/*
 * 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.Activity;
import android.app.AlarmManager;
import android.app.AlertDialog;
import android.app.PendingIntent;
import android.app.SearchManager;
import android.appwidget.AppWidgetManager;
import android.content.ContentUris;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.Paint;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.text.Spannable;
import android.text.SpannableString;
import android.text.TextUtils;
import android.text.format.DateUtils;
import android.text.style.BackgroundColorSpan;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.WindowManager;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

import net.micode.notes.R;
import net.micode.notes.data.Notes;
import net.micode.notes.data.Notes.TextNote;
import net.micode.notes.model.WorkingNote;
import net.micode.notes.model.WorkingNote.NoteSettingChangedListener;
import net.micode.notes.tool.DataUtils;
import net.micode.notes.tool.ResourceParser;
import net.micode.notes.tool.ResourceParser.TextAppearanceResources;
import net.micode.notes.ui.DateTimePickerDialog.OnDateTimeSetListener;
import net.micode.notes.ui.NoteEditText.OnTextViewChangeListener;
import net.micode.notes.widget.NoteWidgetProvider_2x;
import net.micode.notes.widget.NoteWidgetProvider_4x;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;


/**
 * 笔记编辑活动
 * 负责处理笔记的创建、编辑和预览功能
 * 实现了笔记设置变化监听器和文本视图变化监听器接口
 */
public class NoteEditActivity extends Activity implements OnClickListener,
        NoteSettingChangedListener, OnTextViewChangeListener {
    /**
     * 头部视图持有者类
     * 用于缓存头部视图的控件引用，提高性能
     */
    private class HeadViewHolder {
        public TextView tvModified;       // 最后修改时间文本视图
        public ImageView ivAlertIcon;     // 提醒图标
        public TextView tvAlertDate;      // 提醒日期文本视图
        public ImageView ibSetBgColor;    // 设置背景颜色按钮
    }

    /**
     * 背景选择器按钮映射
     * 用于将背景选择按钮ID映射到对应的背景颜色常量
     */
    private static final Map<Integer, Integer> sBgSelectorBtnsMap = new HashMap<Integer, Integer>();
    static {
        sBgSelectorBtnsMap.put(R.id.iv_bg_yellow, ResourceParser.YELLOW);
        sBgSelectorBtnsMap.put(R.id.iv_bg_red, ResourceParser.RED);
        sBgSelectorBtnsMap.put(R.id.iv_bg_blue, ResourceParser.BLUE);
        sBgSelectorBtnsMap.put(R.id.iv_bg_green, ResourceParser.GREEN);
        sBgSelectorBtnsMap.put(R.id.iv_bg_white, ResourceParser.WHITE);
    }

    /**
     * 背景选择器选中状态映射
     * 用于将背景颜色常量映射到对应的选中状态图标ID
     */
    private static final Map<Integer, Integer> sBgSelectorSelectionMap = new HashMap<Integer, Integer>();
    static {
        sBgSelectorSelectionMap.put(ResourceParser.YELLOW, R.id.iv_bg_yellow_select);
        sBgSelectorSelectionMap.put(ResourceParser.RED, R.id.iv_bg_red_select);
        sBgSelectorSelectionMap.put(ResourceParser.BLUE, R.id.iv_bg_blue_select);
        sBgSelectorSelectionMap.put(ResourceParser.GREEN, R.id.iv_bg_green_select);
        sBgSelectorSelectionMap.put(ResourceParser.WHITE, R.id.iv_bg_white_select);
    }

    /**
     * 字体大小按钮映射
     * 用于将字体大小选择按钮ID映射到对应的字体大小常量
     */
    private static final Map<Integer, Integer> sFontSizeBtnsMap = new HashMap<Integer, Integer>();
    static {
        sFontSizeBtnsMap.put(R.id.ll_font_large, ResourceParser.TEXT_LARGE);
        sFontSizeBtnsMap.put(R.id.ll_font_small, ResourceParser.TEXT_SMALL);
        sFontSizeBtnsMap.put(R.id.ll_font_normal, ResourceParser.TEXT_MEDIUM);
        sFontSizeBtnsMap.put(R.id.ll_font_super, ResourceParser.TEXT_SUPER);
    }

    /**
     * 字体选择器选中状态映射
     * 用于将字体大小常量映射到对应的选中状态图标ID
     */
    private static final Map<Integer, Integer> sFontSelectorSelectionMap = new HashMap<Integer, Integer>();
    static {
        sFontSelectorSelectionMap.put(ResourceParser.TEXT_LARGE, R.id.iv_large_select);
        sFontSelectorSelectionMap.put(ResourceParser.TEXT_SMALL, R.id.iv_small_select);
        sFontSelectorSelectionMap.put(ResourceParser.TEXT_MEDIUM, R.id.iv_medium_select);
        sFontSelectorSelectionMap.put(ResourceParser.TEXT_SUPER, R.id.iv_super_select);
    }

