import { GraphQLError} from 'graphql'
const jwt = require('jsonwebtoken');
require('dotenv').config();

export const VerifyToken = token => {
    try {
        if (token) {
            const verification = jwt.verify( token , 'RGlobal^')
            return verification;
        }
        return null
    } catch (err) {
        if(err.name === 'TokenExpiredError'){
            return err;
        }
        return null
    }
}

export const AuthMiddleWare = ( cntx ) => {

    return ({ req }) => {

        //try to retrieve auth & getUser functions from extend
        let user;
        if ( true == true) {
            // get the user token from the headers
            const token = req.headers.authentication || '';
            if(!req.headers.authentication) throw new GraphQLError('No authorization code provided');
            if(req.headers.authentication === '') throw new GraphQLError('Invalid authorization code');

            // try to retrieve a user with the token
            user = VerifyToken(token);
            // optionally block the user
            // we could also check user roles/permissions here
            if (!user) throw new GraphQLError('you must be logged in to query this schema');
            if(user.error) throw new GraphQLError(user.message);

            if( user && user.identity ){
                return {
                    user: user.identity || null,
                    ...cntx
                }
            }
            else{
                throw new GraphQLError('no user identity');
            }

        }
        else {
            
            return {
                user: user || null,
                ...cntx,
            }
        }

    }
}