Notes-master/GTaskManager.java

/*
 * 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.remote;

// 导入所需的Android类和自定义类

import android.app.Activity;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.util.Log;

import net.micode.notes.R;
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.data.MetaData;
import net.micode.notes.gtask.data.Node;
import net.micode.notes.gtask.data.SqlNote;
import net.micode.notes.gtask.data.Task;
import net.micode.notes.gtask.data.TaskList;
import net.micode.notes.gtask.exception.ActionFailureException;
import net.micode.notes.gtask.exception.NetworkFailureException;
import net.micode.notes.tool.DataUtils;
import net.micode.notes.tool.GTaskStringUtils;

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

import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;

// GTaskManager类用于管理与Google Tasks的同步操作
public class GTaskManager {
    // 定义日志标签
    private static final String TAG = GTaskManager.class.getSimpleName();

    // 定义同步状态常量
    public static final int STATE_SUCCESS = 0;
    public static final int STATE_NETWORK_ERROR = 1;
    public static final int STATE_INTERNAL_ERROR = 2;
    public static final int STATE_SYNC_IN_PROGRESS = 3;
    public static final int STATE_SYNC_CANCELLED = 4;

    // 单例模式，GTaskManager的实例
    private static GTaskManager mInstance = null;

    // Activity和Context引用，用于访问Android系统服务
    private Activity mActivity;
    private Context mContext;

    // ContentResolver用于访问和修改内容提供者中的数据
    private ContentResolver mContentResolver;

    // 同步状态标志
    private boolean mSyncing;
    private boolean mCancelled;

    // 用于存储任务列表、任务和元数据的哈希映射
    private HashMap<String, TaskList> mGTaskListHashMap;
    private HashMap<String, Node> mGTaskHashMap;
    private HashMap<String, MetaData> mMetaHashMap;

    // 元数据列表
    private TaskList mMetaList;

    // 本地删除ID映射
    private HashSet<Long> mLocalDeleteIdMap;

    // GID到NID的映射
    private HashMap<String, Long> mGidToNid;

    // NID到GID的映射
    private HashMap<Long, String> mNidToGid;

    // 私有构造函数，确保单例模式
    private GTaskManager() {
        mSyncing = false;
        mCancelled = false;
        mGTaskListHashMap = new HashMap<String, TaskList>();
        mGTaskHashMap = new HashMap<String, Node>();
        mMetaHashMap = new HashMap<String, MetaData>();
        mMetaList = null;
        mLocalDeleteIdMap = new HashSet<Long>();
        mGidToNid = new HashMap<String, Long>();
        mNidToGid = new HashMap<Long, String>();
    }

    // 获取GTaskManager的实例
    public static synchronized GTaskManager getInstance() {
        if (mInstance == null) {
            mInstance = new GTaskManager();
        }
        return mInstance;
    }

    // 设置Activity上下文
    public synchronized void setActivityContext(Activity activity) {
        // 用于获取授权令牌
        mActivity = activity;
    }

    // 同步方法，接受上下文和异步任务参数
    public int sync(Context context, GTaskASyncTask asyncTask) {
        // 如果正在同步，则返回状态码
        if (mSyncing) {
            Log.d(TAG, "Sync is in progress");
            return STATE_SYNC_IN_PROGRESS;
        }
        mContext = context;
        mContentResolver = mContext.getContentResolver();
        mSyncing = true;
        mCancelled = false;
        // 清空哈希映射和集合
        mGTaskListHashMap.clear();
        mGTaskHashMap.clear();
        mMetaHashMap.clear();
        mLocalDeleteIdMap.clear();
        mGidToNid.clear();
        mNidToGid.clear();

        try {
            // 获取GTaskClient实例
            GTaskClient client = GTaskClient.getInstance();
            client.resetUpdateArray();

            // 登录Google Tasks
            if (!mCancelled) {
                if (!client.login(mActivity)) {
                    throw new NetworkFailureException("login google task failed");
                }
            }

            // 从Google获取任务列表
            asyncTask.publishProgess(mContext.getString(R.string.sync_progress_init_list));
            initGTaskList();

