using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using Newtonsoft.Json.Utilities;

namespace WK
{
    /// <summary>
    /// 一般状态机
    /// </summary>
    public class BasicStatemachine
    {
        public delegate void StateEvent();
        public delegate bool StateFinishChecker();
        public class State
        {
            public BasicStatemachine owner;
            public int stateId;

            public virtual void BeginState()
            {
                //reserve function
            }
            public virtual void EndState()
            {
                //reserve function
            }
            //时间单位是毫秒      
            public virtual bool UpdateState(int deltaTimeMS)
            {
                return true;
            }
        }

        private Dictionary<int/*state id*/, State> stateDic = new Dictionary<int/*state id*/, State>();
        private int currentStateId = -1;
        private int stateIdDistributor = 0;

        private int recordLastStateId = -1;

        public int RegisterState(State newState)
        {
            if (newState != null)
            {
                if (stateIdDistributor + 1 > int.MaxValue)
                {
                    LogHelper.LogError("状态机添加状态失败：一个状态机中添加了过多的状态！");
                    return -1;
                }

                stateIdDistributor++;
                if (!stateDic.ContainsKey(stateIdDistributor))
                {
                    stateDic.Add(stateIdDistributor, newState);
                    newState.owner = this;
                    newState.stateId = stateIdDistributor;
                    return stateIdDistributor;
                }
            }
            LogHelper.LogError("状态机添加状态失败：无效的新状态或新状态已存在！");
            return -1;
        }

        public bool RemoveState(State toBeRemoveState)
        {
            if (toBeRemoveState != null)
                return RemoveState(toBeRemoveState.stateId);
            LogHelper.LogError("状态机删除状态失败：无效的状态！");
            return false;
        }

        public bool RemoveState(int stateId)
        {
            if (stateDic.ContainsKey(stateId))
            {
                stateDic.Remove(stateId);
                return true;
            }
            LogHelper.LogError("状态机删除状态失败：该状态不存在！");
            return false;
        }

        public bool Begin(int beginStateId)
        {
            if (!HasBegin())
            {
                ForceGoToState(beginStateId, false);
                return true;
            }

            return false;
        }

        public bool Stop()
        {
            if (HasBegin())
            {
                ForceGoToState(-1);
                return true;
            }

            return false;
        }

        public bool GoToState(int newStateId, bool skipBeginFunc = false, bool forceLoad = false)
        {
            if (HasBegin())
            {
                return ForceGoToState(newStateId, skipBeginFunc, forceLoad);
            }
            return false;
        }

        private bool ForceGoToState(int newStateId)
        {
            return ForceGoToState(newStateId, false);
        }
        private bool ForceGoToState(int newStateId, bool skipBeginFunc, bool bForce = false)
        {
            if (currentStateId != newStateId || bForce)
            {
                OnStateEnd(currentStateId);
                currentStateId = newStateId;
                if (!skipBeginFunc) OnStateBegin(currentStateId);
                return true;
            }
            else
            {
                return false;
            }
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="filterState">剔除的state</param>
        public void RecordCurrentState(int filterState)
        {
            if (currentStateId != filterState)
            {
                recordLastStateId = currentStateId;
            }
        }

        public void ClearRecordState()
        {
            recordLastStateId = -1;
        }

        public void RevertToRecordState(int fallbackState, bool skipBeginFunc, bool bForce = false)
        {
            if (recordLastStateId >= 0 && stateDic.ContainsKey(recordLastStateId))
            {
                GoToState(recordLastStateId, skipBeginFunc, bForce);
            }
            else if (fallbackState >= 0 && stateDic.ContainsKey(fallbackState))
            {
                GoToState(fallbackState, skipBeginFunc, bForce);
            }
        }


        //时间单位是毫秒
        public void OnUpdate(int mSecDeltaTime)
        {
            if (HasBegin())
            {
                UpdateState(currentStateId, mSecDeltaTime);
            }
        }

        public bool HasBegin()
        {
            if (currentStateId != -1 && stateDic.ContainsKey(currentStateId))
                return true;
            else
                return false;
        }

        public bool IsInState(int stateId)
        {
            if (HasBegin())
            {
                return currentStateId == stateId;
            }
            return false;
        }


        public int GetCurrentStateId()
        {
            return currentStateId;
        }

        public State GetState(int stateId)
        {
            if (stateDic.ContainsKey(stateId))
            {
                return stateDic[stateId];
            }
            return null;
        }

        public void Clean()
        {
            stateDic.Clear();
            currentStateId = -1;
            stateIdDistributor = 0;
            recordLastStateId = -1;
        }

        /// <summary>
        /// 重置当前状态(置为-1)
        /// </summary>
        public void ResetCurrentState()
        {
            currentStateId = -1;
        }

        private void OnStateBegin(int stateId)
        {
            if (HasBegin())
            {
                State state = GetState(stateId);
                if (state != null)
                    state.BeginState();
            }
        }

        private void OnStateEnd(int stateId)
        {
            if (HasBegin())
            {
                State state = GetState(stateId);
                if (state != null)
                    state.EndState();
            }
        }
        //时间单位是毫秒
        private void UpdateState(int stateId, int mSecDeltaTime)
        {
            if (HasBegin())
            {
                State state = GetState(stateId);
                if (state != null)
                    state.UpdateState(mSecDeltaTime);
            }
        }
    }

}