experiments-monogame/UPWG/UPWG.Core/StateMachine.cs

using System;
using System.Collections.Generic;

namespace UPWG.Core
{
    public class StateMachine<T>
        where T : Enum
    {
        public T CurrentState { get; private set; }
        public double TimeInState { get; private set; }
        private Dictionary<T, (double, T)> _transitions;

        public StateMachine(T initial)
        {
            CurrentState = initial;
            TimeInState = 0;
            _transitions = new Dictionary<T, (double, T)>();
        }

        public void AddTransition(T from, T to, double after = 0)
        {
            _transitions[from] = (after, to);
        }

        public void SetState(T newState)
        {
            CurrentState = newState;
            TimeInState = 0;
        }

        public void Update(double elapsed)
        {
            TimeInState += elapsed;

            if (!_transitions.ContainsKey(CurrentState))
                return;

            var (maxTime, nextState) = _transitions[CurrentState];
            if (TimeInState > maxTime)
            {
                SetState(nextState);
            }
        }
    }
}