using System;

namespace Bro.Common.AbstractFSM
{
    
    public interface IStateManager : IDisposable 
    {
        void ChangeState(object sender, StateEventArgs eventArgs);
        bool CheckState(object sender, StateEventArgs eventArgs);
    }
    public abstract class StatesManager : IStateManager
    {
        // Declare the delegate (if using non-generic pattern).
        public delegate void StateChangedEventHandler(object sender, StateEventArgs eventArgs);
        // Declare the event.
        public event StateChangedEventHandler StateChanged;

        public StatesManager()
        {
            //build transitions and set an initial state
            m_activeState = BuildTransitionsTable(); 
        }

        public virtual void Dispose()
        {
            //virtual method
        }
        State m_activeState = null;
        public State ActiveState
        {
            get { return m_activeState; }
        }

        Transitions m_transitions = new Transitions();
        public Transitions Transitions
        {
            get { return m_transitions; }
        }
        //returns initial state
        protected abstract State BuildTransitionsTable();
        //
        public virtual void ChangeState(object sender, StateEventArgs eventArgs)
        {
            Transition transition = m_transitions[m_activeState, eventArgs];
            m_activeState = transition.finalState;
            //raise 'StateChanged' event
             if (StateChanged != null)
                 StateChanged(this, eventArgs); 
            if (transition.action != null)
                transition.action(this, eventArgs);
            //if the transitional is automatic - automatically go to the next state:
            if (transition.AutoMode == true && transition.AutoTransition != null)
            {
                m_activeState = transition.AutoTransition.initialState;
                ChangeState(sender, transition.AutoTransition.eventArgs);    
            }
        }
        public virtual bool CheckState(object sender, StateEventArgs eventArgs)
        {
            return m_transitions.ContainsKey(Transition.GetHashCode(m_activeState, eventArgs));
        } 
    }
}