import fs from 'node:fs/promises';
import path from 'node:path';
import sharp from 'sharp';

const roots = ['public', path.join('src', 'assets')];

async function walk(dir) {
  const entries = await fs.readdir(dir, { withFileTypes: true });
  const files = await Promise.all(
    entries.map(async (entry) => {
      const fullPath = path.join(dir, entry.name);
      if (entry.isDirectory()) {
        return walk(fullPath);
      }
      return fullPath;
    }),
  );

  return files.flat();
}

function pickWidth(filePath) {
  const normalized = filePath.replace(/\\/g, '/');

  if (normalized.includes('/images/blog/')) return 1280;
  if (normalized.endsWith('/hero-bg.png')) return 1600;
  if (normalized.endsWith('/process-illustration.png')) return 1600;
  if (normalized.includes('/assets/services/')) return 1200;

  return 1280;
}

async function optimize(filePath) {
  const targetPath = filePath.replace(/\.png$/i, '.webp');
  const width = pickWidth(filePath);
  const image = sharp(filePath, { animated: false }).rotate();
  const metadata = await image.metadata();

  const pipeline =
    metadata.width && metadata.width > width ? image.resize({ width, withoutEnlargement: true }) : image;

  await pipeline.webp({ quality: 76, effort: 6 }).toFile(targetPath);
}

const pngFiles = (
  await Promise.all(
    roots.map(async (root) => {
      try {
        return await walk(root);
      } catch {
        return [];
      }
    }),
  )
)
  .flat()
  .filter((filePath) => filePath.toLowerCase().endsWith('.png'));

await Promise.all(pngFiles.map((filePath) => optimize(filePath)));

console.log(`Optimized ${pngFiles.length} PNG files to WebP.`);