using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class FSMSystem {
    public FSMState currentState;
    private Dictionary<StateId, FSMState> dic;
    public FSMSystem()
    {
        dic=new Dictionary<StateId,FSMState>();
    }
    public void AddState(FSMState state)
    {
        if(state==null)
        {
            Debug.LogError("The state is null");
            return;
        }
        if(dic.ContainsKey(state.ID))
        {
            Debug.LogError("The state is exist");
            return;
        }
        dic.Add(state.ID, state);
    }
    public void DeleteState(StateId id)
    {
        if (id == StateId.NullStateId)
        {
            Debug.LogError("The state you want to delete is null."); return;
        }
        if (!dic.ContainsKey(id))
        {
            Debug.LogError("The state " + id + " you want to delete is not exit."); return;
        }
        dic.Remove(id);
    }
    public void TranslateState(Transtition trans)
    {
        if(trans==Transtition.NullTranstition)
        {
            Debug.LogError("The Transtition is null");
            return;
        }
        StateId id = currentState.GetNextStateID(trans);
        if(id==default(StateId))
        {
            Debug.LogError("Current state is not exist Transtition");
            return;
        }
        FSMState fs;
        if (dic.TryGetValue(id, out fs))
        {
            currentState.BeforeLeaveState();
            currentState = fs;
            currentState.BeforeEnterState();
        }
        else
        {
            Debug.LogError("The FsmSystem is not contain the FsmState.");
            return;
        }        
    }
    public void Start(StateId id)
    {
        FSMState state;
        bool isGet = dic.TryGetValue(id, out state);
        if (isGet)
        {
            state.BeforeEnterState();
            currentState = state;
        }
        else
        {
            Debug.LogError("The state " + id + " is not exit in the fsm.");
        }
    }
    public void DOUpDate()
    {
        Transtition trans=currentState.CheckTranstition();
        if (trans != Transtition.NullTranstition)
            TranslateState(trans);
        currentState.DoUpdate();
    }
}