using System;
using System.IO;
using TMPro;
using UnityEngine;
using UnityEngine.UI;

/// <summary>
/// 文件选择对话框
/// 提供文件选择和保存功能
/// </summary>
public class FileSelectionDialog : BasePanel
{
    [Header("UI组件")]
    public TextMeshProUGUI TitleText;
    public TMP_InputField FilePathInput; // 文件路径输入框
    public Button BrowseButton; // 浏览按钮
    public Button ConfirmButton; // 确认按钮
    public Button CancelButton; // 取消按钮
    public TMP_Dropdown FileTypeDropdown; // 文件类型下拉框
    
    [Header("文件浏览")]
    public ScrollRect DirectoryScrollRect; // 目录滚动视图
    public Transform DirectoryContent; // 目录内容容器
    public GameObject DirectoryItemPrefab; // 目录项预制体
    public GameObject FileItemPrefab; // 文件项预制体
    
    private Action<string> _onConfirm;
    private Action _onCancel;
    private string _currentDirectory = Application.streamingAssetsPath;
    private string[] _fileFilters;
    private bool _isSaveMode;
    private string _defaultFileName;

    public override void Init()
    {
        InitializeButtons();
        _currentDirectory = Application.streamingAssetsPath;
        RefreshDirectoryView();
    }
    
    private void InitializeButtons()
    {
        if (BrowseButton != null)
        {
            BrowseButton.onClick.AddListener(OnBrowseClicked);
        }
        
        if (ConfirmButton != null)
        {
            ConfirmButton.onClick.AddListener(OnConfirmClicked);
        }
        
        if (CancelButton != null)
        {
            CancelButton.onClick.AddListener(OnCancelClicked);
        }
        
        if (FileTypeDropdown != null)
        {
            FileTypeDropdown.onValueChanged.AddListener(OnFileTypeChanged);
        }
    }

    /// <summary>
    /// 显示文件选择对话框
    /// </summary>
    public static void Show(string title, string fileFilter, Action<string> onConfirm, Action onCancel = null)
    {
        var dialog = EnhancedUIManager.Instance.ShowPanel<FileSelectionDialog>(UIPanelType.Dialog, true, true);
        if (dialog != null)
        {
            dialog.ShowFileDialog(title, fileFilter, false, "", onConfirm, onCancel);
        }
    }

    /// <summary>
    /// 显示文件保存对话框
    /// </summary>
    public static void ShowSave(string title, string fileFilter, string defaultFileName, Action<string> onConfirm, Action onCancel = null)
    {
        var dialog = EnhancedUIManager.Instance.ShowPanel<FileSelectionDialog>(UIPanelType.Dialog, true, true);
        if (dialog != null)
        {
            dialog.ShowFileDialog(title, fileFilter, true, defaultFileName, onConfirm, onCancel);
        }
    }

    private void ShowFileDialog(string title, string fileFilter, bool isSaveMode, string defaultFileName, Action<string> onConfirm, Action onCancel)
    {
        _onConfirm = onConfirm;
        _onCancel = onCancel;
        _isSaveMode = isSaveMode;
        _defaultFileName = defaultFileName;
        
        if (TitleText != null)
        {
            TitleText.text = title;
        }
        
        SetupFileFilters(fileFilter);
        
        if (_isSaveMode && !string.IsNullOrEmpty(_defaultFileName))
        {
            if (FilePathInput != null)
            {
                FilePathInput.text = Path.Combine(_currentDirectory, _defaultFileName);
            }
        }
        
        RefreshDirectoryView();
    }

    private void SetupFileFilters(string fileFilter)
    {
        if (FileTypeDropdown != null)
        {
            FileTypeDropdown.options.Clear();
            
            if (string.IsNullOrEmpty(fileFilter))
            {
                FileTypeDropdown.options.Add(new TMP_Dropdown.OptionData("所有文件 (*.*)", null));
                _fileFilters = new string[] { "*.*" };
            }
            else
            {
                // 解析文件过滤器 "描述|*.ext;*.ext2|描述2|*.ext3"
                string[] parts = fileFilter.Split('|');
                _fileFilters = new string[parts.Length / 2];
                
                for (int i = 0; i < parts.Length; i += 2)
                {
                    if (i + 1 < parts.Length)
                    {
                        string description = parts[i];
                        string extensions = parts[i + 1];
                        
                        FileTypeDropdown.options.Add(new TMP_Dropdown.OptionData(description, null));
                        _fileFilters[i / 2] = extensions;
                    }
                }
            }
            
            FileTypeDropdown.value = 0;
            FileTypeDropdown.RefreshShownValue();
        }
    }

    private void RefreshDirectoryView()
    {
        if (DirectoryContent == null) return;
        
