using System;
using System.Collections.Generic;
using System.Linq;
using Convention;
using UnityEngine;

namespace Demo.Game
{
    /// <summary>
    /// 全局扁平化Update调度器
    /// </summary>
    public class UpdateScheduler
    {
        // 永久活跃对象
        private readonly List<IUpdateable> permanentObjects = new();
        
        // 时间范围对象（排序队列）
        private readonly SortedDictionary<float, List<IUpdateable>> activationQueue = new();
        private readonly SortedDictionary<float, List<IUpdateable>> deactivationQueue = new();
        
        // 当前活跃对象
        private readonly List<IUpdateable> activeObjects = new();
        
        // 统计信息
        public int TotalRegistered => permanentObjects.Count + activationQueue.Values.Sum(l => l.Count);
        public int CurrentActive => permanentObjects.Count + activeObjects.Count;
        
        /// <summary>
        /// 注册对象到调度器
        /// </summary>
        public void Register(IUpdateable obj, UpdateMode mode, float startTime = 0f, float endTime = float.MaxValue)
        {
            if (obj == null)
            {
                Debug.LogError("[UpdateScheduler] 尝试注册null对象");
                return;
            }
            
            switch (mode)
            {
                case UpdateMode.Permanent:
                    if (!permanentObjects.Contains(obj))
                    {
                        permanentObjects.Add(obj);
                        Debug.Log($"[UpdateScheduler] 注册永久对象: {obj.GetUpdateName()}");
                    }
                    break;
                    
                case UpdateMode.TimeBound:
                    // 注册激活时间
                    if (!activationQueue.ContainsKey(startTime))
                        activationQueue[startTime] = new List<IUpdateable>();
                    
                    if (!activationQueue[startTime].Contains(obj))
                    {
                        activationQueue[startTime].Add(obj);
                        Debug.Log($"[UpdateScheduler] 注册时间范围对象: {obj.GetUpdateName()} ({startTime:F2}s - {endTime:F2}s)");
                    }
                    
                    // 注册停用时间
                    if (!deactivationQueue.ContainsKey(endTime))
                        deactivationQueue[endTime] = new List<IUpdateable>();
                    
                    if (!deactivationQueue[endTime].Contains(obj))
                    {
                        deactivationQueue[endTime].Add(obj);
                    }
                    break;
                    
                case UpdateMode.Manual:
                    // 手动模式不自动注册
                    Debug.Log($"[UpdateScheduler] 手动模式对象: {obj.GetUpdateName()}");
                    break;
            }
        }
        
        /// <summary>
        /// 手动激活对象（Manual模式）
        /// </summary>
        public void Activate(IUpdateable obj)
        {
            if (!activeObjects.Contains(obj))
            {
                activeObjects.Add(obj);
            }
        }
        
        /// <summary>
        /// 手动停用对象（Manual模式）
        /// </summary>
        public void Deactivate(IUpdateable obj)
        {
            activeObjects.Remove(obj);
        }
        
        /// <summary>
        /// 主Update循环 - 扁平化遍历
        /// </summary>
        public void DoUpdate(float currentTime, float deltaTime, ScriptableObject.TickType tickType)
        {
            // 时间分片管理
            using (Profiler.BeginZone("UpdateScheduler.TimeSlicing"))
            {
                ProcessActivations(currentTime);
                ProcessDeactivations(currentTime);
            }
            
            // 扁平更新所有活跃对象
            using (Profiler.BeginZone($"UpdateScheduler.FlatUpdate (Permanent:{permanentObjects.Count} Active:{activeObjects.Count})"))
            {
                // 永久活跃对象
                for (int i = 0; i < permanentObjects.Count; i++)
                {
                    if (permanentObjects[i]?.IsUpdateReady == true)
                    {
                        permanentObjects[i].DoUpdate(currentTime, deltaTime, tickType);
                    }
                }
                
                // 当前活跃对象
                for (int i = activeObjects.Count - 1; i >= 0; i--)
                {
                    if (activeObjects[i] == null || !activeObjects[i].IsUpdateReady)
                    {
                        activeObjects.RemoveAt(i);
                        continue;
                    }
                    
                    activeObjects[i].DoUpdate(currentTime, deltaTime, tickType);
                }
            }
        }
        
        private void ProcessActivations(float currentTime)
        {
            while (activationQueue.Count > 0)
            {
                var firstKey = activationQueue.Keys.First();
                if (firstKey > currentTime) break;
                
                var objects = activationQueue[firstKey];
                foreach (var obj in objects)
                {
                    if (obj != null && !activeObjects.Contains(obj))
                    {
                        activeObjects.Add(obj);
                        Debug.Log($"[UpdateScheduler] 激活: {obj.GetUpdateName()} @ {currentTime:F2}s");
                    }
                }
                
                activationQueue.Remove(firstKey);
            }
        }
        
        private void ProcessDeactivations(float currentTime)
        {
            while (deactivationQueue.Count > 0)
            {
                var firstKey = deactivationQueue.Keys.First();
                if (firstKey > currentTime) break;
                
                var objects = deactivationQueue[firstKey];
                foreach (var obj in objects)
                {
                    activeObjects.Remove(obj);
                    if (obj != null)
                    {
                        Debug.Log($"[UpdateScheduler] 停用: {obj.GetUpdateName()} @ {currentTime:F2}s");
                    }
                }
                
                deactivationQueue.Remove(firstKey);
            }
        }
        
        /// <summary>
        /// 重置调度器（用于Reset/Restart）
        /// </summary>
        public void Reset()
        {
            activeObjects.Clear();
            Debug.Log("[UpdateScheduler] 重置完成");
        }
        
        /// <summary>
        /// 清空所有注册
        /// </summary>
        public void Clear()
        {
            permanentObjects.Clear();
            activationQueue.Clear();
            deactivationQueue.Clear();
            activeObjects.Clear();
            Debug.Log("[UpdateScheduler] 清空所有注册");
        }
    }
}