ah-notes/java/net/micode/notes/gtask/data/Task.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.data;

import android.database.Cursor;
import android.text.TextUtils;
import android.util.Log;

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

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

/**
 * Task 类表示一个Google Tasks中的任务项，继承自Node基类
 *
 * 主要功能：
 * - 管理任务的基本属性(名称、备注、完成状态等)
 * - 处理本地与远程数据的同步
 * - 生成各种操作(创建、更新)的JSON格式数据
 * - 维护任务在任务列表中的位置关系
 *
 * 继承关系：
 * - 继承自Node基类，拥有ID、名称等基本属性
 */
public class Task extends Node {
    private static final String TAG = Task.class.getSimpleName();

    private boolean mCompleted;// 任务是否已完成

    private String mNotes;// 任务备注内容

    private JSONObject mMetaInfo;// 元数据信息(存储本地笔记相关信息)

    private Task mPriorSibling;// 前一个兄弟任务(用于维护任务顺序)

    private TaskList mParent;// 所属任务列表

    public Task() {
        super();// 调用父类构造方法
        mCompleted = false;// 默认未完成
        mNotes = null;// 默认无备注
        mPriorSibling = null;// 默认无前驱任务
        mParent = null;// 默认无父列表
        mMetaInfo = null;// 默认无元数据
    }

    /**
     * 生成创建任务的JSON动作对象
     * @param actionId 动作ID
     * @return 包含创建任务所需数据的JSON对象
     */
    public JSONObject getCreateAction(int actionId) {
        JSONObject js = new JSONObject();

        try {
            // action_type
            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_CREATE);

            // action_id
            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);

            // index
            // 设置任务在列表中的位置索引
            js.put(GTaskStringUtils.GTASK_JSON_INDEX, mParent.getChildTaskIndex(this));

            // entity_delta
            JSONObject entity = new JSONObject();
            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
            entity.put(GTaskStringUtils.GTASK_JSON_CREATOR_ID, "null");
            entity.put(GTaskStringUtils.GTASK_JSON_ENTITY_TYPE,
                    GTaskStringUtils.GTASK_JSON_TYPE_TASK);
            if (getNotes() != null) {
                entity.put(GTaskStringUtils.GTASK_JSON_NOTES, getNotes());
            }
            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);

            // parent_id
            js.put(GTaskStringUtils.GTASK_JSON_PARENT_ID, mParent.getGid());

            // dest_parent_type
            js.put(GTaskStringUtils.GTASK_JSON_DEST_PARENT_TYPE,
                    GTaskStringUtils.GTASK_JSON_TYPE_GROUP);

            // list_id
            js.put(GTaskStringUtils.GTASK_JSON_LIST_ID, mParent.getGid());

            // prior_sibling_id
            // 如果有前驱任务，设置前驱任务ID
            if (mPriorSibling != null) {
                js.put(GTaskStringUtils.GTASK_JSON_PRIOR_SIBLING_ID, mPriorSibling.getGid());
            }

        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new ActionFailureException("fail to generate task-create jsonobject");
        }

        return js;
    }

    /**
     * 生成更新任务的JSON动作对象
     * @param actionId 动作ID
     * @return 包含更新任务所需数据的JSON对象
     */
    public JSONObject getUpdateAction(int actionId) {
        JSONObject js = new JSONObject();

        try {
            // action_type
            js.put(GTaskStringUtils.GTASK_JSON_ACTION_TYPE,
                    GTaskStringUtils.GTASK_JSON_ACTION_TYPE_UPDATE);

            // action_id
            js.put(GTaskStringUtils.GTASK_JSON_ACTION_ID, actionId);

            // id
            js.put(GTaskStringUtils.GTASK_JSON_ID, getGid());

            // entity_delta
            JSONObject entity = new JSONObject();
            entity.put(GTaskStringUtils.GTASK_JSON_NAME, getName());
            if (getNotes() != null) {
                entity.put(GTaskStringUtils.GTASK_JSON_NOTES, getNotes());
            }
            entity.put(GTaskStringUtils.GTASK_JSON_DELETED, getDeleted());
            js.put(GTaskStringUtils.GTASK_JSON_ENTITY_DELTA, entity);

