import { useState, useEffect, forwardRef, useImperativeHandle } from 'react';
import { Folder, ChevronRight, ChevronDown, File, Edit3, Trash2, FolderOpen, Copy, FileText, FolderPlus, ChevronsDown, ChevronsUp } from 'lucide-react';
import { TauriAPI, DirectoryEntry } from '../api/tauri';
import { MessageHub, FileActionRegistry } from '@esengine/editor-core';
import { Core } from '@esengine/ecs-framework';
import { ContextMenu, ContextMenuItem } from './ContextMenu';
import { ConfirmDialog } from './ConfirmDialog';
import { PromptDialog } from './PromptDialog';
import '../styles/FileTree.css';

interface TreeNode {
  name: string;
  path: string;
  type: 'folder' | 'file';
  size?: number;
  modified?: number;
  children?: TreeNode[];
  expanded?: boolean;
  loaded?: boolean;
}

interface FileTreeProps {
  rootPath: string | null;
  onSelectFile?: (path: string) => void;
  selectedPath?: string | null;
  messageHub?: MessageHub;
  searchQuery?: string;
  showFiles?: boolean;
}

export interface FileTreeHandle {
  collapseAll: () => void;
  refresh: () => void;
}

export const FileTree = forwardRef<FileTreeHandle, FileTreeProps>(({ rootPath, onSelectFile, selectedPath, messageHub, searchQuery, showFiles = true }, ref) => {
    const [tree, setTree] = useState<TreeNode[]>([]);
    const [loading, setLoading] = useState(false);
    const [internalSelectedPath, setInternalSelectedPath] = useState<string | null>(null);
    const [contextMenu, setContextMenu] = useState<{
        position: { x: number; y: number };
        node: TreeNode | null;
    } | null>(null);
    const [renamingNode, setRenamingNode] = useState<string | null>(null);
    const [newName, setNewName] = useState('');
    const [deleteDialog, setDeleteDialog] = useState<{ node: TreeNode } | null>(null);
    const [promptDialog, setPromptDialog] = useState<{
        type: 'create-file' | 'create-folder' | 'create-template';
        parentPath: string;
        templateExtension?: string;
        templateContent?: (fileName: string) => Promise<string>;
    } | null>(null);
    const [filteredTree, setFilteredTree] = useState<TreeNode[]>([]);
    const fileActionRegistry = Core.services.resolve(FileActionRegistry);

    const collapseAll = () => {
        const collapseNode = (node: TreeNode): TreeNode => {
            if (node.type === 'folder') {
                return {
                    ...node,
                    expanded: false,
                    children: node.children ? node.children.map(collapseNode) : node.children
                };
            }
            return node;
        };

        const collapsedTree = tree.map(node => collapseNode(node));
        setTree(collapsedTree);
    };

    useImperativeHandle(ref, () => ({
        collapseAll,
        refresh: refreshTree
    }));

    useEffect(() => {
        if (rootPath) {
            loadRootDirectory(rootPath);
        } else {
            setTree([]);
        }
    }, [rootPath]);

    useEffect(() => {
        if (selectedPath) {
            setInternalSelectedPath(selectedPath);
        }
    }, [selectedPath]);

    useEffect(() => {
        const performSearch = async () => {
            const filterByFileType = (nodes: TreeNode[]): TreeNode[] => {
                return nodes
                    .filter(node => showFiles || node.type === 'folder')
                    .map(node => ({
                        ...node,
                        children: node.children ? filterByFileType(node.children) : node.children
                    }));
            };

            let result = filterByFileType(tree);

            if (searchQuery && searchQuery.trim()) {
                const query = searchQuery.toLowerCase();

                const loadAndFilterTree = async (nodes: TreeNode[]): Promise<TreeNode[]> => {
                    const filtered: TreeNode[] = [];

                    for (const node of nodes) {
                        const nameMatches = node.name.toLowerCase().includes(query);
                        let filteredChildren: TreeNode[] = [];

                        if (node.type === 'folder') {
                            let childrenToSearch = node.children || [];

                            if (!node.loaded) {
                                try {
                                    const entries = await TauriAPI.listDirectory(node.path);
                                    childrenToSearch = entriesToNodes(entries);
                                } catch (error) {
                                    console.error('Failed to load children for search:', error);
                                }
                            }

                            if (childrenToSearch.length > 0) {
                                filteredChildren = await loadAndFilterTree(childrenToSearch);
                            }
                        }

