/*
 * 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;

/**
 * Contact类用于根据电话号码从系统联系人中查询对应的联系人姓名，
 * 并提供缓存机制以提高查询效率。
 */
public class Contact {
    // 联系人缓存：键为电话号码，值为对应的联系人姓名
    private static HashMap<String, String> sContactCache;
    private static final String TAG = "Contact";

    // 联系人ID查询的SQL选择条件模板
    // 该条件用于匹配电话号码并确保数据类型为Phone且关联到有效的原始联系人
    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 = '+')";

    /**
     * 根据电话号码从系统联系人中查询对应的联系人姓名
     * 
     * @param context     应用上下文，用于获取ContentResolver
     * @param phoneNumber 要查询的电话号码
     * @return 对应的联系人姓名，如果未找到则返回null
     */
    public static String getContact(Context context, String phoneNumber) {
        // 初始化联系人缓存（如果尚未初始化）
        if(sContactCache == null) {
            sContactCache = new HashMap<String, String>();
        }

        // 优先从缓存中获取联系人姓名
        if(sContactCache.containsKey(phoneNumber)) {
            return sContactCache.get(phoneNumber);
        }

        // 构建查询条件：替换模板中的占位符为实际的最小匹配值
        String selection = CALLER_ID_SELECTION.replace("+",
                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
        
        // 执行联系人查询
        Cursor cursor = context.getContentResolver().query(
                Data.CONTENT_URI,               // 查询联系人数据的URI
                new String [] { Phone.DISPLAY_NAME },  // 只需要显示名称字段
                selection,                      // 使用构建好的查询条件
                new String[] { phoneNumber },   // 查询参数
                null);                          // 不使用排序

        // 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) {
                // 处理可能的索引越界异常
                Log.e(TAG, " Cursor get string error " + e.toString());
                return null;
            } finally {
                // 确保关闭Cursor以防止资源泄漏
                cursor.close();
            }
        } else {
            // 未找到匹配的联系人
            Log.d(TAG, "No contact matched with number:" + phoneNumber);
            return null;
        }
    }
}