// Generate PWA icons
const fs = require('fs');
const path = require('path');

const sizes = [192, 512];

async function main() {
  try {
    const sharp = require('sharp');
    for (const size of sizes) {
      const svg = `<svg xmlns="http://www.w3.org/2000/svg" width="${size}" height="${size}">
  <rect width="${size}" height="${size}" rx="${size * 0.1667}" fill="#0891b2"/>
  <text x="${size / 2}" y="${size * 0.7}" font-family="system-ui, sans-serif" font-size="${size * 0.6}" font-weight="bold" fill="white" text-anchor="middle">M</text>
</svg>`;
      await sharp(Buffer.from(svg)).png().toFile(path.join(__dirname, '..', 'public', `icon-${size}.png`));
      console.log(`Created icon-${size}.png`);
    }
  } catch {
    // sharp not available, create minimal valid PNG manually
    console.log('sharp not available, creating minimal PNGs');
    // Minimal 1x1 blue PNG
    for (const size of [192, 512]) {
      // Create a minimal valid PNG - will just be a solid blue square
      // PNG signature
      const sig = Buffer.from([137, 80, 78, 71, 13, 10, 26, 10]);
      // IHDR chunk
      const ihdrData = Buffer.alloc(13);
      ihdrData.writeUInt32BE(size, 0); // width
      ihdrData.writeUInt32BE(size, 4); // height
      ihdrData[8] = 8;  // bit depth
      ihdrData[9] = 2;  // color type (RGB)
      ihdrData[10] = 0; // compression
      ihdrData[11] = 0; // filter
      ihdrData[12] = 0; // interlace
      
      const ihdrLen = Buffer.alloc(4);
      ihdrLen.writeUInt32BE(13);
      const ihdrType = Buffer.from('IHDR');
      const ihdrCRC = crc32(Buffer.concat([ihdrType, ihdrData]));
      const ihdrCRCbuf = Buffer.alloc(4);
      ihdrCRCbuf.writeUInt32BE(ihdrCRC);
      
      // IDAT - raw filtered image data (each row: filter byte 0 + RGB pixels)
      const rowSize = 1 + size * 3; // filter byte + RGB per pixel
      const rawData = Buffer.alloc(rowSize * size);
      for (let y = 0; y < size; y++) {
        rawData[y * rowSize] = 0; // no filter
        for (let x = 0; x < size; x++) {
          const offset = y * rowSize + 1 + x * 3;
          rawData[offset] = 8;    // R
          rawData[offset+1] = 145; // G  
          rawData[offset+2] = 178; // B
        }
      }
      
      // Zlib compress
      const zlib = require('zlib');
      const compressed = zlib.deflateSync(rawData);
      
      const idatLen = Buffer.alloc(4);
      idatLen.writeUInt32BE(compressed.length);
      const idatType = Buffer.from('IDAT');
      const idatCRC = crc32(Buffer.concat([idatType, compressed]));
      const idatCRCbuf = Buffer.alloc(4);
      idatCRCbuf.writeUInt32BE(idatCRC);
      
      // IEND
      const iendLen = Buffer.alloc(4);
      iendLen.writeUInt32BE(0);
      const iendType = Buffer.from('IEND');
      const iendCRC = crc32(iendType);
      const iendCRCbuf = Buffer.alloc(4);
      iendCRCbuf.writeUInt32BE(iendCRC);
      
      const png = Buffer.concat([
        sig, ihdrLen, ihdrType, ihdrData, ihdrCRCbuf,
        idatLen, idatType, compressed, idatCRCbuf,
        iendLen, iendType, iendCRCbuf
      ]);
      
      fs.writeFileSync(path.join(__dirname, '..', 'public', `icon-${size}.png`), png);
      console.log(`Created icon-${size}.png (minimal)`);
    }
  }
}

function crc32(buf) {
  let crc = 0xFFFFFFFF;
  const table = new Uint32Array(256);
  for (let i = 0; i < 256; i++) {
    let c = i;
    for (let j = 0; j < 8; j++) {
      c = (c & 1) ? (0xEDB88320 ^ (c >>> 1)) : (c >>> 1);
    }
    table[i] = c;
  }
  for (let i = 0; i < buf.length; i++) {
    crc = table[(crc ^ buf[i]) & 0xFF] ^ (crc >>> 8);
  }
  return (crc ^ 0xFFFFFFFF) >>> 0;
}

main();