            // 执行内容同步工作
            asyncTask.publishProgess(mContext.getString(R.string.sync_progress_syncing));
            syncContent();
        } catch (NetworkFailureException e) {
            Log.e(TAG, e.toString());
            return STATE_NETWORK_ERROR;
        } catch (ActionFailureException e) {
            Log.e(TAG, e.toString());
            return STATE_INTERNAL_ERROR;
        } catch (Exception e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            return STATE_INTERNAL_ERROR;
        } finally {
            // 清空哈希映射和集合
            mGTaskListHashMap.clear();
            mGTaskHashMap.clear();
            mMetaHashMap.clear();
            mLocalDeleteIdMap.clear();
            mGidToNid.clear();
            mNidToGid.clear();
            mSyncing = false;
        }

        // 返回同步状态
        return mCancelled ? STATE_SYNC_CANCELLED : STATE_SUCCESS;
    }

    // 初始化GTask列表
    private void initGTaskList() throws NetworkFailureException {
        if (mCancelled)
            return;
        GTaskClient client = GTaskClient.getInstance();
        try {
            // 获取任务列表JSON数组
            JSONArray jsTaskLists = client.getTaskLists();

            // 首先初始化元数据列表
            mMetaList = null;
            for (int i = 0; i < jsTaskLists.length(); i++) {
                JSONObject object = jsTaskLists.getJSONObject(i);
                String gid = object.getString(GTaskStringUtils.GTASK_JSON_ID);
                String name = object.getString(GTaskStringUtils.GTASK_JSON_NAME);

                // 检查是否是元数据列表
                if (name
                        .equals(GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_META)) {
                    mMetaList = new TaskList();
                    mMetaList.setContentByRemoteJSON(object);

                    // 加载元数据
                    JSONArray jsMetas = client.getTaskList(gid);
                    for (int j = 0; j < jsMetas.length(); j++) {
                        object = (JSONObject) jsMetas.getJSONObject(j);
                        MetaData metaData = new MetaData();
                        metaData.setContentByRemoteJSON(object);
                        if (metaData.isWorthSaving()) {
                            mMetaList.addChildTask(metaData);
                            if (metaData.getGid() != null) {
                                mMetaHashMap.put(metaData.getRelatedGid(), metaData);
                            }
                        }
                    }
                }
            }

            // 如果元数据列表不存在，则创建
            if (mMetaList == null) {
                mMetaList = new TaskList();
                mMetaList.setName(GTaskStringUtils.MIUI_FOLDER_PREFFIX
                        + GTaskStringUtils.FOLDER_META);
                GTaskClient.getInstance().createTaskList(mMetaList);
            }

            // 初始化任务列表
            for (int i = 0; i < jsTaskLists.length(); i++) {
                JSONObject object = jsTaskLists.getJSONObject(i);
                String gid = object.getString(GTaskStringUtils.GTASK_JSON_ID);
                String name = object.getString(GTaskStringUtils.GTASK_JSON_NAME);

                // 检查是否是任务列表
                if (name.startsWith(GTaskStringUtils.MIUI_FOLDER_PREFFIX)
                        && !name.equals(GTaskStringUtils.MIUI_FOLDER_PREFFIX
                                + GTaskStringUtils.FOLDER_META)) {
                    TaskList tasklist = new TaskList();
                    tasklist.setContentByRemoteJSON(object);
                    mGTaskListHashMap.put(gid, tasklist);
                    mGTaskHashMap.put(gid, tasklist);

                    // 加载任务
                    JSONArray jsTasks = client.getTaskList(gid);
                    for (int j = 0; j < jsTasks.length(); j++) {
                        object = (JSONObject) jsTasks.getJSONObject(j);
                        gid = object.getString(GTaskStringUtils.GTASK_JSON_ID);
                        Task task = new Task();
                        task.setContentByRemoteJSON(object);
                        if (task.isWorthSaving()) {
                            task.setMetaInfo(mMetaHashMap.get(gid));
                            tasklist.addChildTask(task);
                            mGTaskHashMap.put(gid, task);
                        }
                    }
                }
            }
        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new ActionFailureException("initGTaskList: handing JSONObject failed");
        }
    }

