<?php
/**
 * 📱 信息流接口
 * 
 * 支持多种信息流类型：
 * - recommend: 推荐流（热门+最新+随机混合）
 * - latest: 最新发布
 * - hot: 热门排行
 * - follow: 关注动态（需要用户ID）
 * 
 * 性能优化：支持缓存、Stale模式、多格式输出
 */

$startTime = microtime(true);

define('ZBP_HOOKERROR', false);
require '../zb_system/function/c_system_base.php';
$zbp->Load();

require_once 'cache.php';
require_once 'response.php';

header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, POST, OPTIONS');
header('Cache-Control: public, max-age=300');

$act = strtolower(trim($_GET['act'] ?? 'feed'));
$format = ApiResponse::getFormat();

$forceRefresh = isset($_GET['_refresh']) && $_GET['_refresh'] === '1';
$staleMode = isset($_GET['_stale']) && $_GET['_stale'] === '1';

$cacheableActs = array('feed', 'recommend', 'latest', 'hot', 'personal');

if (in_array($act, $cacheableActs) && !$forceRefresh) {
    $cacheParams = $_GET;
    unset($cacheParams['act']);
    unset($cacheParams['_refresh']);
    unset($cacheParams['_stale']);
    unset($cacheParams['_format']);
    unset($cacheParams['_pretty']);
    
    $cachedResult = ApiCache::get('feed', $cacheParams);
    if ($cachedResult !== null) {
        header('X-Cache: HIT');
        $cachedResult['_cached'] = true;
        $cachedResult['_cache_age'] = ApiCache::getCacheAge('feed', $cacheParams);
        $cachedResult['_query_time'] = round((microtime(true) - $startTime) * 1000, 2) . 'ms';
        ApiResponse::output($cachedResult, $format);
        exit;
    }
    
    if ($staleMode || isset($_SERVER['HTTP_X_STALE_CACHE'])) {
        $staleResult = ApiCache::getStale('feed', $cacheParams);
        if ($staleResult !== null) {
            header('X-Cache: STALE');
            $staleResult['_cached'] = true;
            $staleResult['_stale'] = true;
            $staleResult['_cache_age'] = ApiCache::getCacheAge('feed', $cacheParams);
            $staleResult['_query_time'] = round((microtime(true) - $startTime) * 1000, 2) . 'ms';
            ApiResponse::output($staleResult, $format);
            exit;
        }
    }
}

header('X-Cache: MISS');

$result = array();

switch ($act) {
    case 'feed':
    case 'recommend':
        $result = get_recommend_feed();
        break;
    case 'latest':
        $result = get_latest_feed();
        break;
    case 'hot':
        $result = get_hot_feed();
        break;
    case 'personal':
        $result = get_personal_feed();
        break;
    case 'prefetch':
        $result = get_prefetch_feed();
        break;
    case 'index':
    default:
        $result = get_feed_index();
        break;
}

if (in_array($act, $cacheableActs) && $result['code'] === 200) {
    $cacheParams = $_GET;
    unset($cacheParams['act']);
    unset($cacheParams['_format']);
    unset($cacheParams['_pretty']);
    ApiCache::set('feed', $cacheParams, $result);
}

$result['_query_time'] = round((microtime(true) - $startTime) * 1000, 2) . 'ms';

ApiResponse::output($result, $format);
exit;

/**
 * 信息流接口索引
 */
function get_feed_index() {
    return array(
        'code' => 200,
        'message' => 'success',
        'data' => array(
            'description' => '信息流接口',
            'types' => array(
                array(
                    'type' => 'recommend',
                    'name' => '推荐流',
                    'description' => '热门+最新+随机混合推荐',
                    'example' => '?act=recommend&page=1'
                ),
                array(
                    'type' => 'latest',
                    'name' => '最新流',
                    'description' => '按发布时间排序',
                    'example' => '?act=latest&page=1'
                ),
                array(
                    'type' => 'hot',
                    'name' => '热门流',
                    'description' => '按浏览量排序',
                    'example' => '?act=hot&page=1'
                ),
                array(
                    'type' => 'personal',
                    'name' => '个性化流',
                    'description' => '基于用户偏好推荐',
                    'example' => '?act=personal&user_id=xxx'
                ),
                array(
                    'type' => 'prefetch',
                    'name' => '预加载',
                    'description' => '预加载下一页数据',
                    'example' => '?act=prefetch&pages=3'
                )
            ),
            'params' => array(
                'page' => '页码，默认1',
                'limit' => '每页数量，默认20，最大50',
                'user_id' => '用户ID（个性化流必填）',
                'cate_id' => '分类筛选',
                'exclude' => '排除已读ID，逗号分隔'
            )
        )
    );
}

