/*
 * 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.tool;

import android.content.Context;
import android.content.SharedPreferences;
import android.text.TextUtils;
import android.util.Log;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * SearchHistoryManager - 搜索历史记录管理类
 * 使用SharedPreferences存储搜索历史记录
 */
public class SearchHistoryManager {
    private static final String TAG = "SearchHistoryManager";
    
    // SharedPreferences文件名
    private static final String PREFERENCE_NAME = "search_history";
    
    // 搜索历史键
    private static final String KEY_SEARCH_HISTORY = "search_history";
    
    // 最大历史记录数量
    private static final int MAX_HISTORY_COUNT = 10;
    
    // 单例实例
    private static SearchHistoryManager sInstance;
    
    // SharedPreferences实例
    private SharedPreferences mSharedPreferences;
    
    /**
     * 私有构造函数
     * @param context 上下文
     */
    private SearchHistoryManager(Context context) {
        mSharedPreferences = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
    }
    
    /**
     * 获取单例实例
     * @param context 上下文
     * @return SearchHistoryManager实例
     */
    public static synchronized SearchHistoryManager getInstance(Context context) {
        if (sInstance == null) {
            sInstance = new SearchHistoryManager(context.getApplicationContext());
        }
        return sInstance;
    }
    
    /**
     * 保存搜索关键词到历史记录
     * @param keyword 搜索关键词
     */
    public void saveSearchKeyword(String keyword) {
        if (TextUtils.isEmpty(keyword)) {
            return;
        }
        
        // 获取现有历史记录
        List<String> historyList = getSearchHistoryList();
        
        // 如果已存在，移除旧的位置
        if (historyList.contains(keyword)) {
            historyList.remove(keyword);
        }
        
        // 添加到最前面
        historyList.add(0, keyword);
        
        // 限制历史记录数量
        if (historyList.size() > MAX_HISTORY_COUNT) {
            historyList = historyList.subList(0, MAX_HISTORY_COUNT);
        }
        
        // 保存到SharedPreferences
        saveHistoryList(historyList);
    }
    
    /**
     * 获取搜索历史记录列表
     * @return 搜索历史记录列表
     */
    public List<String> getSearchHistoryList() {
        List<String> historyList = new ArrayList<>();
        
        try {
            String historyJson = mSharedPreferences.getString(KEY_SEARCH_HISTORY, "[]");
            JSONArray jsonArray = new JSONArray(historyJson);
            
            for (int i = 0; i < jsonArray.length(); i++) {
                historyList.add(jsonArray.getString(i));
            }
        } catch (JSONException e) {
            Log.e(TAG, "Failed to parse search history: " + e.getMessage());
        }
        
        return historyList;
    }
    
    /**
     * 清除所有搜索历史记录
     */
    public void clearSearchHistory() {
        mSharedPreferences.edit().remove(KEY_SEARCH_HISTORY).apply();
    }
    
    /**
     * 保存历史记录列表到SharedPreferences
     * @param historyList 历史记录列表
     */
    private void saveHistoryList(List<String> historyList) {
        try {
            JSONArray jsonArray = new JSONArray(historyList);
            mSharedPreferences.edit().putString(KEY_SEARCH_HISTORY, jsonArray.toString()).apply();
        } catch (Exception e) {
            Log.e(TAG, "Failed to save search history: " + e.getMessage());
        }
    }
}