import { Response } from 'express';
import { RESPONSE_TYPE, TokenPayload } from './customTypes';
import jwt from 'jsonwebtoken'; 
import { Readable } from 'stream';

import ObjectId from "mongoose"

 let myObjectId = ObjectId.Types.ObjectId;


 

//let dsecret = getGlobalEnv("JWT_SECRET") as string;

//console.log({dsecret})
/**
 * A function that returns http response as a stream.
 * 
 * @param res - response object.
 * 
 * @param data - data to be sent as response.
 * 
 * @returns - a void promise.
 * 
 * @remarks - this function is used to send response to the client.
 * 
 * @beta
 * 
 * 
 *  
 */
 
export const response = (res: Response, data: RESPONSE_TYPE) => {
  data.status =
    data.status == undefined || data.status == null ? 500 : data.status;
let dataToJson = JSON.stringify(data);

  //res.status(data.status).json(data);
  res.writeHead(data.status, {
    'Content-Length': Buffer.byteLength(dataToJson),
    'Content-Type': 'application/json'
  });
  var stream = new Readable();
  stream.push(dataToJson);    // stream apparently does not accept objects
  stream.push(null);                    // this 
  
stream.pipe(res);

  return;
};


/**
 * A function that extracts the content of a jwt token.
 * 
 * @param token  - token to be extracted.
 * @returns - a promise that resolves to a RESPONSE_TYPE object.
 * 
 * 
 * @remarks
 * 
 * This function uses the jsonwebtoken library to extract the content of the token.
 * 
 * @beta
 * 
 * @example
 * 
 * 
 * extractTokenContent(token)
 * .then((done: RESPONSE_TYPE)=>{
 * console.log(done);
 * })
 * .catch((err: any)=>{
 * console.log(err);
 * })
 * 
 */ 

export const  extractTokenContent  =  (token: string, secret: string): Promise<RESPONSE_TYPE> => {
  
  // let secret = getGlobalEnv("JWT_SECRET") as string;

return new Promise((resolve:any, reject: any)=>{

  try {
    const decoded = jwt.verify(token, secret);

    if (decoded && typeof decoded === 'object' && 'id' in decoded && 'email' in decoded && 'time' in decoded) {
     
let token = {
  id: decoded.id,
  email: decoded.email as string,
  time: decoded.time
}
let done: RESPONSE_TYPE = {
data: [decoded],
message: "token verified.",
status: 200,
statusCode: "SUCCESS"


} 

     resolve(done)
     
      return ;




    }
  } catch (err) {
    
    let error: RESPONSE_TYPE ={
      data:[],
      message:'Failed to verify JWT token',
      status:500,
      statusCode:"UNKNOWN_ERROR"
        }
         reject(error);

return;

  }

  



})



}