/**
 * 推荐信息流（混合推荐）
 */
function get_recommend_feed() {
    global $zbp;
    
    $page = (int) ($_GET['page'] ?? 1);
    $limit = (int) ($_GET['limit'] ?? 20);
    $cateId = (int) ($_GET['cate_id'] ?? 0);
    $excludeIds = isset($_GET['exclude']) ? array_map('intval', explode(',', $_GET['exclude'])) : array();
    
    if ($limit > 50) $limit = 50;
    if ($limit < 1) $limit = 20;
    if ($page < 1) $page = 1;
    
    $tablePost = $zbp->db->dbpre . 'post';
    $tableCategory = $zbp->db->dbpre . 'category';
    $tablePostStat = $zbp->db->dbpre . 'post_stat';
    $tableRecipeIdMap = $zbp->db->dbpre . 'recipe_id_map';
    
    $offset = ($page - 1) * $limit;
    
    $whereSql = "WHERE p.log_Type = 0 AND p.log_Status = 0";
    if ($cateId > 0) {
        $whereSql .= " AND p.log_CateID = $cateId";
    }
    if (!empty($excludeIds)) {
        $excludeList = implode(',', $excludeIds);
        $whereSql .= " AND p.log_ID NOT IN ($excludeList)";
    }
    
    $hotLimit = (int) ($limit * 0.4);
    $latestLimit = (int) ($limit * 0.4);
    $randomLimit = $limit - $hotLimit - $latestLimit;
    
    $hotItems = array();
    $hotSql = "SELECT p.log_ID, p.log_Title, p.log_Intro, p.log_CateID, p.log_PostTime, 
                      p.log_ViewNums, c.cate_Name,
                      COALESCE(s.like_nums, 0) as like_nums,
                      COALESCE(s.recommend_nums, 0) as recommend_nums
               FROM $tablePost p
               LEFT JOIN $tableCategory c ON p.log_CateID = c.cate_ID
               LEFT JOIN $tablePostStat s ON p.log_ID = s.log_id
               $whereSql
               ORDER BY p.log_ViewNums DESC
               LIMIT $hotLimit";
    $hotResults = $zbp->db->Query($hotSql);
    foreach ($hotResults as $row) {
        $hotItems[] = format_feed_item($row, 'hot');
    }
    
    $latestItems = array();
    $latestSql = "SELECT p.log_ID, p.log_Title, p.log_Intro, p.log_CateID, p.log_PostTime,
                         p.log_ViewNums, c.cate_Name,
                         COALESCE(s.like_nums, 0) as like_nums,
                         COALESCE(s.recommend_nums, 0) as recommend_nums
                  FROM $tablePost p
                  LEFT JOIN $tableCategory c ON p.log_CateID = c.cate_ID
                  LEFT JOIN $tablePostStat s ON p.log_ID = s.log_id
                  $whereSql
                  ORDER BY p.log_PostTime DESC
                  LIMIT $latestLimit";
    $latestResults = $zbp->db->Query($latestSql);
    foreach ($latestResults as $row) {
        $latestItems[] = format_feed_item($row, 'latest');
    }
    
    $randomItems = array();
    $randomSql = "SELECT p.log_ID, p.log_Title, p.log_Intro, p.log_CateID, p.log_PostTime,
                         p.log_ViewNums, c.cate_Name,
                         COALESCE(s.like_nums, 0) as like_nums,
                         COALESCE(s.recommend_nums, 0) as recommend_nums
                  FROM $tablePost p
                  LEFT JOIN $tableCategory c ON p.log_CateID = c.cate_ID
                  LEFT JOIN $tablePostStat s ON p.log_ID = s.log_id
                  $whereSql
                  ORDER BY RAND()
                  LIMIT $randomLimit";
    $randomResults = $zbp->db->Query($randomSql);
    foreach ($randomResults as $row) {
        $randomItems[] = format_feed_item($row, 'random');
    }
    
