import {
  verifyToken,
  getUniqueId,
  setCookie,
  getSignedToken,
} from '../services/tokens';
import { getUserIfTokenExists, updateToken } from '../services/users';
import { cookieTokenExpiration, privilegedRoles, cookieTokenVerificationTime, processedCookieExpiration } from '../../config';
import { NextFunction, RequestHandler, Response } from 'express';
import { AuthRequest } from '../../types';
import { cacheManager } from "../utils/cache-manager";

function oAuthVerify(req: AuthRequest, _res: Response, next: NextFunction): Promise<void> {
  // get the last part from a authorization header string like "bearer token-value"
  const token = req.headers.authorization!.split(' ')[1];
  const tenant = (req.headers.tenant = req.headers.tenant as string || '0');

  return verifyToken(token, tenant)
    .then((payload) => setUserPayload(payload, req, next))
    .catch(() => {
      next();
    });
}

async function cookieVerify(req: AuthRequest, res: Response, next: NextFunction): Promise<void> {
  // get the last part from a authorization header string like "bearer token-value"
  const token = req.signedCookies.token || req.cookies.token;
  const tenant = (req.headers.tenant = req.headers.tenant as string || '0');

  try {
    const payload: any = await verifyToken(token, tenant);
    const created = Number(payload.tokenIdentifier?.split(':')[0]);
    if ((Date.now() - created < cookieTokenVerificationTime) || await isCookieProcessed(payload.tokenIdentifier)) {
      setUserPayload(payload, req, next);
      return;
    }
    const newCookieIdentifier = getUniqueId();
    const [user] = await Promise.all([
      getUserIfTokenExists(
          payload.tenant,
          payload.sub,
          payload.tokenIdentifier
      ),
      setCookieAsProcessed(payload.tokenIdentifier)
    ]);
    await updateToken(
      user,
      'cookie',
      payload.tokenIdentifier,
      newCookieIdentifier
    );
    const { token: newToken, payload: newPayload } = getSignedToken(
      user,
      newCookieIdentifier,
      String(cookieTokenExpiration / 1000)
    );

    setCookie(res, newToken);
    setUserPayload(newPayload, req, next);
  } catch (e) {
    next();
  }
}

async function setCookieAsProcessed(tokenIdentifier: string) {
  await cacheManager.setItem(tokenIdentifier, 'tokenIdentifier', {ttl: processedCookieExpiration});
}

async function isCookieProcessed(tokenIdentifier: string) {
  const res = await cacheManager.getItem(tokenIdentifier);
  return res !== undefined ? true : false;
}

function setUserPayload(payload: any, req: AuthRequest, next: NextFunction) {
  req.userPayload = payload;
  req.userPayload.isPrivileged = payload.roles.some((role: string) =>
    privilegedRoles.includes(role)
  );
  next();
}

/**
 *  The Auth Checker middleware function.
 */
export default <RequestHandler>function verifyUser(req: AuthRequest, res: Response, next: NextFunction) {
  if (req.cookies.token || req.signedCookies.token) {
    cookieVerify(req, res, next).catch(next);
  } else if (req.headers.authorization) {
    oAuthVerify(req, res, next).catch(next);
  } else {
    next();
  }
};