/*
 * 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.
 */

// 包声明，定义了这个类所在的包名
package net.micode.notes.data;

// 导入所需的Android类库
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;

// 导入Java的HashMap类，用于存储联系人缓存
import java.util.HashMap;

// 定义Contact类
public class Contact {
    // 定义一个静态的HashMap，用于缓存联系人信息，避免重复查询
    private static HashMap<String, String> sContactCache;
    // 定义一个TAG，用于日志输出
    private static final String TAG = "Contact";

    // 定义一个静态常量，用于构建查询语句
    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 = '+')";

    // 定义一个静态方法，用于根据电话号码获取联系人名称
    public static String getContact(Context context, String phoneNumber) {
        // 如果缓存不存在，则初始化缓存
        if(sContactCache == null) {
            sContactCache = new HashMap<String, String>();
        }

        // 如果电话号码已经在缓存中，则直接返回缓存中的联系人名称
        if(sContactCache.containsKey(phoneNumber)) {
            return sContactCache.get(phoneNumber);
        }

        // 替换查询语句中的占位符，构建具体的查询语句
        String selection = CALLER_ID_SELECTION.replace("+",
                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
        // 使用ContentResolver查询联系人数据
        Cursor cursor = context.getContentResolver().query(
                Data.CONTENT_URI,
                new String [] { Phone.DISPLAY_NAME },
                selection,
                new String[] { phoneNumber },
                null);

        // 如果查询结果不为空，并且至少有一条数据
        if (cursor != null && cursor.moveToFirst()) {
            try {
                // 获取联系人名称
                String name = cursor.getString(0);
                // 将联系人名称放入缓存
                sContactCache.put(phoneNumber, name);
                return name;
            } catch (IndexOutOfBoundsException e) {
                // 如果获取联系人名称时出现异常，记录错误日志
                Log.e(TAG, " Cursor get string error " + e.toString());
                return null;
            } finally {
                // 最后，关闭游标
                cursor.close();
            }
        } else {
            // 如果没有匹配的联系人，记录日志并返回null
            Log.d(TAG, "No contact matched with number:" + phoneNumber);
            return null;
        }
    }
}