/*
 * 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;
/**
 * 联系人工具类 - 提供根据电话号码查询联系人姓名的功能
 * 使用内存缓存避免重复查询，优化性能
 * 基于Android ContactsContract API实现联系人数据库查询
 */
public class Contact {
    // 联系人缓存：存储已查询过的电话号码与对应联系人姓名的映射关系
    private static HashMap<String, String> sContactCache;
    private static final String TAG = "Contact";
    // 联系人查询的SQL选择条件模板
    // 1. 使用PHONE_NUMBERS_EQUAL函数比较电话号码（考虑了格式差异）
    // 2. 限定数据类型为Phone类型
    // 3. 通过phone_lookup表进行优化查询
    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 = '+')";
    /**
     * 根据电话号码获取联系人姓名
     *
     * @param context 应用上下文，用于访问ContentResolver
     * @param phoneNumber 待查询的电话号码
     * @return 对应的联系人姓名，若未找到则返回null
     */
    public static String getContact(Context context, String phoneNumber) {
        // 初始化缓存
        if(sContactCache == null) {
            sContactCache = new HashMap<String, String>();
        }
        // 优先从缓存获取，提高性能
        if(sContactCache.containsKey(phoneNumber)) {
            return sContactCache.get(phoneNumber);
        }
        // 构建查询条件：将电话号码转换为CallerID匹配格式
        String selection = CALLER_ID_SELECTION.replace("+",
                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
        // 执行联系人数据库查询
        Cursor cursor = context.getContentResolver().query(
                Data.CONTENT_URI,
                new String [] { Phone.DISPLAY_NAME },
                selection,
                new String[] { phoneNumber },
                null);
        // 处理查询结果
        if (cursor != null && cursor.moveToFirst()) {
            try {
                // 获取联系人姓名并加入缓存
                String name = cursor.getString(0);
                sContactCache.put(phoneNumber, name);
                return name;
            } catch (IndexOutOfBoundsException e) {
                // 异常处理：查询结果格式错误
                Log.e(TAG, " Cursor get string error " + e.toString());
                return null;
            } finally {
                // 资源释放：确保游标关闭
                cursor.close();
            }
        } else {
            // 未找到匹配联系人
            Log.d(TAG, "No contact matched with number:" + phoneNumber);
            return null;
        }
    }
}