<?php
/**
 * 信息流接口
 * 
 * @file      api_feed.php
 * @author    AI Assistant
 * @date      2026-04-12
 * @version   2.1.0
 * @desc      提供推荐流、最新流、热门流
 * @lastUpdate 2026-04-12 添加评分显示功能，更新字段名 rate_nums/rate_score
 */

$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');

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 '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'
                )
            ),
            'params' => array(
                'page' => '页码，默认1',
                'limit' => '每页数量，默认20，最大50',
                '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';
    
    $offset = ($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.rate_nums, 0) as rate_nums,
                      COALESCE(s.rate_score, 0) as rate_score
               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.rate_nums, 0) as rate_nums,
                         COALESCE(s.rate_score, 0) as rate_score
                  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.rate_nums, 0) as rate_nums,
                         COALESCE(s.rate_score, 0) as rate_score
                  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';
    
    $offset = ($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.rate_nums, 0) as rate_nums,
                   COALESCE(s.rate_score, 0) as rate_score
            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';
    
    $offset = ($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.rate_nums, 0) as rate_nums,
                       COALESCE(s.rate_score, 0) as rate_score
                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.rate_nums, 0) as rate_nums,
                       COALESCE(s.rate_score, 0) as rate_score
                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
        )
    );
}

/**
 * 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;
    }
    
    $cover = '';
    if (preg_match('/<img[^>]+src=["\']([^"\']+)["\']/i', $row['log_Intro'] ?? '', $matches)) {
        $cover = $matches[1];
    }
    
    return array(
        'id' => $recipeId,
        'pic_id' => $picIdCache[$recipeId],
        'title' => $row['log_Title'],
        'intro' => mb_substr(strip_tags($row['log_Intro'] ?? ''), 0, 100),
        'cover' => $cover,
        'category' => array(
            'id' => (int) ($row['log_CateID'] ?? 0),
            'name' => $row['cate_Name'] ?? ''
        ),
        'statistics' => array(
            'view' => (int) ($row['log_ViewNums'] ?? 0),
            'like' => (int) ($row['like_nums'] ?? 0),
            'rate_count' => (int) ($row['rate_nums'] ?? 0),
            'rate_score' => (float) ($row['rate_score'] ?? 0)
        ),
        'rating' => ApiResponse::getRatingSummary(
            (float) ($row['rate_score'] ?? 0),
            (int) ($row['rate_nums'] ?? 0)
        ),
        'source' => $source,
        'publish_time' => $row['log_PostTime'] ?? ''
    );
}