using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;

// The Blank Page item template is documented at https://go.microsoft.com/fwlink/?LinkId=402352&clcid=0x409

namespace TomCafe
{
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    public sealed partial class MainPage : Page
    {
        List<MenuItem> bundleMeals = new List<MenuItem>();
        List<MenuItem> valueMeals = new List<MenuItem>();
        List<MenuItem> sides = new List<MenuItem>();
        List<MenuItem> beverages = new List<MenuItem>();
        Dictionary<string, MenuItem> tradeIns = new Dictionary<string, MenuItem>();

        List<string> tradeInIds;

        List<MenuItem> menu = new List<MenuItem>();
        Order cart = new Order();

        // displayText
        string alert;
        double total = -1;
        string content;
        string receipt;

        public MainPage()
        {
            this.InitializeComponent();
            resetContent();
            createItems();
            displayItemsList();
            displayDisplayText();
        }

        private void resetContent()
        {
            content = @"Welcome to Tom's Cafe!

Choose your item from the menu.";
        }

        private void displayItemsList()
        {
            // Render it
            List<string> data = new List<string>();
            foreach (MenuItem i in menu)
            {
                // Check for Value Meal availibility
                bool notAvailable = false;
                foreach (Product p in i.ProductList)
                {
                    if (p is ValueMeal && !((ValueMeal)p).IsAvailable())
                    {
                        notAvailable = true;
                    }
                }
                if (notAvailable) continue;

                data.Add(i.ToString());
            }
            itemsListView.ItemsSource = data;
        }

        private void displayCartsList()
        {
            List<string> data = new List<string>();
            foreach (OrderItem i in cart.ItemList)
            {
                data.Add(i.ToString());
            }
            cartsListView.ItemsSource = data;
        }

        // alert: string or null
        // total: positive or negative (no display)
        // content: string or null
        // receipt: string or null
        private void displayDisplayText()
        {
            string str = "";

            if (alert != null)
            {
                str += alert;
                str += "\n";
            }

            if (total >= 0)
            {
                str += $"Total: ${total:0.00}";
                str += "\n\n";
            }
            else if (alert != null)
            {
                str += "\n";
            }

            if (content != null)
            {
                str += content;
                str += "\n\n";
            }

            if (receipt != null)
            {
                str += receipt;
            }

            displayText.Text = str;
        }

        private void createItems()
        {
            /* Products */
            Beverage cola =     new Beverage("Cola",      2.85,  0.0);
            Beverage greenTea = new Beverage("Green Tea", 3.70,  0.0);
            Beverage coffee =   new Beverage("Coffee",    2.70,  0.0);
            Beverage tea =      new Beverage("Tea",       2.70,  0.0);
            Beverage rootBeer = new Beverage("Root Beer", 9.70,  0.0);
            Beverage mocktail = new Beverage("Mocktail",  15.90, 0.0);

            Side hashBrown =    new Side("Hash brown",    2.10);
            Side truffleFries = new Side("Truffle fries", 3.70);
            Side calamari =     new Side("Calamari",      3.40);
            Side caesarSalad =  new Side("Caesar salad",  4.30);

            ValueMeal hotcakeWithSausage = new ValueMeal("Hotcake with sausage", 6.90,  new DateTime(), new DateTime());
            ValueMeal hamburger =          new ValueMeal("Hamburger",            7.50,  new DateTime(), new DateTime());
            ValueMeal nasiLemak =          new ValueMeal("Nasi Lemak",           5.40,  new DateTime(), new DateTime());
            ValueMeal ribeyeSteak =        new ValueMeal("Ribeye steak",         10.20, new DateTime(), new DateTime());

            /* Menu Item */
            beverages.Add(new MenuItem(cola));
            beverages.Add(new MenuItem(greenTea));
            beverages.Add(new MenuItem(coffee));
            beverages.Add(new MenuItem(tea));
            beverages.Add(new MenuItem(rootBeer));
            beverages.Add(new MenuItem(mocktail));

            sides.Add(new MenuItem(hashBrown));
            sides.Add(new MenuItem(truffleFries));
            sides.Add(new MenuItem(calamari));
            sides.Add(new MenuItem(caesarSalad));

            valueMeals.Add(new MenuItem(hotcakeWithSausage));
            valueMeals.Add(new MenuItem(hamburger));
            valueMeals.Add(new MenuItem(nasiLemak));
            valueMeals.Add(new MenuItem(ribeyeSteak));

            MenuItem breakfastSet = new MenuItem("Breakfast set", 7.90);
            breakfastSet.ProductList.Add(hotcakeWithSausage);
            breakfastSet.ProductList.Add(hashBrown);
            bundleMeals.Add(breakfastSet);

            MenuItem hamburgerCombo = new MenuItem("Hamburger combo", 10.20);
            hamburgerCombo.ProductList.Add(hamburger);
            hamburgerCombo.ProductList.Add(truffleFries);
            hamburgerCombo.ProductList.Add(cola);
            bundleMeals.Add(hamburgerCombo);

