MainForm.cs

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;
using InventoryApp.Models;

namespace InventoryApp 
    {
    public partial class MainForm : Form
        {
        private BindingList<Product> allProducts = new BindingList<Product>();
        private int _nextProductId;
        private int _nextPartId;


        public MainForm()
            {
            InitializeComponent();
            Inventory.InitializeIDs();
            TextBoxSearchProducts.TextChanged += TextBoxSearchProducts_TextChanged;

            SetupDataGrids();

            DataGridViewParts.CellMouseEnter += DataGridViewParts_CellMouseEnter;  // Makes hover color work
            DataGridViewParts.CellMouseLeave += DataGridViewParts_CellMouseLeave;  // Makes hover color work
            DataGridViewProducts.CellMouseEnter += DataGridViewProducts_CellMouseEnter;  // Makes hover color work
            DataGridViewProducts.CellMouseLeave += DataGridViewProducts_CellMouseLeave;  // Makes hover color work
            DataGridViewParts.CellDoubleClick += DataGridViewParts_CellDoubleClick;  // Makes double-clicking work to modify
            DataGridViewProducts.CellDoubleClick += DataGridViewProducts_CellDoubleClick;  // Makes double-clicking work to modify
            DataGridViewParts.KeyDown += DataGridViewParts_KeyDown;   // Makes Enter Button work in Parts grid
            DataGridViewProducts.KeyDown += DataGridViewProducts_KeyDown;  // Makes Enter Button work in Products grid
            }

        private BindingList<Part> filteredParts;
        private BindingList<Product> filteredProducts;

        private void SetupDataGrids()
            {
            filteredParts = new BindingList<Part>(Inventory.Parts.ToList());
            filteredProducts = new BindingList<Product>(Inventory.Products.ToList());

            ConfigurePartsGrid();
            ConfigureProductsGrid();
            }

        private void ConfigurePartsGrid()
            {
            DataGridViewParts.Columns.Clear();
            DataGridViewParts.AutoGenerateColumns = false;
            DataGridViewParts.AllowUserToAddRows = false;
            DataGridViewParts.ReadOnly = true;
            DataGridViewParts.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
            DataGridViewParts.MultiSelect = false;
            DataGridViewParts.RowHeadersVisible = false;
            DataGridViewParts.ScrollBars = ScrollBars.Vertical;
            DataGridViewParts.DefaultCellStyle.BackColor = Color.White;
            DataGridViewParts.DefaultCellStyle.SelectionBackColor = Color.SkyBlue;
            DataGridViewParts.DefaultCellStyle.SelectionForeColor = Color.White;

            DataGridViewParts.DataSource = filteredParts;

            DataGridViewParts.Columns.Add(new DataGridViewTextBoxColumn() { DataPropertyName = "ID", HeaderText = "ID", AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells });
            DataGridViewParts.Columns.Add(new DataGridViewTextBoxColumn() { DataPropertyName = "Name", HeaderText = "Name", AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill });
            DataGridViewParts.Columns.Add(new DataGridViewTextBoxColumn() { DataPropertyName = "InStock", HeaderText = "Inventory", AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells });
            DataGridViewParts.Columns.Add(new DataGridViewTextBoxColumn() { DataPropertyName = "Price", HeaderText = "Price", AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells });
            DataGridViewParts.Columns.Add(new DataGridViewTextBoxColumn() { DataPropertyName = "Min", HeaderText = "Min", AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells });
            DataGridViewParts.Columns.Add(new DataGridViewTextBoxColumn() { DataPropertyName = "Max", HeaderText = "Max", AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells });
            }

        private void ConfigureProductsGrid()
            {
            DataGridViewProducts.Columns.Clear();
            DataGridViewProducts.AutoGenerateColumns = false;
            DataGridViewProducts.AllowUserToAddRows = false;
            DataGridViewProducts.ReadOnly = true;
            DataGridViewProducts.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
            DataGridViewProducts.MultiSelect = false;
            DataGridViewProducts.RowHeadersVisible = false;
            DataGridViewProducts.ScrollBars = ScrollBars.Vertical;
            DataGridViewProducts.DefaultCellStyle.BackColor = Color.White;
            DataGridViewProducts.DefaultCellStyle.SelectionBackColor = Color.SkyBlue;
            DataGridViewProducts.DefaultCellStyle.SelectionForeColor = Color.White;