    $allItems = array_merge($hotItems, $latestItems, $randomItems);
    shuffle($allItems);
    
    $countSql = "SELECT COUNT(*) as total FROM $tablePost p $whereSql";
    $countResult = $zbp->db->Query($countSql);
    $total = (int) ($countResult[0]['total'] ?? 0);
    
    return array(
        'code' => 200,
        'message' => 'success',
        'data' => array(
            'type' => 'recommend',
            'list' => $allItems,
            'page' => $page,
            'limit' => $limit,
            'total' => $total,
            'has_more' => ($page * $limit) < $total,
            'mix_ratio' => array(
                'hot' => $hotLimit,
                'latest' => $latestLimit,
                'random' => $randomLimit
            )
        )
    );
}

/**
 * 最新信息流
 */
function get_latest_feed() {
    global $zbp;
    
    $page = (int) ($_GET['page'] ?? 1);
    $limit = (int) ($_GET['limit'] ?? 20);
    $cateId = (int) ($_GET['cate_id'] ?? 0);
    $excludeIds = isset($_GET['exclude']) ? array_map('intval', explode(',', $_GET['exclude'])) : array();
    
    if ($limit > 50) $limit = 50;
    if ($limit < 1) $limit = 20;
    
    $tablePost = $zbp->db->dbpre . 'post';
    $tableCategory = $zbp->db->dbpre . 'category';
    $tablePostStat = $zbp->db->dbpre . 'post_stat';
    $tableRecipeIdMap = $zbp->db->dbpre . 'recipe_id_map';
    
    $offset = ($page - 1) * $limit;
    
    $whereSql = "WHERE p.log_Type = 0 AND p.log_Status = 0";
    if ($cateId > 0) {
        $whereSql .= " AND p.log_CateID = $cateId";
    }
    if (!empty($excludeIds)) {
        $excludeList = implode(',', $excludeIds);
        $whereSql .= " AND p.log_ID NOT IN ($excludeList)";
    }
    
    $sql = "SELECT p.log_ID, p.log_Title, p.log_Intro, p.log_CateID, p.log_PostTime,
                   p.log_ViewNums, c.cate_Name,
                   COALESCE(s.like_nums, 0) as like_nums,
                   COALESCE(s.recommend_nums, 0) as recommend_nums
            FROM $tablePost p
            LEFT JOIN $tableCategory c ON p.log_CateID = c.cate_ID
            LEFT JOIN $tablePostStat s ON p.log_ID = s.log_id
            $whereSql
            ORDER BY p.log_PostTime DESC
            LIMIT $offset, $limit";
    
    $results = $zbp->db->Query($sql);
    
    $list = array();
    foreach ($results as $row) {
        $list[] = format_feed_item($row, 'latest');
    }
    
    $countSql = "SELECT COUNT(*) as total FROM $tablePost p $whereSql";
    $countResult = $zbp->db->Query($countSql);
    $total = (int) ($countResult[0]['total'] ?? 0);
    
    return array(
        'code' => 200,
        'message' => 'success',
        'data' => array(
            'type' => 'latest',
            'list' => $list,
            'page' => $page,
            'limit' => $limit,
            'total' => $total,
            'has_more' => ($page * $limit) < $total
        )
    );
}

/**
 * 热门信息流
 */
function get_hot_feed() {
    global $zbp;
    
    $page = (int) ($_GET['page'] ?? 1);
    $limit = (int) ($_GET['limit'] ?? 20);
    $cateId = (int) ($_GET['cate_id'] ?? 0);
    $period = trim($_GET['period'] ?? 'total');
    
    if ($limit > 50) $limit = 50;
    if ($limit < 1) $limit = 20;
    
    $tablePost = $zbp->db->dbpre . 'post';
    $tableCategory = $zbp->db->dbpre . 'category';
    $tablePostStat = $zbp->db->dbpre . 'post_stat';
    $tableStatLog = $zbp->db->dbpre . 'recipe_stat_log';
    $tableRecipeIdMap = $zbp->db->dbpre . 'recipe_id_map';
    
    $offset = ($page - 1) * $limit;
    
