import { sign, verify } from 'jsonwebtoken';
import { createDecipheriv, createCipheriv } from 'crypto';
import * as Moment from 'moment';
import { Service, Inject } from '@rxdi/core';
import { AUTH_MODULE_CONFIG, AuthModuleConfig, TokenData } from './auth.config';

@Service()
export class AuthInternalService {

    constructor(
        @Inject(AUTH_MODULE_CONFIG) private config: AuthModuleConfig
    ) { }

    verifyToken(token): TokenData {
        return verify(token, this.config.cert, { algorithm: 'HS256' });
    }

    decrypt(password: string) {
        const decipher = createDecipheriv(this.config.cyper.algorithm, this.config.cyper.privateKey, this.config.cyper.iv);
        let dec = decipher.update(password, 'hex', 'utf8');
        dec += decipher.final('utf8');
        return dec;
    }

    encrypt(password: string) {
        const cipher = createCipheriv(this.config.cyper.algorithm, this.config.cyper.privateKey, this.config.cyper.iv);
        let crypted = cipher.update(password, 'utf8', 'hex');
        crypted += cipher.final('hex');
        return crypted;
    }

    validate(token, callback) {
        // Check token timestamp
        const ttl = 30 * 1000 * 60;
        const diff = Moment().diff(Moment(token.iat * 1000));
        if (diff > ttl) {
            return callback(null, false);
        }
        callback(null, true, token);
    }

    sign(tokenData: TokenData): string {
        return sign(tokenData, this.config.cert, { algorithm: this.config.algorithm });
    }

}