using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

/* References */
// Using a delegate to trigger method on the customer view form
// https://www.coderslexicon.com/passing-data-between-forms-using-delegates-and-events/

namespace QueueSys
{
    public partial class frmEmployeeView : Form
    {
        public frmEmployeeView()
        {
            InitializeComponent();
        }

        // Our delegate (which "points" at any method which takes an object and EventArgs)
        // Look familiar? This is the signature of most control events on a form
        public delegate void SendMessage(object obj, EventArgs e);

        // Here is the event we trigger to send messages out to listeners
        public event SendMessage OnSendMessage;

        /* Execute when program / main form loads.
         * Pop up the customer view screen to drag onto second monitor 
         * creates our second form, says "attach its MessageReceived function to the event"
         */
        private void frmEmployeeView_Load(object sender, EventArgs e)
        {
            frmCustomerView frm = new frmCustomerView();
            OnSendMessage += frm.MessageReceived;
            frm.Show();
        }

        /* Enable options menu. */
        private void optionsToolStripMenuItem_Click(object sender, EventArgs e)
        {
            frmOptions frm = new frmOptions();
            frm.Show();
            frm.Activate();
        }

        // Exits the application.
        private void exitAltF4ToolStripMenuItem_Click(object sender, EventArgs e) => Application.Exit();

        private void generateReportToolStripMenuItem_Click(object sender, EventArgs e)
        {
            MessageBox.Show("To-do: Generate excel report from SQL Database.");
        }

        private void btnAdd_Click(object sender, EventArgs e)
        {
            SqliteDataAccess sda = new SqliteDataAccess();
            EmployeeView evNewCx = new EmployeeView();

            evNewCx.customer_name = tbCustomerName.Text;
            evNewCx.num_bags = Int32.Parse(cbNumBags.Text);
            evNewCx.employee = tbEmployeeName.Text;

            sda.SaveCustomer(evNewCx);

            //Invoke the delegate to update customer view.
            OnSendMessage?.Invoke(this, e);

            tbCustomerName.Text = "";
            cbNumBags.Text = "";
            tbEmployeeName.Text = "";

            MessageBox.Show("Customer has been added!", "Queue System", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }
    }
}