    private static final String TAG = "NoteEditActivity";  // 日志标签

    private HeadViewHolder mNoteHeaderHolder;        // 头部视图持有者
    private View mHeadViewPanel;                    // 头部视图面板
    private View mNoteBgColorSelector;              // 背景颜色选择器
    private View mFontSizeSelector;                 // 字体大小选择器
    private EditText mNoteEditor;                   // 笔记编辑器
    private View mNoteEditorPanel;                  // 笔记编辑器面板
    private WorkingNote mWorkingNote;               // 工作笔记对象
    private SharedPreferences mSharedPrefs;         // 共享偏好设置
    private int mFontSizeId;                        // 字体大小ID

    private static final String PREFERENCE_FONT_SIZE = "pref_font_size";  // 字体大小偏好设置键
    private static final int SHORTCUT_ICON_TITLE_MAX_LEN = 10;  // 快捷图标标题最大长度

    public static final String TAG_CHECKED = String.valueOf('\u221A');  // 已勾选标记
    public static final String TAG_UNCHECKED = String.valueOf('\u25A1');  // 未勾选标记

    private LinearLayout mEditTextList;             // 编辑文本列表（用于清单模式）
    private String mUserQuery;                      // 用户查询字符串
    private Pattern mPattern;                       // 正则表达式模式（用于高亮查询结果）

    /**
     * 创建活动时调用
     * @param savedInstanceState 保存的实例状态
     */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.setContentView(R.layout.note_edit);  // 设置布局

        // 如果没有保存的状态且无法初始化活动状态，则结束活动
        if (savedInstanceState == null && !initActivityState(getIntent())) {
            finish();
            return;
        }
        initResources();  // 初始化资源
    }

    /**
     * 当前活动在内存不足时可能被杀死。一旦被杀死，当用户再次加载此活动时，我们应该恢复以前的状态
     */
    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);
        if (savedInstanceState != null && savedInstanceState.containsKey(Intent.EXTRA_UID)) {
            Intent intent = new Intent(Intent.ACTION_VIEW);
            intent.putExtra(Intent.EXTRA_UID, savedInstanceState.getLong(Intent.EXTRA_UID));
            if (!initActivityState(intent)) {
                finish();
                return;
            }
            Log.d(TAG, "Restoring from killed activity");
        }
    }

    /**
     * 初始化活动状态
     * 根据传入的意图设置工作笔记的状态
     * @param intent 传入的意图
     * @return 是否初始化成功
     */
    private boolean initActivityState(Intent intent) {
        /**
         * If the user specified the {@link Intent#ACTION_VIEW} but not provided with id,
         * then jump to the NotesListActivity
         */
        mWorkingNote = null;
        if (TextUtils.equals(Intent.ACTION_VIEW, intent.getAction())) {
            long noteId = intent.getLongExtra(Intent.EXTRA_UID, 0);
            mUserQuery = "";

            /**
             * Starting from the searched result
             */
            if (intent.hasExtra(SearchManager.EXTRA_DATA_KEY)) {
                noteId = Long.parseLong(intent.getStringExtra(SearchManager.EXTRA_DATA_KEY));
                mUserQuery = intent.getStringExtra(SearchManager.USER_QUERY);
            }

            if (!DataUtils.visibleInNoteDatabase(getContentResolver(), noteId, Notes.TYPE_NOTE)) {
                Intent jump = new Intent(this, NotesListActivity.class);
                startActivity(jump);
                showToast(R.string.error_note_not_exist);
                finish();
                return false;
            } else {
                mWorkingNote = WorkingNote.load(this, noteId);
                if (mWorkingNote == null) {
                    Log.e(TAG, "load note failed with note id" + noteId);
                    finish();
                    return false;
                }
            }
            getWindow().setSoftInputMode(
                    WindowManager.LayoutParams.SOFT_INPUT_STATE_HIDDEN
                            | WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE);
        } else if(TextUtils.equals(Intent.ACTION_INSERT_OR_EDIT, intent.getAction())) {
            // New note
            long folderId = intent.getLongExtra(Notes.INTENT_EXTRA_FOLDER_ID, 0);
            int widgetId = intent.getIntExtra(Notes.INTENT_EXTRA_WIDGET_ID,
                    AppWidgetManager.INVALID_APPWIDGET_ID);
            int widgetType = intent.getIntExtra(Notes.INTENT_EXTRA_WIDGET_TYPE,
                    Notes.TYPE_WIDGET_INVALIDE);
            int bgResId = intent.getIntExtra(Notes.INTENT_EXTRA_BACKGROUND_ID,
                    ResourceParser.getDefaultBgId(this));