        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            throw new ActionFailureException("fail to generate task-update jsonobject");
        }

        return js;
    }

    /**
     * 从远程JSON数据设置任务内容
     * @param js 包含远程任务数据的JSON对象
     */
    public void setContentByRemoteJSON(JSONObject js) {
        if (js != null) {
            try {
                // id
                if (js.has(GTaskStringUtils.GTASK_JSON_ID)) {
                    setGid(js.getString(GTaskStringUtils.GTASK_JSON_ID));
                }

                // last_modified
                if (js.has(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED)) {
                    setLastModified(js.getLong(GTaskStringUtils.GTASK_JSON_LAST_MODIFIED));
                }

                // name
                if (js.has(GTaskStringUtils.GTASK_JSON_NAME)) {
                    setName(js.getString(GTaskStringUtils.GTASK_JSON_NAME));
                }

                // notes
                if (js.has(GTaskStringUtils.GTASK_JSON_NOTES)) {
                    setNotes(js.getString(GTaskStringUtils.GTASK_JSON_NOTES));
                }

                // deleted
                if (js.has(GTaskStringUtils.GTASK_JSON_DELETED)) {
                    setDeleted(js.getBoolean(GTaskStringUtils.GTASK_JSON_DELETED));
                }

                // completed
                if (js.has(GTaskStringUtils.GTASK_JSON_COMPLETED)) {
                    setCompleted(js.getBoolean(GTaskStringUtils.GTASK_JSON_COMPLETED));
                }
            } catch (JSONException e) {
                Log.e(TAG, e.toString());
                e.printStackTrace();
                throw new ActionFailureException("fail to get task content from jsonobject");
            }
        }
    }
    /**
     * 从本地JSON数据设置任务内容
     * @param js 包含本地笔记数据的JSON对象
     */
    public void setContentByLocalJSON(JSONObject js) {
        if (js == null || !js.has(GTaskStringUtils.META_HEAD_NOTE)
                || !js.has(GTaskStringUtils.META_HEAD_DATA)) {
            Log.w(TAG, "setContentByLocalJSON: nothing is avaiable");
        }

        try {
            JSONObject note = js.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
            JSONArray dataArray = js.getJSONArray(GTaskStringUtils.META_HEAD_DATA);

            if (note.getInt(NoteColumns.TYPE) != Notes.TYPE_NOTE) {
                Log.e(TAG, "invalid type");
                return;
            }

            for (int i = 0; i < dataArray.length(); i++) {
                JSONObject data = dataArray.getJSONObject(i);
                if (TextUtils.equals(data.getString(DataColumns.MIME_TYPE), DataConstants.NOTE)) {
                    setName(data.getString(DataColumns.CONTENT));
                    break;
                }
            }

        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
        }
    }

    /**
     * 从任务内容生成本地JSON数据
     * @return 包含任务数据的JSON对象
     */
    public JSONObject getLocalJSONFromContent() {
        String name = getName();
        try {
            if (mMetaInfo == null) {
                // new task created from web
                if (name == null) {
                    Log.w(TAG, "the note seems to be an empty one");
                    return null;
                }

                JSONObject js = new JSONObject();
                JSONObject note = new JSONObject();
                JSONArray dataArray = new JSONArray();
                JSONObject data = new JSONObject();
                data.put(DataColumns.CONTENT, name);
                dataArray.put(data);
                js.put(GTaskStringUtils.META_HEAD_DATA, dataArray);
                note.put(NoteColumns.TYPE, Notes.TYPE_NOTE);
                js.put(GTaskStringUtils.META_HEAD_NOTE, note);
                return js;
            } else {
                // synced task
                JSONObject note = mMetaInfo.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
                JSONArray dataArray = mMetaInfo.getJSONArray(GTaskStringUtils.META_HEAD_DATA);
                // 从数据数组中查找笔记内容
                for (int i = 0; i < dataArray.length(); i++) {
                    JSONObject data = dataArray.getJSONObject(i);
                    if (TextUtils.equals(data.getString(DataColumns.MIME_TYPE), DataConstants.NOTE)) {
                        // 找到笔记内容数据，设置为任务名称
                        data.put(DataColumns.CONTENT, getName());
                        break;
                    }
                }

