// Copyright (c) 2023 Tudor Stanciu

import { request } from "./utils/axios";
import { localStorage } from "@flare/utiliyo";
import { storageKeys } from "./constants";
import { getUrlTemplates } from "./config";
import { isValidURL } from "./utils/validations";
import type { UrlTemplates } from "./config";
import type { TuitioLoginResponse, TuitioLogoutResponse, TuitioUserInfo } from "./types";

const { setItem, getItem, removeItem } = localStorage;

const computeSafetyMargin = (expiresIn: number): number => {
  let safetyMargin = 10; // 10 seconds of safety margin
  const factor = expiresIn / safetyMargin;
  if (factor <= 1) safetyMargin = 0;
  else if (factor < 5) safetyMargin = 5;
  return safetyMargin;
};

const computeValidUntil = (expiresIn: number): Date => {
  const safetyMargin = computeSafetyMargin(expiresIn);
  const _expiresIn = expiresIn - safetyMargin;
  const currentDate = new Date();
  const validUntil = new Date(currentDate.getTime() + _expiresIn * 1000); // adding "expiresIn" seconds in milliseconds
  return validUntil;
};

class TuitioClient {
  tuitioUrl: string;
  urlTemplates: UrlTemplates;

  constructor(tuitioUrl: string | null) {
    if (tuitioUrl === null || tuitioUrl === "" || isValidURL(tuitioUrl) === false) {
      throw new Error(`TuitioClient: ${tuitioUrl} is not a valid URL.`);
    }

    this.tuitioUrl = tuitioUrl;
    this.urlTemplates = getUrlTemplates(this.tuitioUrl);
  }

  async login(userName: string, password: string): Promise<TuitioLoginResponse> {
    const url = this.urlTemplates.login.replace("{username}", userName).replace("{password}", encodeURIComponent(password));

    const response = await request(url, "post");
    if (!response.error) {
      const validUntil = computeValidUntil(response.result.expiresIn);
      const authData = { token: response.result.token, validUntil, userName };
      setItem(storageKeys.AUTH_DATA, authData);
      response.result.validUntil = validUntil;
    }

    return response;
  }

  async logout(): Promise<TuitioLogoutResponse> {
    const authData = getItem(storageKeys.AUTH_DATA);
    if (!authData) return { result: null, error: "UNAUTHENTICATED" } as TuitioLogoutResponse;
    const url = this.urlTemplates.logout.replace("{token}", authData.token);
    const response = await request(url, "post");
    if (!response.error) {
      removeItem(storageKeys.AUTH_DATA);
    }
    return response;
  }

  async getUserInfo(): Promise<TuitioUserInfo> {
    const url = this.urlTemplates.userInfo;
    const response = await request(url, "get");
    return response;
  }
}

export { TuitioClient };
export default TuitioClient;