e-commercee/ECommerce/data/class/DClient.ts

This package contains a backend of what would be the logic of a e-commercee software, the architecture used is made in 3 layers

import { Client } from "../../shared/entity/Client";
import { DataException } from "../../shared/exceptions/dataexception";
import { Conexion } from "../Conection";
import { IDClient } from "../interfaces/IDClient";


export class DClient implements IDClient {

    private static instancia: DClient;
    private constructor() { }
    public static getInstance(): DClient {
        if (!DClient.instancia) {
            DClient.instancia = new DClient();
        }

        return DClient.instancia;
    }
    public async addClient(dtclient: Client) {
        try {

           let cn = await Conexion.uri().connect();
            const collection = cn.db("ECommerce").collection("Client");
            const result = await collection.insertOne(dtclient);
            cn.close();

        }
        catch (e) {
            throw new DataException("Client could not be added" + e.message);
        }
    }
     public async getClient(idcard:string) {

        let cliobj= null;
        try {
            let cn = await Conexion.uri().connect();
            const collection = cn.db("ECommerce").collection("Client");
            const client = await collection.findOne({_identitycard:idcard});

            if (client == null) 
            { return null; }
            cliobj = new Client(client._salt,client._identitycard,
                client._completename,client._password,client._username,client._shippingaddress,
                client._creditcardnumber
               );
            return cliobj;
            cn.close();

        }
        catch (e) {
            throw new DataException("Client could not be searched");
        }

    }
    public async getClientbyusername(username:string) {

        let cliobj= null;
        try {
            let cn = await Conexion.uri().connect();
            const collection = cn.db("ECommerce").collection("Client");
            const client = await collection.findOne({_username:username});

            if (client == null) 
            { return null; }
           
            cliobj = new Client(client._salt,client._identitycard,
                client._completename,client._password,client._username,client._shippingaddress,
                client._creditcardnumber
               );
           
            return cliobj;
            cn.close();

        }
        catch (e) {
            throw new DataException("Client could not be searched");
        }

    }  
    public async loginClient(username:string,password:string) {

        let cliobj= null;
        try {
            let cn = await Conexion.uri().connect();
            const collection = cn.db("ECommerce").collection("Client");
            const client = await collection.findOne({_username:username,_password:password});

            if (client == null) 
            { return null; }
           
            cliobj = new Client(client._salt,client._identitycard,
                client._completename,client._password,client._username,client._shippingaddress,
                client._creditcardnumber
               );
           
            return cliobj;
            cn.close();

        }
        catch (e) {
            throw new DataException("Client could not be searched");
        }

    }  
    public async updateClient(dtclient: Client) {
        try {

            let cn = await Conexion.uri().connect();
            let query = { _identitycard:dtclient.identitycard };
            var newvalues = { $set: { _completename: dtclient.completename,
                _password: dtclient.password,
                _salt: dtclient.salt,
                _shippingaddress: dtclient.shippingaddress,
                _creditcardnumber: dtclient.creditcardnumber,
                
               } };
            const coladvert = cn.db("ECommerce").collection("Client");
            const result = await coladvert.updateOne(query,newvalues);


            cn.close();

        }
        catch (e) {
            throw new DataException("Client could not be updated" + e.message);
        }

    }
    public async deleteClient(dtclient: Client) {
        try {

            let cn = await Conexion.uri().connect();
            let query = { _identitycard: dtclient.identitycard };
            const colcat = cn.db("ECommerce").collection("Client");
            const result = await colcat.deleteOne(query);
            cn.close();

        }
        catch (e) {
            throw new DataException("Client could not be deleted" + e.message);
        }

    }

    public async getClients() {
      

        try {
            let cn = await Conexion.uri().connect();
            const collection = cn.db("ECommerce").collection("Client");
            const result = await collection.find({}).toArray();

            let array = [];
            for (var client of result) {
               var cliobj = new Client(client._salt,client._identitycard,
                    client._completename,client._password,client._username,client._shippingaddress,
                    client._creditcardnumber
                   );
                   array.push(cliobj);
            }

            return array;
            cn.close();

        }
        catch (e) {
            throw new DataException("Clients could not be listed" + e.message);
        }

    }
   
}