using System.Collections.Generic;
using Lean.Pool;
using UnityEngine;

namespace Ichni.RhythmGame
{
    public class NoteManager : MonoBehaviour
    {
        #region [核心管家字段] Fields
        // 挂起队列：存放还未进入判定时间序列休眠的预设
        private List<(float activationTime, NoteBase note)> _pendingNotes = new List<(float, NoteBase)>();
        // 活跃队列：存活在场上的有效音符，统一进行中央更新
        private List<NoteBase> _activeNotes = new List<NoteBase>(500);
        private int _nextNoteIndex = 0;
        #endregion

        #region [队列注册与控制] Registration
        public void RegisterNote(NoteBase note, float activationTime)
        {
            _pendingNotes.Add((activationTime, note));
        }

        public void AllNotesRegistered()
        {
            _pendingNotes.Sort((a, b) => a.activationTime.CompareTo(b.activationTime));
            _nextNoteIndex = 0;
        }
        #endregion

        #region [中央集权主循环] Manager-Driven Tick
        public void ManualUpdate(float currentSongTime)
        {
            if (!GameManager.Instance.songPlayer.isUpdating) return;

            // 1. 唤醒 pending 并推进入场
            while (_nextNoteIndex < _pendingNotes.Count && 
                   currentSongTime >= _pendingNotes[_nextNoteIndex].activationTime)
            {
                NoteBase noteToActivate = _pendingNotes[_nextNoteIndex].note;
                noteToActivate.gameObject.SetActive(true);
                _activeNotes.Add(noteToActivate);
                _nextNoteIndex++;
            }

            // 2. 集中处理场内活跃 Note (倒序遍历以防越界)
            for (int i = _activeNotes.Count - 1; i >= 0; i--)
            {
                if (!_activeNotes[i].ManualUpdate(currentSongTime))
                {
                    _activeNotes.RemoveAt(i);
                }
            }
        }
        
        public void ManualLateUpdate(float currentSongTime)
        {
            if (!GameManager.Instance.songPlayer.isUpdating) return;

            for (int i = _activeNotes.Count - 1; i >= 0; i--)
            {
                if (_activeNotes[i] is Hold hold)
                {
                    hold.isHolding = false;
                }
            }
        }
        
        #endregion

        #region [生命回收] Pool Management
        public void DespawnNote(NoteBase note)
        {
            if (note.gameObject.activeSelf) 
            {
                LeanPool.Despawn(note.gameObject);
            }
        }
        #endregion
    }
}