index.js

import sharp from "sharp";
import { existsSync, mkdirSync } from "fs";
import yargs from "yargs";
import { hideBin } from "yargs/helpers";

// Command line arguments
const argv = yargs(hideBin(process.argv))
  .option("source", {
    alias: "s",
    description: "The image source",
    type: "string",
    demandOption: true,
  })
  .option("max", {
    alias: "m",
    description: "The optimized max image width",
    type: "number",
    default: 5120,
  })
  .option("output", {
    alias: "o",
    description: "The output directory",
    type: "string",
    default: "./output",
  })
  .help()
  .alias("help", "h").argv;

// Configurations
const imageSizes = [
  320, 440, 512, 768, 1024, 1280, 1536, 1792, 2048, 2560, 3072, 3584, 5120,
];
const sourceDir = "./images";
const outputDir = argv.output;
const maxSize = argv.max;
const sourceImages = argv.source.split(",");
const sizes = imageSizes.filter((size) => size <= maxSize);

if (!existsSync(outputDir)) {
  mkdirSync(outputDir, { recursive: true });
}

// Process image metadata
function processImage(imagePath) {
  const formatRegex = /\.(jpg|jpeg|png|gif)$/i;
  const match = imagePath.match(formatRegex);

  if (match) {
    const [fullMatch, format] = match;
    const imageName = imagePath.replace(fullMatch, "");
    return { name: imageName, format };
  } else {
    console.error(`✖ Unsupported image format for ${imagePath}`);
    return null;
  }
}

// Resize images to each specified size
async function resizeImage(size, imageData) {
  const inputPath = `${sourceDir}/${imageData.name}.${imageData.format}`;
  const outputPath = `${outputDir}/${imageData.name}-${size}.${imageData.format}`;

  if (!existsSync(inputPath)) {
    console.error(`✖ Source image ${inputPath} does not exist!`);
    return;
  }

  try {
    await sharp(inputPath)
      .resize(size)
      .toFormat(imageData.format, { quality: 80 })
      .toFile(outputPath);

    console.log(
      `✓ ${imageData.name} resized to ${size} and saved to ${outputPath}`
    );
  } catch (error) {
    console.error(
      `✖ Error resizing ${imageData.name} to ${size}: ${error.message}`
    );
  }
}

// Main function to process and resize all images
(async function () {
  const imagesData = sourceImages.map(processImage).filter(Boolean); // Filter out nulls

  await Promise.all(
    imagesData.map(async (imageData) => {
      await Promise.all(sizes.map((size) => resizeImage(size, imageData)));
      console.log(
        `%c✓ ${imageData.name} optimized and resized to ${sizes.join(", ")}`,
        "color: #FFD700"
      );
    })
  );
})();