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

namespace BrewMonster.Scripts.Task.UI
{
    public class TaskTreeView : MonoBehaviour, IRefreshLayout
    {
        [SerializeField] private TaskTreeViewHolder m_pTreeViewHolder;
        
        [Header("DEBUG")]
        [SerializeField] private TaskTreeViewHolder _currentSelectedItem = null;
        [SerializeField] private TaskTreeViewHolder[] m_aTreeViewItems;
        
        private RectTransform _rectTransform;
        private void Awake()
        {
            _rectTransform = GetComponent<RectTransform>();
        }

        private void Start()
        {
            EventBus.Subscribe<TaskItemClickEvent>(evt =>
            {
                SetSelectedItem(evt.Data);
            });
        }
        
        public void SetItemData(TaskTreeViewHolder item, uint taskType)
        {
            item.SetItemData(taskType);
        }

        public uint GetItemData(TaskTreeViewHolder item)
        {
            if (item == null)
                return 0;
            return item.GetItemData();
        }
        
        public TaskTreeViewHolder GetNextSiblingItem(TaskTreeViewHolder item)
        {
            
            if (m_aTreeViewItems == null)
            {
                m_aTreeViewItems = GetComponentsInChildren<TaskTreeViewHolder>(true);
            }

            for (int i = 0; i < m_aTreeViewItems.Length - 1; i++)
            {
                if (m_aTreeViewItems[i] == item)
                {
                    return m_aTreeViewItems[i + 1];
                }
            }

            return null;
        }
        
        public TaskTreeViewHolder InsertItem(string text, TaskTreeViewHolder pParent, TaskTreeViewHolder pAfter)
        {
            //caculate treelevel first  
            int treeLevel = pParent != null ? pParent.GetTreeLevel() + 1 : 0;
            // Create a new item GameObject and component
            TaskTreeViewHolder pItem = Instantiate(m_pTreeViewHolder);
            
            if(pParent != null)
            {
                pParent.SetLastItem(false);
            }
            pItem.SetLastItem(true);
            GameObject go = pItem.gameObject;
            // go.name = $"Task_{}";
            if (pItem == null) return null;

            // Parent: root (this) if null; otherwise under given parent item
            var parentTransform = (pParent != null ? pParent.transform : this.transform);
            go.transform.SetParent(parentTransform, false);

            // Set sibling position: after specific item if provided; otherwise append to end
            if (pAfter != null && pAfter.transform.parent == parentTransform)
            {
                int afterIndex = pAfter.transform.GetSiblingIndex();
                go.transform.SetSiblingIndex(afterIndex + 1);
            }
            else
            {
                go.transform.SetAsLastSibling();
            }

            // Optionally set label text if a TMP_Text is attached under the item (not required here)
            // var label = go.GetComponentInChildren<TMPro.TMP_Text>(true);
            // if (label != null) label.text = text ?? string.Empty;
            pItem.SetItemText(text);
            pItem.SetTreeLevel(treeLevel);

            // Refresh local cache of items
            m_aTreeViewItems = GetComponentsInChildren<TaskTreeViewHolder>(true);
            
            // pParent.RefreshLayout();
            if(pParent) pParent.OnExpand(false); // Collapse parent to show new item only when expanded
            
            return pItem;
        }

        public void DeleteAllItems()
        {
            List<Transform> childrenCopy = new();
            foreach (Transform child in transform)
            {
                // Destroy(child.GetComponent<TaskTreeViewHolder>());
                childrenCopy.Add(child);
            }
            
            foreach (var child in childrenCopy)
            {
                child.SetParent(null);
                Destroy(child.gameObject);
            }
            
            m_aTreeViewItems = null;
            // m_aTreeViewItems = GetComponentsInChildren<TaskTreeViewHolder>(true);
            _currentSelectedItem = null;
        }
        

        public TaskTreeViewHolder GetItemByData(uint taskType)
        {
            
            if (m_aTreeViewItems == null)
            {
                m_aTreeViewItems = new TaskTreeViewHolder[this.transform.childCount];
                m_aTreeViewItems = GetComponentsInChildren<TaskTreeViewHolder>(true);
            }

            foreach (var item in m_aTreeViewItems)
            {
                if (item.GetItemData() == taskType)
                {
                    return item;
                }
            }

            return null;
        }

        public TaskTreeViewHolder GetFirstChild()
        {
            return transform.childCount == 0 ? null : transform.GetChild(0).GetComponent<TaskTreeViewHolder>();
        }
        
        public TaskTreeViewHolder GetSelectedItem()
        {
            return _currentSelectedItem;
        }

        void SetSelectedItem(uint idItem)
        {
            _currentSelectedItem = GetItemByData(idItem);
        }
        
        public void RefreshLayout()
        {
            var parent = _rectTransform;
            foreach(var child in GetComponentsInChildren<TaskTreeViewHolder>(true))
            {
                child.RefreshSelf();
            }
            // Force Unity to rebuild layout immediately
            parent.ForceUpdateRectTransforms();
            LayoutRebuilder.ForceRebuildLayoutImmediate(parent);
        }

        /// <summary>
        /// Resolve all prefabs after quest loading is complete
        /// This should be called after all items are added and SetLastItem() calls are done
        /// 在任务加载完成后解析所有预制体
        /// 这应该在所有项目添加完成且SetLastItem()调用完成后调用
        /// </summary>
        public void ResolveAllPrefabs()
        {
            // Refresh cache to get all items
            m_aTreeViewItems = GetComponentsInChildren<TaskTreeViewHolder>(true);
            
            if (m_aTreeViewItems == null) return;
            
            // Resolve prefab for each item
            foreach (var item in m_aTreeViewItems)
            {
                if (item != null)
                {
                    item.ResolvePrefab();
                    item.RefreshSelf();
                }
            }
        }

    }
}