/*
 * 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.gtask.data;

import android.appwidget.AppWidgetManager;
import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.util.Log;

import net.micode.notes.data.Notes;
import net.micode.notes.data.Notes.DataColumns;
import net.micode.notes.data.Notes.NoteColumns;
import net.micode.notes.gtask.exception.ActionFailureException;
import net.micode.notes.tool.GTaskStringUtils;
import net.micode.notes.tool.ResourceParser;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;


public class SqlNote {
    private static final String TAG/*私有静态常量*/ = SqlNote.class.getSimpleName();

    private static final int INVALID_ID = -99999;//无效的 ID

    public static final String[] PROJECTION_NOTE = new String[]
            //需要在查询中选择的笔记属性
            {
            NoteColumns.ID, NoteColumns.ALERTED_DATE, NoteColumns.BG_COLOR_ID,
            NoteColumns.CREATED_DATE, NoteColumns.HAS_ATTACHMENT, NoteColumns.MODIFIED_DATE,
            NoteColumns.NOTES_COUNT, NoteColumns.PARENT_ID, NoteColumns.SNIPPET, NoteColumns.TYPE,
            NoteColumns.WIDGET_ID, NoteColumns.WIDGET_TYPE, NoteColumns.SYNC_ID,
            NoteColumns.LOCAL_MODIFIED, NoteColumns.ORIGIN_PARENT_ID, NoteColumns.GTASK_ID,
            NoteColumns.VERSION
    };

    public static final int ID_COLUMN = 0;//ID 属性在 PROJECTION_NOTE 数组中的下标为 0

    public static final int ALERTED_DATE_COLUMN = 1;

    public static final int BG_COLOR_ID_COLUMN = 2;

    public static final int CREATED_DATE_COLUMN = 3;

    public static final int HAS_ATTACHMENT_COLUMN = 4;

    public static final int MODIFIED_DATE_COLUMN = 5;

    public static final int NOTES_COUNT_COLUMN = 6;

    public static final int PARENT_ID_COLUMN = 7;

    public static final int SNIPPET_COLUMN = 8;

    public static final int TYPE_COLUMN = 9;

    public static final int WIDGET_ID_COLUMN = 10;

    public static final int WIDGET_TYPE_COLUMN = 11;

    public static final int SYNC_ID_COLUMN = 12;

    public static final int LOCAL_MODIFIED_COLUMN = 13;

    public static final int ORIGIN_PARENT_ID_COLUMN = 14;

    public static final int GTASK_ID_COLUMN = 15;

    public static final int VERSION_COLUMN = 16;

    private Context mContext;//上下文

    private ContentResolver mContentResolver;//ContentResolver 对象

    private boolean mIsCreate;//表示是否在数据库中创建新笔记

    private long mId;//笔记的 ID

    private long mAlertDate;//提醒日期

    private int mBgColorId;//背景颜色 ID

    private long mCreatedDate;//创建日期

    private int mHasAttachment;//是否有附件

    private long mModifiedDate;//修改日期

    private long mParentId;//父笔记 ID

    private String mSnippet;//笔记的摘要

    private int mType;//笔记类型

    private int mWidgetId;//小部件 ID

    private int mWidgetType;//小部件类型

    private long mOriginParent;//原始父笔记 ID

    private long mVersion;//版本号

    private ContentValues mDiffNoteValues;// ContentValues 类型的 mDiffNoteValues

    private ArrayList<SqlData> mDataList;//SqlData 对象的列表

    public SqlNote(Context context) {
        mContext = context;
        mContentResolver = context.getContentResolver();
        //将传入的上下文对象赋值给成员变量 mContext 和 mContentResolver
        mIsCreate = true;
        //将 mIsCreate 置为 true，表示该笔记是要被创建的
        mId = INVALID_ID;
        //mId 赋值为常量 INVALID_ID，表示该笔记的 ID 是无效的
        mAlertDate = 0;
        mBgColorId = ResourceParser.getDefaultBgId(context);//
        // 将 mBgColorId 设为默认背景颜色 ID；
        mCreatedDate = System.currentTimeMillis();
        // 将 mCreatedDate 和 mModifiedDate 设为当前时间戳。
        mHasAttachment = 0;
        //mHasAttachment 设为 0，表示该笔记没有附件
        mModifiedDate = System.currentTimeMillis();
        mParentId = 0;
        //mParentId 设为 0，表示该笔记的父 ID 是无效的
        mSnippet = "";//mSnippet 设为空字符串，表示该笔记没有摘要
        mType = Notes.TYPE_NOTE;
        mWidgetId = AppWidgetManager.INVALID_APPWIDGET_ID;//该笔记没有小部件 ID
        mWidgetType = Notes.TYPE_WIDGET_INVALIDE;//该笔记不是小部件
        mOriginParent = 0;//该笔记没有原始父笔记
        mVersion = 0;//笔记的版本号是 0
        mDiffNoteValues = new ContentValues();
        //建一个空的 ContentValues 对象赋值给 mDiffNoteValues
        mDataList = new ArrayList<SqlData>();
        //创建一个空的 SqlData 对象列表 mDataList
    }