    $whereSql = "WHERE p.log_Type = 0 AND p.log_Status = 0";
    if ($cateId > 0) {
        $whereSql .= " AND p.log_CateID = $cateId";
    }
    
    $orderBy = 'p.log_ViewNums DESC';
    if ($period === 'today') {
        $today = date('Y-m-d');
        $sql = "SELECT p.log_ID, p.log_Title, p.log_Intro, p.log_CateID, p.log_PostTime,
                       p.log_ViewNums, c.cate_Name, l.view_count,
                       COALESCE(s.like_nums, 0) as like_nums,
                       COALESCE(s.recommend_nums, 0) as recommend_nums
                FROM $tableStatLog l
                INNER JOIN $tablePost p ON l.log_id = p.log_ID
                LEFT JOIN $tableCategory c ON p.log_CateID = c.cate_ID
                LEFT JOIN $tablePostStat s ON p.log_ID = s.log_id
                WHERE l.stat_date = '$today' AND p.log_Type = 0 AND p.log_Status = 0
                ORDER BY l.view_count DESC
                LIMIT $offset, $limit";
    } else {
        $sql = "SELECT p.log_ID, p.log_Title, p.log_Intro, p.log_CateID, p.log_PostTime,
                       p.log_ViewNums, c.cate_Name,
                       COALESCE(s.like_nums, 0) as like_nums,
                       COALESCE(s.recommend_nums, 0) as recommend_nums
                FROM $tablePost p
                LEFT JOIN $tableCategory c ON p.log_CateID = c.cate_ID
                LEFT JOIN $tablePostStat s ON p.log_ID = s.log_id
                $whereSql
                ORDER BY $orderBy
                LIMIT $offset, $limit";
    }
    
    $results = $zbp->db->Query($sql);
    
    $list = array();
    foreach ($results as $row) {
        $list[] = format_feed_item($row, 'hot');
    }
    
    return array(
        'code' => 200,
        'message' => 'success',
        'data' => array(
            'type' => 'hot',
            'period' => $period,
            'list' => $list,
            'page' => $page,
            'limit' => $limit,
            'has_more' => count($list) >= $limit
        )
    );
}

/**
 * 个性化信息流 - 智能推荐算法
 */
function get_personal_feed() {
    global $zbp;
    
    $userId = trim($_GET['user_id'] ?? '');
    $page = (int) ($_GET['page'] ?? 1);
    $limit = (int) ($_GET['limit'] ?? 20);
    $debug = isset($_GET['_debug']) && $_GET['_debug'] === '1';
    
    if (empty($userId)) {
        return array('code' => 400, 'message' => '缺少用户ID参数');
    }
    
    if ($limit > 50) $limit = 50;
    if ($limit < 1) $limit = 20;
    
    $preference = load_user_preference_data($userId);
    $preferredTags = $preference['preferred_tags'] ?? array();
    $preferredCategories = $preference['preferred_categories'] ?? array();
    $blockedAllergens = $preference['blocked_allergens'] ?? array();
    
    $viewHistory = load_user_view_history($userId);
    $categoryViewCount = $viewHistory['categories'] ?? array();
    
    $adminRecommend = get_admin_recommend_config();
    $topCategories = $adminRecommend['top_categories'] ?? array();
    $recommendCategories = $adminRecommend['recommend_categories'] ?? array();
    
    $tablePost = $zbp->db->dbpre . 'post';
    $tableCategory = $zbp->db->dbpre . 'category';
    $tablePostStat = $zbp->db->dbpre . 'post_stat';
    $tableIngredient = $zbp->db->dbpre . 'recipe_ingredient';
    $tableRecipeIdMap = $zbp->db->dbpre . 'recipe_id_map';
    
    $fetchLimit = $limit * 5;
    $sql = "SELECT p.log_ID, p.log_Title, p.log_Intro, p.log_CateID, p.log_PostTime, p.log_Tag,
                   p.log_ViewNums, c.cate_Name,
                   COALESCE(s.like_nums, 0) as like_nums,
                   COALESCE(s.recommend_nums, 0) as recommend_nums
            FROM $tablePost p
            LEFT JOIN $tableCategory c ON p.log_CateID = c.cate_ID
            LEFT JOIN $tablePostStat s ON p.log_ID = s.log_id
            WHERE p.log_Type = 0 AND p.log_Status = 0
            ORDER BY p.log_PostTime DESC
            LIMIT $fetchLimit";
    
