import sharp from 'sharp';
import { readdir, stat, rename } from 'fs/promises';
import { join, extname, basename, dirname } from 'path';

const IMG_DIR = 'public/images';
const MAX_WIDTH = 1920;
const QUALITY = 80;
const EXTENSIONS = new Set(['.jpg', '.jpeg', '.png']);

async function getImages(dir) {
  const entries = await readdir(dir, { withFileTypes: true });
  const files = [];
  for (const entry of entries) {
    const fullPath = join(dir, entry.name);
    if (entry.isDirectory()) {
      files.push(...await getImages(fullPath));
    } else if (EXTENSIONS.has(extname(entry.name).toLowerCase())) {
      files.push(fullPath);
    }
  }
  return files;
}

async function optimizeImage(filePath) {
  const ext = extname(filePath).toLowerCase();
  const dir = dirname(filePath);
  const name = basename(filePath, ext);
  const webpPath = join(dir, `${name}.webp`);

  const before = (await stat(filePath)).size;

  try {
    const image = sharp(filePath);
    const metadata = await image.metadata();

    // Resize if wider than MAX_WIDTH
    const resizeOpts = metadata.width > MAX_WIDTH ? { width: MAX_WIDTH } : {};

    // Create WebP version
    await image
      .resize(resizeOpts)
      .webp({ quality: QUALITY })
      .toFile(webpPath);

    // Also optimize the original JPEG in-place (for fallback)
    const optimizedJpeg = await sharp(filePath)
      .resize(resizeOpts)
      .jpeg({ quality: QUALITY, mozjpeg: true })
      .toBuffer();

    // Write optimized JPEG back
    const { writeFile } = await import('fs/promises');
    await writeFile(filePath, optimizedJpeg);

    const afterJpeg = (await stat(filePath)).size;
    const afterWebp = (await stat(webpPath)).size;
    const saved = ((before - afterWebp) / before * 100).toFixed(0);

    console.log(`✓ ${filePath} — ${(before/1024).toFixed(0)}KB → ${(afterWebp/1024).toFixed(0)}KB WebP (${saved}% saved)`);
  } catch (err) {
    console.error(`✗ ${filePath}: ${err.message}`);
  }
}

const images = await getImages(IMG_DIR);
console.log(`Found ${images.length} images to optimize...\n`);

// Process in batches of 8 for memory
const BATCH = 8;
for (let i = 0; i < images.length; i += BATCH) {
  await Promise.all(images.slice(i, i + BATCH).map(optimizeImage));
}

console.log('\nDone!');