CVS

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

namespace Clones
{
    public class CloneVersionSystem : ICloneVersionSystem
    {
        public static List<Clone> clones;

        public string Execute(string query)
        {
            if (query.Split()[0] == "learn")
            {
                var newClone = new Clone
                {
                    CloneID = int.Parse(query.Split()[1]),
                    ProgrammID = query.Split()[2]
                };
                clones.Add(newClone);
            }

            if (query.Split()[0] == "rollback")
            {
                foreach (var clone in clones)
                {
                    if (clone.CloneID == int.Parse(query.Split()[1]))
                    {
                        clone.SuccessfulActionStack.RemoveLast();
                        clone.ProgrammID = clone.SuccessfulActionStack.Last().ProgrammID;
                        clone.FailedActionStack.Push(new ActionInfo("rollback", clone.CloneID, clone.ProgrammID));
                    }
                }
            }

            if (query.Split()[0] == "relearn")
            {
                foreach (var clone in clones)
                {
                    if (clone.CloneID == int.Parse(query.Split()[1]))
                    {
                        clone.ProgrammID = clone.FailedActionStack.Last().ProgrammID;
                        clone.FailedActionStack.Pop();
                    }
                }
            }

            if (query.Split()[0] == "clone")
            {
                var newClone = new Clone() { CloneID = int.Parse(query.Split()[1] + 1) };
                foreach (var clone in clones)
                    if (clone.CloneID == int.Parse(query.Split()[1]))
                        newClone.ProgrammID = clone.ProgrammID;
                clones.Add(newClone);
            }

            if (query.Split()[0] == "check")
            {
                foreach (var clone in clones)
                    if (clone.CloneID == int.Parse(query.Split()[1]))
                        return clone.ProgrammID;
            }

            return null;
        }
    }

    public class Clone
    {
        public int CloneID { get; set; }
        public string ProgrammID { get; set; }
        public LimitedSizeStack<ActionInfo> SuccessfulActionStack { get; set; }
        public LimitedSizeStack<ActionInfo> FailedActionStack { get; set; }

        public Clone()
        {

        }
    }

    public class ActionInfo
    {
        public string ActionName { get; set; }
        public int CloneID { get; set; }
        public string ProgrammID { get; set; }

        public ActionInfo(string actionName, int cloneID, string programmID)
        {
            ActionName = actionName;
            CloneID = cloneID;
            ProgrammID = programmID;
        }
    }

    public class LimitedSizeStack<T>
    {
        private int StackLimit { get; set; }
        private static LinkedList<T> linkedList;

        public LimitedSizeStack(int limit)
        {
            StackLimit = limit;
            linkedList = new LinkedList<T>();
        }

        public void Push(T item)
        {
            if (this.Count + 1 > StackLimit)
                linkedList.RemoveFirst();
            linkedList.AddLast(item);
        }

        public T Pop()
        {
            var last = linkedList.Last;
            linkedList.RemoveLast();
            return last.Value;
        }

        public void RemoveLast()
        {
            linkedList.RemoveLast();
        }

        public int Count
        {
            get { return linkedList.Count; }
        }

        public T Last()
        {
            return linkedList.Last.Value;
        }
    }
}