                        if (nameMatches || filteredChildren.length > 0) {
                            filtered.push({
                                ...node,
                                expanded: filteredChildren.length > 0,
                                loaded: true,
                                children: filteredChildren.length > 0 ? filteredChildren : (node.type === 'folder' ? [] : undefined)
                            });
                        }
                    }

                    return filtered;
                };

                result = await loadAndFilterTree(result);
            }

            setFilteredTree(result);
        };

        performSearch();
    }, [searchQuery, tree, showFiles]);

    const loadRootDirectory = async (path: string) => {
        setLoading(true);
        try {
            const entries = await TauriAPI.listDirectory(path);
            const children = entriesToNodes(entries);

            // 创建根节点
            const rootName = path.split(/[/\\]/).filter((p) => p).pop() || 'Project';
            const rootNode: TreeNode = {
                name: rootName,
                path: path,
                type: 'folder',
                children: children,
                expanded: true,
                loaded: true
            };

            setTree([rootNode]);
        } catch (error) {
            console.error('Failed to load directory:', error);
            setTree([]);
        } finally {
            setLoading(false);
        }
    };

    const entriesToNodes = (entries: DirectoryEntry[]): TreeNode[] => {
        return entries
            .sort((a, b) => {
                if (a.is_dir === b.is_dir) return a.name.localeCompare(b.name);
                return a.is_dir ? -1 : 1;
            })
            .map((entry) => ({
                name: entry.name,
                path: entry.path,
                type: entry.is_dir ? 'folder' as const : 'file' as const,
                size: entry.size,
                modified: entry.modified,
                children: entry.is_dir ? [] : undefined,
                expanded: false,
                loaded: entry.is_dir ? false : undefined
            }));
    };

    const loadChildren = async (node: TreeNode): Promise<TreeNode[]> => {
        try {
            const entries = await TauriAPI.listDirectory(node.path);
            return entriesToNodes(entries);
        } catch (error) {
            console.error('Failed to load children:', error);
            return [];
        }
    };

    const toggleNode = async (nodePath: string) => {
        const updateTree = async (nodes: TreeNode[]): Promise<TreeNode[]> => {
            const newNodes: TreeNode[] = [];
            for (const node of nodes) {
                if (node.path === nodePath) {
                    if (!node.loaded) {
                        const children = await loadChildren(node);
                        newNodes.push({
                            ...node,
                            expanded: true,
                            loaded: true,
                            children
                        });
                    } else {
                        newNodes.push({
                            ...node,
                            expanded: !node.expanded
                        });
                    }
                } else if (node.children) {
                    newNodes.push({
                        ...node,
                        children: await updateTree(node.children)
                    });
                } else {
                    newNodes.push(node);
                }
            }
            return newNodes;
        };

        const newTree = await updateTree(tree);
        setTree(newTree);
    };

    const refreshTree = async () => {
        if (!rootPath) return;

        // 保存当前展开状态
        const expandedPaths = new Set<string>();
        const collectExpandedPaths = (nodes: TreeNode[]) => {
            for (const node of nodes) {
                if (node.type === 'folder' && node.expanded) {
                    expandedPaths.add(node.path);
                    if (node.children) {
                        collectExpandedPaths(node.children);
                    }
                }
            }
        };
        collectExpandedPaths(tree);

        // 重新加载根目录，获取最新的文件结构
        try {
            const entries = await TauriAPI.listDirectory(rootPath);
            const children = entriesToNodes(entries);

            const rootName = rootPath.split(/[/\\]/).filter((p) => p).pop() || 'Project';
            let rootNode: TreeNode = {
                name: rootName,
                path: rootPath,
                type: 'folder',
                children: children,
                expanded: true,
                loaded: true
            };

            // 恢复展开状态
            if (expandedPaths.size > 0) {
                const restoreExpandedState = async (node: TreeNode): Promise<TreeNode> => {
                    if (node.type === 'folder' && expandedPaths.has(node.path)) {
                        let children = node.children || [];
                        if (!node.loaded && node.children) {
                            children = await loadChildren(node);
                        }
                        const restoredChildren = await Promise.all(
                            children.map(child => restoreExpandedState(child))
                        );
                        return {
                            ...node,
                            expanded: true,
                            loaded: true,
                            children: restoredChildren
                        };
                    } else if (node.type === 'folder' && node.children) {
                        const restoredChildren = await Promise.all(
                            node.children.map(child => restoreExpandedState(child))
                        );
                        return {
                            ...node,
                            children: restoredChildren
                        };
                    }
                    return node;
                };

                rootNode = await restoreExpandedState(rootNode);
            }

            setTree([rootNode]);
        } catch (error) {
            console.error('Failed to refresh directory:', error);
        }
    };

