using System;
using System.Collections.Generic;

namespace IntroductionToCSharpSession3
{
    /// <summary>
    /// Types of item that can be found in the menu
    /// </summary>
    public enum MenuType
    {
        Food,
        HotDrink,
        ColdDrink,
        Sweet,
        Snack
    }

    /// <summary>
    /// Represents an item in the menu
    /// </summary>
    public class MenuItem
    {
        public string ItemName { get; set;}
        public decimal Prices { get; set; }
        public decimal Calories { get; set; }
        public MenuType ItemType { get; set; }

        public MenuItem(string itemName, decimal price, decimal calories, MenuType itemType)
        {
            ItemName = itemName;
            Prices = price;
            Calories = calories;
            ItemType = itemType;
        }
    }

    /// <summary>
    /// Represents a menu
    /// </summary>
    public class Menu
    {
        public List<MenuItem> MainMenu = new List<MenuItem>();

        /// <summary>
        /// Default constructor, let's construct the menu here.
        /// </summary>
        public Menu()
        {
            //create several MenuItem and then add it to the list;
            MenuItem item1 = new MenuItem("Laksa", 5.50m, 587, MenuType.Food);
            MainMenu.Add(item1);

        }

        /// <summary>
        /// Displays the menu
        /// </summary>
        public void DisplayTheMenu()
        {
            foreach(MenuItem item in MainMenu)
            {
                Console.WriteLine(item.ItemName);
            }
        }
    }

    /// <summary>
    /// This is the main program class
    /// </summary>
    class MainClass
    {
        public static void Main(string[] args)
        {
            Console.WriteLine("Welcome to Bersama-Sama Restaurant!");

            //create an instance of the menu
            Menu myRestaurantMenu = new Menu();

            //this represent the orders that have been done by the customer
            Dictionary<MenuItem, int> Orders = new Dictionary<MenuItem, int>();

            //Step 1 - displays the menu

            //Step 2 - ask the user what they want to order, until they
            //         type "done"

            //need to check if what ordered by the customer is found in "myRestaurant" menu.
            //if it is found, then add it to "Orders"
            //if not found, show error message.


            //Step 3 - when the order is finished, calculates the total
            //for the bill, apply 6% GST, apply 10% service charge
            //and then inform the customer the amount of calories in their food

        }

        /// <summary>
        /// Calculates the total calories given the orders
        /// </summary>
        /// <returns>The total calories.</returns>
        /// <param name="orders">Orders.</param>
        public static decimal CalculateTotalCalories(Dictionary<MenuItem, int> orders)
        {
            decimal totalCalories = 0;

            foreach(MenuItem item in orders.Keys)
            {
                int quantity = orders[item];
                decimal calories = item.Calories;
                decimal itemCalories = quantity * calories;
                totalCalories += itemCalories;
            }

            return totalCalories;
        }

        /// <summary>
        /// Calculate the total of the receipt
        /// </summary>
        /// <returns>The total.</returns>
        /// <param name="orders">Orders.</param>
        public static decimal CalculateTotal(Dictionary<MenuItem, int> orders)
        {
            //todo: write a loop that will calculate the total amount of the order.
            return 0;
        }

        /// <summary>
        /// Calculates the GST
        /// </summary>
        /// <returns>The gst.</returns>
        /// <param name="total">Total.</param>
        public static decimal CalculateGST(decimal total)
        {
            //todo: calculate the 6% GST
            return 0;
        }
    }
}