/*
 * 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 {
    private static HashMap<String, String> sContactCache; // 静态HashMap用于缓存联系人信息
    private static final String TAG = "Contact"; // 用于日志记录的标签

    // 这是一个SQL查询片段，用于在联系人数据库中查找与给定电话号码匹配的联系人
    // 此查询片段使用了PHONE_NUMBERS_EQUAL函数来匹配电话号码，并检查MIME类型是否为联系人类型
    // 然后，它使用子查询从phone_lookup表中选择具有最佳匹配的raw_contact_id
    // 请注意，这里的"?"是一个参数占位符，用于在执行查询时插入实际的电话号码
    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 = '+')";

    /**
     * 根据电话号码从联系人数据库中获取联系人的姓名，并缓存结果。
     *
     * @param context 当前应用的上下文，用于访问内容解析器。
     * @param phoneNumber 要查询的电话号码。
     * @return 匹配电话号码的联系人姓名，如果未找到匹配项或发生错误，则返回null。
     */

    public static String getContact(Context context, String phoneNumber) {
        // 检查缓存是否已初始化，如果未初始化，则进行初始化
        if(sContactCache == null) {
            sContactCache = new HashMap<String, String>();
        }
        // 检查缓存中是否已经存在该电话号码的联系人姓名
        if(sContactCache.containsKey(phoneNumber)) {
            return sContactCache.get(phoneNumber);
        }
        // 替换CALLER_ID_SELECTION中的占位符"+"为实际的电话号码匹配最小值
        String selection = CALLER_ID_SELECTION.replace("+",
                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
        // 使用内容解析器查询联系人数据库
        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 {
                String name = cursor.getString(0);
                sContactCache.put(phoneNumber, name);
                return name;
            } catch (IndexOutOfBoundsException e) {
                // 如果Cursor中没有预期的列，则记录错误并返回null
                Log.e(TAG, " Cursor get string error " + e.toString());
                return null;
            } finally {
                cursor.close();
            }
        } else {
            Log.d(TAG, "No contact matched with number:" + phoneNumber);
            return null;
        }
    }
}