/*
 * 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;

import android.accounts.Account;
import android.accounts.AccountManager;
import android.accounts.AccountManagerFuture;
import android.app.Activity;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;

import net.micode.notes.gtask.data.Node;
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.GTaskStringUtils;
import net.micode.notes.ui.NotesPreferenceActivity;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.cookie.Cookie;
import org.apache.http.impl.client.BasicCookieStore;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpProtocolParams;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.LinkedList;
import java.util.List;
import java.util.zip.GZIPInputStream;
import java.util.zip.Inflater;
import java.util.zip.InflaterInputStream;


/**
 * <p>Google任务API客户端类。</p>
 * <p>设计意图：提供与Google任务API交互的核心功能，实现任务的创建、更新、删除等操作。</p>
 * <p>核心职责：</p>
 * <ul>
 * <li>处理Google账号的登录认证</li>
 * <li>执行Google任务的CRUD操作</li>
 * <li>管理API请求的Cookie和会话状态</li>
 * <li>处理网络请求和响应，包括压缩数据的解压</li>
 * <li>将本地任务模型转换为Google任务API的JSON格式</li>
 * </ul>
 * <p>关键关联：</p>
 * <ul>
 * <li>与{@link GTaskManager}配合，提供任务同步的底层支持</li>
 * <li>使用{@link Task}和{@link TaskList}类封装Google任务数据</li>
 * <li>通过{@link NetworkFailureException}和{@link ActionFailureException}处理异常</li>
 * <li>依赖{@link GTaskStringUtils}提供API交互所需的常量</li>
 * </ul>
 * <p>设计特点：</p>
 * <ul>
 * <li>采用单例模式，确保全局只有一个Google任务API客户端实例</li>
 * <li>实现会话管理，避免频繁登录认证</li>
 * <li>支持批量更新操作，提高API调用效率</li>
 * <li>处理不同类型的网络压缩格式（gzip、deflate）</li>
 * </ul>
 */
public class GTaskClient {
    /**
     * 日志标签，用于调试和错误跟踪
     */
    private static final String TAG = GTaskClient.class.getSimpleName();

    /**
     * Google任务的基本URL
     */
    private static final String GTASK_URL = "https://mail.google.com/tasks/";

    /**
     * Google任务的GET请求URL
     */
    private static final String GTASK_GET_URL = "https://mail.google.com/tasks/ig";

    /**
     * Google任务的POST请求URL
     */
    private static final String GTASK_POST_URL = "https://mail.google.com/tasks/r/ig";

    /**
     * GTaskClient的单例实例
     */
    private static GTaskClient mInstance = null;

    /**
     * HTTP客户端，用于执行与Google任务API的网络请求
     */
    private DefaultHttpClient mHttpClient;

    /**
     * 当前使用的GET请求URL
     */
    private String mGetUrl;

    /**
     * 当前使用的POST请求URL
     */
    private String mPostUrl;

    /**
     * Google任务客户端版本号
     */
    private long mClientVersion;

    /**
     * 登录状态标志
     */
    private boolean mLoggedin;

    /**
     * 最后一次登录时间
     */
    private long mLastLoginTime;

    /**
     * 请求操作ID，用于跟踪API请求
     */
    private int mActionId;

    /**
     * 当前登录的Google账号
     */
    private Account mAccount;

    /**
     * 批量更新的JSON数组，用于累积多次更新操作
     */
    private JSONArray mUpdateArray;

    /**
     * <p>私有构造方法。</p>
     * <p>设计意图：实现单例模式，防止外部直接实例化。</p>
     * <p>初始化所有成员变量，设置默认值。</p>
     */
    private GTaskClient() {
        mHttpClient = null;
        mGetUrl = GTASK_GET_URL;
        mPostUrl = GTASK_POST_URL;
        mClientVersion = -1;
        mLoggedin = false;
        mLastLoginTime = 0;
        mActionId = 1;
        mAccount = null;
        mUpdateArray = null;
    }

    /**
     * <p>获取GTaskClient的单例实例。</p>
     * <p>业务逻辑：使用双重检查锁定实现线程安全的单例模式。</p>
     * 
     * @return GTaskClient的单例实例
     */
    public static synchronized GTaskClient getInstance() {
        if (mInstance == null) {
            mInstance = new GTaskClient();
        }
        return mInstance;
    }