    const expandAll = async () => {
        const expandNode = async (node: TreeNode): Promise<TreeNode> => {
            if (node.type === 'folder') {
                let children = node.children || [];

                if (!node.loaded) {
                    try {
                        const entries = await TauriAPI.listDirectory(node.path);
                        children = entriesToNodes(entries);
                    } catch (error) {
                        console.error('Failed to load children:', error);
                        children = [];
                    }
                }

                const expandedChildren = await Promise.all(
                    children.map(child => expandNode(child))
                );

                return {
                    ...node,
                    expanded: true,
                    loaded: true,
                    children: expandedChildren
                };
            }
            return node;
        };

        const expandedTree = await Promise.all(tree.map(node => expandNode(node)));
        setTree(expandedTree);
    };

    const handleRename = async (node: TreeNode) => {
        if (!newName || newName === node.name) {
            setRenamingNode(null);
            return;
        }

        const pathParts = node.path.split(/[/\\]/);
        pathParts[pathParts.length - 1] = newName;
        const newPath = pathParts.join('/');

        try {
            await TauriAPI.renameFileOrFolder(node.path, newPath);
            await refreshTree();
            setRenamingNode(null);
            setNewName('');
        } catch (error) {
            console.error('Failed to rename:', error);
            alert(`重命名失败: ${error}`);
        }
    };

    const handleDeleteClick = (node: TreeNode) => {
        setContextMenu(null);
        setDeleteDialog({ node });
    };

    const handleDeleteConfirm = async () => {
        if (!deleteDialog) return;

        const node = deleteDialog.node;
        setDeleteDialog(null);

        try {
            if (node.type === 'folder') {
                await TauriAPI.deleteFolder(node.path);
            } else {
                await TauriAPI.deleteFile(node.path);
            }
            await refreshTree();
        } catch (error) {
            console.error('Failed to delete:', error);
            alert(`删除失败: ${error}`);
        }
    };

    const handleCreateFileClick = (parentPath: string) => {
        setContextMenu(null);
        setPromptDialog({ type: 'create-file', parentPath });
    };

    const handleCreateFolderClick = (parentPath: string) => {
        setContextMenu(null);
        setPromptDialog({ type: 'create-folder', parentPath });
    };

    const handleCreateTemplateFileClick = (parentPath: string, template: any) => {
        setContextMenu(null);
        setPromptDialog({
            type: 'create-template',
            parentPath,
            templateExtension: template.extension,
            templateContent: template.createContent
        });
    };

    const handlePromptConfirm = async (value: string) => {
        if (!promptDialog) return;

        const { type, parentPath, templateExtension, templateContent } = promptDialog;
        setPromptDialog(null);

        let fileName = value;
        let targetPath = `${parentPath}/${value}`;

        try {
            if (type === 'create-file') {
                await TauriAPI.createFile(targetPath);
            } else if (type === 'create-folder') {
                await TauriAPI.createDirectory(targetPath);
            } else if (type === 'create-template' && templateExtension && templateContent) {
                if (!fileName.endsWith(`.${templateExtension}`)) {
                    fileName = `${fileName}.${templateExtension}`;
                    targetPath = `${parentPath}/${fileName}`;
                }

                const content = await templateContent(fileName);
                await TauriAPI.writeFileContent(targetPath, content);
            }
            await refreshTree();
        } catch (error) {
            console.error(`Failed to ${type}:`, error);
            alert(`${type === 'create-file' ? '创建文件' : type === 'create-folder' ? '创建文件夹' : '创建模板文件'}失败: ${error}`);
        }
    };

    const getContextMenuItems = (node: TreeNode | null): ContextMenuItem[] => {
        if (!node) {
            const baseItems: ContextMenuItem[] = [
                {
                    label: '新建文件',
                    icon: <FileText size={16} />,
                    onClick: () => rootPath && handleCreateFileClick(rootPath)
                },
                {
                    label: '新建文件夹',
                    icon: <FolderPlus size={16} />,
                    onClick: () => rootPath && handleCreateFolderClick(rootPath)
                }
            ];

            if (fileActionRegistry && rootPath) {
                const templates = fileActionRegistry.getCreationTemplates();
                if (templates.length > 0) {
                    baseItems.push({ label: '', separator: true, onClick: () => {} });
                    for (const template of templates) {
                        baseItems.push({
                            label: template.label,
                            icon: template.icon,
                            onClick: () => handleCreateTemplateFileClick(rootPath, template)
                        });
                    }
                }
            }

            return baseItems;
        }

        const items: ContextMenuItem[] = [];

