math.max(width, height);
const minBlobRadius = Math.max(3, maxAxis * 0.18);
const maxBlobRadius = Math.max(minBlobRadius + 1, maxAxis * 0.38);
const frameTimeSeconds = intervalMs / 1000;

const paletteStops = [
  { stop: 0.0, color: hexToRgb('050319') },
  { stop: 0.28, color: hexToRgb('2a0c4f') },
  { stop: 0.55, color: hexToRgb('8f1f73') },
  { stop: 0.75, color: hexToRgb('ff4a22') },
  { stop: 0.9, color: hexToRgb('ff9333') },
  { stop: 1.0, color: hexToRgb('fff7b0') },
];

const blobs = createBlobs(blobCount);

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

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

function createBlobs(count) {
  const blobList = [];
  for (let index = 0; index < count; ++index) {
    const angle = Math.random() * Math.PI * 2;
    const speed = BASE_BLOB_SPEED * (0.6 + Math.random() * 0.8);
    blobList.push({
      x: Math.random() * Math.max(1, width - 1),
      y: Math.random() * Math.max(1, height - 1),
      vx: Math.cos(angle) * speed,
      vy: Math.sin(angle) * speed,
      minRadius: minBlobRadius * (0.6 + Math.random() * 0.3),
      maxRadius: maxBlobRadius * (0.8 + Math.random() * 0.4),
      intensity: 0.8 + Math.random() * 0.7,
      phase: Math.random() * Math.PI * 2,
      phaseVelocity: PHASE_SPEED_MIN + Math.random() * (PHASE_SPEED_MAX - PHASE_SPEED_MIN),
    });
  }
  return blobList;
}

function updateBlobs(deltaSeconds) {
  const maxX = Math.max(0, width - 1);
  const maxY = Math.max(0, height - 1);

  blobs.forEach((blob) => {
    blob.x += blob.vx * deltaSeconds;
    blob.y += blob.vy * deltaSeconds;

    if (blob.x < 0) {
      blob.x = -blob.x;
      blob.vx = Math.abs(blob.vx);
    } else if (blob.x > maxX) {
      blob.x = 2 * maxX - blob.x;
      blob.vx = -Math.abs(blob.vx);
    }

    if (blob.y < 0) {
      blob.y = -blob.y;
      blob.vy = Math.abs(blob.vy);
    } else if (blob.y > maxY) {
      blob.y = 2 * maxY - blob.y;
      blob.vy = -Math.abs(blob.vy);
    }

    blob.phase += blob.phaseVelocity * deltaSeconds;
  });
}

function generateFrame() {
  updateBlobs(frameTimeSeconds);

  const frame = new Array(totalPixels);

  for (let row = 0; row < height; ++row) {
    for (let col = 0; col < width; ++col) {
      const energy = calculateEnergyAt(col, row);
      const color = samplePalette(energy);
      frame[toIndex(col, row)] = color;
    }
  }

  return 'RAW:' + frame.join('');
}

function calculateEnergyAt(col, row) {
  let energy = 0;

  blobs.forEach((blob) => {
    const radius = getBlobRadius(blob);
    const dx = col - blob.x;
    const dy = row - blob.y;
    const distance = Math.hypot(dx, dy);
    const falloff = Math.max(0, 1 - distance / radius);
    energy += blob.intensity * falloff * falloff;
  });

  return clamp(energy / blobs.length, 0, 1);
}

function getBlobRadius(blob) {
  const oscillation = (Math.sin(blob.phase) + 1) * 0.5;
  return blob.minRadius + (blob.maxRadius - blob.minRadius) * oscillation;
}

function toIndex(col, row) {
  if (!SERPENTINE_WIRING || row % 2 === 0) {
    return row * width + col;
  }
  return row * width + (width - 1 - col);
}

function samplePalette(value) {
  const clampedValue = clamp(value, 0, 1);

  for (let index = 0; index < paletteStops.length - 1; ++index) {
    const left = paletteStops[index];
    const right = paletteStops[index + 1];
    if (clampedValue <= right.stop) {
      const span = right.stop - left.stop || 1;
      const t = clamp((clampedValue - left.stop) / span, 0, 1);
      const interpolatedColor = lerpRgb(left.color, right.color, t);
      return rgbToHex(interpolatedColor);
    }
  }

  return rgbToHex(paletteStops[paletteStops.length - 1].color);
}

function lerpRgb(lhs, rhs, t) {
  return {
    r: Math.round(lhs.r + (rhs.r - lhs.r) * t),
    g: Math.round(lhs.g + (rhs.g - lhs.g) * t),
    b: Math.round(lhs.b + (rhs.b - lhs.b) * t),
  };
}

function hexToRgb(hex) {
  const normalizedHex = hex.trim().toLowerCase();
  const value = normalizedHex.startsWith('#') ? normalizedHex.slice(1) : normalizedHex;
  return {
    r: parseInt(value.slice(0, 2), 16),
    g: parseInt(value.slice(2, 4), 16),
    b: parseInt(value.slice(4, 6), 16),
  };
}

function rgbToHex(rgb) {
  return toHex(rgb.r) + toHex(rgb.g) + toHex(rgb.b);
}

function toHex(value) {
  const boundedValue = clamp(Math.round(value), 0, 255);
  const hex = boundedValue.toString(16);
  return hex.length === 1 ? '0' + hex : hex;
}

function clamp(value, min, max) {
  return Math.max(min, Math.min(max, value));
}

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

setInterval(sendFrame, intervalMs);

console.log(
  `Streaming lava lamp to ${host}:${port} (${width}x${height}, interval=${intervalMs}ms, blobs=${blobCount})`,
);