SecureFileWrapper/src/index.ts

import { Observable, Lock } from "@hibas123/utils";
//this references global on node and window in browser
const fetch = typeof window !== "undefined" && typeof window.fetch !== undefined ? window.fetch : require("cross-fetch").default;

export interface IFileVersion {
   version: string;
   time: Date;
   preview: string;
   deleted: boolean;
}

export interface IFile {
   _id: string;
   type: string;
   name: string;
   folder: string;
   deleted: boolean;
   active: IFileVersion;
   versions: IFileVersion[];
   user: string;
   application: string;
}

export interface IHistory {
   file: IFile;
   history: IFileVersion[];
}


export class NoConnection extends Error {
   type: string;
   constructor() {
      super("No connection");
      this.type = "noconnection"
   }
}

export class Unauthorized extends Error {
   type: string;
   constructor() {
      super("Not authorized");
      this.type = "unauthorized"
   }
}

export class NoPermission extends Error {
   type: string;
   constructor() {
      super("No permission");
      this.type = "nopermission"
   }
}

export class NotFound extends Error {
   type: string;
   constructor() {
      super("Not found");
      this.type = "notfound"
   }
}

export class BadRequest extends Error {
   type: string;
   constructor() {
      super("Bad request");
      this.type = "badrequest"
   }
}

function statusParser(res: Response) {
   if (res.status !== 200) {
      switch (res.status) {
         case 400:
            throw new BadRequest();
         case 404:
            throw new NotFound();
         case 403:
            throw new NoPermission();
         case 401:
            throw new Unauthorized();
         default:
            throw new Error(res.statusText);
      }
   }
}

export type JWTCallback = (err: Error | null | string, jwt: string) => void;

export default class SecureFileWrapper {
   private _jwtObservableServer: Observable<JWTCallback> = new Observable();
   jwtObservable = this._jwtObservableServer.getPublicApi();

   private jwt: string;

   private auth_lock = new Lock();

   constructor(private server: string) {
      if (this.server.endsWith("/")) {
         this.server += "api/v1";
      } else {
         this.server += "/api/v1";
      }
   }

   public async getJWT() {
      if (!this.auth_lock.locked) {
         let lock = await this.auth_lock.getLock();
         await new Promise((yes, no) => {
            this._jwtObservableServer.send((err: Error | null | string, jwt: string) => {
               if (err) {
                  this.jwt = undefined;
                  no(err);
               }
               else {
                  this.jwt = jwt;
                  yes();
               }
            });
         }).finally(() => lock.release())
      }

      await this.auth_lock.getLock().then(lock => lock.release())
   }

   public async makeRequest(endpoint: string, method: "POST" | "GET" | "PUT" | "DELETE", query: any, body?: ArrayBuffer | ArrayBufferView, second = false) {
      if (!this.jwt || this.jwt === undefined) {
         await this.getJWT();
      }

      let query_str = "?";
      let first = true;
      for (let key in query) {
         if (!first) query_str += "&";
         query_str += encodeURIComponent(key) + "=" + encodeURIComponent(query[key]);
         first = false;
      }
      var headers = {
         "pragma": "no-cache",
         "cache-control": "no-cache",
         "x-jwt": this.jwt
      };

      if (body) {
         headers["Content-Type"] = "application/octet-stream"
      }
      try {
         let res = await fetch(this.server + endpoint + query_str, { method, body, headers });
         if (res.status === 401 && !second) {
            await this.getJWT();
            return this.makeRequest(endpoint, method, query, body, true);
         } else {
            statusParser(res);
            return res;
         }
      } catch (err) {
         if (err instanceof TypeError || err.errno === "ECONNREFUSED")
            throw new NoConnection();
         throw err;
      }
   }

   private fixIFileVersion(version: IFileVersion): IFileVersion {
      version.time = new Date(version.time)
      return version;
   }

   private fixIFile(file: IFile): IFile {
      file.active.time = new Date(file.active.time)
      if (file.versions) {
         file.versions = file.versions.map(e => this.fixIFileVersion(e))
      }
      return file;
   }

   // async test(jwt): Promise<{ user: string, test: true }> {
   //    let res = await this.makeRequest("/test", "GET", {}, undefined, this.jwt_enabled);
   //    statusParser(res);
   //    return await res.json();
   // }

   async list(folder?: string): Promise<IFile[]> {
      let query: any = {}
      if (folder) query.folder = folder;
      let res = await this.makeRequest("/files", "GET", query);
      let d: { files: IFile[] } = await res.json();
      return d.files.map(e => this.fixIFile(e));
   }

   async create(name: string, data: ArrayBuffer | ArrayBufferView, type: "text" | "binary", folder?: string, preview?: string, id?: string, date?: Date): Promise<IFile> {
      let params: any = { type: type, name: name };
      if (preview)
         params.preview = preview;

      if (folder)
         params.folder = folder;

      if (id)
         params.id = id

      if (date)
         params.date = date.toJSON()


      let res = await this.makeRequest("/files", "POST", params, data);
      return this.fixIFile((await res.json()).file);
   }

   async get(id: string, version?: string): Promise<ArrayBuffer> {
      let res: Response;
      if (typeof version === "string") {
         res = await this.makeRequest(`/files/${id}/history/${version}`, "GET", {});
      } else {
         res = await this.makeRequest("/files/" + id, "GET", {});
      }

      return res.arrayBuffer()
   }

   async update(id: string, data: ArrayBuffer | ArrayBufferView, preview?: string, date?: Date, old = false): Promise<IFile> {
      let params: any = { old };
      if (preview) params.preview = preview;
      if (date)
         params.date = date.toJSON()
      let res = await this.makeRequest("/files/" + id, "PUT", params, data);

      let json = await res.json()
      return this.fixIFile(json.file);
   }

   async delete(id: string): Promise<void> {
      let res = await this.makeRequest("/files/" + id, "DELETE", {});
   }

   async history(id: string): Promise<IHistory> {
      let res = await this.makeRequest(`/files/${id}/history`, "GET", {});
      let data: IHistory = await res.json();
      data.file = this.fixIFile(data.file)
      data.history = data.history.map(v => this.fixIFileVersion(v));
      return data;
   }

   async restore(id: string, version: string) {
      await this.makeRequest(`/files/${id}/history/${version}/restore`, "PUT", {});
   }

   async clean(id: string, val: number | Date): Promise<void> {
      let query = typeof val === "number" ? { count: val } : { date: val.toISOString() };
      return this.makeRequest(`/files/${id}/history/clean`, "PUT", query);
   }
}