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

/// <summary>
/// 通用滑动列表组件
/// 支持动态添加、删除和更新列表项，带有滚动功能
/// </summary>
public class ScrollableListView : MonoBehaviour
{
    [Header("滚动设置")]
    public ScrollRect ScrollRect; // 滚动组件
    public RectTransform Content; // 内容容器
    public GameObject ItemPrefab; // 列表项预制件
    
    [Header("布局设置")]
    public float ItemHeight = 80f; // 列表项高度
    public float ItemSpacing = 5f; // 列表项间距
    public bool AutoResize = true; // 自动调整内容大小
    
    [Header("样式设置")]
    public Color AlternateRowColor = new Color(0.9f, 0.9f, 0.9f, 0.3f); // 交替行颜色
    public bool UseAlternateRowColors = true; // 是否使用交替行颜色
    
    private List<ScrollableListItem> _items = new List<ScrollableListItem>();
    private VerticalLayoutGroup _layoutGroup;
    
    void Awake()
    {
        InitializeComponents();
    }
    
    private void InitializeComponents()
    {
        // 如果没有设置ScrollRect，尝试获取
        if (ScrollRect == null)
        {
            ScrollRect = GetComponent<ScrollRect>();
        }
        
        // 如果没有设置Content，尝试从ScrollRect获取
        if (Content == null && ScrollRect != null)
        {
            Content = ScrollRect.content;
        }
        
        // 确保Content有VerticalLayoutGroup
        if (Content != null)
        {
            _layoutGroup = Content.GetComponent<VerticalLayoutGroup>();
            if (_layoutGroup == null)
            {
                _layoutGroup = Content.gameObject.AddComponent<VerticalLayoutGroup>();
            }
            
            // 配置VerticalLayoutGroup
            _layoutGroup.childControlHeight = false;
            _layoutGroup.childControlWidth = true;
            _layoutGroup.childForceExpandHeight = false;
            _layoutGroup.childForceExpandWidth = false;
            _layoutGroup.spacing = ItemSpacing;
            _layoutGroup.padding = new RectOffset(5, 5, 5, 5);
        }
        
        // 确保ItemPrefab不活跃
        if (ItemPrefab != null)
        {
            ItemPrefab.SetActive(false);
        }
    }
    
    /// <summary>
    /// 添加列表项
    /// </summary>
    public ScrollableListItem AddItem(object data = null)
    {
        if (ItemPrefab == null || Content == null)
        {
            Debug.LogError("ItemPrefab or Content is null!");
            return null;
        }
        
        // 创建新项
        GameObject itemGO = Instantiate(ItemPrefab, Content);
        itemGO.SetActive(true);
        
        // 设置高度
        RectTransform itemRect = itemGO.GetComponent<RectTransform>();
        if (itemRect != null)
        {
            itemRect.sizeDelta = new Vector2(itemRect.sizeDelta.x, ItemHeight);
        }
        
        // 获取或添加ScrollableListItem组件
        ScrollableListItem item = itemGO.GetComponent<ScrollableListItem>();
        if (item == null)
        {
            item = itemGO.AddComponent<ScrollableListItem>();
        }
        
        // 设置数据和索引
        item.Initialize(data, _items.Count, this);
        _items.Add(item);
        
        // 设置交替行颜色
        if (UseAlternateRowColors && _items.Count % 2 == 0)
        {
            var bgImage = itemGO.GetComponent<Image>();
            if (bgImage == null)
            {
                bgImage = itemGO.AddComponent<Image>();
            }
            bgImage.color = AlternateRowColor;
        }
        
        // 更新内容大小
        if (AutoResize)
        {
            UpdateContentSize();
        }
        
        return item;
    }
    
    /// <summary>
    /// 删除指定列表项
    /// </summary>
    public void RemoveItem(ScrollableListItem item)
    {
        if (_items.Remove(item))
        {
            if (item.gameObject != null)
            {
                Destroy(item.gameObject);
            }
            
            // 更新剩余项的索引
            UpdateItemIndices();
            
            if (AutoResize)
            {
                UpdateContentSize();
            }
        }
    }
    
    /// <summary>
    /// 删除指定索引的列表项
    /// </summary>
    public void RemoveItemAt(int index)
    {
        if (index >= 0 && index < _items.Count)
        {
            RemoveItem(_items[index]);
        }
    }
    
    /// <summary>
    /// 清空所有列表项
    /// </summary>
    public void ClearItems()
    {
        foreach (var item in _items)
        {
            if (item != null && item.gameObject != null)
            {
                Destroy(item.gameObject);
            }
        }
        _items.Clear();
        
        if (AutoResize)
        {
            UpdateContentSize();
        }
    }
    
    /// <summary>
    /// 获取列表项数量
    /// </summary>
    public int GetItemCount()
    {
        return _items.Count;
    }
    
