import sharp from 'sharp';

export function createSharpImageRenderer() {
  return async function renderDerivative({ data, maxWidth }) {
    if (!Buffer.isBuffer(data)) {
      throw new TypeError('Image data must be provided as a Buffer.');
    }

    if (!Number.isInteger(maxWidth) || maxWidth <= 0) {
      throw new TypeError('maxWidth must be a positive integer.');
    }

    const image = sharp(data);
    const metadata = await image.metadata();

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

    return resized.webp().toBuffer();
  };
}