    public SqlNote(Context context, Cursor c)
    //将传入的 Cursor 对象中的数据加载到 SqlNote 对象中
    {
        mContext = context;
        mContentResolver = context.getContentResolver();
        //分别赋值为传入的上下文
        mIsCreate = false;//这是一个已经存在的笔记
        loadFromCursor(c);//从 Cursor 对象中读取数据并加载到 SqlNote 对象中
        mDataList = new ArrayList<SqlData>();//创建一个空的 SqlData 对象列表 mDataList
        if (mType == Notes.TYPE_NOTE)
            //如果该笔记是普通笔记，则调用 loadDataContent() 方法从数据库读取笔记内容和附件信息
            loadDataContent();
        mDiffNoteValues = new ContentValues();
        //创建一个空的 ContentValues 对象赋值给 mDiffNoteValues
    }

    public SqlNote(Context context, long id)
    //根据笔记 ID 加载笔记数据
    {
        mContext = context;
        mContentResolver = context.getContentResolver();//初始化
        mIsCreate = false;//已经存在的笔记
        loadFromCursor(id);
        mDataList = new ArrayList<SqlData>();
        if (mType == Notes.TYPE_NOTE)
            loadDataContent();
        mDiffNoteValues = new ContentValues();
//创建一个空的 ContentValues 对象赋值给 mDiffNoteValues
    }

    private void loadFromCursor(long id)
    //根据给定的笔记 ID 从数据库中加载笔记信息
    {
        Cursor c = null;
        try {
            c = mContentResolver.query(Notes.CONTENT_NOTE_URI, PROJECTION_NOTE, "(_id=?)",
                   //查询指定 ID 的笔记数据
                    new String[] {
                        String.valueOf(id)
                    }, null);//对获取数据进行判空
            if (c != null) {
                c.moveToNext();
                loadFromCursor(c);
                // 不为空，将游标移动到第一行，
                // 并调用 loadFromCursor(Cursor c) 方法将数据加载到 SqlNote 对象中
            } else {
                Log.w(TAG, "loadFromCursor: cursor = null");//为空，则打印一条警告日志
            }
        } finally {
            if (c != null)
                c.close();
        }
    }

    private void loadFromCursor(Cursor c)
    //从 Cursor 对象中加载笔记数据
    {
        mId = c.getLong(ID_COLUMN);//笔记的 ID
        mAlertDate = c.getLong(ALERTED_DATE_COLUMN);//提醒时间
        mBgColorId = c.getInt(BG_COLOR_ID_COLUMN);//背景颜色 ID
        mCreatedDate = c.getLong(CREATED_DATE_COLUMN);//创建时间
        mHasAttachment = c.getInt(HAS_ATTACHMENT_COLUMN);//是否有附件
        mModifiedDate = c.getLong(MODIFIED_DATE_COLUMN);//修改时间
        mParentId = c.getLong(PARENT_ID_COLUMN);//父亲笔记的 ID
        mSnippet = c.getString(SNIPPET_COLUMN);//笔记片段
        mType = c.getInt(TYPE_COLUMN);//笔记类型
        mWidgetId = c.getInt(WIDGET_ID_COLUMN);//挂件 ID
        mWidgetType = c.getInt(WIDGET_TYPE_COLUMN);//挂件类型
        mVersion = c.getLong(VERSION_COLUMN);//版本号
    }

