export type BrowserImageFile = {
  name: string;
  mimeType: string;
  source: string;
  intrinsicSize: { w: number; h: number };
  release(): void;
};

export async function decodeBrowserImageFile(file: File): Promise<BrowserImageFile | undefined> {
  if (!file.type.startsWith("image/")) return undefined;
  if (file.size > 128 * 1024 * 1024) throw new Error("Image file is too large. The import limit is 128 MB.");
  const objectUrl = URL.createObjectURL(file);
  let intrinsicSize: { w: number; h: number };
  try {
    intrinsicSize = await loadImageSize(objectUrl);
    assertCanvasRasterSize(intrinsicSize.w, intrinsicSize.h, "Imported image");
  } finally {
    URL.revokeObjectURL(objectUrl);
  }
  const source = await fileToDataUrl(file);
  return { name: file.name, mimeType: file.type, source, intrinsicSize, release: () => undefined };
}

function fileToDataUrl(file: File): Promise<string> {
  return new Promise((resolve, reject) => {
    const reader = new FileReader();
    reader.onload = () => typeof reader.result === "string" ? resolve(reader.result) : reject(new Error("Failed to read image file"));
    reader.onerror = () => reject(reader.error ?? new Error("Failed to read image file"));
    reader.readAsDataURL(file);
  });
}

function loadImageSize(source: string): Promise<{ w: number; h: number }> {
  return new Promise((resolve, reject) => {
    const image = new Image();
    image.onload = () => resolve({ w: image.naturalWidth, h: image.naturalHeight });
    image.onerror = () => reject(new Error("Failed to load image"));
    image.src = source;
  });
}
import { assertCanvasRasterSize } from "./rasterLimits";