            // Parse call-record note
            String phoneNumber = intent.getStringExtra(Intent.EXTRA_PHONE_NUMBER);
            long callDate = intent.getLongExtra(Notes.INTENT_EXTRA_CALL_DATE, 0);
            if (callDate != 0 && phoneNumber != null) {
                if (TextUtils.isEmpty(phoneNumber)) {
                    Log.w(TAG, "The call record number is null");
                }
                long noteId = 0;
                if ((noteId = DataUtils.getNoteIdByPhoneNumberAndCallDate(getContentResolver(),
                        phoneNumber, callDate)) > 0) {
                    mWorkingNote = WorkingNote.load(this, noteId);
                    if (mWorkingNote == null) {
                        Log.e(TAG, "load call note failed with note id" + noteId);
                        finish();
                        return false;
                    }
                } else {
                    mWorkingNote = WorkingNote.createEmptyNote(this, folderId, widgetId,
                            widgetType, bgResId);
                    mWorkingNote.convertToCallNote(phoneNumber, callDate);
                }
            } else {
                mWorkingNote = WorkingNote.createEmptyNote(this, folderId, widgetId, widgetType,
                        bgResId);
            }

            getWindow().setSoftInputMode(
                    WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE
                            | WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE);
        } else {
            Log.e(TAG, "Intent not specified action, should not support");
            finish();
            return false;
        }
        mWorkingNote.setOnSettingStatusChangedListener(this);
        return true;
    }

    /**
     * 活动恢复时调用
     */
    @Override
    protected void onResume() {
        super.onResume();
        initNoteScreen();  // 初始化笔记屏幕
    }

    /**
     * 初始化笔记屏幕
     * 设置笔记编辑器的文本外观、内容和选择模式
     */
    private void initNoteScreen() {
        // 设置笔记编辑器的文本外观
        mNoteEditor.setTextAppearance(this, TextAppearanceResources
                .getTexAppearanceResource(mFontSizeId));
        
        // 根据笔记模式设置显示方式
        if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {
            switchToListMode(mWorkingNote.getContent());  // 切换到清单模式
        } else {
            // 设置笔记内容并高亮查询结果
            mNoteEditor.setText(getHighlightQueryResult(mWorkingNote.getContent(), mUserQuery));
            // 将光标定位到文本末尾
            mNoteEditor.setSelection(mNoteEditor.getText().length());
        }
        
        // 隐藏所有背景选择的选中状态
        for (Integer id : sBgSelectorSelectionMap.keySet()) {
            findViewById(sBgSelectorSelectionMap.get(id)).setVisibility(View.GONE);
        }
        
        // 设置头部视图和编辑器面板的背景
        mHeadViewPanel.setBackgroundResource(mWorkingNote.getTitleBgResId());
        mNoteEditorPanel.setBackgroundResource(mWorkingNote.getBgColorResId());

        // 设置最后修改时间
        mNoteHeaderHolder.tvModified.setText(DateUtils.formatDateTime(this,
                mWorkingNote.getModifiedDate(), DateUtils.FORMAT_SHOW_DATE
                        | DateUtils.FORMAT_NUMERIC_DATE | DateUtils.FORMAT_SHOW_TIME
                        | DateUtils.FORMAT_SHOW_YEAR));

        /**
         * TODO: Add the menu for setting alert. Currently disable it because the DateTimePicker
         * is not ready
         */
        showAlertHeader();  // 显示提醒头部
    }

    /**
     * 显示提醒头部
     * 根据笔记的提醒设置显示或隐藏提醒信息
     */
    private void showAlertHeader() {
        if (mWorkingNote.hasClockAlert()) {
            long time = System.currentTimeMillis();
            if (time > mWorkingNote.getAlertDate()) {
                mNoteHeaderHolder.tvAlertDate.setText(R.string.note_alert_expired);
            } else {
                mNoteHeaderHolder.tvAlertDate.setText(DateUtils.getRelativeTimeSpanString(
                        mWorkingNote.getAlertDate(), time, DateUtils.MINUTE_IN_MILLIS));
            }
            mNoteHeaderHolder.tvAlertDate.setVisibility(View.VISIBLE);
            mNoteHeaderHolder.ivAlertIcon.setVisibility(View.VISIBLE);
        } else {
            mNoteHeaderHolder.tvAlertDate.setVisibility(View.GONE);
            mNoteHeaderHolder.ivAlertIcon.setVisibility(View.GONE);
        };
    }

    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);
        initActivityState(intent);
    }

    /**
     * 保存活动状态
     * @param outState 保存状态的Bundle
     */
    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        /**
         * For new note without note id, we should firstly save it to
         * generate a id. If the editing note is not worth saving, there
         * is no id which is equivalent to create new note
         */
        if (!mWorkingNote.existInDatabase()) {
            saveNote();
        }
        outState.putLong(Intent.EXTRA_UID, mWorkingNote.getNoteId());
        Log.d(TAG, "Save working note id: " + mWorkingNote.getNoteId() + " onSaveInstanceState");
    }

    /**
     * 分发触摸事件
     * 处理背景颜色选择器和字体大小选择器的点击外部关闭逻辑
     * @param ev 触摸事件
     * @return 是否消费了事件
     */
    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        if (mNoteBgColorSelector.getVisibility() == View.VISIBLE
                && !inRangeOfView(mNoteBgColorSelector, ev)) {
            mNoteBgColorSelector.setVisibility(View.GONE);
            return true;
        }

        if (mFontSizeSelector.getVisibility() == View.VISIBLE
                && !inRangeOfView(mFontSizeSelector, ev)) {
            mFontSizeSelector.setVisibility(View.GONE);
            return true;
        }
        return super.dispatchTouchEvent(ev);
    }