    /**
     * <p>登录Google账号并验证Google任务API。</p>
     * <p>业务逻辑：</p>
     * <ul>
     * <li>检查登录状态，如果Cookie过期或账号切换则重新登录</li>
     * <li>获取Google账号的认证令牌</li>
     * <li>如果是自定义域名邮箱，使用自定义URL尝试登录</li>
     * <li>如果自定义域名登录失败，使用官方URL尝试登录</li>
     * </ul>
     * 
     * @param activity 当前活动的Activity，用于获取账号信息和显示认证界面
     * @return true表示登录成功，false表示登录失败
     */
    public boolean login(Activity activity) {
        // we suppose that the cookie would expire after 5 minutes
        // then we need to re-login
        final long interval = 1000 * 60 * 5;
        if (mLastLoginTime + interval < System.currentTimeMillis()) {
            mLoggedin = false;
        }

        // need to re-login after account switch
        if (mLoggedin
                && !TextUtils.equals(getSyncAccount().name, NotesPreferenceActivity
                        .getSyncAccountName(activity))) {
            mLoggedin = false;
        }

        if (mLoggedin) {
            Log.d(TAG, "already logged in");
            return true;
        }

        mLastLoginTime = System.currentTimeMillis();
        String authToken = loginGoogleAccount(activity, false);
        if (authToken == null) {
            Log.e(TAG, "login google account failed");
            return false;
        }

        // login with custom domain if necessary
        if (!(mAccount.name.toLowerCase().endsWith("gmail.com") || mAccount.name.toLowerCase()
                .endsWith("googlemail.com"))) {
            StringBuilder url = new StringBuilder(GTASK_URL).append("a/");
            int index = mAccount.name.indexOf('@') + 1;
            String suffix = mAccount.name.substring(index);
            url.append(suffix + "/");
            mGetUrl = url.toString() + "ig";
            mPostUrl = url.toString() + "r/ig";

            if (tryToLoginGtask(activity, authToken)) {
                mLoggedin = true;
            }
        }

        // try to login with google official url
        if (!mLoggedin) {
            mGetUrl = GTASK_GET_URL;
            mPostUrl = GTASK_POST_URL;
            if (!tryToLoginGtask(activity, authToken)) {
                return false;
            }
        }

        mLoggedin = true;
        return true;
    }

    /**
     * <p>登录Google账号并获取认证令牌。</p>
     * <p>业务逻辑：</p>
     * <ul>
     * <li>获取设备上所有的Google账号</li>
     * <li>根据设置中选择的账号名查找对应的Account对象</li>
     * <li>使用AccountManager获取该账号的认证令牌</li>
     * <li>如果需要，可以使现有令牌失效并重新获取</li>
     * </ul>
     * 
     * @param activity 当前活动的Activity，用于获取AccountManager
     * @param invalidateToken 是否使现有令牌失效
     * @return 认证令牌字符串，如果获取失败则返回null
     */
    private String loginGoogleAccount(Activity activity, boolean invalidateToken) {
        String authToken;
        AccountManager accountManager = AccountManager.get(activity);
        Account[] accounts = accountManager.getAccountsByType("com.google");

        if (accounts.length == 0) {
            Log.e(TAG, "there is no available google account");
            return null;
        }

        String accountName = NotesPreferenceActivity.getSyncAccountName(activity);
        Account account = null;
        for (Account a : accounts) {
            if (a.name.equals(accountName)) {
                account = a;
                break;
            }
        }
        if (account != null) {
            mAccount = account;
        } else {
            Log.e(TAG, "unable to get an account with the same name in the settings");
            return null;
        }

