Testable Applications

using System;
using System.Collections.Generic;
using System.Text;
using System.Data.SqlClient;
using System.Data;

namespace TestableApplication.Testable.Dalc
{
    public class InvoiceDalc : DalcBase<Invoice>, IInvoiceDalc
    {
        Invoice _invoice;
        public InvoiceDalc(Invoice invoice)
        {
            _invoice = invoice;
        }
        public Invoice IssueInvoice(string description, ICustomer customer, List<InvoiceItem> items)
        {
            Console.WriteLine("--- IssueInvoice Method was invoked from object {0} ", this);
            Console.WriteLine("press enter to continue ....");
            Console.ReadLine();

            List<SqlParameter> parameters = new List<SqlParameter>();
            SqlParameter param = new SqlParameter("@DESCRIPTION", SqlDbType.NVarChar);
            param.Value = description;
            parameters.Add(param);

            param = new SqlParameter("@CUS_ID", SqlDbType.Int);
            param.Value = customer.ID; ;
            parameters.Add(param);

            DateTime issueDate = DateTime.Now;
            param = new SqlParameter("@ISSUE_DATE", SqlDbType.DateTime);
            param.Value = issueDate;
            parameters.Add(param);

            param = new SqlParameter("@DUE_DATE", SqlDbType.DateTime);
            param.Value = issueDate.AddMonths(1); ;
            parameters.Add(param);

            object idObj = ExecuteStoredScalerProcedure("stp_add_invoice_header", parameters);
            // for test only
            idObj = DateTime.Now.Millisecond;
            int invoiceNumber = int.Parse(idObj.ToString());

            parameters.Clear();
            int seq = 0;
            foreach (InvoiceItem item in items)
            {

                param = new SqlParameter("@INV_ID", SqlDbType.Int);
                param.Value = invoiceNumber;
                parameters.Add(param);

                param = new SqlParameter("@QTY", SqlDbType.Int);
                param.Value = item.Quantity;
                parameters.Add(param);

                param = new SqlParameter("@SEQ_NUM", SqlDbType.Int);
                param.Value = ++seq;
                parameters.Add(param);
                ExecuteStoredScalerProcedure("stp_add_invoice_line", parameters);

            }
            Invoice newInvoice = new Invoice(invoiceNumber, description, customer, issueDate, Status.Issued, items);
            customer.Debt(newInvoice.TotalAmount, newInvoice.Description, newInvoice.InvoiceNumber, newInvoice.IssueDate);
            return newInvoice;
        }
        public void PayOffInvoice(ICustomer customer)
        {
            Console.WriteLine("--- IssueInvoice Method was invoked from object {0} ", this);
            Console.WriteLine("press enter to continue ....");
            Console.ReadLine();

            List<SqlParameter> parameters = new List<SqlParameter>();
            SqlParameter param = new SqlParameter("@INV_ID", SqlDbType.Int);
            param.Value = _invoice.InvoiceNumber;
            parameters.Add(param);

            param = new SqlParameter("@CUS_ID", SqlDbType.Int);
            param.Value = customer.ID; ;
            parameters.Add(param);

            DateTime issueDate = DateTime.Now;
            param = new SqlParameter("@PAY_OFF_DATE", SqlDbType.DateTime);
            param.Value = DateTime.Now;
            parameters.Add(param);

            object idObj = ExecuteStoredScalerProcedure("stp_pay_off_invoice", parameters);
            _invoice._status = Status.Paid;
            customer.Credit(_invoice.TotalAmount, _invoice.Description, _invoice.InvoiceNumber, _invoice.IssueDate);
        }
        public override Invoice Make(DataRow dr)
        {
           // Customer cus = new Customer().GetCustomer(int.Parse(dr["CUS_ID"].ToString()));
           // List<InvoiceItem> items = new InvoiceItem().GetItems(int.Parse(dr["INV_ID"].ToString()));
           // return new Invoice(int.Parse(dr["INV_ID"].ToString()), dr["DESCRIPTION"].ToString(), cus, DateTime.Parse(dr["@ISSUE_DATE"].ToString()), (Status)Enum.Parse(typeof(Status), dr["STATUS"].ToString()), items);
            return new Invoice(DateTime.Now.Millisecond, "qq", new Customer(1, "aa", "bb"));
        }
        public Invoice GetInvoice(int invoiceNomber)
        {
            List<SqlParameter> parameters = new List<SqlParameter>();
            SqlParameter param = new SqlParameter("@ID", SqlDbType.Int);
            param.Value = invoiceNomber;
            parameters.Add(param);

            DataTable dt = ExecuteStoredProcedure("stp_get_Invoice", parameters);
            #region for test only
            dt.Rows.Add(dt.NewRow());
            #endregion 
            return Make(dt.Rows[0]);
        }
        public void Update()
        {
            throw new InvalidOperationException("Invoice Update method, This Error did in purpose as Example of Invoice  Dependency Error");
            
            
            Console.WriteLine("--- Update Method was invoked from object {0} ", this);
            Console.WriteLine("press enter to continue ....");
            Console.ReadLine();

            List<SqlParameter> parameters = new List<SqlParameter>();
            SqlParameter param = new SqlParameter("@INV_ID", SqlDbType.Int);
            param.Value = _invoice.InvoiceNumber;
            parameters.Add(param);

            param = new SqlParameter("@DESCRIPTION", SqlDbType.NVarChar);
            param.Value = _invoice.Description;
            parameters.Add(param);

            param = new SqlParameter("@CUS_ID", SqlDbType.Int);
            param.Value = _invoice.Customer.ID;
            parameters.Add(param);


            param = new SqlParameter("@ISSUE_DATE", SqlDbType.DateTime);
            param.Value = _invoice.IssueDate;
            parameters.Add(param);

            param = new SqlParameter("@DUE_DATE", SqlDbType.DateTime);
            param.Value = _invoice.DueDate;
            parameters.Add(param);

            ExecuteStoredScalerProcedure("stp_update_invoice_header", parameters);
        }
    }
}