                note.put(NoteColumns.TYPE, Notes.TYPE_NOTE);
                return mMetaInfo;
            }
        } catch (JSONException e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 设置元数据信息
     * @param metaData 包含笔记元数据的对象
     */
    public void setMetaInfo(MetaData metaData) {
        if (metaData != null && metaData.getNotes() != null) {
            try {
                mMetaInfo = new JSONObject(metaData.getNotes());
            } catch (JSONException e) {
                Log.w(TAG, e.toString());
                mMetaInfo = null;
            }
        }
    }

    /**
     * 确定同步动作类型
     * @param c 数据库游标(包含本地笔记数据)
     * @return 同步动作类型常量
     */
    public int getSyncAction(Cursor c) {
        try {
            JSONObject noteInfo = null;
            if (mMetaInfo != null && mMetaInfo.has(GTaskStringUtils.META_HEAD_NOTE)) {
                noteInfo = mMetaInfo.getJSONObject(GTaskStringUtils.META_HEAD_NOTE);
            }

            if (noteInfo == null) {
                Log.w(TAG, "it seems that note meta has been deleted");
                return SYNC_ACTION_UPDATE_REMOTE;
            }

            if (!noteInfo.has(NoteColumns.ID)) {
                Log.w(TAG, "remote note id seems to be deleted");
                return SYNC_ACTION_UPDATE_LOCAL;
            }

            // validate the note id now
            if (c.getLong(SqlNote.ID_COLUMN) != noteInfo.getLong(NoteColumns.ID)) {
                Log.w(TAG, "note id doesn't match");
                return SYNC_ACTION_UPDATE_LOCAL;
            }
            if (c.getInt(SqlNote.LOCAL_MODIFIED_COLUMN) == 0) {
                // there is no local update
                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
                    // no update both side
                    return SYNC_ACTION_NONE;
                } else {
                    // apply remote to local
                    return SYNC_ACTION_UPDATE_LOCAL;
                }
            } else {
                // validate gtask id
                if (!c.getString(SqlNote.GTASK_ID_COLUMN).equals(getGid())) {
                    Log.e(TAG, "gtask id doesn't match");
                    return SYNC_ACTION_ERROR;
                }
                if (c.getLong(SqlNote.SYNC_ID_COLUMN) == getLastModified()) {
                    // local modification only
                    return SYNC_ACTION_UPDATE_REMOTE;
                } else {
                    return SYNC_ACTION_UPDATE_CONFLICT;
                }
            }
        } catch (Exception e) {
            Log.e(TAG, e.toString());
            e.printStackTrace();
        }

        return SYNC_ACTION_ERROR;
    }

    /**
     * 检查任务是否值得保存
     * @return 如果任务有名称、备注或元数据则返回true
     */
    public boolean isWorthSaving() {
        return mMetaInfo != null || (getName() != null && getName().trim().length() > 0)
                || (getNotes() != null && getNotes().trim().length() > 0);
    }

    public void setCompleted(boolean completed) {
        this.mCompleted = completed;
    }

    public void setNotes(String notes) {
        this.mNotes = notes;
    }

    public void setPriorSibling(Task priorSibling) {
        this.mPriorSibling = priorSibling;
    }

    public void setParent(TaskList parent) {
        this.mParent = parent;
    }

    public boolean getCompleted() {
        return this.mCompleted;
    }

    public String getNotes() {
        return this.mNotes;
    }

    public Task getPriorSibling() {
        return this.mPriorSibling;
    }

    public TaskList getParent() {
        return this.mParent;
    }

}