Function downloadFile

src/files/download.ts:12–108

(
  url: string,
  destPath: string,
  opts?: DownloadOpts,
)

}

export async function downloadFile(
  url: string,
  destPath: string,
  opts?: DownloadOpts,
): Promise<{ size: number }> {
  // Fix: Alibaba Cloud OSS US East blocks HTTP from certain regions.
  // Force HTTPS to ensure reliable downloads.
  const downloadUrl = url.startsWith('http://') ? url.replace('http://', 'https://') : url;
  const maxRetries = opts?.retries ?? 3;
  const baseDelay = opts?.retryDelayMs ?? 1000;
  let lastError: Error | undefined;

  for (let attempt = 0; attempt <= maxRetries; attempt++) {
    try {
      if (attempt > 0) {
        const delay = baseDelay * Math.pow(2, attempt - 1);
        if (!opts?.quiet) {
          process.stderr.write(`\n  Retry ${attempt}/${maxRetries} in ${delay}ms...\n`);
        }
        await new Promise(r => setTimeout(r, delay));
      }

      const res = await fetch(downloadUrl);

      if (!res.ok) {
        throw new CLIError(`Download failed: HTTP ${res.status}`, ExitCode.GENERAL);
      }

      const contentLength = Number(res.headers.get('content-length') || 0);
      const reader = res.body?.getReader();
      if (!reader) throw new CLIError('No response body', ExitCode.GENERAL);

      const tmpPath = `${destPath}.tmp-${process.pid}-${Date.now()}-${attempt}-${Math.random().toString(36).slice(2)}`;
      const writer = createWriteStream(tmpPath);
      const progress = contentLength > 0 && !opts?.quiet
        ? createProgressBar(contentLength, 'Downloading')
        : null;

      let received = 0;
      let readComplete = false;
      let completed = false;

      try {
        const writeError = new Promise<never>((_, reject) => {
          writer.on('error', reject);
        });

        while (true) {
          const { done, value } = await Promise.race([
            reader.read(),
            writeError,
          ]) as ReadableStreamReadResult<Uint8Array>;
          if (done) break;

          const ok = writer.write(value);
          if (!ok) await new Promise(r => writer.once('drain', r));

          received += value.byteLength;