fn_generate_favicons

#!/usr/bin/env node

import fs from "fs";
import path from "path";
import {readFile, writeFile} from "fs/promises";
import imagemin from "imagemin";
import imageminPngquant from "imagemin-pngquant";
import sharp from "sharp";
import {optimize} from "svgo";
import png2icons from "png2icons";

const { version } = JSON.parse(fs.readFileSync(new URL('./package.json', import.meta.url), 'utf8'));

async function main() {
  const args = {};
  const cliArgs = process.argv.slice(2);

  for (let i = 0; i < cliArgs.length; i++) {
    const arg = cliArgs[i];
    switch (arg) {
    case "--png":
    case "-p":
      args.pngSrc = cliArgs[++i];
      break;
    case "--svg":
    case "-s":
      args.svgSrc = cliArgs[++i];
      break;
    case "--dist":
    case "-d":
      args.dist = cliArgs[++i];
      break;
    case "--version":
    case "-v":
      console.log(version);
      process.exit(0);
      break;
    case "--help":
    case "-h":
      console.log(`
  Usage:
    favgen [--png <path>] [--svg <path>] [--dist <output-dir>]

  PNG source is required: either pass --png flag or place favicon_src.png in current directory.

  Arguments:
    --png, -p     Path to PNG source. Defaults to "favicon_src.png".
    --svg, -s     Path to SVG source. Defaults to "favicon_src.svg".
                  If file not found, SVG processing is skipped.
    --dist, -d    Output directory. Creates temporary directory if not specified.
    --version, -v  Print version and exit.
    --help, -h    Show this help message and exit.

  Generated files:
    favicon.ico, favicon-16x16.png, favicon-32x32.png, favicon-48x48.png,
    apple-touch-icon.png, icon-192.png, icon-512.png, [favicon.svg]
      `);
      process.exit(0);
    }
  }

  const pngSrc = path.resolve(process.cwd(), args.pngSrc || "favicon_src.png");
  if (!fs.existsSync(pngSrc)) {
    console.error("PNG source file not found");
    process.exit(1);
  }
  const svgSrc = args.svgSrc
    ? path.resolve(process.cwd(), args.svgSrc)
    : path.resolve(process.cwd(), "favicon_src.svg");
  if (args.svgSrc && !fs.existsSync(svgSrc)) {
    console.error("SVG source file not found");
    process.exit(1);
  }

  const distDir = args.dist || fs.mkdtempSync(path.join(process.cwd(), "favicons_"));

  if (args.dist) {fs.mkdirSync(distDir, {recursive: true});}

  const generatedFiles = [];

  try {
    const pngBuffer = await readFile(pngSrc);
    const optimizedPng = await sharp(pngBuffer)
      .resize(256, 256, {
        fit: "contain",
        background: { r: 0, g: 0, b: 0, alpha: 0 }
      })
      .png({ compressionLevel: 9, palette: true, colors: 128 })
      .toBuffer();
    const icoBuffer = png2icons.createICO(optimizedPng, 2, 256, true);
    await writeFile(path.join(distDir, "favicon.ico"), icoBuffer);
    generatedFiles.push("favicon.ico");
  } catch (err) {
    console.error("ICO generation failed:", err.message);
  }

  const pngSizes = [
    {name: "favicon-16x16.png", size: 16},
    {name: "favicon-32x32.png", size: 32},
    {name: "favicon-48x48.png", size: 48},
    {name: "apple-touch-icon.png", size: 180},
    {name: "icon-192.png", size: 192},
    {name: "icon-512.png", size: 512}
  ];

  await Promise.all(
    pngSizes.map(async ({name, size}) => {
      try {
        const outputPath = path.join(distDir, name);
        await sharp(pngSrc)
          .resize(size, size, {
            fit: "contain",
            background: {r: 0, g: 0, b: 0, alpha: 0}
          })
          .png({compressionLevel: 6})
          .toFile(outputPath);

        await imagemin([outputPath], {
          destination: distDir,
          plugins: [imageminPngquant({quality: [0.7, 0.85]})]
        });
        generatedFiles.push(name);
      } catch (err) {
        console.error(`Failed to process ${name}:`, err.message);
      }
    })
  );

  if (fs.existsSync(svgSrc)) {
    try {
      const svgContent = await readFile(svgSrc, "utf8");
      const optimized = optimize(svgContent, { multipass: true });
      await writeFile(path.join(distDir, "favicon.svg"), optimized.data);
      generatedFiles.push("favicon.svg");
    } catch (err) {
      console.error("SVG optimization failed:", err.message);
    }
  }

  console.log(`Generated ${generatedFiles.length} files → ${distDir}`);
}

main().catch((err) => {
  console.error("Unexpected error:", err.message);
});