   // 私有方法，用于同步内容，可能会抛出网络故障异常
private void syncContent() throws NetworkFailureException {
    int syncType; // 同步类型
    Cursor c = null; // 数据库游标
    String gid; // 用于存储全局ID
    Node node; // 节点对象

    mLocalDeleteIdMap.clear(); // 清除本地删除ID映射

    if (mCancelled) {
        return; // 如果取消同步，则直接返回
    }

    // 处理本地已删除的笔记
    try {
        c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE,
                "(type<>? AND parent_id=?)", new String[] {
                        String.valueOf(Notes.TYPE_SYSTEM), String.valueOf(Notes.ID_TRASH_FOLER)
                }, null);
        if (c != null) {
            while (c.moveToNext()) {
                gid = c.getString(SqlNote.GTASK_ID_COLUMN);
                node = mGTaskHashMap.get(gid);
                if (node != null) {
                    mGTaskHashMap.remove(gid);
                    doContentSync(Node.SYNC_ACTION_DEL_REMOTE, node, c);
                }

                mLocalDeleteIdMap.add(c.getLong(SqlNote.ID_COLUMN));
            }
        } else {
            Log.w(TAG, "failed to query trash folder");
        }
    } finally {
        if (c != null) {
            c.close();
            c = null;
        }
    }

    // 首先同步文件夹
    syncFolder();

    // 处理数据库中存在的笔记
    try {
        c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE,
                "(type=? AND parent_id<>?)", new String[] {
                        String.valueOf(Notes.TYPE_NOTE), String.valueOf(Notes.ID_TRASH_FOLER)
                }, NoteColumns.TYPE + " DESC");
        if (c != null) {
            while (c.moveToNext()) {
                gid = c.getString(SqlNote.GTASK_ID_COLUMN);
                node = mGTaskHashMap.get(gid);
                if (node != null) {
                    mGTaskHashMap.remove(gid);
                    mGidToNid.put(gid, c.getLong(SqlNote.ID_COLUMN));
                    mNidToGid.put(c.getLong(SqlNote.ID_COLUMN), gid);
                    syncType = node.getSyncAction(c);
                } else {
                    if (c.getString(SqlNote.GTASK_ID_COLUMN).trim().length() == 0) {
                        // 本地添加
                        syncType = Node.SYNC_ACTION_ADD_REMOTE;
                    } else {
                        // 远程删除
                        syncType = Node.SYNC_ACTION_DEL_LOCAL;
                    }
                }
                doContentSync(syncType, node, c);
            }
        } else {
            Log.w(TAG, "failed to query existing note in database");
        }

    } finally {
        if (c != null) {
            c.close();
            c = null;
        }
    }

    // 处理剩余项
    Iterator<Map.Entry<String, Node>> iter = mGTaskHashMap.entrySet().iterator();
    while (iter.hasNext()) {
        Map.Entry<String, Node> entry = iter.next();
        node = entry.getValue();
        doContentSync(Node.SYNC_ACTION_ADD_LOCAL, node, null);
    }

    // 如果没有被取消，则清除本地删除表
    if (!mCancelled) {
        if (!DataUtils.batchDeleteNotes(mContentResolver, mLocalDeleteIdMap)) {
            throw new ActionFailureException("failed to batch-delete local deleted notes");
        }
    }

    // 如果没有被取消，则刷新本地同步ID
    if (!mCancelled) {
        GTaskClient.getInstance().commitUpdate();
        refreshLocalSyncId();
    }
}

// 私有方法，用于同步文件夹，可能会抛出网络故障异常
private void syncFolder() throws NetworkFailureException {
    Cursor c = null; // 数据库游标
    String gid; // 用于存储全局ID
    Node node; // 节点对象
    int syncType; // 同步类型

    if (mCancelled) {
        return; // 如果取消同步，则直接返回
    }

    // 处理根文件夹
    try {
        c = mContentResolver.query(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI,
                Notes.ID_ROOT_FOLDER), SqlNote.PROJECTION_NOTE, null, null, null);
        if (c != null) {
            c.moveToNext();
            gid = c.getString(SqlNote.GTASK_ID_COLUMN);
            node = mGTaskHashMap.get(gid);
            if (node != null) {
                mGTaskHashMap.remove(gid);
                mGidToNid.put(gid, (long) Notes.ID_ROOT_FOLDER);
                mNidToGid.put((long) Notes.ID_ROOT_FOLDER, gid);
                // 对于系统文件夹，只有在必要时才更新远程名称
                if (!node.getName().equals(
                        GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_DEFAULT))
                    doContentSync(Node.SYNC_ACTION_UPDATE_REMOTE, node, c);
            } else {
                doContentSync(Node.SYNC_ACTION_ADD_REMOTE, node, c);
            }
        } else {
            Log.w(TAG, "failed to query root folder");
        }
    } finally {
        if (c != null) {
            c.close();
            c = null;
        }
    }

