// 推荐产品: 根据相同tag来推荐产品，一共8个；不足的话就选择同分类下的随机
$tag_string = $product['tag'];
$tag_arr = explode(',', $tag_string);


$all_res = Db::table('yg_product')->select();
$related_arr = array();
$related_id_arr = array();
for($i=0; $i<count($all_res); $i++){
    if($all_res[$i]['id'] == $id){
        continue;
    }
    $t_string = $all_res[$i]['tag'];
    $t_arr = explode(',', $t_string);


    $res_arr = array_intersect($tag_arr,$t_arr);
    if(count($res_arr)>0){
        array_push($related_arr, $all_res[$i]);
        array_push($related_id_arr, $all_res[$i]['id']);
    }
}


// 如果相同tag标签的产品数量不足8个，则获取同分类下的产品
if(count($related_id_arr) < 8){
    $need_num = 8 - count($related_id_arr);
    $same_cate_res = Db::table('yg_product')
        ->where('procatelog_id', $product['procatelog_id'])
        ->where('id','not in',$related_id_arr)->limit($need_num)->select();
    $related_arr = array_merge($related_arr, $same_cate_res);
}else if(count($related_id_arr) > 8){
    $related_arr = array_slice($related_arr,0,8);
}

$this->assign([
    'product'=>$product,
    'related_arr'=>$related_arr,
]);