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


/// <summary>
/// 每帧检查一次的 可作用于UI的Timer
/// </summary>
public class UITimer : MonoBehaviour {

    /// <summary>
    /// UI Timer 触发事件风格
    /// </summary>
    public enum eTriggerStyle
    {
        Once,                                           // 只触发一次事件 执行后自动失效 默认类型
        Loop,                                           // 循环触发事件 直到手动关闭 (实际作用次数20亿次)
        Count,                                          // 指定次数触发事件 直到剩余次数为0自行关闭
    }

    /// <summary>
    /// UI Timer Data
    /// </summary>
    public class Data
    {
        #region member

        private eTriggerStyle m_Type;                   // 事件触发风格 
        private int m_id;                               // 编号
        private int m_space;                            // 事件触发间隔时长 单位:ms
        private int m_leftCount;                        // 时间
        private UInt64 m_nextTime;                         // 下一次触发时间
        private Action m_Callback;                      // 返回值int的类型的事件


        #endregion

        #region property

        public eTriggerStyle Type
        {
            get { return m_Type; }
            set { m_Type = value; }
        }

        public int id
        {
            get { return m_id; }
            set { m_id = value; }
        }

        public int space
        {
            get { return m_space; }
            set { m_space = value; }
        }

        public int leftCount
        {
            get { return m_leftCount; }
            set { m_leftCount = value; }
        }

        public Action CallBack
        {
            get { return m_Callback; }
            set { m_Callback = value; }
        }

        public UInt64 nextTime
        {
            get { return m_nextTime; }
            set { m_nextTime = value; }
        }

        #endregion

        #region function

        public Data(eTriggerStyle _Type, int _id, int _space, int _leftCount, Action _Callback)
        {
            Type = _Type;
            id = _id;
            space = _space;            
            CallBack += _Callback;

            if (Type == eTriggerStyle.Once)
                leftCount = 1;
            else if (Type == eTriggerStyle.Loop)
                leftCount = MAX_TRIGGER_COUNT;
            else
                leftCount = _leftCount;
        }

        public void InitNextTime(UInt64 _curTimerPassTime)
        {
            nextTime = _curTimerPassTime + (UInt64)space;
        }

        private void RefreshNextTime()
        {
            nextTime += (UInt64)space;
        }

        public void Run()
        {
            if(CallBack != null)
                CallBack();

            leftCount--;

            if(leftCount > 0)
                RefreshNextTime();
        }

        #endregion
    }

    /// <summary>
    /// 唯一实例
    /// </summary>
    private static UITimer m_Instance;
    private UITimer() { }
    public static UITimer Instance
    {
        get
        {
            if (m_Instance == null)
                Debug.LogError("Error, m_Instance == null.");

            return m_Instance;
        }
    }

    public static readonly int MAX_TRIGGER_COUNT = 2000000000;
    private static int s_nextId = 0;

    #region member

    private List<Data> m_DataLst;

    private double m_time;              // 运行时间 单位:s

    private List<Data> m_NeedRemoveList;

    #endregion

    #region property

    public List<Data> DataLst {

        get
        {
            if (m_DataLst == null)
                m_DataLst = new List<Data>();
            return m_DataLst;
        }

    }

    public List<Data> NeedRemoveList
    {
        get
        {
            if (m_NeedRemoveList == null)
                m_NeedRemoveList = new List<Data>();

            return m_NeedRemoveList;
        }
    }




    private static int NextId
    {
        get { return ++s_nextId; }
    }

    #endregion

    #region function
    void Awake()
    {
        m_Instance = this;
    }

    void Update()
    {     
        if (!IsNeedRun())
            return;

        Run();
    }

    /// <summary>
    /// 创建一个Timer
    /// </summary>
    /// <param name="_triggerSpace">触发间隔 单位:ms</param>
    /// <param name="_Callback">触发回调事件</param>
    /// <param name="_TriggerStyle">触发风格</param>
    /// <param name="_count">触发次数 _TriggerStyle == eTriggerStyle.Count 有用</param>
    /// <returns></returns>
    public Data Create(int _triggerSpace, Action _Callback, eTriggerStyle _TriggerStyle = eTriggerStyle.Once, int _count = 1)
    {
        Data vData = new Data(_TriggerStyle, UITimer.NextId, _triggerSpace, _count, _Callback);
        vData.InitNextTime(GetTimeMs());
        InsertData(vData);
        return vData;
    }

    public void Remove(Data _Data)
    {
        for(int i = 0; i < DataLst.Count; i++)
        {
            if(DataLst[i].id == _Data.id)
            {
                DataLst.Remove(DataLst[i]);
                break;
            }                
        }

        if (!IsNeedRun())
            Reset();
    }

    private UInt64 GetTimeMs()
    {
        UInt64 passMs = Convert.ToUInt64(m_time * 1000);
        return passMs;
    }

    private bool IsNeedRun()
    {
        return (DataLst.Count > 0);
    }

    void Reset()
    {
        m_time = 0.0f;
    }
    
    private void Run()
    {
        m_time += Time.deltaTime;

        NeedRemoveList.Clear();

        Trigger();

        if (NeedRemoveList.Count <= 0)
            return;

        RemoveStopData();
    }

    // 是不是可以用2分插入法优化一下
    private void InsertData(Data _Data)
    {
        DataLst.Add(_Data);
    }

    private void Trigger()
    {
        UInt64 curPassTime = GetTimeMs();

        for (int i = 0; i < DataLst.Count; i++)
        {
            if (DataLst[i].nextTime <= curPassTime)
            {
                DataLst[i].Run();

                if (DataLst[i].leftCount <= 0)
                    NeedRemoveList.Add(DataLst[i]);    
            }
        }
    }

    private void RemoveStopData()
    {
        for(int i = 0; i < NeedRemoveList.Count; i++)
        {
            this.Remove(NeedRemoveList[i]);
        }
    }

    #endregion
}