    /**
     * 检查触摸事件是否在视图范围内
     * @param view 视图对象
     * @param ev 触摸事件
     * @return 是否在范围内
     */
    private boolean inRangeOfView(View view, MotionEvent ev) {
        int []location = new int[2];
        view.getLocationOnScreen(location);
        int x = location[0];
        int y = location[1];
        if (ev.getX() < x
                || ev.getX() > (x + view.getWidth())
                || ev.getY() < y
                || ev.getY() > (y + view.getHeight())) {
                    return false;
                }
        return true;
    }

    /**
     * 初始化资源
     * 初始化所有UI控件和资源引用
     */
    private void initResources() {
        mHeadViewPanel = findViewById(R.id.note_title);
        mNoteHeaderHolder = new HeadViewHolder();
        mNoteHeaderHolder.tvModified = (TextView) findViewById(R.id.tv_modified_date);
        mNoteHeaderHolder.ivAlertIcon = (ImageView) findViewById(R.id.iv_alert_icon);
        mNoteHeaderHolder.tvAlertDate = (TextView) findViewById(R.id.tv_alert_date);
        mNoteHeaderHolder.ibSetBgColor = (ImageView) findViewById(R.id.btn_set_bg_color);
        mNoteHeaderHolder.ibSetBgColor.setOnClickListener(this);
        mNoteEditor = (EditText) findViewById(R.id.note_edit_view);
        mNoteEditorPanel = findViewById(R.id.sv_note_edit);
        mNoteBgColorSelector = findViewById(R.id.note_bg_color_selector);
        
        // 为所有背景选择按钮设置点击监听器
        for (int id : sBgSelectorBtnsMap.keySet()) {
            ImageView iv = (ImageView) findViewById(id);
            iv.setOnClickListener(this);
        }

        mFontSizeSelector = findViewById(R.id.font_size_selector);
        
        // 为所有字体大小选择按钮设置点击监听器
        for (int id : sFontSizeBtnsMap.keySet()) {
            View view = findViewById(id);
            view.setOnClickListener(this);
        };
        
        // 初始化共享偏好设置和字体大小
        mSharedPrefs = PreferenceManager.getDefaultSharedPreferences(this);
        mFontSizeId = mSharedPrefs.getInt(PREFERENCE_FONT_SIZE, ResourceParser.BG_DEFAULT_FONT_SIZE);
        
        /**
         * HACKME: Fix bug of store the resource id in shared preference.
         * The id may larger than the length of resources, in this case,
         * return the {@link ResourceParser#BG_DEFAULT_FONT_SIZE}
         */
        if(mFontSizeId >= TextAppearanceResources.getResourcesSize()) {
            mFontSizeId = ResourceParser.BG_DEFAULT_FONT_SIZE;
        }
        
        mEditTextList = (LinearLayout) findViewById(R.id.note_edit_list);
    }

    /**
     * 活动暂停时调用
     * 保存笔记并清除设置状态
     */
    @Override
    protected void onPause() {
        super.onPause();
        if(saveNote()) {
            Log.d(TAG, "Note data was saved with length:" + mWorkingNote.getContent().length());
        }
        clearSettingState();
    }

    /**
     * 更新小部件
     * 更新与当前笔记关联的小部件内容
     */
    private void updateWidget() {
        Intent intent = new Intent(AppWidgetManager.ACTION_APPWIDGET_UPDATE);
        
        // 根据小部件类型设置对应的小部件提供器
        if (mWorkingNote.getWidgetType() == Notes.TYPE_WIDGET_2X) {
            intent.setClass(this, NoteWidgetProvider_2x.class);
        } else if (mWorkingNote.getWidgetType() == Notes.TYPE_WIDGET_4X) {
            intent.setClass(this, NoteWidgetProvider_4x.class);
        } else {
            Log.e(TAG, "Unspported widget type");
            return;
        }

        intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, new int[] {
            mWorkingNote.getWidgetId()
        });

        sendBroadcast(intent);  // 发送广播更新小部件
        setResult(RESULT_OK, intent);
    }

    /**
     * 点击事件处理
     * 处理各种UI控件的点击事件
     * @param v 被点击的视图
     */
    public void onClick(View v) {
        int id = v.getId();
        if (id == R.id.btn_set_bg_color) {
            // 显示背景颜色选择器
            mNoteBgColorSelector.setVisibility(View.VISIBLE);
            findViewById(sBgSelectorSelectionMap.get(mWorkingNote.getBgColorId())).setVisibility(
                    View.VISIBLE);
        } else if (sBgSelectorBtnsMap.containsKey(id)) {
            // 处理背景颜色选择
            findViewById(sBgSelectorSelectionMap.get(mWorkingNote.getBgColorId())).setVisibility(
                    View.GONE);
            mWorkingNote.setBgColorId(sBgSelectorBtnsMap.get(id));
            mNoteBgColorSelector.setVisibility(View.GONE);
        } else if (sFontSizeBtnsMap.containsKey(id)) {
            // 处理字体大小选择
            findViewById(sFontSelectorSelectionMap.get(mFontSizeId)).setVisibility(View.GONE);
            mFontSizeId = sFontSizeBtnsMap.get(id);
            mSharedPrefs.edit().putInt(PREFERENCE_FONT_SIZE, mFontSizeId).commit();
            findViewById(sFontSelectorSelectionMap.get(mFontSizeId)).setVisibility(View.VISIBLE);
            