    $results = $zbp->db->Query($sql);
    
    $scoredItems = array();
    foreach ($results as $row) {
        $itemId = (int) $row['log_ID'];
        $cateId = (int) $row['log_CateID'];
        
        if (!empty($blockedAllergens)) {
            $hasAllergen = check_item_allergen($itemId, $blockedAllergens);
            if ($hasAllergen) {
                continue;
            }
        }
        
        $score = calculate_item_score(
            $row,
            $preferredTags,
            $preferredCategories,
            $categoryViewCount,
            $topCategories,
            $recommendCategories
        );
        
        $item = format_feed_item($row, 'personal');
        $item['_score'] = $score;
        $item['_score_detail'] = $debug ? get_score_detail(
            $row,
            $preferredTags,
            $preferredCategories,
            $categoryViewCount,
            $topCategories,
            $recommendCategories
        ) : null;
        
        $scoredItems[] = $item;
    }
    
    usort($scoredItems, function($a, $b) {
        return $b['_score'] <=> $a['_score'];
    });
    
    $offset = ($page - 1) * $limit;
    $list = array_slice($scoredItems, $offset, $limit);
    
    foreach ($list as &$item) {
        unset($item['_score']);
        if (!$debug) {
            unset($item['_score_detail']);
        }
    }
    
    return array(
        'code' => 200,
        'message' => 'success',
        'data' => array(
            'type' => 'personal',
            'user_id' => $userId,
            'list' => $list,
            'page' => $page,
            'limit' => $limit,
            'total' => count($scoredItems),
            'has_more' => ($page * $limit) < count($scoredItems),
            'preference' => array(
                'tags' => count($preferredTags),
                'categories' => count($preferredCategories),
                'blocked_allergens' => count($blockedAllergens),
                'view_history_categories' => count($categoryViewCount)
            ),
            'admin_config' => array(
                'top_categories' => count($topCategories),
                'recommend_categories' => count($recommendCategories)
            )
        )
    );
}

/**
 * 加载用户偏好数据
 */
function load_user_preference_data($userId) {
    $cacheFile = sys_get_temp_dir() . '/user_preference_' . md5($userId) . '.json';
    
    if (file_exists($cacheFile)) {
        $data = json_decode(file_get_contents($cacheFile), true);
        if ($data && isset($data['expire_time']) && $data['expire_time'] > time()) {
            return $data;
        }
    }
    
    return array(
        'user_id' => $userId,
        'preferred_tags' => array(),
        'preferred_categories' => array(),
        'blocked_allergens' => array(),
        'expire_time' => time() + 86400
    );
}

/**
 * 计算内容评分
 */
function calculate_item_score($row, $preferredTags, $preferredCategories, $categoryViewCount, $topCategories, $recommendCategories) {
    $score = 0;
    $cateId = (int) $row['log_CateID'];
    $tagStr = $row['log_Tag'] ?? '';
    
    if (in_array($cateId, $topCategories)) {
        $score += 50;
    } elseif (in_array($cateId, $recommendCategories)) {
        $score += 30;
    }
    
    if (in_array($cateId, $preferredCategories)) {
        $score += 25;
    }
    
    if (!empty($preferredTags) && !empty($tagStr)) {
        $tagIds = explode(',', $tagStr);
        $matchedTags = array_intersect($tagIds, $preferredTags);
        $score += count($matchedTags) * 30;
    }
    
    if (isset($categoryViewCount[$cateId])) {
        $viewWeight = min($categoryViewCount[$cateId] * 5, 20);
        $score += $viewWeight;
    }
    
    $viewScore = min(floor(($row['log_ViewNums'] ?? 0) / 100), 20);
    $score += $viewScore;
    
    $likeScore = min(($row['like_nums'] ?? 0) * 2, 15);
    $score += $likeScore;
    
    $recommendScore = min(($row['recommend_nums'] ?? 0) * 3, 15);
    $score += $recommendScore;
    
