import fs from "node:fs";
import path from "node:path";
import { Readable } from "node:stream";

import { ReleaseUpdate, sanitizeFileName } from "./update-utils";

type UpdateDownloadConfig = {
  tempDirectory: string;
};

export async function downloadInstaller(update: ReleaseUpdate, config: UpdateDownloadConfig): Promise<string> {
  const safeFileName = sanitizeFileName(update.installer.name);
  const downloadDirectory = path.join(config.tempDirectory, "scoreko-updates");
  const targetPath = path.join(downloadDirectory, safeFileName);

  fs.mkdirSync(downloadDirectory, { recursive: true });

  const response = await fetch(update.installer.downloadUrl);
  if (!response.ok || !response.body) {
    throw new Error(`Could not download update installer. HTTP ${response.status}.`);
  }

  await new Promise<void>((resolve, reject) => {
    const fileStream = fs.createWriteStream(targetPath);
    const responseStream = Readable.fromWeb(response.body as Parameters<typeof Readable.fromWeb>[0]);

    responseStream.on("error", reject);
    fileStream.on("error", reject);
    fileStream.on("finish", resolve);
    responseStream.pipe(fileStream);
  });

  return targetPath;
}