            // 根据当前模式更新字体大小
            if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {
                getWorkingText();
                switchToListMode(mWorkingNote.getContent());
            } else {
                mNoteEditor.setTextAppearance(this,
                        TextAppearanceResources.getTexAppearanceResource(mFontSizeId));
            }
            mFontSizeSelector.setVisibility(View.GONE);
        }
    }

    /**
     * 按下返回键时调用
     */
    @Override
    public void onBackPressed() {
        if(clearSettingState()) {
            return;
        }

        saveNote();
        super.onBackPressed();
    }

    /**
     * 清除设置状态
     * 隐藏所有设置面板
     * @return 是否有设置面板被隐藏
     */
    private boolean clearSettingState() {
        if (mNoteBgColorSelector.getVisibility() == View.VISIBLE) {
            mNoteBgColorSelector.setVisibility(View.GONE);
            return true;
        } else if (mFontSizeSelector.getVisibility() == View.VISIBLE) {
            mFontSizeSelector.setVisibility(View.GONE);
            return true;
        }
        return false;
    }

    /**
     * 背景颜色改变时调用
     * 实现NoteSettingChangedListener接口
     */
    public void onBackgroundColorChanged() {
        findViewById(sBgSelectorSelectionMap.get(mWorkingNote.getBgColorId())).setVisibility(
                View.VISIBLE);
        mNoteEditorPanel.setBackgroundResource(mWorkingNote.getBgColorResId());
        mHeadViewPanel.setBackgroundResource(mWorkingNote.getTitleBgResId());
    }

    /**
     * 准备菜单时调用
     * @param menu 菜单对象
     * @return 是否准备成功
     */
    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        if (isFinishing()) {
            return true;
        }
        clearSettingState();
        menu.clear();
        if (mWorkingNote.getFolderId() == Notes.ID_CALL_RECORD_FOLDER) {
            getMenuInflater().inflate(R.menu.call_note_edit, menu);
        } else {
            getMenuInflater().inflate(R.menu.note_edit, menu);
        }
        if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {
            menu.findItem(R.id.menu_list_mode).setTitle(R.string.menu_normal_mode);
        } else {
            menu.findItem(R.id.menu_list_mode).setTitle(R.string.menu_list_mode);
        }
        if (mWorkingNote.hasClockAlert()) {
            menu.findItem(R.id.menu_alert).setVisible(false);
        } else {
            menu.findItem(R.id.menu_delete_remind).setVisible(false);
        }
        return true;
    }

    /**
     * 菜单项选择处理
     * 处理各种菜单按钮的点击事件
     * @param item 选择的菜单项
     * @return 是否处理了该事件
     */
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.menu_new_note:
                createNewNote();  // 创建新笔记
                break;
            case R.id.menu_delete:
                // 显示删除确认对话框
                AlertDialog.Builder builder = new AlertDialog.Builder(this);
                builder.setTitle(getString(R.string.alert_title_delete));
                builder.setIcon(android.R.drawable.ic_dialog_alert);
                builder.setMessage(getString(R.string.alert_message_delete_note));
                builder.setPositiveButton(android.R.string.ok,
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int which) {
                                deleteCurrentNote();  // 删除当前笔记
                                finish();
                            }
                        });
                builder.setNegativeButton(android.R.string.cancel, null);
                builder.show();
                break;
            case R.id.menu_font_size:
                // 显示字体大小选择器
                mFontSizeSelector.setVisibility(View.VISIBLE);
                findViewById(sFontSelectorSelectionMap.get(mFontSizeId)).setVisibility(View.VISIBLE);
                break;
            case R.id.menu_list_mode:
                // 切换笔记模式（普通模式/清单模式）
                mWorkingNote.setCheckListMode(mWorkingNote.getCheckListMode() == 0 ?
                        TextNote.MODE_CHECK_LIST : 0);
                break;
            case R.id.menu_share:
                getWorkingText();  // 获取当前工作文本
                sendTo(this, mWorkingNote.getContent());  // 分享笔记内容
                break;
            case R.id.menu_send_to_desktop:
                sendToDesktop();  // 发送到桌面
                break;
            case R.id.menu_alert:
                setReminder();  // 设置提醒
                break;
            case R.id.menu_delete_remind:
                mWorkingNote.setAlertDate(0, false);  // 删除提醒
                break;
            default:
                break;
        }
        return true;
    }

