export async function imageSourceToDataUrl(source: string): Promise<string> {
  if (source.startsWith("data:")) return source;
  const image = await loadImage(source);
  const canvas = document.createElement("canvas");
  canvas.width = image.naturalWidth;
  canvas.height = image.naturalHeight;
  const context = canvas.getContext("2d");
  if (!context) throw new Error("Unable to read selected image");
  context.drawImage(image, 0, 0);
  return canvas.toDataURL("image/png");
}

export function loadImageSize(source: string): Promise<{ w: number; h: number }> {
  return loadImage(source).then((image) => ({ w: image.naturalWidth, h: image.naturalHeight }));
}

function loadImage(source: string): Promise<HTMLImageElement> {
  return new Promise((resolve, reject) => {
    const image = new Image();
    image.onload = () => resolve(image);
    image.onerror = () => reject(new Error("Failed to load image"));
    image.src = source;
  });
}