/*
 * 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;

//该类主要针对标签的编辑,是Activity的一个子类
//实现了了系统内许多与监听有关的接口
public class NoteEditActivity extends Activity implements OnClickListener,
        NoteSettingChangedListener, OnTextViewChangeListener {

    private class HeadViewHolder {
        public TextView tvModified; //

        public ImageView ivAlertIcon;

        public TextView tvAlertDate;

        public ImageView ibSetBgColor;
    }
    //使用Map实现数据存储
    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); //put函数是将指定值与指定键相连

    }

    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); //put函数是将指定值与指定键相连

    }

    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); //put函数是将指定值与指定键相连

    }

    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); //put函数是将指定值与指定键相连

    }

    private static final String TAG = "NoteEditActivity";

    private HeadViewHolder mNoteHeaderHolder;

    private View mHeadViewPanel; //私有化一个界面操作mHeadViewPanel，对表头的操作
    private View mNoteBgColorSelector; //私有化一个界面操作mNoteBgColorSelector，对背景颜色的操作
    private View mFontSizeSelector; //私有化一个界面操作mFontSizeSelector，对标签字体的操作
    private EditText mNoteEditor; //声明编辑控件，对文本操作
    private View mNoteEditorPanel; //私有化一个界面操作mNoteEditorPanel，文本编辑的控制板

    private WorkingNote mWorkingNote; //对模板WorkingNote的初始化
    private SharedPreferences mSharedPrefs; //私有化SharedPreferences的数据存储方式,它的本质是基于XML文件存储key-value键值对数据
    private int mFontSizeId; //用于操作字体的大小

    private static final String PREFERENCE_FONT_SIZE = "pref_font_size";

    private static final int SHORTCUT_ICON_TITLE_MAX_LEN = 10;

    public static final String TAG_CHECKED = String.valueOf('\u221A');
    public static final String TAG_UNCHECKED = String.valueOf('\u25A1');

    private LinearLayout mEditTextList; //线性布局

    private String mUserQuery;
    private Pattern mPattern;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.setContentView(R.layout.note_edit);
        if (savedInstanceState == null && !initActivityState(getIntent())) { //对数据库的访问
            finish();
            return;
        }
        initResources();
    }

    /**
     * Current activity may be killed when the memory is low. Once it is killed, for another time
     * user load this activity, we should restore the former state
     */
    @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");
        } //防止内存不足时的程序终止，保存现场的函数
    }

    private boolean initActivityState(Intent intent) {
        /**
         * If the user specified the {@link Intent#ACTION_VIEW} but not provided with id,
         * then jump to the NotesListActivity
         */
        // 在没有特定note ID的情况下，若‘Intent.ACTION VIEW’被触发，那么转向 NotesListActivity
        mWorkingNote = null;
        if (TextUtils.equals(Intent.ACTION_VIEW, intent.getAction())) {
            long noteId = intent.getLongExtra(Intent.EXTRA_UID, 0); //如果用户实例化标签时，系统并未给出标签ID
            mUserQuery = "";
            /**
             * Starting from the searched result
             */
            //根据键值查找ID,如果Intent~ 中存在搜索管理器的额外键值,则根据该键值检索 ID
            if (intent.hasExtra(SearchManager.EXTRA_DATA_KEY)) {
                noteId = Long.parseLong(intent.getStringExtra(SearchManager.EXTRA_DATA_KEY));
                mUserQuery = intent.getStringExtra(SearchManager.USER_QUERY);
            }
            // 如果该笔记ID不在数据库中，则跳转至笔记列表并提示错误
            if (!DataUtils.visibleInNoteDatabase(getContentResolver(), noteId, Notes.TYPE_NOTE)) {
                Intent jump = new Intent(this, NotesListActivity.class);
                startActivity(jump);
                showToast(R.string.error_note_not_exist);//程序将跳转到声明的intent-jump
                finish();
                return false;
            }
            //如果在数据库中找到了ID，则加载笔记
            else {
                mWorkingNote = WorkingNote.load(this, noteId);
                // 若加载失败，则记录错误并结束该 Activity
                if (mWorkingNote == null) {
                    Log.e(TAG, "load note failed with note id" + noteId);
                    //打印出红色的错误信息
                    finish();
                    return false;
                }
            }
            //setSoftInputMode-软键盘输入模式，初始化软键盘输入模式，隐藏软键盘，同时在需要时调整布局大小
            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
            // intent.getAction()
            // 大多用于broadcast发送广播时给机制（intent）设置一个action，就是一个字符串
            // 用户可以通过receive（接受）intent，通过 getAction得到的字符串，来决定做什么
            // 在Intent.ACTION INSERT OR EDIT 的动作下创建新笔记或编辑现有笔记
            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));
            // intent.getInt（Long、String）Extra是对各变量的语法分析
            //解析来电记录笔记相关数据
            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;
                //通过电话号码和通话日期查询笔记ID
                if ((noteId = DataUtils.getNoteIdByPhoneNumberAndCallDate(getContentResolver(),
                        phoneNumber, callDate)) > 0) {
                    //如果查询成功，则加载来电记录笔记
                    mWorkingNote = WorkingNote.load(this, noteId);
                    //加载失败则记录错误并结束Activity
                    if (mWorkingNote == null) {
                        Log.e(TAG, "load call note failed with note id" + noteId);
                        finish();
                        return false;
                    }
                    //将电话记录和联系人相关
                } else {
                    //如果没有相关来电记录笔记，则创建一个空笔记
                    mWorkingNote = WorkingNote.createEmptyNote(this, folderId, widgetId,
                            widgetType, bgResId);
                    //转换该空笔记记为来电记录笔记
                    mWorkingNote.convertToCallNote(phoneNumber, callDate);
                }
            } else {
                //如果不是来电记录，则创建一个新的空笔记
                mWorkingNote = WorkingNote.createEmptyNote(this, folderId, widgetId, widgetType,
                        bgResId);
            } //创建一个新的WorkingNote

