using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


public static class SMvcr
{

    private static StateVCR _concreteState;

    public delegate void VCREventHandler();

    public static event VCREventHandler evStopbutton;

    public static event VCREventHandler evEndtape;

    public static event VCREventHandler evRecordbutton;

    public static event VCREventHandler evPlaybutton;

    public static event VCREventHandler evBeginningtape;

    public static event VCREventHandler evRewindbutton;

    public static event VCREventHandler evFastforwardbutton;

    public static void initSMvcr()
    {
        setState(new SvcrStandBy());
    }

    public static void setState(StateVCR e)
    {
        _concreteState = null;
        _concreteState = e;
    }

}


public abstract class StateVCR
{
    public abstract void evStopbutton();
    public abstract void evEndtape();
    public abstract void evRecordbutton();
    public abstract void evPlaybutton();
    public abstract void evBeginningtape();
    public abstract void evRewindbutton();
    public abstract void evFastforwardbutton();
}

public class SvcrStandBy : StateVCR
{

    public SvcrStandBy()
    {
        Debug.Print("Standby\n");

        SMvcr.evRecordbutton += evRecordbutton;
        SMvcr.evPlaybutton += evPlaybutton;
        SMvcr.evRewindbutton += evRewindbutton;

    }
    public override void evStopbutton()
    {
        
    }

    public override void evEndtape()
    {
        
    }

    public override void evRecordbutton()
    {
        SMvcr.evRecordbutton -= evRecordbutton;
        SMvcr.evPlaybutton -= evPlaybutton;
        SMvcr.evRewindbutton -= evRewindbutton;

        SMvcr.setState(new SvcrRecord());
    }

    public override void evPlaybutton()
    {
        SMvcr.evRecordbutton -= evRecordbutton;
        SMvcr.evPlaybutton -= evPlaybutton;
        SMvcr.evRewindbutton -= evRewindbutton;

        SMvcr.setState(new SvcrPlay());
    }

    public override void evBeginningtape()
    {
        
    }

    public override void evRewindbutton()
    {
        SMvcr.evRecordbutton -= evRecordbutton;
        SMvcr.evPlaybutton -= evPlaybutton;
        SMvcr.evRewindbutton -= evRewindbutton;

        SMvcr.setState(new SvcrRewind());
    }

    public override void evFastforwardbutton()
    {
        
    }
}

public class SvcrPlay : StateVCR
{
    public SvcrPlay()
    {
        Debug.Print("Play\n");

        SMvcr.evStopbutton += evStopbutton;
        SMvcr.evEndtape += evEndtape;
        SMvcr.evRewindbutton += evRewindbutton;
        SMvcr.evFastforwardbutton += evFastforwardbutton;
    }
    public override void evStopbutton()
    {
        SMvcr.evStopbutton -= evStopbutton;
        SMvcr.evEndtape -= evEndtape;
        SMvcr.evRewindbutton -= evRewindbutton;
        SMvcr.evFastforwardbutton -= evFastforwardbutton;

        SMvcr.setState(new SvcrStandBy());
    }

    public override void evEndtape()
    {
        SMvcr.evStopbutton -= evStopbutton;
        SMvcr.evEndtape -= evEndtape;
        SMvcr.evRewindbutton -= evRewindbutton;
        SMvcr.evFastforwardbutton -= evFastforwardbutton;

        SMvcr.setState(new SvcrStandBy());
    }

    public override void evRecordbutton()
    {
        
    }

    public override void evPlaybutton()
    {
       
    }

    public override void evBeginningtape()
    {
       
    }

    public override void evRewindbutton()
    {
        SMvcr.evStopbutton -= evStopbutton;
        SMvcr.evEndtape -= evEndtape;
        SMvcr.evRewindbutton -= evRewindbutton;
        SMvcr.evFastforwardbutton -= evFastforwardbutton;

        SMvcr.setState(new SvcrRewind());
    }

    public override void evFastforwardbutton()
    {
        SMvcr.evStopbutton -= evStopbutton;
        SMvcr.evEndtape -= evEndtape;
        SMvcr.evRewindbutton -= evRewindbutton;
        SMvcr.evFastforwardbutton -= evFastforwardbutton;

