const maxCanvasDimension = 16_384;
const maxCanvasPixels = 64 * 1024 * 1024;
const maxProcessingPixels = 24 * 1024 * 1024;

export function assertCanvasRasterSize(width: number, height: number, label = "Image") {
  assertRasterSize(width, height, maxCanvasPixels, label);
}

export function assertProcessingRasterSize(width: number, height: number, label = "Image") {
  assertRasterSize(width, height, maxProcessingPixels, label);
}

function assertRasterSize(width: number, height: number, maxPixels: number, label: string) {
  const w = Math.round(width);
  const h = Math.round(height);
  if (!Number.isSafeInteger(w) || !Number.isSafeInteger(h) || w <= 0 || h <= 0) throw new Error(`${label} dimensions are invalid.`);
  if (w > maxCanvasDimension || h > maxCanvasDimension || w * h > maxPixels) {
    throw new Error(`${label} is too large (${w} x ${h}). Maximum processing size is ${maxCanvasDimension} px per side and ${Math.floor(maxPixels / 1_000_000)} megapixels.`);
  }
}