Hướng Dẫn Tải File Dung Lượng Lớn Theo Chunks Bằng JavaScript

[------------- Tệp Tin 100MB Trên Đĩa Cứng -------------]
  |-- Chunk 0 (0 đến 5MB)      --> POST /upload?chunk=0
  |-- Chunk 1 (5 đến 10MB)     --> POST /upload?chunk=1
  |-- Chunk 2 (10 đến 15MB)    --> POST /upload?chunk=2
  |-- ...
  +-- Tín hiệu hoàn tất        --> POST /upload/complete

interface UploadOptions {
  file: File;
  endpoint: string;
  chunkSize?: number; // mặc định 5MB
  onProgress?: (percent: number) => void;
}

async function uploadFileInChunks({
  file,
  endpoint,
  chunkSize = 5 * 1024 * 1024,
  onProgress,
}: UploadOptions): Promise<void> {
  const totalChunks = Math.ceil(file.size / chunkSize);
  const uploadId = crypto.randomUUID();

  for (let chunkIndex = 0; chunkIndex < totalChunks; chunkIndex++) {
    const start = chunkIndex * chunkSize;
    const end = Math.min(start + chunkSize, file.size);
    const chunkBlob = file.slice(start, end);

    let success = false;
    let retries = 3;

    while (!success && retries > 0) {
      try {
        const formData = new FormData();
        formData.append('file', chunkBlob, file.name);
        formData.append('uploadId', uploadId);
        formData.append('chunkIndex', String(chunkIndex));
        formData.append('totalChunks', String(totalChunks));

        const res = await fetch(endpoint, {
          method: 'POST',
          body: formData,
        });

        if (!res.ok) throw new Error(`Upload thất bại với mã lỗi ${res.status}`);
        success = true;

        if (onProgress) {
          const percent = Math.round(((chunkIndex + 1) / totalChunks) * 100);
          onProgress(percent);
        }
      } catch (err) {
        retries--;
        if (retries === 0) throw err;
        await new Promise((r) => setTimeout(r, 1000 * (4 - retries))); // Exponential backoff
      }
    }
  }
}