    // 处理通话记录文件夹
    try {
        c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE, "(_id=?)",
                new String[] {
                    String.valueOf(Notes.ID_CALL_RECORD_FOLDER)
                }, null);
        if (c != null) {
            if (c.moveToNext()) {
                gid = c.getString(SqlNote.GTASK_ID_COLUMN);
                node = mGTaskHashMap.get(gid);
                if (node != null) {
                    mGTaskHashMap.remove(gid);
                    mGidToNid.put(gid, (long) Notes.ID_CALL_RECORD_FOLDER);
                    mNidToGid.put((long) Notes.ID_CALL_RECORD_FOLDER, gid);
                    // 对于系统文件夹，只有在必要时才更新远程名称
                    if (!node.getName().equals(
                            GTaskStringUtils.MIUI_FOLDER_PREFFIX
                                    + GTaskStringUtils.FOLDER_CALL_NOTE))
                        doContentSync(Node.SYNC_ACTION_UPDATE_REMOTE, node, c);
                } else {
                    doContentSync(Node.SYNC_ACTION_ADD_REMOTE, node, c);
                }
            }
        } else {
            Log.w(TAG, "failed to query call note folder");
        }
    } finally {
        if (c != null) {
            c.close();
            c = null;
        }
    }

    // 处理本地存在的文件夹
    try {
        c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE,
                "(type=? AND parent_id<>?)", new String[] {
                        String.valueOf(Notes.TYPE_FOLDER), String.valueOf(Notes.ID_TRASH_FOLER)
                }, NoteColumns.TYPE + " DESC");
        if (c != null) {
            while (c.moveToNext()) {
                gid = c.getString(SqlNote.GTASK_ID_COLUMN);
                node = mGTaskHashMap.get(gid);
                if (node != null) {
                    mGTaskHashMap.remove(gid);
                    mGidToNid.put(gid, c.getLong(SqlNote.ID_COLUMN));
                    mNidToGid.put(c.getLong(SqlNote.ID_COLUMN), gid);
                    syncType = node.getSyncAction(c);
                } else {
                    if (c.getString(SqlNote.GTASK_ID_COLUMN).trim().length() == 0) {
                        // 本地添加
                        syncType = Node.SYNC_ACTION_ADD_REMOTE;
                    } else {
                        // 远程删除
                        syncType = Node.SYNC_ACTION_DEL_LOCAL;
                    }
                }
                doContentSync(syncType, node, c);
            }
        } else {
            Log.w(TAG, "failed to query existing folder");
        }
    } finally {
        if (c != null) {
            c.close();
            c = null;
        }
    }

    // 处理远程添加的文件夹
    Iterator<Map.Entry<String, TaskList>> iter = mGTaskListHashMap.entrySet().iterator();
    while (iter.hasNext()) {
        Map.Entry<String, TaskList> entry = iter.next();
        gid = entry.getKey();
        node = entry.getValue();
        if (mGTaskHashMap.containsKey(gid)) {
            mGTaskHashMap.remove(gid);
            doContentSync(Node.SYNC_ACTION_ADD_LOCAL, node, null);
        }
    }

    if (!mCancelled)
        GTaskClient.getInstance().commitUpdate();
}

    // 同步内容的方法，根据同步类型（syncType）、节点（node）和游标（c）执行不同的同步操作
private void doContentSync(int syncType, Node node, Cursor c) throws NetworkFailureException {
    // 如果同步被取消，则直接返回
    if (mCancelled) {
        return;
    }