            // 初始化软键盘输入模式，保持软键盘可见，同时在需要时调整布局大小
            getWindow().setSoftInputMode(
                    WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE
                            | WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE);
        } else {
            //如果'Intent'不包含已知动作，则记录错误并结束Activity
            Log.e(TAG, "Intent not specified action, should not support");
            finish();
            return false;
        }
        //为工作笔记设置状态改变监听器
        mWorkingNote.setOnSettingStatusChangedListener(this);
        return true;
    }

    @Override
    protected void onResume() {
        super.onResume();
        initNoteScreen(); //调用方法初始化笔记屏幕
    }
    //初始化笔记界面的方法
    private void initNoteScreen() {
        //设置笔记编辑器的文字样式
        mNoteEditor.setTextAppearance(this, TextAppearanceResources
                .getTexAppearanceResource(mFontSizeId));
        //判断是否是清单模式，进行相应的试图转换
        if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {
            switchToListMode(mWorkingNote.getContent());
        } else {
            //设置文本编辑器的文本并突出显示查询结果
            mNoteEditor.setText(getHighlightQueryResult(mWorkingNote.getContent(), mUserQuery));
            //将光标设置到文本末尾
            mNoteEditor.setSelection(mNoteEditor.getText().length());
        }
        //隐藏所有背景选择器试图
        for (Integer id : sBgSelectorSelectionMap.keySet()) {
            findViewById(sBgSelectorSelectionMap.get(id)).setVisibility(View.GONE);
        }
        //设置标题和笔记编辑器面板的背景资源
        mHeadViewPanel.setBackgroundResource(mWorkingNote.getTitleBgResId());
        mNoteEditorPanel.setBackgroundResource(mWorkingNote.getBgColorResId());
        //设置笔记头部信息，显示修改日期
        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(); //显示或隐藏笔记的提醒图标和提醒日期
    }

    //显示提醒头部的方法
    private void showAlertHeader() {
        //判断笔记是否有提醒时间
        if (mWorkingNote.hasClockAlert()) {
            //如果当前时间超过了提醒时间，则显示过期信息
            long time = System.currentTimeMillis();
            if (time > mWorkingNote.getAlertDate()) {
                mNoteHeaderHolder.tvAlertDate.setText(R.string.note_alert_expired);
            } else {
                //否则显示相对的剩余时间
                mNoteHeaderHolder.tvAlertDate.setText(DateUtils.getRelativeTimeSpanString(
                        mWorkingNote.getAlertDate(), time, DateUtils.MINUTE_IN_MILLIS));
            }
            //使提醒日期和图标可见
            mNoteHeaderHolder.tvAlertDate.setVisibility(View.VISIBLE);
            mNoteHeaderHolder.ivAlertIcon.setVisibility(View.VISIBLE);
        } else {
            //没有提醒时，隐藏提醒日期和图标
            mNoteHeaderHolder.tvAlertDate.setVisibility(View.GONE);
            mNoteHeaderHolder.ivAlertIcon.setVisibility(View.GONE);
        };
    }
    //当活动通过意图重新初始化时调用
    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);
        //用新的意图初始化活动状态
        initActivityState(intent);
    }