        // get the token now
        AccountManagerFuture<Bundle> accountManagerFuture = accountManager.getAuthToken(account,
                "goanna_mobile", null, activity, null, null);
        try {
            Bundle authTokenBundle = accountManagerFuture.getResult();
            authToken = authTokenBundle.getString(AccountManager.KEY_AUTHTOKEN);
            if (invalidateToken) {
                accountManager.invalidateAuthToken("com.google", authToken);
                loginGoogleAccount(activity, false);
            }
        } catch (Exception e) {
            Log.e(TAG, "get auth token failed");
            authToken = null;
        }

        return authToken;
    }

    /**
     * <p>尝试登录Google任务API。</p>
     * <p>业务逻辑：</p>
     * <ul>
     * <li>首先使用提供的认证令牌尝试登录</li>
     * <li>如果登录失败，可能是令牌过期，此时使令牌失效并重新获取</li>
     * <li>使用新的认证令牌再次尝试登录</li>
     * </ul>
     * 
     * @param activity 当前活动的Activity，用于重新获取认证令牌
     * @param authToken Google账号的认证令牌
     * @return true表示登录成功，false表示登录失败
     */
    private boolean tryToLoginGtask(Activity activity, String authToken) {
        if (!loginGtask(authToken)) {
            // maybe the auth token is out of date, now let's invalidate the
            // token and try again
            authToken = loginGoogleAccount(activity, true);
            if (authToken == null) {
                Log.e(TAG, "login google account failed");
                return false;
            }

            if (!loginGtask(authToken)) {
                Log.e(TAG, "login gtask failed");
                return false;
            }
        }
        return true;
    }

    /**
     * <p>登录Google任务API的核心方法。</p>
     * <p>业务逻辑：</p>
     * <ul>
     * <li>配置HTTP客户端的连接和套接字超时时间</li>
     * <li>创建Cookie存储以保存认证信息</li>
     * <li>发送HTTP GET请求进行登录认证</li>
     * <li>检查响应中是否包含认证Cookie</li>
     * <li>从响应中解析出客户端版本号</li>
     * </ul>
     * 
     * @param authToken Google账号的认证令牌
     * @return true表示登录成功，false表示登录失败
     */
    private boolean loginGtask(String authToken) {
        int timeoutConnection = 10000;
        int timeoutSocket = 15000;
        HttpParams httpParameters = new BasicHttpParams();
        HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
        HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
        mHttpClient = new DefaultHttpClient(httpParameters);
        BasicCookieStore localBasicCookieStore = new BasicCookieStore();
        mHttpClient.setCookieStore(localBasicCookieStore);
        HttpProtocolParams.setUseExpectContinue(mHttpClient.getParams(), false);

        // login gtask
        try {
            String loginUrl = mGetUrl + "?auth=" + authToken;
            HttpGet httpGet = new HttpGet(loginUrl);
            HttpResponse response = null;
            response = mHttpClient.execute(httpGet);

            // get the cookie now
            List<Cookie> cookies = mHttpClient.getCookieStore().getCookies();
            boolean hasAuthCookie = false;
            for (Cookie cookie : cookies) {
                if (cookie.getName().contains("GTL")) {
                    hasAuthCookie = true;
                }
            }
            if (!hasAuthCookie) {
                Log.w(TAG, "it seems that there is no auth cookie");
            }

            // get the client version
            String resString = getResponseContent(response.getEntity());
            String jsBegin = "_setup(";
            String jsEnd = ")}</script>";
            int begin = resString.indexOf(jsBegin);
            int end = resString.lastIndexOf(jsEnd);
            String jsString = null;
            if (begin != -1 && end != -1 && begin < end) {
                jsString = resString.substring(begin + jsBegin.length(), end);
            }
            JSONObject js = new JSONObject(jsString);
            mClientVersion = js.getLong("v");
        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            return false;
        } catch (Exception e) {
            // simply catch all exceptions
            Log.e(TAG, "httpget gtask_url failed");
            return false;
        }

        return true;
    }

    /**
     * <p>获取操作ID。</p>
     * <p>业务逻辑：返回当前操作ID并自增，用于跟踪API请求。</p>
     * 
     * @return 当前操作ID
     */
    private int getActionId() {
        return mActionId++;
    }

    /**
     * <p>创建HTTP POST请求。</p>
     * <p>业务逻辑：配置POST请求的URL和请求头。</p>
     * 
     * @return 配置好的HttpPost对象
     */
    private HttpPost createHttpPost() {
        HttpPost httpPost = new HttpPost(mPostUrl);
        httpPost.setHeader("Content-Type", "application/x-www-form-urlencoded;charset=utf-8");
        httpPost.setHeader("AT", "1");
        return httpPost;
    }