        SMvcr.setState(new SvcrFastForward());
    }
}

public class SvcrRewind : StateVCR
{

    public SvcrRewind()
    {
        Debug.Print("Rewind\n");

        SMvcr.evStopbutton += evStopbutton;
        SMvcr.evBeginningtape += evBeginningtape;
        SMvcr.evPlaybutton += evPlaybutton;
        SMvcr.evFastforwardbutton += evFastforwardbutton;
    }
    public override void evStopbutton()
    {
        SMvcr.evStopbutton -= evStopbutton;
        SMvcr.evBeginningtape -= evBeginningtape;
        SMvcr.evPlaybutton -= evPlaybutton;
        SMvcr.evFastforwardbutton -= evFastforwardbutton;

        SMvcr.setState(new SvcrStandBy());
    }

    public override void evEndtape()
    {
    }

    public override void evRecordbutton()
    {
    }

    public override void evPlaybutton()
    {
        SMvcr.evStopbutton -= evStopbutton;
        SMvcr.evBeginningtape -= evBeginningtape;
        SMvcr.evPlaybutton -= evPlaybutton;
        SMvcr.evFastforwardbutton -= evFastforwardbutton;

        SMvcr.setState(new SvcrPlay());
    }

    public override void evBeginningtape()
    {
        SMvcr.evStopbutton -= evStopbutton;
        SMvcr.evBeginningtape -= evBeginningtape;
        SMvcr.evPlaybutton -= evPlaybutton;
        SMvcr.evFastforwardbutton -= evFastforwardbutton;

        SMvcr.setState(new SvcrStandBy());
    }

    public override void evRewindbutton()
    {
    }

    public override void evFastforwardbutton()
    {
        SMvcr.evStopbutton -= evStopbutton;
        SMvcr.evBeginningtape -= evBeginningtape;
        SMvcr.evPlaybutton -= evPlaybutton;
        SMvcr.evFastforwardbutton -= evFastforwardbutton;

        SMvcr.setState(new SvcrFastForward());
    }
}

public class SvcrFastForward : StateVCR
{
    public SvcrFastForward()
    {
        Debug.Print("FastForward\n");

        SMvcr.evStopbutton += evStopbutton;
        SMvcr.evEndtape += evEndtape;
        SMvcr.evRewindbutton += evRewindbutton;
    }
    public override void evStopbutton()
    {
        SMvcr.evStopbutton -= evStopbutton;
        SMvcr.evEndtape -= evEndtape;
        SMvcr.evRewindbutton -= evRewindbutton;

        SMvcr.setState(new SvcrStandBy());
    }

    public override void evEndtape()
    {
        SMvcr.evStopbutton -= evStopbutton;
        SMvcr.evEndtape -= evEndtape;
        SMvcr.evRewindbutton -= evRewindbutton;

        SMvcr.setState(new SvcrStandBy());
    }

    public override void evRecordbutton()
    {
    }

    public override void evPlaybutton()
    {
    }

    public override void evBeginningtape()
    {
    }

    public override void evRewindbutton()
    {
        SMvcr.evStopbutton -= evStopbutton;
        SMvcr.evEndtape -= evEndtape;
        SMvcr.evRewindbutton -= evRewindbutton;

        SMvcr.setState(new SvcrRewind());
    }

    public override void evFastforwardbutton()
    {
    }
}

public class SvcrRecord : StateVCR
{
    public SvcrRecord()
    {
        Debug.Print("Record\n");

        SMvcr.evStopbutton += evStopbutton;
        SMvcr.evEndtape += evEndtape;
    }
    public override void evStopbutton()
    {
        SMvcr.evStopbutton -= evStopbutton;
        SMvcr.evEndtape -= evEndtape;

        SMvcr.setState(new SvcrStandBy());
    }

    public override void evEndtape()
    {
        SMvcr.evStopbutton -= evStopbutton;
        SMvcr.evEndtape -= evEndtape;

        SMvcr.setState(new SvcrStandBy());
    }

    public override void evRecordbutton()
    {
    }

    public override void evPlaybutton()
    {
    }

    public override void evBeginningtape()
    {
    }

    public override void evRewindbutton()
    {
    }

    public override void evFastforwardbutton()
    {
    }
}