using System;

namespace State
{
    public class LeaveFlow
    {
        private const int START_STATE = 0;
        private const int APPLY_STATE = 1;
        private const int HR_STATE = 2;
        private const int STOP_STATE = 3;
        private int current_state;
        private int totalCount = 7;

        public LeaveFlow()
        {
            current_state = START_STATE;
        }

        public void nextState()
        {
            switch (current_state)
            {
                case START_STATE:
                    current_state = APPLY_STATE;
                    Console.WriteLine("提出申請");
                    break;
                case APPLY_STATE:
                    current_state = HR_STATE;
                    Console.WriteLine("核准假單");
                    break;
                case HR_STATE:
                    if (totalCount == 0)
                    {
                        current_state = APPLY_STATE;
                        Console.WriteLine("回申請流程");
                    }
                    else
                    {
                        totalCount--;
                        current_state = STOP_STATE;
                        Console.WriteLine("結束流程");
                    }

                    break;
                case STOP_STATE:
                    Console.WriteLine("已結束流程");
                    break;
            }
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            LeaveFlow leave = new LeaveFlow();
            leave.nextState();
            leave.nextState();
            leave.nextState();

            Console.ReadLine();
        }
    }
}

using System;

namespace StatePattern
{
    public class LeaveFlow
    {
        private State state;
        private int totalCount = 7;

        public int TotalCount
        {
            get { return totalCount; }
            set { totalCount = value; }
        }

        public LeaveFlow()
        {
            state = new StartState();
        }

        public void nextState()
        {
            state.nextState(this);
        }

        public void setState(State state)
        {
            this.state = state;
        }
    }

    public abstract class State
    {
        abstract public void nextState(LeaveFlow flow);
    }

    public class StartState : State
    {

        public override void nextState(LeaveFlow flow)
        {
            flow.setState(new ApplyState());
            Console.WriteLine("提出申請");
        }
    }

    public class ApplyState : State
    {
        public override void nextState(LeaveFlow flow)
        {
            flow.setState(new HRState());
            Console.WriteLine("核准假單");
        }
    }

    public class HRState : State
    {
        public override void nextState(LeaveFlow flow)
        {
            if (flow.TotalCount == 0)
            {
                flow.setState(new ApplyState());
                Console.WriteLine("回申請流程");
            }
            else
            {
                flow.TotalCount = flow.TotalCount - 1;
                flow.setState(new StopState());
                Console.WriteLine("結束流程");
            }
        }
    }

    public class StopState : State
    {
        public override void nextState(LeaveFlow flow)
        {
            Console.WriteLine("流程已結束");
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            LeaveFlow leave = new LeaveFlow();
            leave.nextState();
            leave.nextState();
            leave.nextState();

            Console.ReadLine();
        }
    }
}