    /// <summary>
    /// 获取指定索引的列表项
    /// </summary>
    public ScrollableListItem GetItem(int index)
    {
        if (index >= 0 && index < _items.Count)
        {
            return _items[index];
        }
        return null;
    }
    
    /// <summary>
    /// 获取所有列表项
    /// </summary>
    public List<ScrollableListItem> GetAllItems()
    {
        return new List<ScrollableListItem>(_items);
    }
    
    /// <summary>
    /// 滚动到指定列表项
    /// </summary>
    public void ScrollToItem(ScrollableListItem item)
    {
        if (ScrollRect == null || Content == null || item == null) return;
        
        int index = _items.IndexOf(item);
        if (index >= 0)
        {
            ScrollToIndex(index);
        }
    }
    
    /// <summary>
    /// 滚动到指定索引
    /// </summary>
    public void ScrollToIndex(int index)
    {
        if (ScrollRect == null || Content == null || index < 0 || index >= _items.Count) return;
        
        float itemY = index * (ItemHeight + ItemSpacing);
        float contentHeight = Content.rect.height;
        float viewportHeight = ScrollRect.viewport.rect.height;
        
        if (contentHeight > viewportHeight)
        {
            float normalizedPosition = 1f - (itemY / (contentHeight - viewportHeight));
            normalizedPosition = Mathf.Clamp01(normalizedPosition);
            ScrollRect.verticalNormalizedPosition = normalizedPosition;
        }
    }
    
    /// <summary>
    /// 滚动到顶部
    /// </summary>
    public void ScrollToTop()
    {
        if (ScrollRect != null)
        {
            ScrollRect.verticalNormalizedPosition = 1f;
        }
    }
    
    /// <summary>
    /// 滚动到底部
    /// </summary>
    public void ScrollToBottom()
    {
        if (ScrollRect != null)
        {
            ScrollRect.verticalNormalizedPosition = 0f;
        }
    }
    
    /// <summary>
    /// 更新内容大小
    /// </summary>
    private void UpdateContentSize()
    {
        if (Content == null) return;
        
        float totalHeight = _items.Count * ItemHeight + (_items.Count - 1) * ItemSpacing + _layoutGroup.padding.top + _layoutGroup.padding.bottom;
        Content.sizeDelta = new Vector2(Content.sizeDelta.x, totalHeight);
    }
    
    /// <summary>
    /// 更新所有项的索引
    /// </summary>
    private void UpdateItemIndices()
    {
        for (int i = 0; i < _items.Count; i++)
        {
            if (_items[i] != null)
            {
                _items[i].SetIndex(i);
            }
        }
    }
    
    /// <summary>
    /// 刷新列表显示
    /// </summary>
    public void RefreshList()
    {
        // 移除已被销毁的项
        _items.RemoveAll(item => item == null || item.gameObject == null);
        
        // 更新索引
        UpdateItemIndices();
        
        // 更新内容大小
        if (AutoResize)
        {
            UpdateContentSize();
        }
    }
}

/// <summary>
/// 滚动列表项基类
/// </summary>
public class ScrollableListItem : MonoBehaviour
{
    public object Data { get; private set; }
    public int Index { get; private set; }
    public ScrollableListView ListView { get; private set; }
    
    public event Action<ScrollableListItem> OnItemClicked;
    public event Action<ScrollableListItem> OnItemSelected;
    
    private Button _button;
    private Toggle _toggle;
    
    void Awake()
    {
        // 获取按钮组件
        _button = GetComponent<Button>();
        if (_button != null)
        {
            _button.onClick.AddListener(OnButtonClicked);
        }
        
        // 获取Toggle组件
        _toggle = GetComponent<Toggle>();
        if (_toggle != null)
        {
            _toggle.onValueChanged.AddListener(OnToggleChanged);
        }
    }
    
    public void Initialize(object data, int index, ScrollableListView listView)
    {
        Data = data;
        Index = index;
        ListView = listView;
        
        // 子类可以重写此方法来更新UI
        UpdateUI();
    }
    
    public void SetIndex(int index)
    {
        Index = index;
    }
    
    protected virtual void UpdateUI()
    {
        // 子类重写此方法来更新UI显示
    }
    
    private void OnButtonClicked()
    {
        OnItemClicked?.Invoke(this);
    }
    
    private void OnToggleChanged(bool isOn)
    {
        if (isOn)
        {
            OnItemSelected?.Invoke(this);
        }
    }
    
    /// <summary>
    /// 删除此项
    /// </summary>
    public void RemoveFromList()
    {
        ListView?.RemoveItem(this);
    }
}