    private void loadDataContent()
    //从数据库中读取笔记的内容和附件信息，并将其存储在 mDataList
    {
        Cursor c = null;
        mDataList.clear();
        //清空 mDataList 列表
        try {
            c = mContentResolver.query(Notes.CONTENT_DATA_URI, SqlData.PROJECTION_DATA,
                    "(note_id=?)", new String[] {
                        String.valueOf(mId)
                    }, null);//判断获取到的 Cursor 对象是否为空
            if (c != null) {// 不为空，则判断游标中是否有数据
                if (c.getCount() == 0) {
                    Log.w(TAG, "it seems that the note has not data");
                    //无数据，则打印一条警告日志并返回
                    return;
                }
                while (c.moveToNext()) {
                    SqlData data = new SqlData(mContext, c);
                    mDataList.add(data);
                }//遍历游标中的每一行数据，创建 SqlData 对象并添加到 mDataList 列表
            } else {
                Log.w(TAG, "loadDataContent: cursor = null");
            }
        } finally {
            if (c != null)
                c.close();
        }
    }

    public boolean setContent(JSONObject js)
    //据传入的 JSONObject 对象设置笔记的内容
    {
        try {
            JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
            if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_SYSTEM) {
                Log.w(TAG, "cannot set system folder");
            } else if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_FOLDER) {
                // for folder we can only update the snnipet and type
                String snippet = note.has(NoteColumns.SNIPPET) ? note
                        .getString(NoteColumns.SNIPPET) : "";
                if (mIsCreate || !mSnippet.equals(snippet)) {
                    mDiffNoteValues.put(NoteColumns.SNIPPET, snippet);
                }
                mSnippet = snippet;

                int type = note.has(NoteColumns.TYPE) ? note.getInt(NoteColumns.TYPE)
                        : Notes.TYPE_NOTE;
                if (mIsCreate || mType != type) {
                    mDiffNoteValues.put(NoteColumns.TYPE, type);
                }
                mType = type;
            } else if (note.getInt(NoteColumns.TYPE) == Notes.TYPE_NOTE) {
                JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
                long id = note.has(NoteColumns.ID) ? note.getLong(NoteColumns.ID) : INVALID_ID;
                if (mIsCreate || mId != id) {
                    mDiffNoteValues.put(NoteColumns.ID, id);
                }
                mId = id;

                long alertDate = note.has(NoteColumns.ALERTED_DATE) ? note
                        .getLong(NoteColumns.ALERTED_DATE) : 0;
                if (mIsCreate || mAlertDate != alertDate) {
                    mDiffNoteValues.put(NoteColumns.ALERTED_DATE, alertDate);
                }
                mAlertDate = alertDate;

                int bgColorId = note.has(NoteColumns.BG_COLOR_ID) ? note
                        .getInt(NoteColumns.BG_COLOR_ID) : ResourceParser.getDefaultBgId(mContext);
                if (mIsCreate || mBgColorId != bgColorId) {
                    mDiffNoteValues.put(NoteColumns.BG_COLOR_ID, bgColorId);
                }
                mBgColorId = bgColorId;
//系统文件夹或者文件夹类型的笔记，只能更新摘要和类型，而对于笔记类型的笔记，会解析出一系列字段，并将它们保存在一个 List 中
                long createDate = note.has(NoteColumns.CREATED_DATE) ? note
                        .getLong(NoteColumns.CREATED_DATE) : System.currentTimeMillis();
                if (mIsCreate || mCreatedDate != createDate) {
                    mDiffNoteValues.put(NoteColumns.CREATED_DATE, createDate);
                }
                mCreatedDate = createDate;

                int hasAttachment = note.has(NoteColumns.HAS_ATTACHMENT) ? note
                        .getInt(NoteColumns.HAS_ATTACHMENT) : 0;
                if (mIsCreate || mHasAttachment != hasAttachment) {
                    mDiffNoteValues.put(NoteColumns.HAS_ATTACHMENT, hasAttachment);
                }
                mHasAttachment = hasAttachment;

                long modifiedDate = note.has(NoteColumns.MODIFIED_DATE) ? note
                        .getLong(NoteColumns.MODIFIED_DATE) : System.currentTimeMillis();
                if (mIsCreate || mModifiedDate != modifiedDate) {
                    mDiffNoteValues.put(NoteColumns.MODIFIED_DATE, modifiedDate);
                }
                mModifiedDate = modifiedDate;

                long parentId = note.has(NoteColumns.PARENT_ID) ? note
                        .getLong(NoteColumns.PARENT_ID) : 0;
                if (mIsCreate || mParentId != parentId) {
                    mDiffNoteValues.put(NoteColumns.PARENT_ID, parentId);
                }
                mParentId = parentId;