        // 清空现有项目
        foreach (Transform child in DirectoryContent)
        {
            Destroy(child.gameObject);
        }
        
        try
        {
            // 添加返回上级目录项
            var parentDir = Directory.GetParent(_currentDirectory);
            if (parentDir != null)
            {
                CreateDirectoryItem("..", parentDir.FullName, true);
            }
            
            // 添加子目录
            string[] directories = Directory.GetDirectories(_currentDirectory);
            foreach (string dir in directories)
            {
                string dirName = Path.GetFileName(dir);
                CreateDirectoryItem(dirName, dir, false);
            }
            
            // 添加文件
            string[] files = Directory.GetFiles(_currentDirectory);
            foreach (string file in files)
            {
                if (IsFileMatchFilter(file))
                {
                    string fileName = Path.GetFileName(file);
                    CreateFileItem(fileName, file);
                }
            }
        }
        catch (Exception ex)
        {
            Debug.LogError($"刷新目录视图失败: {ex.Message}");
        }
    }

    private bool IsFileMatchFilter(string filePath)
    {
        if (_fileFilters == null || _fileFilters.Length == 0) return true;
        
        string selectedFilter = _fileFilters[FileTypeDropdown?.value ?? 0];
        if (selectedFilter == "*.*") return true;
        
        string[] extensions = selectedFilter.Split(';');
        string fileExtension = Path.GetExtension(filePath).ToLower();
        
        foreach (string ext in extensions)
        {
            string filterExt = ext.Replace("*", "").ToLower();
            if (fileExtension == filterExt) return true;
        }
        
        return false;
    }

    private void CreateDirectoryItem(string name, string path, bool isParent)
    {
        if (DirectoryItemPrefab == null) return;
        
        var item = Instantiate(DirectoryItemPrefab, DirectoryContent);
        var text = item.GetComponentInChildren<TextMeshProUGUI>();
        if (text != null)
        {
            text.text = isParent ? ".. (上级目录)" : $"[{name}]";
        }
        
        var button = item.GetComponent<Button>();
        if (button != null)
        {
            button.onClick.AddListener(() => {
                _currentDirectory = path;
                RefreshDirectoryView();
                UpdatePathInput();
            });
        }
    }

    private void CreateFileItem(string name, string path)
    {
        if (FileItemPrefab == null) return;
        
        var item = Instantiate(FileItemPrefab, DirectoryContent);
        var text = item.GetComponentInChildren<TextMeshProUGUI>();
        if (text != null)
        {
            text.text = name;
        }
        
        var button = item.GetComponent<Button>();
        if (button != null)
        {
            button.onClick.AddListener(() => {
                if (FilePathInput != null)
                {
                    FilePathInput.text = path;
                }
            });
        }
    }

    private void UpdatePathInput()
    {
        if (FilePathInput != null)
        {
            if (_isSaveMode && !string.IsNullOrEmpty(_defaultFileName))
            {
                FilePathInput.text = Path.Combine(_currentDirectory, _defaultFileName);
            }
            else
            {
                FilePathInput.text = _currentDirectory;
            }
        }
    }

    private void OnBrowseClicked()
    {
        // 这里可以集成系统文件对话框，如果有需要的话
        Debug.Log("打开系统文件选择对话框");
    }

    private void OnConfirmClicked()
    {
        string selectedPath = FilePathInput?.text ?? "";
        
        if (string.IsNullOrEmpty(selectedPath))
        {
            ConfirmDialog.Show("提示", "请选择或输入文件路径", () => { });
            return;
        }
        
        if (_isSaveMode)
        {
            // 保存模式：检查目录是否存在
            string directory = Path.GetDirectoryName(selectedPath);
            if (!Directory.Exists(directory))
            {
                ConfirmDialog.Show("错误", "目录不存在", () => { });
                return;
            }
        }
        else
        {
            // 打开模式：检查文件是否存在
            if (!File.Exists(selectedPath))
            {
                ConfirmDialog.Show("错误", "文件不存在", () => { });
                return;
            }
        }
        
        _onConfirm?.Invoke(selectedPath);
        CloseDialog();
    }

    private void OnCancelClicked()
    {
        _onCancel?.Invoke();
        CloseDialog();
    }

    private void OnFileTypeChanged(int index)
    {
        RefreshDirectoryView();
    }

    private void CloseDialog()
    {
        EnhancedUIManager.Instance.HidePanel<FileSelectionDialog>(true);
    }

    protected override void OnBackButtonPressed()
    {
        OnCancelClicked();
    }
}