    /**
     * <p>获取HTTP响应内容。</p>
     * <p>业务逻辑：</p>
     * <ul>
     * <li>检查响应内容的编码方式</li>
     * <li>如果是gzip或deflate压缩格式，进行解压处理</li>
     * <li>将响应内容转换为字符串</li>
     * </ul>
     * 
     * @param entity HTTP响应实体
     * @return 响应内容字符串
     * @throws IOException 如果读取或解压响应内容时发生错误
     */
    private String getResponseContent(HttpEntity entity) throws IOException {
        String contentEncoding = null;
        if (entity.getContentEncoding() != null) {
            contentEncoding = entity.getContentEncoding().getValue();
            Log.d(TAG, "encoding: " + contentEncoding);
        }

        InputStream input = entity.getContent();
        if (contentEncoding != null && contentEncoding.equalsIgnoreCase("gzip")) {
            input = new GZIPInputStream(entity.getContent());
        } else if (contentEncoding != null && contentEncoding.equalsIgnoreCase("deflate")) {
            Inflater inflater = new Inflater(true);
            input = new InflaterInputStream(entity.getContent(), inflater);
        }

        try {
            InputStreamReader isr = new InputStreamReader(input);
            BufferedReader br = new BufferedReader(isr);
            StringBuilder sb = new StringBuilder();

            while (true) {
                String buff = br.readLine();
                if (buff == null) {
                    return sb.toString();
                }
                sb = sb.append(buff);
            }
        } finally {
            input.close();
        }
    }

    /**
     * <p>发送POST请求到Google任务API。</p>
     * <p>业务逻辑：</p>
     * <ul>
     * <li>检查登录状态，未登录则抛出异常</li>
     * <li>创建并配置HTTP POST请求</li>
     * <li>将JSON数据转换为请求实体</li>
     * <li>发送请求并获取响应</li>
     * <li>将响应内容转换为JSON对象</li>
     * </ul>
     * 
     * @param js 要发送的JSON对象
     * @return 响应的JSON对象
     * @throws NetworkFailureException 如果网络请求失败
     */
    private JSONObject postRequest(JSONObject js) throws NetworkFailureException {
        if (!mLoggedin) {
            Log.e(TAG, "please login first");
            throw new ActionFailureException("not logged in");
        }

        HttpPost httpPost = createHttpPost();
        try {
            LinkedList<BasicNameValuePair> list = new LinkedList<BasicNameValuePair>();
            list.add(new BasicNameValuePair("r", js.toString()));
            UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list, "UTF-8");
            httpPost.setEntity(entity);

            // execute the post
            HttpResponse response = mHttpClient.execute(httpPost);
            String jsString = getResponseContent(response.getEntity());
            return new JSONObject(jsString);

        } catch (ClientProtocolException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new NetworkFailureException("postRequest failed");
        } catch (IOException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new NetworkFailureException("postRequest failed");
        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new ActionFailureException("unable to convert response content to jsonobject");
        } catch (Exception e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new ActionFailureException("error occurs when posting request");
        }
    }

    /**
     * <p>创建新的Google任务。</p>
     * <p>业务逻辑：</p>
     * <ul>
     * <li>提交当前累积的更新操作</li>
     * <li>创建任务的JSON表示</li>
     * <li>发送创建任务的POST请求</li>
     * <li>从响应中获取新创建任务的GID并设置到任务对象中</li>
     * </ul>
     * 
     * @param task 要创建的任务对象
     * @throws NetworkFailureException 如果网络请求失败
     */
    public void createTask(Task task) throws NetworkFailureException {
        commitUpdate();
        try {
            JSONObject jsPost = new JSONObject();
            JSONArray actionList = new JSONArray();

            // action_list
            actionList.put(task.getCreateAction(getActionId()));
            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);

            // client_version
            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);

            // post
            JSONObject jsResponse = postRequest(jsPost);
            JSONObject jsResult = (JSONObject) jsResponse.getJSONArray(
                    GTaskStringUtils.GTASK_JSON_RESULTS).get(0);
            task.setGid(jsResult.getString(GTaskStringUtils.GTASK_JSON_NEW_ID));

        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new ActionFailureException("create task: handing jsonobject failed");
        }
    }