                String snippet = note.has(NoteColumns.SNIPPET) ? note
                        .getString(NoteColumns.SNIPPET) : "";
                if (mIsCreate || !mSnippet.equals(snippet)) {
                    mDiffNoteValues.put(NoteColumns.SNIPPET, snippet);
                }
                mSnippet = snippet;

                int type = note.has(NoteColumns.TYPE) ? note.getInt(NoteColumns.TYPE)
                        : Notes.TYPE_NOTE;
                if (mIsCreate || mType != type) {
                    mDiffNoteValues.put(NoteColumns.TYPE, type);
                }
                mType = type;

                int widgetId = note.has(NoteColumns.WIDGET_ID) ? note.getInt(NoteColumns.WIDGET_ID)
                        : AppWidgetManager.INVALID_APPWIDGET_ID;
                if (mIsCreate || mWidgetId != widgetId) {
                    mDiffNoteValues.put(NoteColumns.WIDGET_ID, widgetId);
                }
                mWidgetId = widgetId;

                int widgetType = note.has(NoteColumns.WIDGET_TYPE) ? note
                        .getInt(NoteColumns.WIDGET_TYPE) : Notes.TYPE_WIDGET_INVALIDE;
                if (mIsCreate || mWidgetType != widgetType) {
                    mDiffNoteValues.put(NoteColumns.WIDGET_TYPE, widgetType);
                }
                mWidgetType = widgetType;

                long originParent = note.has(NoteColumns.ORIGIN_PARENT_ID) ? note
                        .getLong(NoteColumns.ORIGIN_PARENT_ID) : 0;
                if (mIsCreate || mOriginParent != originParent) {
                    mDiffNoteValues.put(NoteColumns.ORIGIN_PARENT_ID, originParent);
                }
                mOriginParent = originParent;
//分别解析
                for (int i = 0; i < dataArray.length(); i++)

                {
                    JSONObject data = dataArray.getJSONObject(i);
                    SqlData sqlData = null;//未找到设置为null
                    if (data.has(DataColumns.ID)) //根据数据块 ID 在 mDataList 中查找对应的 SqlData 对象
                         {
                        long dataId = data.getLong(DataColumns.ID);//赋值
                        for (SqlData temp : mDataList) {
                            if (dataId == temp.getId()) {
                                sqlData = temp;
                            }
                        }
                    }

                    if (sqlData == null) {
                        sqlData = new SqlData(mContext);
                        mDataList.add(sqlData);//没找到对像，则新建一个对象并添加到 mDataList 中
                    }

                    sqlData.setContent(data);
                }
            }
        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            return false;
        }//当 JSON 解析出错时，将会抛出 JSONException 异常并被 catch 住
        return true;
    }

    public JSONObject getContent()
    //将 SqlData 对象转换为 JSONObject
     {
        try {
            JSONObject js = new JSONObject();
            //判断 SqlData 对象是否已经存入数据库中

            if (mIsCreate) {
                Log.e(TAG, "it seems that we haven't created this in database yet");
                return null;
                //未存储，返回 null
            }

            JSONObject note = new JSONObject();
            if (mType == Notes.TYPE_NOTE) {
                note.put(NoteColumns.ID, mId);
                note.put(NoteColumns.ALERTED_DATE, mAlertDate);
                note.put(NoteColumns.BG_COLOR_ID, mBgColorId);
                note.put(NoteColumns.CREATED_DATE, mCreatedDate);
                note.put(NoteColumns.HAS_ATTACHMENT, mHasAttachment);
                note.put(NoteColumns.MODIFIED_DATE, mModifiedDate);
                note.put(NoteColumns.PARENT_ID, mParentId);
                note.put(NoteColumns.SNIPPET, mSnippet);
                note.put(NoteColumns.TYPE, mType);
                note.put(NoteColumns.WIDGET_ID, mWidgetId);
                note.put(NoteColumns.WIDGET_TYPE, mWidgetType);
                note.put(NoteColumns.ORIGIN_PARENT_ID, mOriginParent);
                js.put(GTaskStringUtils.META_HEAD_NOTE, note);

