/*
 * 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.AlarmManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.ContentUris;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;

import net.micode.notes.data.Notes;
import net.micode.notes.data.Notes.NoteColumns;


public class AlarmInitReceiver extends BroadcastReceiver {

    private static final String [] PROJECTION = new String [] {
        NoteColumns.ID,
        NoteColumns.ALERTED_DATE
    };//定义了一个字符串数组

    private static final int COLUMN_ID                = 0;//一栏的id
    private static final int COLUMN_ALERTED_DATE      = 1;//一栏的闹钟响的日期

    @Override
    public void onReceive(Context context, Intent intent) {/*
        每个receiver类都必须重写父类Receiver的onReceive方法，对接收到的广播进行处理
         */
        long currentDate = System.currentTimeMillis();//获取当前时间，毫秒为单位
        Cursor c = context.getContentResolver().query(Notes.CONTENT_NOTE_URI,//URI代表数据库的中的某个表
                PROJECTION,//要查询的列
                NoteColumns.ALERTED_DATE + ">? AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE,/*
                where 后面的条件，？为占位符，selectionArgs参数替代占位符
                */
                new String[] { String.valueOf(currentDate) },//替代占位符的
                null);//order by  排序，当前null默认升序
        /* 内容解析器提供的query（查询）方法，会将参数转化为一条select语句，用于在数据库中进行操作，返回的结果，相当于游标的缓冲区，
        cursor为指向每行的游标指针
        */

        if (c != null) {//查询结果成功
            if (c.moveToFirst()) {//移动到第一行
                do {
                    long alertDate = c.getLong(COLUMN_ALERTED_DATE);//将COLUMN_ALERTED_DATE列的值转化为long赋值给变量
                    Intent sender = new Intent(context, AlarmReceiver.class);//向AlarmReceiver类传递intent对象
                    sender.setData(ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, c.getLong(COLUMN_ID)));/*
                    设置sender对象的data的URI，向给定的URI路径末尾添加一个id,有id后的URI代表那个id指向的资源
                    */
                    PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, sender, 0);/*
                    调用PendingIntent.getBroadcast方法，以获得一个PendingIntent对象，激发该对象时，该对象会启动一个它能启动组件，
                    只能是activity，service，broadcast这3个组件，当前是创建了一个激发时能启动broadcast的对象，广播传递的intent
                    是sender
                    */
                    AlarmManager alermManager = (AlarmManager) context
                            .getSystemService(Context.ALARM_SERVICE);//通过系统服务来获得当前的闹钟管理器
                    alermManager.set(AlarmManager.RTC_WAKEUP, alertDate, pendingIntent);/*
                    设置闹钟，闹钟类型是使用现实时间的闹钟，会唤醒系统进行提示 响，设置了响的时间，响时会传递的消息
                    */
                } while (c.moveToNext());//c指向下一行
            }
            c.close();//关闭游标
        }
    }
}