/*
 * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package net.micode.notes.ui;

import android.app.AlertDialog;
import android.content.Context;
import android.os.Bundle;
import android.text.InputFilter;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.TranslateAnimation;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.lifecycle.ViewModelProvider;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import net.micode.notes.R;
import net.micode.notes.data.Notes;
import net.micode.notes.data.NotesRepository;
import net.micode.notes.viewmodel.FolderListViewModel;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * 侧栏Fragment
 * <p>
 * 显示文件夹树、菜单项和操作按钮
 * 提供文件夹导航、创建、展开/收起等功能
 * </p>
 */
public class SidebarFragment extends Fragment {

    private static final String TAG = "SidebarFragment";
    private static final int MAX_FOLDER_NAME_LENGTH = 50;

    // 视图组件
    private RecyclerView rvFolderTree;
    private TextView tvRootFolder;
    private TextView menuSync;
    private TextView menuLogin;
    private TextView menuExport;
    private TextView menuSettings;
    private TextView menuTrash;

    // 适配器和数据
    private FolderTreeAdapter adapter;
    private FolderListViewModel viewModel;

    // 单击和双击检测
    private long lastClickTime = 0;
    private View lastClickedView = null;
    private static final long DOUBLE_CLICK_INTERVAL = 300; // 毫秒

    // 回调接口
    private OnSidebarItemSelectedListener listener;

    /**
     * 侧栏项选择回调接口
     */
    public interface OnSidebarItemSelectedListener {
        /**
         * 跳转到指定文件夹
         * @param folderId 文件夹ID
         */
        void onFolderSelected(long folderId);

        /**
         * 打开回收站
         */
        void onTrashSelected();

        /**
         * 同步
         */
        void onSyncSelected();

        /**
         * 登录
         */
        void onLoginSelected();

        /**
         * 导出
         */
        void onExportSelected();

        /**
         * 设置
         */
        void onSettingsSelected();

        /**
         * 创建文件夹
         */
        void onCreateFolder();

        /**
         * 关闭侧栏
         */
        void onCloseSidebar();
    }

    @Override
    public void onAttach(@NonNull Context context) {
        super.onAttach(context);
        if (context instanceof OnSidebarItemSelectedListener) {
            listener = (OnSidebarItemSelectedListener) context;
        } else {
            throw new RuntimeException(context.toString() + " must implement OnSidebarItemSelectedListener");
        }
    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        viewModel = new ViewModelProvider(this).get(FolderListViewModel.class);
    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,
                         @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.sidebar_layout, container, false);
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        initViews(view);
        setupListeners();
        observeViewModel();
    }

    /**
     * 刷新文件夹树（供外部调用，如删除笔记后）
     */
    public void refreshFolderTree() {
        if (viewModel != null) {
            viewModel.loadFolderTree();
        }
    }

    /**
     * 初始化视图
     */
    private void initViews(View view) {
        rvFolderTree = view.findViewById(R.id.rv_folder_tree);
        tvRootFolder = view.findViewById(R.id.tv_root_folder);
        menuSync = view.findViewById(R.id.menu_sync);
        menuLogin = view.findViewById(R.id.menu_login);
        menuExport = view.findViewById(R.id.menu_export);
        menuSettings = view.findViewById(R.id.menu_settings);
        menuTrash = view.findViewById(R.id.menu_trash);

        // 设置RecyclerView
        rvFolderTree.setLayoutManager(new LinearLayoutManager(requireContext()));
        adapter = new FolderTreeAdapter(new ArrayList<>(), viewModel);
        adapter.setOnFolderItemClickListener(this::handleFolderItemClick);
        rvFolderTree.setAdapter(adapter);
    }

    /**
     * 设置监听器
     */
    private void setupListeners() {
        View view = getView();
        if (view == null) return;

        // 根文件夹（单击展开/收起，双击跳转）
        setupFolderClickListener(tvRootFolder, Notes.ID_ROOT_FOLDER);

        // 关闭侧栏
        view.findViewById(R.id.btn_close_sidebar).setOnClickListener(v -> {
            if (listener != null) {
                listener.onCloseSidebar();
            }
        });

        // 创建文件夹
        view.findViewById(R.id.btn_create_folder).setOnClickListener(v -> showCreateFolderDialog());

        // 菜单项
        menuSync.setOnClickListener(v -> {
            if (listener != null) {
                listener.onSyncSelected();
            }
        });

        menuLogin.setOnClickListener(v -> {
            if (listener != null) {
                listener.onLoginSelected();
            }
        });

        menuExport.setOnClickListener(v -> {
            if (listener != null) {
                listener.onExportSelected();
            }
        });

        menuSettings.setOnClickListener(v -> {
            if (listener != null) {
                listener.onSettingsSelected();
            }
        });

        menuTrash.setOnClickListener(v -> {
            if (listener != null) {
                listener.onTrashSelected();
            }
        });
    }