                JSONArray dataArray = new JSONArray();
                for (SqlData sqlData : mDataList) {
                    JSONObject data = sqlData.getContent();
                    if (data != null) {
                        dataArray.put(data);
                    }
                }//根据 SqlData 对象的类型不同，分别构造 Note 和 Data 两个 JSONObject，
                // 并放入 META_HEAD_NOTE 和 META_HEAD_DATA 字段中
                js.put(GTaskStringUtils.META_HEAD_DATA, dataArray);
            } else if (mType == Notes.TYPE_FOLDER || mType == Notes.TYPE_SYSTEM) {
                note.put(NoteColumns.ID, mId);
                note.put(NoteColumns.TYPE, mType);
                note.put(NoteColumns.SNIPPET, mSnippet);
                js.put(GTaskStringUtils.META_HEAD_NOTE, note);
            }

            return js;//将其内容转换为 JSONObject 对象并返回
        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
        }
        return null;//遇到错误会打印日志并返回 null
    }

    public void setParentId(long id)
    //设置 SqlData 对象的父节点 ID
    {
        mParentId = id;
        mDiffNoteValues.put(NoteColumns.PARENT_ID, id);
    }

    public void setGtaskId(String gid) {
        mDiffNoteValues.put(NoteColumns.GTASK_ID, gid);
    }

    public void setSyncId(long syncId) {
        mDiffNoteValues.put(NoteColumns.SYNC_ID, syncId);
    }

    public void resetLocalModified() {
        mDiffNoteValues.put(NoteColumns.LOCAL_MODIFIED, 0);
    }

    public long getId() {
        return mId;
    }

    public long getParentId() {
        return mParentId;
    }

    public String getSnippet() {
        return mSnippet;
    }

    public boolean isNoteType() {
        return mType == Notes.TYPE_NOTE;
    }

    public void commit(boolean validateVersion)
    //将 SqlData 对象中的属性变化保存到数据库中
    {
        if (mIsCreate)
        //判断该对象是新创建的还是已经存在于数据库中
        {
            if (mId == INVALID_ID && mDiffNoteValues.containsKey(NoteColumns.ID)) {
                mDiffNoteValues.remove(NoteColumns.ID);
            }

            Uri uri = mContentResolver.insert(Notes.CONTENT_NOTE_URI, mDiffNoteValues);
            //新建的对象，则调用 insert 方法将其保存到数据库中
            try {
                mId = Long.valueOf(uri.getPathSegments().get(1));
            } catch (NumberFormatException e) {
                Log.e(TAG, "Get note id error :" + e.toString());
                throw new ActionFailureException("create note failed");
            }
            if (mId == 0) {
                throw new IllegalStateException("Create thread id failed");
            }//对是否为新值进行判定

            if (mType == Notes.TYPE_NOTE) {
                for (SqlData sqlData : mDataList) {
                    sqlData.commit(mId, false, -1);
                    //validateVersion 参数指定为 false，mVersion 参数指定为 -1
                }
            }
        } else {
            if (mId <= 0 && mId != Notes.ID_ROOT_FOLDER && mId != Notes.ID_CALL_RECORD_FOLDER) {
                Log.e(TAG, "No such note");
                throw new IllegalStateException("Try to update note with invalid id");
            }
            //判断当前对象的 ID 是否合法，如果不合法则抛出异常
            if (mDiffNoteValues.size() > 0) {
                mVersion ++;
                int result = 0;
                if (!validateVersion) {
                    result = mContentResolver.update(Notes.CONTENT_NOTE_URI, mDiffNoteValues, "("
                            + NoteColumns.ID + "=?)", new String[] {
                        String.valueOf(mId)
                    });
                } else {
                    result = mContentResolver.update(Notes.CONTENT_NOTE_URI, mDiffNoteValues, "("
                            + NoteColumns.ID + "=?) AND (" + NoteColumns.VERSION + "<=?)",
                            new String[] {
                                    String.valueOf(mId), String.valueOf(mVersion)
                            });
                }
                if (result == 0) {
                    Log.w(TAG, "there is no update. maybe user updates note when syncing");
                }
            }//判断笔记是否被成功更新，并在更新失败时输出一些日志信息。

            if (mType == Notes.TYPE_NOTE)//检查当前对象是否表示笔记对象
                 {
                for (SqlData sqlData : mDataList) {
                    sqlData.commit(mId, validateVersion, mVersion);//对比参数，不对校验版本号
                }
            }
        }

        // refresh local info
        loadFromCursor(mId);//逐一转换为 SqlData 对象，并添加到 mDataList 变量中
        if (mType == Notes.TYPE_NOTE)//加载笔记内容
            loadDataContent();

        mDiffNoteValues.clear();//清空 mDiffNoteValues 变量
        mIsCreate = false;//标记设置为 false，表示当前对象已经存在于数据库中
    }
}