import hosts from "../utils/constants";
import TokenManager from "../api/token-manager";

export default class FileStorage {
  constructor(fs, storage) {
    this.fs = fs;
    this.tokenManager = new TokenManager(storage);
    this._queue = [];
  }

  async downloadFile(groupId, filename, chunkSize, metadata) {
    const url = `${hosts.API_HOST}/s3?name=${filename}`;
    const token = await this.tokenManager.getAccessToken();
    const { execute, cancel } = this.fs.downloadFile(filename, {
      metadata,
      url,
      chunkSize,
      headers: { Authorization: `Bearer ${token}` },
    });
    this._queue.push({ groupId, filename, cancel, type: "download" });
    const result = await execute();
    this._deleteOp(groupId, "download");
    return result;
  }

  async uploadFile(groupId, filename) {
    const token = await this.tokenManager.getAccessToken();
    const url = `${hosts.API_HOST}/s3?name=${filename}`;
    const { execute, cancel } = this.fs.uploadFile(filename, {
      url,
      headers: { Authorization: `Bearer ${token}` },
    });
    this._queue.push({ groupId, filename, cancel, type: "upload" });
    const result = await execute();
    this._deleteOp(groupId, "upload");
    return result;
  }

  async cancel(groupId, type = undefined) {
    const [op] = this._deleteOp(groupId, type);
    if (!op) return;
    await op.cancel("Operation canceled.");
  }

  _deleteOp(groupId, type = undefined) {
    const opIndex = this._queue.findIndex(
      (item) => item.groupId === groupId && (!type || item.type === type)
    );
    if (opIndex < 0) return [];
    return this._queue.splice(opIndex, 1);
  }

  readEncrypted(filename, encryptionKey, cipherData) {
    return this.fs.readEncrypted(filename, encryptionKey, cipherData);
  }

  writeEncrypted(filename, data, type, encryptionKey) {
    return this.fs.writeEncrypted(filename, {
      data,
      type,
      key: encryptionKey,
    });
  }

  async deleteFile(filename, localOnly) {
    if (localOnly) return await this.fs.deleteFile(filename);

    const token = await this.tokenManager.getAccessToken();
    const url = `${hosts.API_HOST}/s3?name=${filename}`;
    return await this.fs.deleteFile(filename, {
      url,
      headers: { Authorization: `Bearer ${token}` },
    });
  }

  /**
   *
   * @param {string} filename
   * @returns {Promise<boolean>}
   */
  exists(filename) {
    return this.fs.exists(filename);
  }

  /**
   *
   * @returns {Promise<void>}
   */
  clear() {
    return this.fs.clearFileStorage();
  }
}