    /**
     * 设置文件夹的单击/双击监听器
     */
    private void setupFolderClickListener(View view, long folderId) {
        view.setOnClickListener(v -> {
            android.util.Log.d(TAG, "setupFolderClickListener: folderId=" + folderId);
            long currentTime = System.currentTimeMillis();
            if (lastClickedView == view && (currentTime - lastClickTime) < DOUBLE_CLICK_INTERVAL) {
                android.util.Log.d(TAG, "Double click on root folder, jumping to: " + folderId);
                // 这是双击，执行跳转
                if (listener != null) {
                    // 根文件夹也可以跳转（回到根）
                    listener.onFolderSelected(folderId);
                }
                // 重置双击状态
                lastClickTime = 0;
                lastClickedView = null;
            } else {
                android.util.Log.d(TAG, "Single click on root folder, will toggle expand in " + DOUBLE_CLICK_INTERVAL + "ms");
                // 可能是单击，延迟处理
                lastClickTime = currentTime;
                lastClickedView = view;
                view.postDelayed(() -> {
                    // 如果在延迟期间没有发生双击，则执行单击操作（展开/收起）
                    if (System.currentTimeMillis() - lastClickTime >= DOUBLE_CLICK_INTERVAL) {
                        android.util.Log.d(TAG, "Toggling root folder expand");
                        toggleFolderExpand(folderId);
                    }
                }, DOUBLE_CLICK_INTERVAL);
            }
        });
    }

    /**
     * 观察ViewModel数据变化
     */
    private void observeViewModel() {
        viewModel.getFolderTree().observe(getViewLifecycleOwner(), folderItems -> {
            if (folderItems != null) {
                adapter.setData(folderItems);
                adapter.notifyDataSetChanged();
            }
        });

        viewModel.loadFolderTree();
    }

    /**
     * 切换文件夹展开/收起状态
     */
    private void toggleFolderExpand(long folderId) {
        android.util.Log.d(TAG, "toggleFolderExpand: folderId=" + folderId);
        viewModel.toggleFolderExpand(folderId);
    }

    /**
     * 处理文件夹项点击（单击/双击）
     */
    private void handleFolderItemClick(long folderId) {
        android.util.Log.d(TAG, "handleFolderItemClick: folderId=" + folderId);
        long currentTime = System.currentTimeMillis();
        if (lastClickedFolderId == folderId && (currentTime - lastFolderClickTime) < DOUBLE_CLICK_INTERVAL) {
            android.util.Log.d(TAG, "Double click detected, jumping to folder: " + folderId);
            // 这是双击，执行跳转
            if (listener != null) {
                listener.onFolderSelected(folderId);
            }
            // 重置双击状态
            lastFolderClickTime = 0;
            lastClickedFolderId = -1;
        } else {
            android.util.Log.d(TAG, "Single click, will toggle expand in " + DOUBLE_CLICK_INTERVAL + "ms");
            // 可能是单击，延迟处理
            lastFolderClickTime = currentTime;
            lastClickedFolderId = folderId;
            new android.os.Handler().postDelayed(() -> {
                // 如果在延迟期间没有发生双击，则执行单击操作（展开/收起）
                if (System.currentTimeMillis() - lastFolderClickTime >= DOUBLE_CLICK_INTERVAL) {
                    android.util.Log.d(TAG, "Toggling folder expand: " + folderId);
                    toggleFolderExpand(folderId);
                }
            }, DOUBLE_CLICK_INTERVAL);
        }
    }

    // 双击检测专用变量（针对文件夹列表项）
    private long lastFolderClickTime = 0;
    private long lastClickedFolderId = -1;

    /**
     * 显示创建文件夹对话框
     */
    private void showCreateFolderDialog() {
        AlertDialog.Builder builder = new AlertDialog.Builder(requireContext());
        builder.setTitle(R.string.dialog_create_folder_title);

        final EditText input = new EditText(requireContext());
        input.setHint(R.string.dialog_create_folder_hint);
        input.setFilters(new InputFilter[]{new InputFilter.LengthFilter(MAX_FOLDER_NAME_LENGTH)});

        builder.setView(input);

        builder.setPositiveButton(R.string.menu_create_folder, (dialog, which) -> {
            String folderName = input.getText().toString().trim();
            if (TextUtils.isEmpty(folderName)) {
                Toast.makeText(requireContext(), R.string.error_folder_name_empty, Toast.LENGTH_SHORT).show();
                return;
            }
            if (folderName.length() > MAX_FOLDER_NAME_LENGTH) {
                Toast.makeText(requireContext(), R.string.error_folder_name_too_long, Toast.LENGTH_SHORT).show();
                return;
            }

