/*
 * 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 {
    /**
     * Contact - 联系人工具类
     * 功能：提供从手机通讯录中查询联系人名称的功能，并带有缓存机制
     *
     * 主要特性：
     * 1. 使用静态HashMap实现联系人缓存，避免重复查询
     * 2. 通过电话号码查询联系人显示名称
     * 3. 使用ContentResolver访问Android联系人数据库
     * 4. 包含错误处理和日志记录
     */
    private static HashMap<String, String> sContactCache;
    private static final String TAG = "Contact";

    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 = '+')";
    // 联系人查询的SQL选择条件
    public static String getContact(Context context, String phoneNumber) {
        /**
         * 根据电话号码获取联系人名称
         *
         * @param context Android上下文对象，用于获取ContentResolver
         * @param phoneNumber 要查询的电话号码
         * @return 联系人的显示名称，如果未找到则返回null
         *
         * 方法逻辑：
         * 1. 首先检查缓存中是否已有该号码对应的名称
         * 2. 若缓存中没有，则构建查询条件查询联系人数据库
         * 3. 查询成功则将结果存入缓存
         * 4. 处理可能的异常情况并记录日志
         */
        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;
        }
    }
}