03. Inventory

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Demo
{
    class Program
    {


        static void Main(string[] args)
        {
            // Read The Input

            List<string> inventory = Console.ReadLine()
                .Split(", ", StringSplitOptions.RemoveEmptyEntries)
                .ToList();


            while (true)
            {
                string line = Console.ReadLine();
                if (line == "Craft!")
                {
                    break;
                }

                string[] command = line
                    .Split(" - ", StringSplitOptions.RemoveEmptyEntries)
                    .ToArray();
                string firstCommand = command[0];


                switch (firstCommand)
                {
                    case "Collect":
                        if (!inventory.Contains(command[1]))
                        {
                            inventory.Add(command[1]);
                        }
                        break;

                    case "Drop":
                        if (inventory.Contains(command[1]))
                        {
                            inventory.Remove(command[1]);
                        }
                        break;

                    case "Combine Items":
                        string oldItem = string.Empty;
                        string newItem = string.Empty;

                        for (int i = 1; i < command.Length; i++)
                        {
                            string[] combineItem = command[i]
                                .Split(":", StringSplitOptions.RemoveEmptyEntries);

                            oldItem = combineItem[0];
                            newItem = combineItem[1];
                        }

                        if (inventory.Contains(oldItem))
                        {
                            for (int i = 0; i < inventory.Count; i++)
                            {
                                if (inventory[i] == oldItem)
                                {
                                   int index = i + 1;
                                    if (index > 0)
                                    {
                                        inventory.Insert(index, newItem);
                                    }
                                    break;
                                }
                            }
                        }
                        break;

                    case "Renew":
                        if (inventory.Contains(command[1]))
                        {
                            string firstElement = inventory[0];

                            inventory.Add(command[1]);
                            inventory.Remove(firstElement);
                        }
                        break;
                }

            }

            Console.WriteLine(string.Join(", ", inventory));


        }
    }
}