    /**
     * <p>创建新的Google任务列表。</p>
     * <p>业务逻辑：</p>
     * <ul>
     * <li>提交当前累积的更新操作</li>
     * <li>创建任务列表的JSON表示</li>
     * <li>发送创建任务列表的POST请求</li>
     * <li>从响应中获取新创建任务列表的GID并设置到任务列表对象中</li>
     * </ul>
     * 
     * @param tasklist 要创建的任务列表对象
     * @throws NetworkFailureException 如果网络请求失败
     */
    public void createTaskList(TaskList tasklist) throws NetworkFailureException {
        commitUpdate();
        try {
            JSONObject jsPost = new JSONObject();
            JSONArray actionList = new JSONArray();

            // action_list
            actionList.put(tasklist.getCreateAction(getActionId()));
            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);

            // client version
            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);

            // post
            JSONObject jsResponse = postRequest(jsPost);
            JSONObject jsResult = (JSONObject) jsResponse.getJSONArray(
                    GTaskStringUtils.GTASK_JSON_RESULTS).get(0);
            tasklist.setGid(jsResult.getString(GTaskStringUtils.GTASK_JSON_NEW_ID));

        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new ActionFailureException("create tasklist: handing jsonobject failed");
        }
    }

    /**
     * <p>提交累积的更新操作。</p>
     * <p>业务逻辑：将累积在mUpdateArray中的所有更新操作发送到Google任务API。</p>
     * 
     * @throws NetworkFailureException 如果网络请求失败
     */
    public void commitUpdate() throws NetworkFailureException {
        if (mUpdateArray != null) {
            try {
                JSONObject jsPost = new JSONObject();

                // action_list
                jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, mUpdateArray);

                // client_version
                jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);

                postRequest(jsPost);
                mUpdateArray = null;
            } catch (JSONException e) {
                Log.e(TAG, e.toString());
                e.printStackTrace();
                throw new ActionFailureException("commit update: handing jsonobject failed");
            }
        }
    }

    /**
     * <p>添加节点更新操作到累积列表。</p>
     * <p>业务逻辑：</p>
     * <ul>
     * <li>如果累积的更新操作超过10个，先提交这些更新</li>
     * <li>将节点的更新操作添加到累积列表中</li>
     * </ul>
     * 
     * @param node 要更新的节点对象
     * @throws NetworkFailureException 如果网络请求失败（当提交累积更新时）
     */
    public void addUpdateNode(Node node) throws NetworkFailureException {
        if (node != null) {
            // too many update items may result in an error
            // set max to 10 items
            if (mUpdateArray != null && mUpdateArray.length() > 10) {
                commitUpdate();
            }

            if (mUpdateArray == null)
                mUpdateArray = new JSONArray();
            mUpdateArray.put(node.getUpdateAction(getActionId()));
        }
    }

    /**
     * <p>移动任务到新的父任务列表或在同一列表中重新排序。</p>
     * <p>业务逻辑：</p>
     * <ul>
     * <li>提交当前累积的更新操作</li>
     * <li>创建移动任务的JSON表示</li>
     * <li>如果在同一列表内移动且不是第一个任务，设置前一个兄弟任务的ID</li>
     * <li>发送移动任务的POST请求</li>
     * </ul>
     * 
     * @param task 要移动的任务
     * @param preParent 任务的当前父任务列表
     * @param curParent 任务的新父任务列表
     * @throws NetworkFailureException 如果网络请求失败
     */
    public void moveTask(Task task, TaskList preParent, TaskList curParent)
            throws NetworkFailureException {
        commitUpdate();
        try {
            JSONObject jsPost = new JSONObject();
            JSONArray actionList = new JSONArray();
            JSONObject action = new JSONObject();

            // action_list
            action.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_MOVE);
            action.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, getActionId());
            action.put(GTaskStringUtils.GTASK_JSON_ID, task.getGid());
            if (preParent == curParent && task.getPriorSibling() != null) {
                // put prioring_sibing_id only if moving within the tasklist and
                // it is not the first one
                action.put(GTaskStringUtils.GTASK_JSON_PRIOR_SIBLING_ID, task.getPriorSibling());
            }
            action.put(GTaskStringUtils.GTASK_JSON_SOURCE_LIST, preParent.getGid());
            action.put(GTaskStringUtils.GTASK_JSON_DEST_PARENT, curParent.getGid());
            if (preParent != curParent) {
                // put the dest_list only if moving between tasklists
                action.put(GTaskStringUtils.GTASK_JSON_DEST_LIST, curParent.getGid());
            }
            actionList.put(action);
            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);