    /**
     * 设置提醒
     * 显示日期时间选择器，设置笔记的提醒时间
     */
    private void setReminder() {
        DateTimePickerDialog d = new DateTimePickerDialog(this, System.currentTimeMillis());
        d.setOnDateTimeSetListener(new OnDateTimeSetListener() {
            public void OnDateTimeSet(AlertDialog dialog, long date) {
                mWorkingNote.setAlertDate(date	, true);
            }
        });
        d.show();
    }

    /**
     * 分享笔记
     * 分享笔记内容到支持{@link Intent#ACTION_SEND}动作和{@text/plain}类型的应用
     * @param context 上下文对象
     * @param info 要分享的内容
     */
    private void sendTo(Context context, String info) {
        Intent intent = new Intent(Intent.ACTION_SEND);
        intent.putExtra(Intent.EXTRA_TEXT, info);
        intent.setType("text/plain");
        context.startActivity(intent);
    }

    /**
     * 创建新笔记
     * 保存当前笔记并创建一个新的笔记
     */
    private void createNewNote() {
        // 首先保存当前编辑的笔记
        saveNote();

        // 为了安全起见，启动一个新的NoteEditActivity
        finish();
        Intent intent = new Intent(this, NoteEditActivity.class);
        intent.setAction(Intent.ACTION_INSERT_OR_EDIT);
        intent.putExtra(Notes.INTENT_EXTRA_FOLDER_ID, mWorkingNote.getFolderId());
        startActivity(intent);
    }

    /**
     * 删除当前笔记
     * 根据同步模式决定是直接删除还是移动到回收站
     */
    private void deleteCurrentNote() {
        if (mWorkingNote.existInDatabase()) {
            HashSet<Long> ids = new HashSet<Long>();
            long id = mWorkingNote.getNoteId();
            if (id != Notes.ID_ROOT_FOLDER) {
                ids.add(id);
            } else {
                Log.d(TAG, "Wrong note id, should not happen");
            }
            if (!isSyncMode()) {
                // 非同步模式下直接删除
                if (!DataUtils.batchDeleteNotes(getContentResolver(), ids)) {
                    Log.e(TAG, "Delete Note error");
                }
            } else {
                // 同步模式下移动到回收站
                if (!DataUtils.batchMoveToFolder(getContentResolver(), ids, Notes.ID_TRASH_FOLER)) {
                    Log.e(TAG, "Move notes to trash folder error, should not happens");
                }
            }
        }
        mWorkingNote.markDeleted(true);
    }

    /**
     * 检查是否为同步模式
     * @return 是否为同步模式
     */
    private boolean isSyncMode() {
        return NotesPreferenceActivity.getSyncAccountName(this).trim().length() > 0;
    }

    /**
     * 提醒时间改变时调用
     * 实现NoteSettingChangedListener接口
     * @param date 提醒时间
     * @param set 是否设置提醒
     */
    public void onClockAlertChanged(long date, boolean set) {
        /**
         * User could set clock to an unsaved note, so before setting the
         * alert clock, we should save the note first
         */
        if (!mWorkingNote.existInDatabase()) {
            saveNote();
        }
        if (mWorkingNote.getNoteId() > 0) {
            Intent intent = new Intent(this, AlarmReceiver.class);
            intent.setData(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, mWorkingNote.getNoteId()));
            PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);
            AlarmManager alarmManager = ((AlarmManager) getSystemService(ALARM_SERVICE));
            showAlertHeader();
            if(!set) {
                alarmManager.cancel(pendingIntent);
            } else {
                alarmManager.set(AlarmManager.RTC_WAKEUP, date, pendingIntent);
            }
        } else {
            /**
             * There is the condition that user has input nothing (the note is
             * not worthy saving), we have no note id, remind the user that he
             * should input something
             */
            Log.e(TAG, "Clock alert setting error");
            showToast(R.string.error_note_empty_for_clock);
        }
    }

    /**
     * 小部件改变时调用
     * 实现NoteSettingChangedListener接口
     */
    public void onWidgetChanged() {
        updateWidget();
    }

    /**
     * 编辑文本删除时调用
     * 实现OnTextViewChangeListener接口
     * @param index 删除的索引
     * @param text 删除的文本
     */
    public void onEditTextDelete(int index, String text) {
        int childCount = mEditTextList.getChildCount();
        if (childCount == 1) {
            return;
        }

        for (int i = index + 1; i < childCount; i++) {
            ((NoteEditText) mEditTextList.getChildAt(i).findViewById(R.id.et_edit_text))
                    .setIndex(i - 1);
        }

        mEditTextList.removeViewAt(index);
        NoteEditText edit = null;
        if(index == 0) {
            edit = (NoteEditText) mEditTextList.getChildAt(0).findViewById(
                    R.id.et_edit_text);
        } else {
            edit = (NoteEditText) mEditTextList.getChildAt(index - 1).findViewById(
                    R.id.et_edit_text);
        }
        int length = edit.length();
        edit.append(text);
        edit.requestFocus();
        edit.setSelection(length);
    }