            DataGridViewProducts.DataSource = filteredProducts;

            DataGridViewProducts.Columns.Add(new DataGridViewTextBoxColumn() { DataPropertyName = "ProductID", HeaderText = "ID", AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells });
            DataGridViewProducts.Columns.Add(new DataGridViewTextBoxColumn() { DataPropertyName = "Name", HeaderText = "Name", AutoSizeMode = DataGridViewAutoSizeColumnMode.Fill });
            DataGridViewProducts.Columns.Add(new DataGridViewTextBoxColumn() { DataPropertyName = "InStock", HeaderText = "Inventory", AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells });
            DataGridViewProducts.Columns.Add(new DataGridViewTextBoxColumn() { DataPropertyName = "Price", HeaderText = "Price", AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells });
            DataGridViewProducts.Columns.Add(new DataGridViewTextBoxColumn() { DataPropertyName = "Min", HeaderText = "Min", AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells });
            DataGridViewProducts.Columns.Add(new DataGridViewTextBoxColumn() { DataPropertyName = "Max", HeaderText = "Max", AutoSizeMode = DataGridViewAutoSizeColumnMode.AllCells });
            }

        // PARTS: Cool color effect on rows when mouse-hovering Parts Table
        private void DataGridViewParts_CellMouseEnter(object sender, DataGridViewCellEventArgs e)
            {
            if (e.RowIndex >= 0)
                DataGridViewParts.Rows[e.RowIndex].DefaultCellStyle.BackColor = Color.LightBlue;
            }
        private void DataGridViewParts_CellMouseLeave(object sender, DataGridViewCellEventArgs e)
            {
            if (e.RowIndex >= 0)
                DataGridViewParts.Rows[e.RowIndex].DefaultCellStyle.BackColor = DataGridViewParts.DefaultCellStyle.BackColor;
            }
        private void DataGridViewProducts_CellMouseEnter(object sender, DataGridViewCellEventArgs e)
            {
            if (e.RowIndex >= 0)
                DataGridViewProducts.Rows[e.RowIndex].DefaultCellStyle.BackColor = Color.LightBlue;
            }
        // PRODUCTS: Cool color effect on rows when mouse-hovering Products Table
        private void DataGridViewProducts_CellMouseLeave(object sender, DataGridViewCellEventArgs e)
            {
            if (e.RowIndex >= 0)
                DataGridViewProducts.Rows[e.RowIndex].DefaultCellStyle.BackColor = DataGridViewProducts.DefaultCellStyle.BackColor;
            }

        // Code for Parts search Box 
        private void ButtonSearchParts_Click(object sender, EventArgs e)
            {
            ApplyPartsFilter();
            }

        // Parts search box code that makes the ENTER Button work
        private void TextBoxSearchParts_KeyDown(object sender, KeyEventArgs e)
            {
            if (e.KeyCode == Keys.Enter)
                {
                e.SuppressKeyPress = true;
                e.Handled = true;

                ButtonSearchParts.PerformClick();

                string searchText = TextBoxSearchParts.Text.Trim().ToLower();
                var filtered = Inventory.Parts
                    .Where(p => p.Name.ToLower().Contains(searchText) || p.ID.ToString() == searchText)
                    .ToList();

                if (filtered.Count == 1)
                    {
                    var selectedPart = filtered[0];

                    // Delay showing the modify form to prevent "ding" and UI issues
                    this.BeginInvoke((MethodInvoker)delegate
                        {
                            var modifyForm = new Parts(this, selectedPart); // Pass MainForm (this) and the selected part
                            modifyForm.ShowDialog();
                            });
                    }
                else
                    {
                    DataGridViewParts.DataSource = new BindingList<Part>(filtered);
                    }
                }
            }

        private void TextBoxSearchParts_TextChanged(object sender, EventArgs e)
            {
            ApplyPartsFilter();
            }

        // Code to make the Parts search box work
        private void ApplyPartsFilter()
            {
            string searchTerm = TextBoxSearchParts.Text.Trim().ToLower();

            if (string.IsNullOrWhiteSpace(searchTerm))
                {
                filteredParts = new BindingList<Part>(Inventory.Parts.ToList());
                DataGridViewParts.DataSource = filteredParts;
                return;
                }

            var results = Inventory.Parts
                .Where(p => p.ID.ToString().Contains(searchTerm) || p.Name.ToLower().Contains(searchTerm))
                .ToList();

            filteredParts = new BindingList<Part>(results);
            DataGridViewParts.DataSource = filteredParts;
            }

        public void AddPart(Part part)
            {
            Inventory.Parts.Add(part);
            }

        public void UpdatePart(Part updatedPart)
            {
            var existing = Inventory.LookupPart(updatedPart.ID);
            if (existing != null)
                {
                int index = Inventory.Parts.IndexOf(existing);
                Inventory.Parts[index] = updatedPart;
                }
            }