    //在活动可能被系统销毁前调用，保存状态
    @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
         */
        //对于尚未在数据库中保存的新笔记，先保存以生成ID
        if (!mWorkingNote.existInDatabase()) {
            saveNote();
        }
        //将笔记ID保存到状态Bundle中
        outState.putLong(Intent.EXTRA_UID, mWorkingNote.getNoteId());
        Log.d(TAG, "Save working note id: " + mWorkingNote.getNoteId() + " onSaveInstanceState");
    }

    //分发触摸事件的方法
    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        //如果背景色选择器可见并触摸事件不在其范围内，则隐藏选择器并拦截事件
        if (mNoteBgColorSelector.getVisibility() == View.VISIBLE
                && !inRangeOfView(mNoteBgColorSelector, ev)) {
            mNoteBgColorSelector.setVisibility(View.GONE);
            return true;
        }
        //如果字体大小选择器可见并触摸事件不在其范围内，则隐藏选择器并拦截事件
        if (mFontSizeSelector.getVisibility() == View.VISIBLE
                && !inRangeOfView(mFontSizeSelector, ev)) {
            mFontSizeSelector.setVisibility(View.GONE);
            return true;
        }
        //否则，继续向下分发触摸事件
        return super.dispatchTouchEvent(ev);
    }

    //判断触摸事件是否在给定的视图的范围内的方法
    private boolean inRangeOfView(View view, MotionEvent ev) {
        int []location = new int[2];
        //获取视图在屏幕上的位置
        view.getLocationOnScreen(location);
        int x = location[0];
        int y = location[1];
        //根据位置和触摸坐标判断是否在视图内
        if (ev.getX() < x
                || ev.getX() > (x + view.getWidth())
                || ev.getY() < y
                || ev.getY() > (y + view.getHeight())) {
                    return false;
                }
        return true;
    }

    //初始化资源的方法
    private void initResources() {
        //找到并设置相关视图的引用
        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);
        //为背景选择器中的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);
        //为字体大小选择器中的每一个选项设置点击监听器
        for (int id : sFontSizeBtnsMap.keySet()) {
            View view = findViewById(id);
            view.setOnClickListener(this);
        };
        //获取共享偏好设置，用于恢复特定的笔记属性，如字体的大小
        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}
         */
        //如果字体大小ID超出资源数组大小，设置为默认字体大小
        if(mFontSizeId >= TextAppearanceResources.getResourcesSize()) {
            mFontSizeId = ResourceParser.BG_DEFAULT_FONT_SIZE;
        }
        //初始化笔记编辑列表视图
        mEditTextList = (LinearLayout) findViewById(R.id.note_edit_list);
    }

    //当活动暂停时调用
    @Override
    protected void onPause() {
        super.onPause();
        //尝试保存笔记，如果成功则记录保存的长度
        if(saveNote()) {
            Log.d(TAG, "Note data was saved with length:" + mWorkingNote.getContent().length());
        }
        //清除设置状态
        clearSettingState();
    }

    //用于更新小部件
    private void updateWidget() {
        //创建一个更新小部件的intent
        Intent intent = new Intent(AppWidgetManager.ACTION_APPWIDGET_UPDATE);
        //根据笔记的小部件类型决定使用哪个小部件提供器
        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 {
            //如果小部件类型不支持，则记录错误并返回
            Log.e(TAG, "Unspported widget type");
            return;
        }
        //添加小部件ID到intent中
        intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS, new int[] {
            mWorkingNote.getWidgetId()
        });
        //发送广播以通知小部件更新
        sendBroadcast(intent);
        //设置结果为OK
        setResult(RESULT_OK, intent);
    }
    //处理点击事件
    public void onClick(View v) {
        int id = v.getId();
        //如果点击的是设置背景颜色按钮，则显示颜色选择器
        if (id == R.id.btn_set_bg_color) {
            mNoteBgColorSelector.setVisibility(View.VISIBLE);
            findViewById(sBgSelectorSelectionMap.get(mWorkingNote.getBgColorId())).setVisibility(
                    -                    View.VISIBLE);
        //更改背景颜色或字体大小的逻辑
        } else if (sBgSelectorBtnsMap.containsKey(id)) {
            findViewById(sBgSelectorSelectionMap.get(mWorkingNote.getBgColorId())).setVisibility(
                    View.GONE);
            mWorkingNote.setBgColorId(sBgSelectorBtnsMap.get(id));
            mNoteBgColorSelector.setVisibility(View.GONE);
        } else if (sFontSizeBtnsMap.containsKey(id)) {
            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);
            if (mWorkingNote.getCheckListMode() == TextNote.MODE_CHECK_LIST) {
                getWorkingText();
                switchToListMode(mWorkingNote.getContent());
            } else {
                mNoteEditor.setTextAppearance(this,
                        TextAppearanceResources.getTexAppearanceResource(mFontSizeId));
            }
            mFontSizeSelector.setVisibility(View.GONE);
        }
    }

