export interface DownloadFileOptions {
  downloadUrl: string;
  fileName: string;
}

const isMobile =
  /Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(
    navigator.userAgent,
  );

export async function downloadBlobFile({
  downloadUrl,
  fileName,
}: DownloadFileOptions): Promise<void> {
  // Use window.open for desktop, blob download for mobile
  if (!isMobile) {
    window.open(downloadUrl, "_blank");
    return;
  }

  const response = await fetch(downloadUrl);
  const blob = await response.blob();

  const contentType: string | null = response.headers.get("Content-Type");

  const extensionMap: Record<string, string> = {
    "application/pdf": "pdf",
    "image/jpeg": "jpg",
    "image/png": "png",
    "image/gif": "gif",
    "application/zip": "zip",
    "application/vnd.openxmlformats-officedocument.wordprocessingml.document":
      "docx",
    "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet": "xlsx",
  };

  let extension = contentType ? extensionMap[contentType] : undefined;

  if (!extension) {
    const urlWithoutQuery = downloadUrl.split("?")[0];
    extension = urlWithoutQuery.includes(".")
      ? urlWithoutQuery.split(".").pop()
      : "pdf";
  }

  const blobForDownload = new Blob([blob], {
    type: "application/octet-stream",
  });
  const url = URL.createObjectURL(blobForDownload);
  const link = document.createElement("a");
  link.href = url;
  link.download = `${fileName}.${extension}`;
  document.body.appendChild(link);
  link.click();
  setTimeout(() => {
    document.body.removeChild(link);
    URL.revokeObjectURL(url);
  }, 100);
}