// Generate PNG icons for the Chrome extension
import { writeFileSync, mkdirSync } from 'fs';
import { join, dirname } from 'path';
import { fileURLToPath } from 'url';
import zlib from 'zlib';

const __dirname = dirname(fileURLToPath(import.meta.url));
const iconsDir = join(__dirname, '..', 'src', 'icons');
mkdirSync(iconsDir, { recursive: true });

function crc32(buf) {
  var crc = 0xFFFFFFFF;
  for (var i = 0; i < buf.length; i++) {
    crc ^= buf[i];
    for (var j = 0; j < 8; j++) {
      crc = (crc >>> 1) ^ (crc & 1 ? 0xEDB88320 : 0);
    }
  }
  return (crc ^ 0xFFFFFFFF) >>> 0;
}

function makeChunk(type, data) {
  var len = Buffer.alloc(4);
  len.writeUInt32BE(data.length, 0);
  var typeBuffer = Buffer.from(type, 'ascii');
  var crcData = Buffer.concat([typeBuffer, data]);
  var crc = crc32(crcData);
  var crcBuf = Buffer.alloc(4);
  crcBuf.writeUInt32BE(crc, 0);
  return Buffer.concat([len, typeBuffer, data, crcBuf]);
}

function createPNG(width, height) {
  var signature = Buffer.from([137, 80, 78, 71, 13, 10, 26, 10]);
  var ihdrData = Buffer.alloc(13);
  ihdrData.writeUInt32BE(width, 0);
  ihdrData.writeUInt32BE(height, 4);
  ihdrData[8] = 8; ihdrData[9] = 2; ihdrData[10] = 0; ihdrData[11] = 0; ihdrData[12] = 0;
  var ihdr = makeChunk('IHDR', ihdrData);

  var rawData = [];
  var cx = width / 2, cy = height / 2;
  var maxDist = Math.sqrt(cx * cx + cy * cy);
  var innerR = Math.min(width, height) * 0.35;
  var handleR = Math.min(width, height) * 0.08;

  for (var y = 0; y < height; y++) {
    rawData.push(0); // filter byte
    for (var x = 0; x < width; x++) {
      var dist = Math.sqrt((x - cx) * (x - cx) + (y - cy) * (y - cy));
      var t = dist / maxDist;

      // Background gradient: #667eea to #764ba2
      var bgR = Math.round(102 * (1 - t) + 118 * t);
      var bgG = Math.round(126 * (1 - t) + 75 * t);
      var bgB = Math.round(234 * (1 - t) + 162 * t);

      var pr = bgR, pg = bgG, pb = bgB;

      // White circle (magnifying glass lens)
      if (dist < innerR) {
        pr = 255; pg = 255; pb = 255;
        // Inner dark ring (lens border)
        if (dist > innerR * 0.8) {
          pr = 80; pg = 80; pb = 120;
        }
      }

      // Handle (bottom-right diagonal)
      var handleStart = innerR * 0.9;
      var handleLen = maxDist * 0.5;
      var hx = x - cx, hy = y - cy;
      var proj = (hx + hy) / Math.sqrt(2);
      var perp = Math.abs(hx - hy) / Math.sqrt(2);
      if (proj > handleStart && proj < handleStart + handleLen && perp < handleR) {
        pr = 200; pg = 200; pb = 220;
      }

      rawData.push(pr, pg, pb);
    }
  }

  var deflated = zlib.deflateSync(Buffer.from(rawData));
  var idat = makeChunk('IDAT', deflated);
  var iend = makeChunk('IEND', Buffer.alloc(0));
  return Buffer.concat([signature, ihdr, idat, iend]);
}

var sizes = [16, 48, 128];
sizes.forEach(function (size) {
  var png = createPNG(size, size);
  var filepath = join(iconsDir, 'icon-' + size + '.png');
  writeFileSync(filepath, png);
  console.log('Created ' + filepath + ' (' + png.length + ' bytes)');
});
console.log('Icons generated.');