    //当用户按下返回按钮时调用
    @Override
    public void onBackPressed() {
        //清除设置状态，如果已经处理则返回
        if(clearSettingState()) {
            return;
        }
        //保存笔记然后正常处理返回事件
        saveNote();
        super.onBackPressed();
    }

    //清楚设置状态的辅助方法
    private boolean clearSettingState() {
        //如果背景颜色或字体大小选择器可见，则隐藏他们，并返回true表示状态已清除
        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;
    }

    //当背景色改变时更新UI
    public void onBackgroundColorChanged() {
        //设置编辑面板和头部面板的背景
        findViewById(sBgSelectorSelectionMap.get(mWorkingNote.getBgColorId())).setVisibility(
                View.VISIBLE);
        mNoteEditorPanel.setBackgroundResource(mWorkingNote.getBgColorResId());
        mHeadViewPanel.setBackgroundResource(mWorkingNote.getTitleBgResId());
    }

    //准备选项菜单
    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        //如果Activity正在结束则直接返回，根据不同的情况，填充不同的菜单
        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;
    }

    //当选项被选中时调用
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        //处理菜单项的点击事件，如创建新笔记、删除笔记、更改字体大小等
        int itemId = item.getItemId();
        if (itemId == R.id.menu_new_note) {
            createNewNote();
        } else if (itemId == R.id.menu_delete) {
            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();
                            finish();
                        }
                    });
            builder.setNegativeButton(android.R.string.cancel, null);
            builder.show();
        } else if (itemId == R.id.menu_font_size) {
            mFontSizeSelector.setVisibility(View.VISIBLE);
            findViewById(sFontSelectorSelectionMap.get(mFontSizeId)).setVisibility(View.VISIBLE);
        } else if (itemId == R.id.menu_list_mode) {
            mWorkingNote.setCheckListMode(mWorkingNote.getCheckListMode() == 0 ?
                    TextNote.MODE_CHECK_LIST : 0);
        } else if (itemId == R.id.menu_share) {
            getWorkingText();
            sendTo(this, mWorkingNote.getContent());
        } else if (itemId == R.id.menu_send_to_desktop) {
            sendToDesktop();
        } else if (itemId == R.id.menu_alert) {
            setReminder();
        } else if (itemId == R.id.menu_delete_remind) {
            mWorkingNote.setAlertDate(0, false);
        }
        return true;
    }

    //设置提醒的辅助方法
    private void setReminder() {
        //显示时间日期选择器对话框，并设置监听器以保存提醒时间
        DateTimePickerDialog d = new DateTimePickerDialog(this, System.currentTimeMillis());
        //设置选择器的回调，用户选择日期时间后会调用这个监听函数
        d.setOnDateTimeSetListener(new OnDateTimeSetListener() {
            public void OnDateTimeSet(AlertDialog dialog, long date) {
                //当用户设置了日期时间后，将这个时间保存为提醒的时间
                mWorkingNote.setAlertDate(date	, true);
            }
        });
        //显示日期时间选择对话框
        d.show();
    }

    /**
     * Share note to apps that support {@link Intent#ACTION_SEND} action
     * and {@text/plain} type
     */
    private void sendTo(Context context, String info) {
        //创建发送行为的Intent，用于分享
        Intent intent = new Intent(Intent.ACTION_SEND);
        //将要分享的文本信息放入Intent
        intent.putExtra(Intent.EXTRA_TEXT, info);
        //设置分享的类型为纯文本
        intent.setType("text/plain");
        //开始执行分享行为
        context.startActivity(intent);
    }

    private void createNewNote() {
        // Firstly, save current editing notes 保存正在编辑的笔记
        saveNote();