    // 根据不同的同步类型执行不同的操作
    MetaData meta; // 用于存储元数据
    switch (syncType) {
        case Node.SYNC_ACTION_ADD_LOCAL: // 本地添加节点
            addLocalNode(node);
            break;
        case Node.SYNC_ACTION_ADD_REMOTE: // 远程添加节点
            addRemoteNode(node, c);
            break;
        case Node.SYNC_ACTION_DEL_LOCAL: // 本地删除节点
            meta = mMetaHashMap.get(c.getString(SqlNote.GTASK_ID_COLUMN)); // 获取元数据
            if (meta != null) {
                GTaskClient.getInstance().deleteNode(meta); // 删除节点
            }
            mLocalDeleteIdMap.add(c.getLong(SqlNote.ID_COLUMN)); // 添加到本地删除ID映射
            break;
        case Node.SYNC_ACTION_DEL_REMOTE: // 远程删除节点
            meta = mMetaHashMap.get(node.getGid()); // 获取元数据
            if (meta != null) {
                GTaskClient.getInstance().deleteNode(meta); // 删除节点
            }
            GTaskClient.getInstance().deleteNode(node); // 删除节点
            break;
        case Node.SYNC_ACTION_UPDATE_LOCAL: // 本地更新节点
            updateLocalNode(node, c);
            break;
        case Node.SYNC_ACTION_UPDATE_REMOTE: // 远程更新节点
            updateRemoteNode(node, c);
            break;
        case Node.SYNC_ACTION_UPDATE_CONFLICT: // 更新冲突，目前使用本地更新
            updateRemoteNode(node, c);
            break;
        case Node.SYNC_ACTION_NONE: // 无操作
            break;
        case Node.SYNC_ACTION_ERROR: // 错误处理
        default:
            throw new ActionFailureException("unknown sync action type"); // 抛出异常
    }
}

// 本地添加节点的方法
private void addLocalNode(Node node) throws NetworkFailureException {
    // 如果同步被取消，则直接返回
    if (mCancelled) {
        return;
    }

    SqlNote sqlNote; // SQL笔记对象
    // 根据节点类型创建不同的SQL笔记对象
    if (node instanceof TaskList) {
        // 处理任务列表
        if (node.getName().equals(
                GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_DEFAULT)) {
            sqlNote = new SqlNote(mContext, Notes.ID_ROOT_FOLDER);
        } else if (node.getName().equals(
                GTaskStringUtils.MIUI_FOLDER_PREFFIX + GTaskStringUtils.FOLDER_CALL_NOTE)) {
            sqlNote = new SqlNote(mContext, Notes.ID_CALL_RECORD_FOLDER);
        } else {
            sqlNote = new SqlNote(mContext);
            sqlNote.setContent(node.getLocalJSONFromContent()); // 设置内容
            sqlNote.setParentId(Notes.ID_ROOT_FOLDER); // 设置父ID
        }
    } else {
        // 处理任务
        sqlNote = new SqlNote(mContext);
        JSONObject js = node.getLocalJSONFromContent();
        try {
            // 处理ID冲突
            if (js.has(GTaskStringUtils.META_HEAD_NOTE)) {
                JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
                if (note.has(NoteColumns.ID)) {
                    long id = note.getLong(NoteColumns.ID);
                    if (DataUtils.existInNoteDatabase(mContentResolver, id)) {
                        note.remove(NoteColumns.ID);
                    }
                }
            }

            if (js.has(GTaskStringUtils.META_HEAD_DATA)) {
                JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
                for (int i = 0; i < dataArray.length(); i++) {
                    JSONObject data = dataArray.getJSONObject(i);
                    if (data.has(DataColumns.ID)) {
                        long dataId = data.getLong(DataColumns.ID);
                        if (DataUtils.existInDataDatabase(mContentResolver, dataId)) {
                            data.remove(DataColumns.ID);
                        }
                    }
                }
            }
        } catch (JSONException e) {
            Log.w(TAG, e.toString());
            e.printStackTrace();
        }
        sqlNote.setContent(js); // 设置内容

        Long parentId = mGidToNid.get(((Task) node).getParent().getGid()); // 获取父ID
        if (parentId == null) {
            Log.e(TAG, "cannot find task's parent id locally");
            throw new ActionFailureException("cannot add local node");
        }
        sqlNote.setParentId(parentId.longValue()); // 设置父ID
    }

