/*
 * 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.data;

import android.content.Context;
import android.database.Cursor;
import android.provider.ContactsContract.CommonDataKinds.Phone;
import android.provider.ContactsContract.Data;
import android.telephony.PhoneNumberUtils;
import android.util.Log;

import java.util.HashMap;

public class Contact {
    //联系人数据库
    /*hashmap是一系列的键-值队（以键查找值），hashmap的特点是：无序，键不重复   <String,String>是泛型的概念，这里意思是，键是字符串，值也是字符串*/
    private static HashMap<String, String> sContactCache;//创建实体类来存储所写联系人信息
    private static final String TAG = "Contact";//定义该类的名称
    private static final String CALLER_ID_SELECTION = "PHONE_NUMBERS_EQUAL(" + Phone.NUMBER
    + ",?) AND " + Data.MIMETYPE + "='" + Phone.CONTENT_ITEM_TYPE + "'"
    + " AND " + Data.RAW_CONTACT_ID + " IN "
            + "(SELECT raw_contact_id "
            + " FROM phone_lookup"
            + " WHERE min_match = '+')";//在数据库中查找电话号码
    public static String getContact(Context context, String phoneNumber) {
        if(sContactCache == null) {
            //创建实体类缓存列表
            sContactCache = new HashMap<String, String>();
        }
        if(sContactCache.containsKey(phoneNumber)) {
            //如果在数据库中包含此键值则返回电话号码
            return sContactCache.get(phoneNumber);
        }
        //toCallerIDMinMatch是安卓自带的号码匹配工具，截取查询号码的后7位作为匹配依据
        String selection = CALLER_ID_SELECTION.replace("+",
                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
        //cursor类是对数据库的操作，获取整行的数据，从数据库中查询联系人内容
        Cursor cursor = context.getContentResolver().query(
                Data.CONTENT_URI,//数据储存的地址
                new String [] { Phone.DISPLAY_NAME },
                selection,
                new String[] { phoneNumber },
                null);
        if (cursor != null && cursor.moveToFirst()) {
            //若数据库存在，则游标移动到游标所表示的信息元组的第一行开始
            try {
                String name = cursor.getString(0);
                sContactCache.put(phoneNumber, name);//把找到的联系人电话和名字移到缓存列表中
                return name;
            } catch (IndexOutOfBoundsException e) {
                Log.e(TAG, " Cursor get string error " + e.toString());//异常处理
                return null;
            } finally {
                cursor.close();//关闭数据库的访问
            }
        } else {
            //数据库不存在或没找到此联系电话
            Log.d(TAG, "No contact matched with number:" + phoneNumber);
            return null;
        }
    }
}