        if (node.type === 'file') {
            items.push({
                label: '打开文件',
                icon: <File size={16} />,
                onClick: async () => {
                    try {
                        await TauriAPI.openFileWithSystemApp(node.path);
                    } catch (error) {
                        console.error('Failed to open file:', error);
                    }
                }
            });

            if (fileActionRegistry) {
                const handlers = fileActionRegistry.getHandlersForFile(node.path);
                for (const handler of handlers) {
                    if (handler.getContextMenuItems) {
                        const parentPath = node.path.substring(0, node.path.lastIndexOf('/'));
                        const pluginItems = handler.getContextMenuItems(node.path, parentPath);
                        for (const pluginItem of pluginItems) {
                            items.push({
                                label: pluginItem.label,
                                icon: pluginItem.icon,
                                onClick: () => pluginItem.onClick(node.path, parentPath),
                                disabled: pluginItem.disabled,
                                separator: pluginItem.separator
                            });
                        }
                    }
                }
            }
        }

        items.push({
            label: '重命名',
            icon: <Edit3 size={16} />,
            onClick: () => {
                setRenamingNode(node.path);
                setNewName(node.name);
            }
        });

        items.push({
            label: '删除',
            icon: <Trash2 size={16} />,
            onClick: () => handleDeleteClick(node)
        });

        items.push({ label: '', separator: true, onClick: () => {} });

        if (node.type === 'folder') {
            items.push({
                label: '新建文件',
                icon: <FileText size={16} />,
                onClick: () => handleCreateFileClick(node.path)
            });

            items.push({
                label: '新建文件夹',
                icon: <FolderPlus size={16} />,
                onClick: () => handleCreateFolderClick(node.path)
            });

            if (fileActionRegistry) {
                const templates = fileActionRegistry.getCreationTemplates();
                if (templates.length > 0) {
                    items.push({ label: '', separator: true, onClick: () => {} });
                    for (const template of templates) {
                        items.push({
                            label: template.label,
                            icon: template.icon,
                            onClick: () => handleCreateTemplateFileClick(node.path, template)
                        });
                    }
                }
            }

            items.push({ label: '', separator: true, onClick: () => {} });
        }

        items.push({
            label: '在文件管理器中显示',
            icon: <FolderOpen size={16} />,
            onClick: async () => {
                try {
                    await TauriAPI.showInFolder(node.path);
                } catch (error) {
                    console.error('Failed to show in folder:', error);
                }
            }
        });

        items.push({
            label: '复制路径',
            icon: <Copy size={16} />,
            onClick: () => {
                navigator.clipboard.writeText(node.path);
            }
        });

        return items;
    };

    const handleNodeClick = (node: TreeNode) => {
        if (node.type === 'folder') {
            setInternalSelectedPath(node.path);
            onSelectFile?.(node.path);
            toggleNode(node.path);
        } else {
            setInternalSelectedPath(node.path);
            const extension = node.name.includes('.') ? node.name.split('.').pop() : undefined;
            messageHub?.publish('asset-file:selected', {
                fileInfo: {
                    name: node.name,
                    path: node.path,
                    extension,
                    size: node.size,
                    modified: node.modified,
                    isDirectory: false
                }
            });
        }
    };

    const handleNodeDoubleClick = async (node: TreeNode) => {
        if (node.type === 'file') {
            if (fileActionRegistry) {
                const handled = await fileActionRegistry.handleDoubleClick(node.path);
                if (handled) {
                    return;
                }
            }

            try {
                await TauriAPI.openFileWithSystemApp(node.path);
            } catch (error) {
                console.error('Failed to open file:', error);
            }
        }
    };

    const handleContextMenu = (e: React.MouseEvent, node: TreeNode | null) => {
        e.preventDefault();
        e.stopPropagation();
        setContextMenu({
            position: { x: e.clientX, y: e.clientY },
            node
        });
    };

    const renderNode = (node: TreeNode, level: number = 0) => {
        const isSelected = (internalSelectedPath || selectedPath) === node.path;
        const isRenaming = renamingNode === node.path;
        const indent = level * 16;

        return (
            <div key={node.path}>
                <div
                    className={`tree-node ${isSelected ? 'selected' : ''}`}
                    style={{ paddingLeft: `${indent}px`, cursor: node.type === 'file' ? 'grab' : 'pointer' }}
                    onClick={() => !isRenaming && handleNodeClick(node)}
                    onDoubleClick={() => !isRenaming && handleNodeDoubleClick(node)}
                    onContextMenu={(e) => handleContextMenu(e, node)}
                    draggable={node.type === 'file' && !isRenaming}
                    onDragStart={(e) => {
                        if (node.type === 'file' && !isRenaming) {
                            e.dataTransfer.effectAllowed = 'copy';
                            // 设置拖拽的数据
                            e.dataTransfer.setData('asset-path', node.path);
                            e.dataTransfer.setData('asset-name', node.name);
                            const ext = node.name.includes('.') ? node.name.split('.').pop() : '';
                            e.dataTransfer.setData('asset-extension', ext || '');
                            e.dataTransfer.setData('text/plain', node.path);