    $postTime = strtotime($row['log_PostTime']);
    if ($postTime) {
        $daysAgo = (time() - $postTime) / 86400;
        if ($daysAgo < 1) {
            $score += 15;
        } elseif ($daysAgo < 7) {
            $score += 10;
        } elseif ($daysAgo < 30) {
            $score += 5;
        }
    }
    
    return $score;
}

/**
 * 获取评分详情（调试用）
 */
function get_score_detail($row, $preferredTags, $preferredCategories, $categoryViewCount, $topCategories, $recommendCategories) {
    $cateId = (int) $row['log_CateID'];
    $tagStr = $row['log_Tag'] ?? '';
    
    $detail = array(
        'admin_top' => in_array($cateId, $topCategories) ? 50 : 0,
        'admin_recommend' => in_array($cateId, $recommendCategories) ? 30 : 0,
        'preferred_category' => in_array($cateId, $preferredCategories) ? 25 : 0,
        'preferred_tags' => 0,
        'view_history' => isset($categoryViewCount[$cateId]) ? min($categoryViewCount[$cateId] * 5, 20) : 0,
        'hot_view' => min(floor(($row['log_ViewNums'] ?? 0) / 100), 20),
        'hot_like' => min(($row['like_nums'] ?? 0) * 2, 15),
        'hot_recommend' => min(($row['recommend_nums'] ?? 0) * 3, 15),
        'time_bonus' => 0
    );
    
    if (!empty($preferredTags) && !empty($tagStr)) {
        $tagIds = explode(',', $tagStr);
        $matchedTags = array_intersect($tagIds, $preferredTags);
        $detail['preferred_tags'] = count($matchedTags) * 30;
    }
    
    $postTime = strtotime($row['log_PostTime']);
    if ($postTime) {
        $daysAgo = (time() - $postTime) / 86400;
        if ($daysAgo < 1) {
            $detail['time_bonus'] = 15;
        } elseif ($daysAgo < 7) {
            $detail['time_bonus'] = 10;
        } elseif ($daysAgo < 30) {
            $detail['time_bonus'] = 5;
        }
    }
    
    $detail['total'] = array_sum($detail);
    return $detail;
}

/**
 * 检查内容是否包含过敏原
 */
function check_item_allergen($itemId, $blockedAllergens) {
    global $zbp;
    
    $tableIngredient = $zbp->db->dbpre . 'recipe_ingredient';
    
    $allergenMap = array(
        'nuts' => array('核桃', '杏仁', '腰果', '榛子', '松子', '开心果', '栗子', '花生'),
        'seafood' => array('鱼', '虾', '蟹', '贝', '海参', '鲍鱼', '扇贝'),
        'dairy' => array('牛奶', '奶粉', '奶酪', '奶油', '酸奶', '黄油'),
        'eggs' => array('鸡蛋', '鸭蛋', '鹅蛋', '鸽蛋', '鹌鹑蛋'),
        'grains' => array('小麦', '面粉', '面包', '面条'),
        'beans' => array('黄豆', '绿豆', '红豆', '蚕豆', '豌豆'),
        'meat' => array('猪肉', '牛肉', '羊肉', '鸡肉', '鸭肉', '鹅肉'),
        'fruits' => array('桃', '芒果', '菠萝', '草莓', '猕猴桃'),
        'vegetables' => array('芹菜', '茄子', '韭菜', '香菜', '姜', '蒜'),
        'mushrooms' => array('香菇', '金针菇', '木耳', '银耳'),
        'seasonings' => array('胡椒', '花椒', '芥末', '味精', '料酒'),
        'other' => array('蜂蜜', '巧克力', '可可', '芝麻')
    );
    
    $checkIngredients = array();
    foreach ($blockedAllergens as $allergenType) {
        if (isset($allergenMap[$allergenType])) {
            $checkIngredients = array_merge($checkIngredients, $allergenMap[$allergenType]);
        }
    }
    
    if (empty($checkIngredients)) {
        return false;
    }
    
    $ingredientList = array_map(function($item) use ($zbp) {
        return "'" . $zbp->db->EscapeString($item) . "'";
    }, $checkIngredients);
    $ingredientStr = implode(',', $ingredientList);
    
    $sql = "SELECT COUNT(*) as cnt FROM $tableIngredient 
            WHERE log_id = $itemId AND ingredient_name IN ($ingredientStr)";
    