    // 创建本地节点
    sqlNote.setGtaskId(node.getGid()); // 设置GTask ID
    sqlNote.commit(false); // 提交

    // 更新GID-NID映射
    mGidToNid.put(node.getGid(), sqlNote.getId());
    mNidToGid.put(sqlNote.getId(), node.getGid());

    // 更新元数据
    updateRemoteMeta(node.getGid(), sqlNote);
}

// 本地更新节点的方法
private void updateLocalNode(Node node, Cursor c) throws NetworkFailureException {
    // 如果同步被取消，则直接返回
    if (mCancelled) {
        return;
    }

    SqlNote sqlNote; // SQL笔记对象
    // 更新本地笔记
    sqlNote = new SqlNote(mContext, c);
    sqlNote.setContent(node.getLocalJSONFromContent()); // 设置内容

    Long parentId = (node instanceof Task) ? mGidToNid.get(((Task) node).getParent().getGid())
            : new Long(Notes.ID_ROOT_FOLDER);
    if (parentId == null) {
        Log.e(TAG, "cannot find task's parent id locally");
        throw new ActionFailureException("cannot update local node");
    }
    sqlNote.setParentId(parentId.longValue()); // 设置父ID
    sqlNote.commit(true); // 提交

    // 更新元数据信息
    updateRemoteMeta(node.getGid(), sqlNote);
}

// 远程添加节点的方法
private void addRemoteNode(Node node, Cursor c) throws NetworkFailureException {
    // 如果同步被取消，则直接返回
    if (mCancelled) {
        return;
    }

    SqlNote sqlNote = new SqlNote(mContext, c); // SQL笔记对象
    Node n; // 节点对象

    // 远程更新
    if (sqlNote.isNoteType()) {
        Task task = new Task(); // 任务对象
        task.setContentByLocalJSON(sqlNote.getContent()); // 设置内容

        String parentGid = mNidToGid.get(sqlNote.getParentId()); // 获取父GID
        if (parentGid == null) {
            Log.e(TAG, "cannot find task's parent tasklist");
            throw new ActionFailureException("cannot add remote task");
        }
        mGTaskListHashMap.get(parentGid).addChildTask(task); // 添加任务到任务列表

        GTaskClient.getInstance().createTask(task); // 创建任务
        n = (Node) task; // 转换为节点

        // 添加元数据
        updateRemoteMeta(task.getGid(), sqlNote);
    } else {
        TaskList tasklist = null; // 任务列表对象

        // 如果文件夹已存在，则跳过
        String folderName = GTaskStringUtils.MIUI_FOLDER_PREFFIX;
        if (sqlNote.getId() == Notes.ID_ROOT_FOLDER)
            folderName += GTaskStringUtils.FOLDER_DEFAULT;
        else if (sqlNote.getId() == Notes.ID_CALL_RECORD_FOLDER)
            folderName += GTaskStringUtils.FOLDER_CALL_NOTE;
        else
            folderName += sqlNote.getSnippet();

        Iterator<Map.Entry<String, TaskList>> iter = mGTaskListHashMap.entrySet().iterator();
        while (iter.hasNext()) {
            Map.Entry<String, TaskList> entry = iter.next();
            String gid = entry.getKey();
            TaskList list = entry.getValue();

            if (list.getName().equals(folderName)) {
                tasklist = list;
                if (mGTaskHashMap.containsKey(gid)) {
                    mGTaskHashMap.remove(gid);
                }
                break;
            }
        }

        // 如果没有匹配，则添加
        if (tasklist == null) {
            tasklist = new TaskList(); // 创建任务列表
            tasklist.setContentByLocalJSON(sqlNote.getContent()); // 设置内容
            GTaskClient.getInstance().createTaskList(tasklist); // 创建任务列表
            mGTaskListHashMap.put(tasklist.getGid(), tasklist); // 添加到映射
        }
        n = (Node) tasklist; // 转换为节点
    }

    // 更新本地笔记
    sqlNote.setGtaskId(n.getGid()); // 设置GTask ID
    sqlNote.commit(false); // 提交
    sqlNote.resetLocalModified(); // 重置本地修改标志
    sqlNote.commit(true); // 提交

