const fs = require("fs");
const path = require("path");
const zlib = require("zlib");

function crc32(buf) {
  const table = new Int32Array(256);
  for (let i = 0; i < 256; i++) {
    let c = i;
    for (let k = 0; k < 8; k++) {
      c = (c & 1) ? (0xedb88320 ^ (c >>> 1)) : (c >>> 1);
    }
    table[i] = c;
  }
  let crc = -1;
  for (let i = 0; i < buf.length; i++) {
    crc = table[(crc ^ buf[i]) & 0xff] ^ (crc >>> 8);
  }
  return (crc ^ -1) >>> 0;
}

function makeChunk(type, data) {
  const typeBuf = Buffer.from(type, "ascii");
  const lenBuf = Buffer.alloc(4);
  lenBuf.writeUInt32BE(data.length, 0);
  const crcData = Buffer.concat([typeBuf, data]);
  const crcBuf = Buffer.alloc(4);
  crcBuf.writeUInt32BE(crc32(crcData), 0);
  return Buffer.concat([lenBuf, typeBuf, data, crcBuf]);
}

function createSolidPng(size, r, g, b) {
  const width = size;
  const height = size;
  const bitDepth = 8;
  const colorType = 2; // RGB

  const signature = Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]);

  const ihdrData = Buffer.alloc(13);
  ihdrData.writeUInt32BE(width, 0);
  ihdrData.writeUInt32BE(height, 4);
  ihdrData.writeUInt8(bitDepth, 8);
  ihdrData.writeUInt8(colorType, 9);
  ihdrData.writeUInt8(0, 10);
  ihdrData.writeUInt8(0, 11);
  ihdrData.writeUInt8(0, 12);
  const ihdrChunk = makeChunk("IHDR", ihdrData);

  const rowSize = 1 + width * 3;
  const imageData = Buffer.alloc(rowSize * height);
  for (let y = 0; y < height; y++) {
    imageData[y * rowSize] = 0;
    for (let x = 0; x < width; x++) {
      const offset = y * rowSize + 1 + x * 3;
      imageData[offset] = r;
      imageData[offset + 1] = g;
      imageData[offset + 2] = b;
    }
  }

  const compressed = zlib.deflateRawSync(imageData);
  const idatChunk = makeChunk("IDAT", compressed);
  const iendChunk = makeChunk("IEND", Buffer.alloc(0));

  return Buffer.concat([signature, ihdrChunk, idatChunk, iendChunk]);
}

const iconsDir = path.join(__dirname, "..", "src", "icons");
fs.mkdirSync(iconsDir, { recursive: true });

const sizes = [16, 48, 128];
for (const size of sizes) {
  const png = createSolidPng(size, 34, 197, 94);
  fs.writeFileSync(path.join(iconsDir, `icon${size}.png`), png);
}

console.log("Icons generated successfully");