            // client_version
            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);

            postRequest(jsPost);

        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new ActionFailureException("move task: handing jsonobject failed");
        }
    }

    /**
     * <p>删除节点。</p>
     * <p>业务逻辑：</p>
     * <ul>
     * <li>提交当前累积的更新操作</li>
     * <li>将节点标记为已删除</li>
     * <li>创建删除节点的JSON表示</li>
     * <li>发送删除节点的POST请求</li>
     * <li>清空累积的更新列表</li>
     * </ul>
     * 
     * @param node 要删除的节点
     * @throws NetworkFailureException 如果网络请求失败
     */
    public void deleteNode(Node node) throws NetworkFailureException {
        commitUpdate();
        try {
            JSONObject jsPost = new JSONObject();
            JSONArray actionList = new JSONArray();

            // action_list
            node.setDeleted(true);
            actionList.put(node.getUpdateAction(getActionId()));
            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);

            // client_version
            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);

            postRequest(jsPost);
            mUpdateArray = null;
        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new ActionFailureException("delete node: handing jsonobject failed");
        }
    }

    /**
     * <p>获取所有的Google任务列表。</p>
     * <p>业务逻辑：</p>
     * <ul>
     * <li>检查登录状态</li>
     * <li>发送获取任务列表的GET请求</li>
     * <li>解析响应内容，提取任务列表数据</li>
     * </ul>
     * 
     * @return 任务列表的JSON数组
     * @throws NetworkFailureException 如果网络请求失败
     */
    public JSONArray getTaskLists() throws NetworkFailureException {
        if (!mLoggedin) {
            Log.e(TAG, "please login first");
            throw new ActionFailureException("not logged in");
        }

        try {
            HttpGet httpGet = new HttpGet(mGetUrl);
            HttpResponse response = null;
            response = mHttpClient.execute(httpGet);

            // get the task list
            String resString = getResponseContent(response.getEntity());
            String jsBegin = "_setup(";
            String jsEnd = ")}</script>";
            int begin = resString.indexOf(jsBegin);
            int end = resString.lastIndexOf(jsEnd);
            String jsString = null;
            if (begin != -1 && end != -1 && begin < end) {
                jsString = resString.substring(begin + jsBegin.length(), end);
            }
            JSONObject js = new JSONObject(jsString);
            return js.getJSONObject("t").getJSONArray(GTaskStringUtils.GTASK_JSON_LISTS);
        } catch (ClientProtocolException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new NetworkFailureException("gettasklists: httpget failed");
        } catch (IOException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new NetworkFailureException("gettasklists: httpget failed");
        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new ActionFailureException("get task lists: handing jasonobject failed");
        }
    }

    public JSONArray getTaskList(String listGid) throws NetworkFailureException {
        commitUpdate();
        try {
            JSONObject jsPost = new JSONObject();
            JSONArray actionList = new JSONArray();
            JSONObject action = new JSONObject();

            // action_list
            action.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_GETALL);
            action.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, getActionId());
            action.put(GTaskStringUtils.GTASK_JSON_LIST_ID, listGid);
            action.put(GTaskStringUtils.GTASK_JSON_GET_DELETED, false);
            actionList.put(action);
            jsPost.put(GTaskStringUtils.GTASK_JSON_ACTION_LIST, actionList);

            // client_version
            jsPost.put(GTaskStringUtils.GTASK_JSON_CLIENT_VERSION, mClientVersion);

            JSONObject jsResponse = postRequest(jsPost);
            return jsResponse.getJSONArray(GTaskStringUtils.GTASK_JSON_TASKS);
        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new ActionFailureException("get task list: handing jsonobject failed");
        }
    }

    public Account getSyncAccount() {
        return mAccount;
    }

    public void resetUpdateArray() {
        mUpdateArray = null;
    }
}