        // Code for Products search Box 
        private void ButtonSearchProducts_Click(object sender, EventArgs e)
            {
            ApplyProductsFilter();
            }

        // Products search box code that makes the ENTER Button work
        private void TextBoxSearchProducts_KeyDown(object sender, KeyEventArgs e)
            {
            if (e.KeyCode == Keys.Enter)
                {
                e.SuppressKeyPress = true;
                e.Handled = true;

                ButtonSearchProducts.PerformClick();

                string searchText = TextBoxSearchProducts.Text.Trim().ToLower();
                var filtered = Inventory.Products
                    .Where(p => p.Name.ToLower().Contains(searchText) || p.ProductID.ToString() == searchText)
                    .ToList();

                if (filtered.Count == 1)
                    {
                    var selectedProduct = filtered[0];

                    // Delay showing the modify form to prevent "ding" and UI issues
                    this.BeginInvoke((MethodInvoker)delegate
                        {
                            // Instantiate the Products form (used for both adding and modifying products)
                            var modifyForm = new Products(this, Inventory.Products, Inventory.Parts, selectedProduct);
                            var result = modifyForm.ShowDialog();
                        });
                    TextBoxSearchProducts.Clear();
                    }
                else
                    {
                    DataGridViewProducts.DataSource = new BindingList<Product>(filtered);
                    TextBoxSearchProducts.Clear();
                    }
                }
            }


        private void TextBoxSearchProducts_TextChanged(object sender, EventArgs e)
            {
            ApplyProductsFilter();
            }

        private void ApplyProductsFilter()
            {
            string searchTerm = TextBoxSearchProducts.Text.Trim().ToLower();

            if (string.IsNullOrWhiteSpace(searchTerm))
                {
                filteredProducts = new BindingList<Product>(Inventory.Products.ToList());
                DataGridViewProducts.DataSource = filteredProducts;
                return;
                }

            var results = Inventory.Products
                .Where(p => p.ProductID.ToString().Contains(searchTerm) || p.Name.ToLower().Contains(searchTerm))
                .ToList();

            filteredProducts = new BindingList<Product>(results);
            DataGridViewProducts.DataSource = filteredProducts;
            }

        // Code that opens the Parts form on click
        private void ButtonAddPart_Click(object sender, EventArgs e)
            {
            var addPart = new Parts(this, null, _nextPartId);
            var result = addPart.ShowDialog();

            if (result == DialogResult.OK)
                {
                _nextPartId++; // Only increment if a part was successfully added
                }

            // Code that refreshes the parts grid with new/live data from Inventory
            filteredParts = new BindingList<Part>(Inventory.Parts.ToList());
            DataGridViewParts.DataSource = filteredParts;
            }

        // Code to Modify the Parts form on click
        private void ButtonModifyPart_Click(object sender, EventArgs e)
            {
            if (DataGridViewParts.CurrentRow?.DataBoundItem is Part selectedPart)
                {
                var partForm = new Parts(this, selectedPart); // partToEdit = Modify mode
                partForm.ShowDialog();
                DataGridViewParts.Refresh(); // Refreshes the DataGridView in case the part was updated

                }
            else
                {
                MessageBox.Show("Please select a part to modify.");
                }
            }

        // Code to open the Products form on click to Add
        private void ButtonAddProduct_Click(object sender, EventArgs e)
            {
            var productForm = new Products(this,Inventory.Products, Inventory.Parts, _nextProductId); // Correctly passing the new Product ID
            var result = productForm.ShowDialog();

            if (result == DialogResult.OK)
                {
                _nextProductId++;  // Only increment if product was saved
                }

            // Refresh the product DataGridView
            filteredProducts = new BindingList<Product>(Inventory.Products.ToList());
            DataGridViewProducts.DataSource = filteredProducts;
            }

        private void ModifySelectedProduct()
            {
            if (DataGridViewProducts.CurrentRow?.DataBoundItem is Product selectedProduct)
                {
                var modifyForm = new Products(this, Inventory.Products, Inventory.Parts, selectedProduct);

                modifyForm.ShowDialog();