            // 创建文件夹
            NotesRepository repository = new NotesRepository(requireContext().getContentResolver());
            long parentId = viewModel.getCurrentFolderId();
            if (parentId == 0) {
                parentId = Notes.ID_ROOT_FOLDER;
            }
            repository.createFolder(parentId, folderName,
                new NotesRepository.Callback<Long>() {
                    @Override
                    public void onSuccess(Long folderId) {
                        if (getActivity() != null) {
                            getActivity().runOnUiThread(() -> {
                                Toast.makeText(requireContext(), R.string.create_folder_success, Toast.LENGTH_SHORT).show();
                                // 刷新文件夹列表
                                viewModel.loadFolderTree();
                            });
                        }
                    }

                    @Override
                    public void onError(Exception error) {
                        if (getActivity() != null) {
                            getActivity().runOnUiThread(() -> {
                                Toast.makeText(requireContext(),
                                        getString(R.string.error_folder_name_too_long) + ": " + error.getMessage(),
                                        Toast.LENGTH_SHORT).show();
                            });
                        }
                    }
                });
        });

        builder.setNegativeButton(android.R.string.cancel, null);
        builder.show();
    }

        /**
         * FolderTreeAdapter
         * 文件夹树适配器，支持层级显示和展开/收起
         */
        private static class FolderTreeAdapter extends RecyclerView.Adapter<FolderTreeAdapter.FolderViewHolder> {

            private List<FolderTreeItem> folderItems;
            private FolderListViewModel viewModel;
            private OnFolderItemClickListener folderItemClickListener;

            public FolderTreeAdapter(List<FolderTreeItem> folderItems, FolderListViewModel viewModel) {
                this.folderItems = folderItems;
                this.viewModel = viewModel;
            }

            public void setData(List<FolderTreeItem> folderItems) {
                this.folderItems = folderItems;
            }

            public void setOnFolderItemClickListener(OnFolderItemClickListener listener) {
                this.folderItemClickListener = listener;
            }

            @NonNull
            @Override
            public FolderViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                View view = LayoutInflater.from(parent.getContext())
                        .inflate(R.layout.sidebar_folder_item, parent, false);
                return new FolderViewHolder(view, folderItemClickListener);
            }

            @Override
            public void onBindViewHolder(@NonNull FolderViewHolder holder, int position) {
                FolderTreeItem item = folderItems.get(position);
                boolean isExpanded = viewModel != null && viewModel.isFolderExpanded(item.folderId);
                holder.bind(item, isExpanded);
            }

            @Override
            public int getItemCount() {
                return folderItems.size();
            }

            static class FolderViewHolder extends RecyclerView.ViewHolder {
                private View indentView;
                private ImageView ivExpandIcon;
                private ImageView ivFolderIcon;
                private TextView tvFolderName;
                private TextView tvNoteCount;
                private FolderTreeItem currentItem;
                private final OnFolderItemClickListener folderItemClickListener;

                public FolderViewHolder(@NonNull View itemView, OnFolderItemClickListener listener) {
                    super(itemView);
                    this.folderItemClickListener = listener;
                    indentView = itemView.findViewById(R.id.indent_view);
                    ivExpandIcon = itemView.findViewById(R.id.iv_expand_icon);
                    ivFolderIcon = itemView.findViewById(R.id.iv_folder_icon);
                    tvFolderName = itemView.findViewById(R.id.tv_folder_name);
                    tvNoteCount = itemView.findViewById(R.id.tv_note_count);
                }

                public void bind(FolderTreeItem item, boolean isExpanded) {
                    this.currentItem = item;

                    // 设置缩进
                    int indent = item.level * 32;
                    indentView.setLayoutParams(new LinearLayout.LayoutParams(indent, LinearLayout.LayoutParams.MATCH_PARENT));

                    // 设置展开/收起图标
                    if (item.hasChildren) {
                        ivExpandIcon.setVisibility(View.VISIBLE);
                        ivExpandIcon.setRotation(isExpanded ? 90 : 0);
                    } else {
                        ivExpandIcon.setVisibility(View.INVISIBLE);
                    }

                    // 设置文件夹名称
                    tvFolderName.setText(item.name);

                    // 设置便签数量
                    tvNoteCount.setText(String.format(itemView.getContext()
                            .getString(R.string.folder_note_count), item.noteCount));

                    // 设置点击监听器
                    itemView.setOnClickListener(v -> {
                        if (folderItemClickListener != null) {
                            folderItemClickListener.onFolderClick(item.folderId);
                        }
                    });
                }
            }
        }

        /**
         * 文件夹项点击监听器接口
         */
        public interface OnFolderItemClickListener {
            void onFolderClick(long folderId);
        }

    /**
     * FolderTreeItem
     * 文件夹树项数据模型
     */
    public static class FolderTreeItem {
        public long folderId;
        public String name;
        public int level; // 层级，0表示顶级
        public boolean hasChildren;
        public int noteCount;

        public FolderTreeItem(long folderId, String name, int level, boolean hasChildren, int noteCount) {
            this.folderId = folderId;
            this.name = name;
            this.level = level;
            this.hasChildren = hasChildren;
            this.noteCount = noteCount;
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        listener = null;
    }
}