    // GID-ID映射
    mGidToNid.put(n.getGid(), sqlNote.getId());
    mNidToGid.put(sqlNote.getId(), n.getGid());
}

// 远程更新节点的方法
private void updateRemoteNode(Node node, Cursor c) throws

NetworkFailureException {
// 如果同步被取消，则直接返回
if (mCancelled) {
return;
}

SqlNote sqlNote = new SqlNote(mContext, c); // SQL笔记对象

// 远程更新
node.setContentByLocalJSON(sqlNote.getContent()); // 设置内容
GTaskClient.getInstance().addUpdateNode(node); // 更新节点

// 更新元数据
updateRemoteMeta(node.getGid(), sqlNote);

// 如果需要，移动任务
if (sqlNote.isNoteType()) {
    Task task = (Task) node; // 任务对象
    TaskList preParentList = task.getParent(); // 之前的父任务列表

    String curParentGid = mNidToGid.get(sqlNote.getParentId()); // 当前的父GID
    if (curParentGid == null) {
        Log.e(TAG, "cannot find task's parent tasklist");
        throw new ActionFailureException("cannot update remote task");
    }
    TaskList curParentList = mGTaskListHashMap.get(curParentGid); // 当前的父任务列表

    if (preParentList != curParentList) {
        preParentList.removeChildTask(task); // 从之前的父任务列表中移除任务
        curParentList.addChildTask(task); // 添加到当前的父任务列表
        GTaskClient.getInstance().moveTask(task, preParentList, curParentList); // 移动任务
    }
}

// 清除本地修改标志
sqlNote.resetLocalModified();
sqlNote.commit(true);
}

// 更新远程元数据的方法
private void updateRemoteMeta(String gid, SqlNote sqlNote) throws NetworkFailureException {
if (sqlNote != null && sqlNote.isNoteType()) {
MetaData metaData = mMetaHashMap.get(gid); // 获取元数据
if (metaData != null) {
metaData.setMeta(gid, sqlNote.getContent()); // 设置元数据
GTaskClient.getInstance().addUpdateNode(metaData); // 更新元数据
} else {
metaData = new MetaData(); // 创建元数据对象
metaData.setMeta(gid, sqlNote.getContent()); // 设置元数据
mMetaList.addChildTask(metaData); // 添加到元数据列表
mMetaHashMap.put(gid, metaData); // 添加到映射
GTaskClient.getInstance().createTask(metaData); // 创建元数据
}
}
}

// 刷新本地同步ID的方法
private void refreshLocalSyncId() throws NetworkFailureException {
if (mCancelled) {
return;
}

// 获取最新的gtask列表
mGTaskHashMap.clear();
mGTaskListHashMap.clear();
mMetaHashMap.clear();
initGTaskList();

Cursor c = null;
try {
    c = mContentResolver.query(Notes.CONTENT_NOTE_URI, SqlNote.PROJECTION_NOTE,
            "(type<>? AND parent_id<>?)", new String[] {
                    String.valueOf(Notes.TYPE_SYSTEM), String.valueOf(Notes.ID_TRASH_FOLER)
            }, NoteColumns.TYPE + " DESC");
    if (c != null) {
        while (c.moveToNext()) {
            String gid = c.getString(SqlNote.GTASK_ID_COLUMN);
            Node node = mGTaskHashMap.get(gid);
            if (node != null) {
                mGTaskHashMap.remove(gid);
                ContentValues values = new ContentValues();
                values.put(NoteColumns.SYNC_ID, node.getLastModified());
                mContentResolver.update(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI,
                        c.getLong(SqlNote.ID_COLUMN)), values, null, null);
            } else {
                Log.e(TAG, "something is missed");
                throw new ActionFailureException(
                        "some local items don't have gid after sync");
            }
        }
    } else {
        Log.w(TAG, "failed to query local note to refresh sync id");
    }
} finally {
    if (c != null) {
        c.close();
        c = null;
    }
}
}

// 获取同步账户的方法
public String getSyncAccount() {
return GTaskClient.getInstance().getSyncAccount().name;
}

// 取消同步的方法
public void cancelSync() {
mCancelled = true;
}