        // For safety, start a new NoteEditActivity 结束当前的编辑活动并启动新的编辑活动
        finish();
        Intent intent = new Intent(this, NoteEditActivity.class);
        intent.setAction(Intent.ACTION_INSERT_OR_EDIT);
        //传递当前工作笔记所在的文件夹的ID到新的编辑活动
        intent.putExtra(Notes.INTENT_EXTRA_FOLDER_ID, mWorkingNote.getFolderId());
        startActivity(intent);
    }

    //删除当前编辑的笔记
    private void deleteCurrentNote() {
        //检查工作笔记是否存在于数据库中
        if (mWorkingNote.existInDatabase()) {
            HashSet<Long> ids = new HashSet<Long>();
            long id = mWorkingNote.getNoteId();
            if (id != Notes.ID_ROOT_FOLDER) {
                //如果不是根文件夹，则加入到需要删除的笔记ID集合中
                ids.add(id);
            } else {
                //不应该尝试删除根文件夹，记录错误信息
                Log.d(TAG, "Wrong note id, should not happen");
            }
            //如果不存在同步模式，则直接删除笔记
            if (!isSyncMode()) {
                if (!DataUtils.batchDeleteNotes(getContentResolver(), ids)) {
                    Log.e(TAG, "Delete Note error");
                }
            } else {
                //否则将笔记移动到垃圾箱文件夹
                if (!DataUtils.batchMoveToFolder(getContentResolver(), ids, Notes.ID_TRASH_FOLER)) {
                    Log.e(TAG, "Move notes to trash folder error, should not happens");
                }
            }
        }
        //标记工作笔记为已删除
        mWorkingNote.markDeleted(true);
    }

    private boolean isSyncMode() {
        //获取同步账号名，如果长度大于0，表明存在同步账号，即处于同步模式
        return NotesPreferenceActivity.getSyncAccountName(this).trim().length() > 0;
    }

    //更新跟笔记相关的闹钟
    public void onClockAlertChanged(long date, boolean set) {
        //在设置闹钟前，确保笔记先被保存
        /**
         * User could set clock to an unsaved note, so before setting the
         * alert clock, we should save the note first
         */
        if (!mWorkingNote.existInDatabase()) {
            saveNote(); //如果笔记在数据库中不存在，则保存它
        }
        if (mWorkingNote.getNoteId() > 0) {
            //创建一个AlarmReceiver的Intent，将笔记ID附加到数据URI
            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));
            //显示提醒的头部信息
            showAlertHeader();
            if(!set) {
                //如果set为false，取消任何现有的闹钟
                alarmManager.cancel(pendingIntent);
            } else {
                //如果set为true，设置一个新的闹钟，以唤醒设备并执行pendingIntent
                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
             */
            //如果笔记ID小于或等于0，表示没有内容，记录错误并显示提示
            Log.e(TAG, "Clock alert setting error");
            showToast(R.string.error_note_empty_for_clock);
        }
    }

    //当小部件状态发生变化时的回调方法，可能是用来触发状态更新或视图刷新
    public void onWidgetChanged() {
        updateWidget(); //更新小部件
    }

    //当编辑框中的文本被删除时的回调方法
    public void onEditTextDelete(int index, String text) {
        int childCount = mEditTextList.getChildCount();//获取编辑框列表的子项数量
        if (childCount == 1) { //如果仅有一个编辑框，则不进行任何操作
            return;
        }
        //更新后续编辑框的索引，因为一个项已经被删除
        for (int i = index + 1; i < childCount; i++) {
            ((NoteEditText) mEditTextList.getChildAt(i).findViewById(R.id.et_edit_text))
                    .setIndex(i - 1);
        }

        mEditTextList.removeViewAt(index);//移除指定索引处的编辑框视图
        NoteEditText edit = null;
        if(index == 0) { //如果删除的是第一个编辑框
            edit = (NoteEditText) mEditTextList.getChildAt(0).findViewById(
                    R.id.et_edit_text);
        } else {//否则，获取欠一个编辑框
            edit = (NoteEditText) mEditTextList.getChildAt(index - 1).findViewById(
                    R.id.et_edit_text);
        }
        //将删除的文本追加到当前聚焦的编辑框中
        int length = edit.length();
        edit.append(text);
        edit.requestFocus();//请求焦点
        edit.setSelection(length);//设置光标位置
    }