                DataGridViewProducts.Refresh(); // Refreshes the DataGridView in case the product was updated
                }
            else
                {
                MessageBox.Show("Please select a product to modify.");
                }
            }

        // Code to Modify the Products form on click
        private void ButtonModifyProduct_Click(object sender, EventArgs e)
            {
            if (DataGridViewProducts.CurrentRow?.DataBoundItem is Product selectedProduct)
                {
                var modifyForm = new Products(this, Inventory.Products, Inventory.Parts, selectedProduct);
                modifyForm.ShowDialog();
                DataGridViewProducts.Refresh(); // Refreshes the DataGridView in case the product was updated
                }
            else
                {
                MessageBox.Show("Please select a part to modify.");
                }
            }

        private void DataGridViewParts_CellDoubleClick(object sender, DataGridViewCellEventArgs e)
            {
            if (e.RowIndex >= 0 && DataGridViewParts.Rows[e.RowIndex].DataBoundItem is Part selectedPart)
                {
                var partsForm = new Parts(this, selectedPart); 
                partsForm.ShowDialog();
                }
            }

        private void DataGridViewProducts_CellDoubleClick(object sender, DataGridViewCellEventArgs e)
            {
            if (e.RowIndex >= 0 && e.RowIndex < DataGridViewProducts.Rows.Count)
                {
                var selectedProduct = DataGridViewProducts.Rows[e.RowIndex].DataBoundItem as Product;
                if (selectedProduct != null)
                    {
                    var modifyForm = new Products(this, Inventory.Products, Inventory.Parts, selectedProduct);
                    modifyForm.ShowDialog();
                    DataGridViewProducts.DataSource = new BindingList<Product>(Inventory.Products);
                    }
                }
            }

        // Code that makes highlighting a row and using Enter key open the Modify Parts form
        private void DataGridViewParts_KeyDown(object sender, KeyEventArgs e)
            {
            if (e.KeyCode == Keys.Enter && DataGridViewParts.CurrentRow?.DataBoundItem is Part)
                {
                e.SuppressKeyPress = true;
                e.Handled = true;
                ButtonModifyPart_Click(sender, e); // reuse your existing Modify Part logic
                }
            }
        // Code that makes highlighting a row and using Enter key open the Modify Products form
        private void DataGridViewProducts_KeyDown(object sender, KeyEventArgs e)
            {
            if (e.KeyCode == Keys.Enter)
                {
                e.SuppressKeyPress = true;
                e.Handled = true; // prevents the ding sound
                ModifySelectedProduct();
                }
            }

        public void ClearSearchBox()
            {
            // Clear the search box
            TextBoxSearchParts.Clear();

            // Reset the data in DataGridView to show all parts
            DataGridViewParts.DataSource = new BindingList<Part>(Inventory.Parts);
            }

        // Code that makes the Parts Delete Button work and ensure Part isn't associated with a Product
        private void ButtonDeletePart_Click(object sender, EventArgs e)
            {
            if (DataGridViewParts.CurrentRow == null)
                {
                MessageBox.Show("Please select a part to delete.");
                return;
                }

            var selectedPart = (Part)DataGridViewParts.CurrentRow.DataBoundItem;

            // Check if this part is associated with any product
            bool isAssociated = Inventory.Products.Any(p => p.AssociatedParts.Contains(selectedPart));

            if (isAssociated)
                {
                MessageBox.Show("This part is associated with a product and cannot be deleted.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
                }

            var result = MessageBox.Show("Are you sure you want to delete this part?", "Confirm Delete", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
            if (result == DialogResult.Yes)
                {
                Inventory.Parts.Remove(selectedPart);
                filteredParts.Remove(selectedPart); // If you're using filteredParts
                }
            }


        // Code that makes the Products Delete Button work, checks if any parts are associated, then confirms if user is sure
        private void ButtonDeleteProduct_Click(object sender, EventArgs e)
            {
            if (DataGridViewProducts.CurrentRow == null)
                {
                MessageBox.Show("Please select a product to delete.");
                return;
                }

            var selectedProduct = (Product)DataGridViewProducts.CurrentRow.DataBoundItem;