    /**
     * 编辑文本回车时调用
     * 实现OnTextViewChangeListener接口
     * @param index 当前索引
     * @param text 文本内容
     */
    public void onEditTextEnter(int index, String text) {
        /**
         * Should not happen, check for debug
         */
        if(index > mEditTextList.getChildCount()) {
            Log.e(TAG, "Index out of mEditTextList boundrary, should not happen");
        }

        View view = getListItem(text, index);
        mEditTextList.addView(view, index);
        NoteEditText edit = (NoteEditText) view.findViewById(R.id.et_edit_text);
        edit.requestFocus();
        edit.setSelection(0);
        for (int i = index + 1; i < mEditTextList.getChildCount(); i++) {
            ((NoteEditText) mEditTextList.getChildAt(i).findViewById(R.id.et_edit_text))
                    .setIndex(i);
        }
    }

    /**
     * 切换到清单模式
     * 将普通文本模式转换为清单模式
     * @param text 要转换的文本内容
     */
    private void switchToListMode(String text) {
        mEditTextList.removeAllViews();  // 清空编辑文本列表
        String[] items = text.split("\n");  // 按行分割文本
        int index = 0;
        for (String item : items) {
            if(!TextUtils.isEmpty(item)) {
                mEditTextList.addView(getListItem(item, index));  // 添加列表项
                index++;
            }
        }
        mEditTextList.addView(getListItem("", index));  // 添加最后一个空列表项
        mEditTextList.getChildAt(index).findViewById(R.id.et_edit_text).requestFocus();  // 设置焦点

        mNoteEditor.setVisibility(View.GONE);  // 隐藏普通编辑器
        mEditTextList.setVisibility(View.VISIBLE);  // 显示清单编辑器
    }

    /**
     * 获取高亮查询结果
     * 对文本中的查询关键词进行高亮处理
     * @param fullText 完整文本
     * @param userQuery 用户查询字符串
     * @return 带有高亮效果的文本
     */
    private Spannable getHighlightQueryResult(String fullText, String userQuery) {
        SpannableString spannable = new SpannableString(fullText == null ? "" : fullText);
        if (!TextUtils.isEmpty(userQuery)) {
            mPattern = Pattern.compile(userQuery);  // 编译正则表达式
            Matcher m = mPattern.matcher(fullText);  // 创建匹配器
            int start = 0;
            while (m.find(start)) {
                // 设置高亮背景色
                spannable.setSpan(
                        new BackgroundColorSpan(this.getResources().getColor(
                                R.color.user_query_highlight)), m.start(), m.end(),
                        Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
                start = m.end();
            }
        }
        return spannable;
    }

    /**
     * 获取列表项视图
     * 创建并初始化清单模式下的单个列表项视图
     * @param item 列表项文本
     * @param index 列表项索引
     * @return 列表项视图
     */
    private View getListItem(String item, int index) {
        View view = LayoutInflater.from(this).inflate(R.layout.note_edit_list_item, null);
        final NoteEditText edit = (NoteEditText) view.findViewById(R.id.et_edit_text);
        edit.setTextAppearance(this, TextAppearanceResources.getTexAppearanceResource(mFontSizeId));
        
        // 设置复选框的选中状态变化监听器
        CheckBox cb = ((CheckBox) view.findViewById(R.id.cb_edit_item));
        cb.setOnCheckedChangeListener(new OnCheckedChangeListener() {
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (isChecked) {
                    edit.setPaintFlags(edit.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
                } else {
                    edit.setPaintFlags(Paint.ANTI_ALIAS_FLAG | Paint.DEV_KERN_TEXT_FLAG);
                }
            }
        });

        // 处理已勾选和未勾选的标记
        if (item.startsWith(TAG_CHECKED)) {
            cb.setChecked(true);
            edit.setPaintFlags(edit.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
            item = item.substring(TAG_CHECKED.length(), item.length()).trim();
        } else if (item.startsWith(TAG_UNCHECKED)) {
            cb.setChecked(false);
            edit.setPaintFlags(Paint.ANTI_ALIAS_FLAG | Paint.DEV_KERN_TEXT_FLAG);
            item = item.substring(TAG_UNCHECKED.length(), item.length()).trim();
        }

        edit.setOnTextViewChangeListener(this);
        edit.setIndex(index);
        edit.setText(getHighlightQueryResult(item, mUserQuery));
        return view;
    }

    /**
     * 文本内容改变时调用
     * 实现OnTextViewChangeListener接口
     * @param index 当前索引
     * @param hasText 是否有文本内容
     */
    public void onTextChange(int index, boolean hasText) {
        if (index >= mEditTextList.getChildCount()) {
            Log.e(TAG, "Wrong index, should not happen");
            return;
        }
        if(hasText) {
            mEditTextList.getChildAt(index).findViewById(R.id.cb_edit_item).setVisibility(View.VISIBLE);
        } else {
            mEditTextList.getChildAt(index).findViewById(R.id.cb_edit_item).setVisibility(View.GONE);
        }
    }