    $result = $zbp->db->Query($sql);
    return (int) ($result[0]['cnt'] ?? 0) > 0;
}

/**
 * 加载用户浏览历史
 */
function load_user_view_history($userId) {
    $cacheFile = sys_get_temp_dir() . '/user_view_history_' . md5($userId) . '.json';
    
    if (file_exists($cacheFile)) {
        $data = json_decode(file_get_contents($cacheFile), true);
        if ($data && isset($data['expire_time']) && $data['expire_time'] > time()) {
            return $data;
        }
    }
    
    return array(
        'categories' => array(),
        'tags' => array(),
        'recent_views' => array(),
        'expire_time' => time() + 86400
    );
}

/**
 * 获取管理员推荐配置
 */
function get_admin_recommend_config() {
    $configFile = dirname(__FILE__) . '/config/admin_recommend.json';
    
    if (file_exists($configFile)) {
        $data = json_decode(file_get_contents($configFile), true);
        if ($data) {
            return array(
                'top_categories' => $data['top_categories'] ?? array(),
                'recommend_categories' => $data['recommend_categories'] ?? array(),
                'top_tags' => $data['top_tags'] ?? array(),
                'expire_time' => time() + 3600
            );
        }
    }
    
    $cacheFile = sys_get_temp_dir() . '/admin_recommend_config.json';
    
    if (file_exists($cacheFile)) {
        $data = json_decode(file_get_contents($cacheFile), true);
        if ($data && isset($data['expire_time']) && $data['expire_time'] > time()) {
            return $data;
        }
    }
    
    return array(
        'top_categories' => array(),
        'recommend_categories' => array(),
        'top_tags' => array(),
        'expire_time' => time() + 3600
    );
}

/**
 * 预加载多页数据
 */
function get_prefetch_feed() {
    global $zbp;
    
    $pages = (int) ($_GET['pages'] ?? 3);
    $limit = (int) ($_GET['limit'] ?? 20);
    
    if ($pages > 5) $pages = 5;
    if ($pages < 1) $pages = 3;
    if ($limit > 30) $limit = 30;
    
    $allData = array();
    
    for ($i = 1; $i <= $pages; $i++) {
        $_GET['page'] = $i;
        $_GET['limit'] = $limit;
        $feedResult = get_recommend_feed();
        if ($feedResult['code'] === 200) {
            $allData['page_' . $i] = $feedResult['data'];
        }
    }
    
    return array(
        'code' => 200,
        'message' => 'success',
        'data' => array(
            'type' => 'prefetch',
            'pages' => $pages,
            'items_per_page' => $limit,
            'total_items' => $pages * $limit,
            'pages_data' => $allData
        )
    );
}

/**
 * 格式化信息流项目
 */
function format_feed_item($row, $source = 'unknown') {
    global $zbp;
    
    static $picIdCache = array();
    $recipeId = (int) $row['log_ID'];
    
    if (!isset($picIdCache[$recipeId])) {
        $tableRecipeIdMap = $zbp->db->dbpre . 'recipe_id_map';
        $idMapSql = "SELECT old_id FROM $tableRecipeIdMap WHERE new_log_id = $recipeId LIMIT 1";
        $idMapResult = $zbp->db->Query($idMapSql);
        $picIdCache[$recipeId] = !empty($idMapResult) ? (int) $idMapResult[0]['old_id'] : null;
    }
    
    $publishTime = strtotime($row['log_PostTime']);
    return array(
        'id' => $recipeId,
        'pic_id' => $picIdCache[$recipeId],
        'title' => $row['log_Title'],
        'intro' => mb_substr(strip_tags($row['log_Intro'] ?? ''), 0, 100),
        'category' => array(
            'id' => (int) ($row['log_CateID'] ?? 0),
            'name' => $row['cate_Name'] ?? ''
        ),
        'statistics' => array(
            'view_count' => (int) ($row['log_ViewNums'] ?? 0),
            'like_count' => (int) ($row['like_nums'] ?? 0),
            'recommend_count' => (int) ($row['recommend_nums'] ?? 0)
        ),
        'publish_time' => $publishTime !== false ? $publishTime : null,
        'source' => $source,
        'url' => '?id=' . $row['log_ID']
    );
}