            // Check for associated parts
            if (selectedProduct.AssociatedParts.Count > 0)
                {
                MessageBox.Show("Please \"Modify\" to remove associated parts before deleting product.",
                                "Delete Error", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
                }

            var result = MessageBox.Show("Are you sure you want to delete this product?", "Confirm Delete", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
            if (result == DialogResult.Yes)
                {
                Inventory.Products.Remove(selectedProduct);
                ApplyProductsFilter();
                }
            }

        // Code that exits the program
        private void ButtonExit_Click(object sender, EventArgs e)
            {
            if (System.Windows.Forms.Application.MessageLoop)
                {
                // If WinForms app
                System.Windows.Forms.Application.Exit();
                }
            else
                {
                // If console app
                System.Environment.Exit(1);
                }
            }

        private void MainForm_Load(object sender, EventArgs e)
            {
            var aliceBlue = Color.AliceBlue;

            DataGridViewParts.BackgroundColor = aliceBlue;
            DataGridViewParts.DefaultCellStyle.BackColor = aliceBlue;
            DataGridViewParts.ColumnHeadersDefaultCellStyle.BackColor = aliceBlue;
            DataGridViewParts.ColumnHeadersDefaultCellStyle.SelectionBackColor = aliceBlue;
            DataGridViewParts.EnableHeadersVisualStyles = false;

            DataGridViewProducts.BackgroundColor = aliceBlue;
            DataGridViewProducts.DefaultCellStyle.BackColor = aliceBlue;
            DataGridViewProducts.ColumnHeadersDefaultCellStyle.BackColor = aliceBlue;
            DataGridViewProducts.ColumnHeadersDefaultCellStyle.SelectionBackColor = aliceBlue;
            DataGridViewProducts.EnableHeadersVisualStyles = false;

            // Add sample parts
            Inventory.Parts.Add(new Inhouse(1, "Wheel", 25.99m, 15, 5, 25, 123));
            Inventory.Parts.Add(new Inhouse(2, "Pedal", 9.99m, 11, 5, 25, 124));
            Inventory.Parts.Add(new Outsourced(3, "Chain", 4.99m, 10, 5, 25, "BikeCo"));
            Inventory.Parts.Add(new Outsourced(4, "Seat", 12.11m, 15, 5, 25, "CycleWorks"));
            Inventory.Parts.Add(new Inhouse(5, "Handlebar", 12.99m, 3, 2, 10, 125));

            // Add sample products
            var redBike = new Product(1, "Red Bicycle", 89.99m, 12, 1, 25); // Red bike
            redBike.AddAssociatedPart(Inventory.Parts[0]); // Wheel
            redBike.AddAssociatedPart(Inventory.Parts[3]); // Seat
            redBike.AddAssociatedPart(Inventory.Parts[4]); // Handlebar
            Inventory.Products.Add(redBike);

            var yellowBike = new Product(2, "Yellow Bicycle", 79.99m, 8, 1, 25); // Yellow bike
            yellowBike.AddAssociatedPart(Inventory.Parts[0]); // Wheel
            yellowBike.AddAssociatedPart(Inventory.Parts[1]); // Pedal
            yellowBike.AddAssociatedPart(Inventory.Parts[3]); // Seat
            Inventory.Products.Add(yellowBike);

            var blueBike = new Product(3, "Blue Bicycle", 84.99m, 6, 1, 25); // Blue bike
            blueBike.AddAssociatedPart(Inventory.Parts[0]); // Wheel
            blueBike.AddAssociatedPart(Inventory.Parts[1]); // Pedal
            blueBike.AddAssociatedPart(Inventory.Parts[2]); // Chain
            blueBike.AddAssociatedPart(Inventory.Parts[3]); // Seat
            Inventory.Products.Add(blueBike);

            var partsBindingSource = new BindingSource();
            partsBindingSource.DataSource = Inventory.Parts;
            DataGridViewParts.DataSource = partsBindingSource;

            var productsBindingSource = new BindingSource();
            productsBindingSource.DataSource = Inventory.Products;
            DataGridViewProducts.DataSource = productsBindingSource;

            allProducts = Inventory.Products;

            _nextProductId = Inventory.Products.Count > 0
                ? Inventory.Products.Max(p => p.ProductID) + 1
                : 1;

            _nextPartId = Inventory.Parts.Count > 0
                ? Inventory.Parts.Max(p => p.ID) + 1
                : 1;

            }
        }
    }