    /**
     * 清单模式改变时调用
     * 实现NoteSettingChangedListener接口
     * @param oldMode 旧模式
     * @param newMode 新模式
     */
    public void onCheckListModeChanged(int oldMode, int newMode) {
        if (newMode == TextNote.MODE_CHECK_LIST) {
            switchToListMode(mNoteEditor.getText().toString());
        } else {
            if (!getWorkingText()) {
                mWorkingNote.setWorkingText(mWorkingNote.getContent().replace(TAG_UNCHECKED + " ",
                        ""));
            }
            mNoteEditor.setText(getHighlightQueryResult(mWorkingNote.getContent(), mUserQuery));
            mEditTextList.setVisibility(View.GONE);
            mNoteEditor.setVisibility(View.VISIBLE);
        }
    }

    /**
     * 获取当前工作文本
     * 根据笔记模式获取当前编辑的文本内容
     * @return 是否有已勾选的项目
     */
    private boolean getWorkingText() {
        boolean hasChecked = false;
        if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < mEditTextList.getChildCount(); i++) {
                View view = mEditTextList.getChildAt(i);
                NoteEditText edit = (NoteEditText) view.findViewById(R.id.et_edit_text);
                if (!TextUtils.isEmpty(edit.getText())) {
                    if (((CheckBox) view.findViewById(R.id.cb_edit_item)).isChecked()) {
                        sb.append(TAG_CHECKED).append(" ").append(edit.getText()).append("\n");
                        hasChecked = true;
                    } else {
                        sb.append(TAG_UNCHECKED).append(" ").append(edit.getText()).append("\n");
                    }
                }
            }
            mWorkingNote.setWorkingText(sb.toString());
        } else {
            mWorkingNote.setWorkingText(mNoteEditor.getText().toString());
        }
        return hasChecked;
    }

    /**
     * 保存笔记
     * @return 是否保存成功
     */
    private boolean saveNote() {
        getWorkingText();  // 获取当前工作文本
        boolean saved = mWorkingNote.saveNote();  // 保存笔记到数据库
        if (saved) {
            /**
             * There are two modes from List view to edit view, open one note,
             * create/edit a node. Opening node requires to the original
             * position in the list when back from edit view, while creating a
             * new node requires to the top of the list. This code
             * {@link #RESULT_OK} is used to identify the create/edit state
             */
            setResult(RESULT_OK);
        }
        return saved;
    }

    /**
     * 发送到桌面
     * 在桌面上创建当前笔记的快捷方式
     */
    private void sendToDesktop() {
        /**
         * Before send message to home, we should make sure that current
         * editing note is exists in databases. So, for new note, firstly
         * save it
         */
        if (!mWorkingNote.existInDatabase()) {
            saveNote();
        }

        if (mWorkingNote.getNoteId() > 0) {
            Intent sender = new Intent();
            Intent shortcutIntent = new Intent(this, NoteEditActivity.class);
            shortcutIntent.setAction(Intent.ACTION_VIEW);
            shortcutIntent.putExtra(Intent.EXTRA_UID, mWorkingNote.getNoteId());
            sender.putExtra(Intent.EXTRA_SHORTCUT_INTENT, shortcutIntent);
            sender.putExtra(Intent.EXTRA_SHORTCUT_NAME,
                    makeShortcutIconTitle(mWorkingNote.getContent()));
            sender.putExtra(Intent.EXTRA_SHORTCUT_ICON_RESOURCE,
                    Intent.ShortcutIconResource.fromContext(this, R.drawable.icon_app));
            sender.putExtra("duplicate", true);
            sender.setAction("com.android.launcher.action.INSTALL_SHORTCUT");
            showToast(R.string.info_note_enter_desktop);
            sendBroadcast(sender);
        } else {
            /**
             * There is the condition that user has input nothing (the note is
             * not worthy saving), we have no note id, remind the user that he
             * should input something
             */
            Log.e(TAG, "Send to desktop error");
            showToast(R.string.error_note_empty_for_send_to_desktop);
        }
    }

    /**
     * 创建快捷图标标题
     * 处理快捷图标标题，移除标记并限制长度
     * @param content 笔记内容
     * @return 快捷图标标题
     */
    private String makeShortcutIconTitle(String content) {
        content = content.replace(TAG_CHECKED, "");
        content = content.replace(TAG_UNCHECKED, "");
        return content.length() > SHORTCUT_ICON_TITLE_MAX_LEN ? content.substring(0,
                SHORTCUT_ICON_TITLE_MAX_LEN) : content;
    }

    /**
     * 显示短时间提示
     * @param resId 提示文本资源ID
     */
    private void showToast(int resId) {
        showToast(resId, Toast.LENGTH_SHORT);
    }

    /**
     * 显示提示
     * @param resId 提示文本资源ID
     * @param duration 提示持续时间
     */
    private void showToast(int resId, int duration) {
        Toast.makeText(this, resId, duration).show();
    }
}
