/*
 * 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;

/**
 * <p>联系人信息查询和缓存类。</p>
 * <p>核心职责：</p>
 * <ul>
 * <li>通过电话号码查询联系人姓名</li>
 * <li>缓存查询结果以提高性能</li>
 * <li>使用Android联系人API进行查询</li>
 * </ul>
 * <p>设计意图：</p>
 * <ul>
 * <li>提供便捷的联系人信息查询接口</li>
 * <li>减少重复查询数据库的次数</li>
 * <li>优化通话便签中显示联系人姓名的性能</li>
 * </ul>
 * <p>关键关联：</p>
 * <ul>
 * <li>使用{@link Context}访问系统联系人Content Provider</li>
 * <li>使用{@link HashMap}实现查询结果缓存</li>
 * <li>被通话便签功能使用，显示来电者姓名</li>
 * </ul>
 */
public class Contact {
    /**
     * <p>联系人缓存，存储电话号码和联系人姓名的映射。</p>
     * <p>业务含义：避免重复查询相同电话号码的联系人信息，提高性能。</p>
     * <p>实现：使用HashMap存储，电话号码为键，联系人为值。</p>
     */
    private static HashMap<String, String> sContactCache;
    
    /**
     * <p>日志标签。</p>
     * <p>业务含义：用于在日志中标识Contact类的相关操作。</p>
     */
    private static final String TAG = "Contact";

    /**
     * <p>联系人查询条件。</p>
     * <p>业务含义：定义查询联系人信息的SQL条件，使用PHONE_NUMBERS_EQUAL函数匹配电话号码。</p>
     * <p>注意：其中的'+'会在查询时被替换为实际的电话号码匹配模式。</p>
     */
    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 = '+')";

    /**
     * <p>根据电话号码获取联系人姓名。</p>
     * <p>功能：通过电话号码查询手机通讯录中的联系人姓名，并缓存结果。</p>
     * 
     * @param context 上下文对象，用于访问ContentResolver
     * @param phoneNumber 电话号码，用于查询联系人
     * 
     * @return 联系人姓名，如果未找到则返回null
     * 
     * <p>查询流程：</p>
     * <ol>
     * <li>检查缓存中是否已存在该电话号码的联系人信息</li>
     * <li>如果缓存中存在，直接返回缓存的联系人姓名</li>
     * <li>如果缓存中不存在，构建查询条件</li>
     * <li>通过ContentResolver查询联系人Content Provider</li>
     * <li>如果查询成功，获取联系人姓名并缓存</li>
     * <li>关闭Cursor</li>
     * <li>返回查询结果</li>
     * </ol>
     * 
     * <p>错误处理：</p>
     * <ul>
     * <li>如果查询过程中发生IndexOutOfBoundsException，记录错误日志并返回null</li>
     * <li>如果未找到匹配的联系人，记录调试日志并返回null</li>
     * </ul>
     */
    public static String getContact(Context context, String phoneNumber) {
        if(sContactCache == null) {
            sContactCache = new HashMap<String, String>();
        }

        if(sContactCache.containsKey(phoneNumber)) {
            return sContactCache.get(phoneNumber);
        }

        String selection = CALLER_ID_SELECTION.replace("+",
                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
        Cursor cursor = context.getContentResolver().query(
                Data.CONTENT_URI,
                new String [] { Phone.DISPLAY_NAME },
                selection,
                new String[] { phoneNumber },
                null);

        if (cursor != null && cursor.moveToFirst()) {
            try {
                String name = cursor.getString(0);
                sContactCache.put(phoneNumber, name);
                return name;
            } catch (IndexOutOfBoundsException e) {
                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;
        }
    }
}