            MenuItem dinnerSet = new MenuItem("Dinner set", 18.50);
            dinnerSet.ProductList.Add(ribeyeSteak);
            dinnerSet.ProductList.Add(truffleFries);
            dinnerSet.ProductList.Add(cola);
            bundleMeals.Add(dinnerSet);
        }

        private void doEmptyState()
        {
            menu = bundleMeals;
            displayItemsList();

            alert = "There is nothing in your cart.";
            displayDisplayText();
        }

        private void mainsButton_Click(object sender, RoutedEventArgs e)
        {
            tradeInIds = null;
            menu = valueMeals;
            displayItemsList();
        }

        private void sidesButton_Click(object sender, RoutedEventArgs e)
        {
            tradeInIds = null;
            menu = sides;
            displayItemsList();
        }

        private void beveragesButton_Click(object sender, RoutedEventArgs e)
        {
            tradeInIds = null;
            menu = beverages;
            displayItemsList();
        }

        private void bundlesButton_Click(object sender, RoutedEventArgs e)
        {
            tradeInIds = null;
            menu = bundleMeals;
            displayItemsList();
        }

        private void addButton_Click(object sender, RoutedEventArgs e)
        {
            // If currently a prompt is being displayed, add the bundle meal instead
            if (tradeInIds != null)
            {
                string tradeInId = tradeInIds[itemsListView.SelectedIndex];
                MenuItem tradeIn = tradeIns[tradeInId];
                orderMenuItem(tradeIn);

                // Display the normal menu
                menu = bundleMeals;
                displayItemsList();

                return;
            }

            MenuItem mi = menu[itemsListView.SelectedIndex];

            // Find the possible beverage
            Beverage beverage = null;
            if (mi.ProductList.Count > 1)
            {
                foreach (Product p in mi.ProductList)
                {
                    if (p is Beverage)
                    {
                        beverage = (Beverage)p;
                        break;
                    }
                }
            }

            // If beverage exists, change menu to beverage selection
            if (beverage != null)
            {
                // Generate new list of MenuItems containing Beverages
                tradeInIds = new List<string>();
                List<MenuItem> tradeInList = new List<MenuItem>();
                foreach (MenuItem i in beverages)
                {
                    Beverage b = (Beverage)i.ProductList[0];

                    string tradeInId = mi.Name + beverage.Name + b.Name;
                    MenuItem tradeIn;

                    if (tradeIns.ContainsKey(tradeInId))
                    {
                        tradeIn = tradeIns[tradeInId];
                    }
                    else
                    {
                        // Create the trade-in beverage
                        double tradeInPrice = Math.Max(0, b.Price - beverage.Price);
                        Beverage tradeInBeverage = new Beverage(b.Name, b.Price, tradeInPrice);

                        // Copy `mi` and change the beverage
                        tradeIn = new MenuItem(mi.Name, mi.Price + tradeInPrice);
                        foreach (Product p in mi.ProductList)
                        {
                            if (p is Beverage)
                            {
                                tradeIn.ProductList.Add(tradeInBeverage);
                            }
                            else
                            {
                                tradeIn.ProductList.Add(p);
                            }
                        }

                        // Add it to the global dict
                        tradeIns.Add(tradeInId, tradeIn);
                    }

                    foreach (Product p in tradeIn.ProductList)
                    {
                        if (p is Beverage)
                        {
                            tradeInIds.Add(tradeInId);
                            tradeInList.Add(new MenuItem((Beverage)p));
                        }
                    }
                }

                // Set the list to menu and display
                menu = tradeInList;
                displayItemsList();

                return;
            }

            // Otherwise add the menu item to the order as per usual
            orderMenuItem(mi);
        }

        private void orderMenuItem(MenuItem mi)
        {
            OrderItem oi = null;

            // If the item exists, increment the quantity
            foreach (OrderItem i in cart.ItemList)
            {
                if (i.Item == mi)
                {
                    i.AddQty();
                    oi = i;
                    break;
                }
            }

            // Otherwise, create a whole new OrderItem
            if (oi == null)
            {
                oi = new OrderItem(mi);
                cart.Add(oi);
            }

            // Refresh the cart
            displayCartsList();

            // Refresh display
            alert = $"{oi.Item.Name} has been added.";
            total = cart.GetTotalAmt();
            displayDisplayText();
        }

        private void orderButton_Click(object sender, RoutedEventArgs e)
        {
            if (cart.ItemList.Count == 0)
            {
                doEmptyState();
                return;
            }

            alert = null;
            total = -1;
            content = "Tom's Cafe";
            receipt = cart.ToString();
            displayDisplayText();
            resetContent();
            receipt = null;

            cart = new Order();
            displayCartsList();
        }

        private void cancelButton_Click(object sender, RoutedEventArgs e)
        {
            if (cart.ItemList.Count == 0)
            {
                doEmptyState();
                return;
            }

            cart = new Order();
            displayCartsList();

            alert = "Your order has been cancelled.";
            total = -1;
            displayDisplayText();
        }

        private void removeButton_Click(object sender, RoutedEventArgs e)
        {
            if (cart.ItemList.Count == 0)
            {
                doEmptyState();
                return;
            }

            OrderItem oi = cart.ItemList[cartsListView.SelectedIndex];
            if (!oi.RemoveQty())
            {
                cart.Remove(cartsListView.SelectedIndex);
            }

            displayCartsList();

            alert = $"{oi.Item.Name} has been removed.";
            total = cart.GetTotalAmt();
            displayDisplayText();
        }
    }
}