                            // 添加视觉反馈
                            e.currentTarget.style.opacity = '0.5';
                        }
                    }}
                    onDragEnd={(e) => {
                        // 恢复透明度
                        e.currentTarget.style.opacity = '1';
                    }}
                >
                    <span className="tree-arrow">
                        {node.type === 'folder' ? (
                            node.expanded ? <ChevronDown size={14} /> : <ChevronRight size={14} />
                        ) : (
                            <span style={{ width: '14px', display: 'inline-block' }} />
                        )}
                    </span>
                    <span className="tree-icon">
                        {node.type === 'folder' ? (
                            node.name.toLowerCase() === 'plugins' || node.name.toLowerCase() === '.ecs' ? (
                                <Folder size={16} className="system-folder-icon" style={{ color: '#42a5f5' }} />
                            ) : (
                                <Folder size={16} style={{ color: '#ffa726' }} />
                            )
                        ) : (
                            <File size={16} style={{ color: '#90caf9' }} />
                        )}
                    </span>
                    {isRenaming ? (
                        <input
                            type="text"
                            className="tree-rename-input"
                            value={newName}
                            onChange={(e) => setNewName(e.target.value)}
                            onBlur={() => handleRename(node)}
                            onKeyDown={(e) => {
                                if (e.key === 'Enter') {
                                    handleRename(node);
                                } else if (e.key === 'Escape') {
                                    setRenamingNode(null);
                                }
                            }}
                            autoFocus
                            onClick={(e) => e.stopPropagation()}
                        />
                    ) : (
                        <span className="tree-label">{node.name}</span>
                    )}
                </div>
                {node.type === 'folder' && node.expanded && node.children && (
                    <div className="tree-children">
                        {node.children.map((child) => renderNode(child, level + 1))}
                    </div>
                )}
            </div>
        );
    };

    if (loading) {
        return <div className="file-tree loading">Loading...</div>;
    }

    if (!rootPath || tree.length === 0) {
        return <div className="file-tree empty">No folders</div>;
    }

    return (
        <>
            <div
                className="file-tree"
                onContextMenu={(e) => {
                    const target = e.target as HTMLElement;
                    if (target.classList.contains('file-tree')) {
                        handleContextMenu(e, null);
                    }
                }}
            >
                {filteredTree.map((node) => renderNode(node))}
            </div>
            {contextMenu && (
                <ContextMenu
                    items={getContextMenuItems(contextMenu.node)}
                    position={contextMenu.position}
                    onClose={() => setContextMenu(null)}
                />
            )}
            {deleteDialog && (
                <ConfirmDialog
                    title="确认删除"
                    message={
                        deleteDialog.node.type === 'folder'
                            ? `确定要删除文件夹 "${deleteDialog.node.name}" 及其所有内容吗？\n此操作无法撤销。`
                            : `确定要删除文件 "${deleteDialog.node.name}" 吗？\n此操作无法撤销。`
                    }
                    confirmText="删除"
                    cancelText="取消"
                    onConfirm={handleDeleteConfirm}
                    onCancel={() => setDeleteDialog(null)}
                />
            )}
            {promptDialog && (
                <PromptDialog
                    title={
                        promptDialog.type === 'create-file' ? '新建文件' :
                        promptDialog.type === 'create-folder' ? '新建文件夹' :
                        '新建文件'
                    }
                    message={
                        promptDialog.type === 'create-file' ? '请输入文件名:' :
                        promptDialog.type === 'create-folder' ? '请输入文件夹名:' :
                        `请输入文件名 (将自动添加 .${promptDialog.templateExtension} 扩展名):`
                    }
                    placeholder={
                        promptDialog.type === 'create-file' ? '例如: config.json' :
                        promptDialog.type === 'create-folder' ? '例如: assets' :
                        '例如: MyFile'
                    }
                    confirmText="创建"
                    cancelText="取消"
                    onConfirm={handlePromptConfirm}
                    onCancel={() => setPromptDialog(null)}
                />
            )}
        </>
    );
});