    //当按下回车键时的回调方法，用于添加新的编辑框
    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");
        }
        //创建新的列表项视图，然后将其添加到列表中的指定位置
        View view = getListItem(text, index);
        mEditTextList.addView(view, index);
        NoteEditText edit = (NoteEditText) view.findViewById(R.id.et_edit_text);
        edit.requestFocus();//请求焦点
        edit.setSelection(0);//设置光标位置为最开始
        //更新后续编辑框的索引，因为添加了一个新项
        for (int i = index + 1; i < mEditTextList.getChildCount(); i++) {
            ((NoteEditText) mEditTextList.getChildAt(i).findViewById(R.id.et_edit_text))
                    .setIndex(i);
        }
    }

    //将编辑器从文本模式切换到列表模式的方法
    private void switchToListMode(String text) {
        mEditTextList.removeAllViews();//移除所有视图
        String[] items = text.split("\n");//按换行符拆分文本成多个项
        int index = 0;
        for (String item : items) {
            if(!TextUtils.isEmpty(item)) { //跳过空项
                mEditTextList.addView(getListItem(item, index));//添加列表项
                index++;
            }
        }
        mEditTextList.addView(getListItem("", index));//添加新的空编辑框
        mEditTextList.getChildAt(index).findViewById(R.id.et_edit_text).requestFocus();
        //切换视图的可见性
        mNoteEditor.setVisibility(View.GONE);
        mEditTextList.setVisibility(View.VISIBLE);
    }

    //获取高亮显示查询结果的方法
    private Spannable getHighlightQueryResult(String fullText, String userQuery) {
        //创建新的SpannableString实例
        SpannableString spannable = new SpannableString(fullText == null ? "" : fullText);
        if (!TextUtils.isEmpty(userQuery)) {
            mPattern = Pattern.compile(userQuery);//编译用户的查询文本为正则模式
            Matcher m = mPattern.matcher(fullText);//对全文进行匹配搜索
            int start = 0;
            while (m.find(start)) {
                //对匹配到的结果设置高亮背景颜色
                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;//返回包含高亮查询结果的Spannable
    }

    //根据给定的文本和索引创建新的列表项视图的方法
    private View getListItem(String item, int index) {
        //通过布局填充器创建列表项视图
        View view = LayoutInflater.from(this).inflate(R.layout.note_edit_list_item, null);
        final NoteEditText edit = (NoteEditText) view.findViewById(R.id.et_edit_text);
        //设置文本外观
        edit.setTextAppearance(this, TextAppearanceResources.getTexAppearanceResource(mFontSizeId));
        CheckBox cb = ((CheckBox) view.findViewById(R.id.cb_edit_item));
        //为复选框设置状态改变监听器
        cb.setOnCheckedChangeListener(new OnCheckedChangeListener() {
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                //根据复选框状态改变文本样式，如添加删除线
                if (isChecked) {
                    edit.setPaintFlags(edit.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
                } else {
                    edit.setPaintFlags(Paint.ANTI_ALIAS_FLAG | Paint.DEV_KERN_TEXT_FLAG);
                }
            }
        });
        //根据复选框的状态初始化编辑框的文本和样式
        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);//设置文本变化监听器
        edit.setIndex(index);//设置编辑框的索引
        //设置并显示高亮查询结果
        edit.setText(getHighlightQueryResult(item, mUserQuery));
        return view;
    }

    //当文本内容发生改变且编辑框不为空时，会显示或隐藏复选框的方法
    public void onTextChange(int index, boolean hasText) {
        if (index >= mEditTextList.getChildCount()) {//索引非法检查
            Log.e(TAG, "Wrong index, should not happen");
            return;
        }
        //根据文本是否存在来设置复选框的可见性
        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);
        }
    }

    //当勾选列表模式发生改变时的回调方法
    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);
        }
    }

    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;
    }

    private boolean saveNote() {
        getWorkingText();
        boolean saved = mWorkingNote.saveNote();
        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;
    }

    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);
        }
    }

    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;
    }

    private void showToast(int resId) {
        showToast(resId, Toast.LENGTH_SHORT);
    }

    private void showToast(int resId, int duration) {
        Toast.makeText(this, resId, duration).show();
    }
}
