import type { IDataStore } from "../repo";
import * as Fs from "fs";
import * as Path from "path";
export default class FSDataStore implements IDataStore {
   #path: string;
   #l = false;

   constructor(path: string) {
      this.#path = path;
   }

   async get(name: string) {
      return Fs.promises.readFile(Path.join(this.#path, name));
   }

   async has(name: string) {
      return Fs.promises
         .access(Path.join(this.#path, name))
         .then(() => true)
         .catch(() => false);
   }

   async set(name: string, data: Uint8Array) {
      const path = Path.join(this.#path, name);
      await Fs.promises.mkdir(Path.dirname(path), { recursive: true });
      await Fs.promises.writeFile(path, data);
   }

   async _delete(name: string) {
      await Fs.promises.rm(Path.join(this.#path, name));
   }

   async getLock() {
      //TODO: This is not atomic yet! FIX
      while ((await this.has("lock")) || this.#l) {
         try {
            let con = (await this.get("lock")).toString("utf-8");

            if (Number(con) < Date.now() - 10000) break;
            await new Promise((y) => setTimeout(y, 10));
         } catch (err) {}
      }
      this.#l = true;

      await this.set("lock", Buffer.from(`${Date.now()}`));

      this.#l = false;

      return async () => {
         await this._delete("lock");
      };
   }
}