<?php

/**
 * 论坛类
 */
class bbs
{
    /** 下沉帖子操作 */
    const ACTION_SINK_TOPIC = 1;

    /**
     * 用户对象
     */
    protected $user;
    protected $db;

    /**
     * 初始化
     *
     * 参数：用户对象（可空）
     */
    public function __construct($user = null)
    {
        if (!is_object($user) or !$user->islogin)
            $this->user = new user;
        else
            $this->user = $user;
        $this->db = new db;
    }

    /**
     * 检查用户是否登录
     */
    protected function checkLogin()
    {
        if ($this->user->islogin)
            return true;
        else
            throw new bbsException('用户未登录或掉线，请先登录。', 401);
    }

    /**
     * 检查用户是否可编辑
     */
    public function canEdit($ownUid, $noException = false)
    {
        try {
            $this->checkLogin();

            if ($this->user->uid == $ownUid || $this->user->hasPermission(User::PERMISSION_EDIT_TOPIC)) {
                return true;
            } else {
                throw new bbsException('您没有权限编辑当前楼层。', 403);
            }
        } catch (Exception $e) {
            if ($noException) {
                return false;
            } else {
                throw $e;
            }
        }
    }

    /**
     * 检查用户是否可删除
     */
    public function canDel($ownUid, $noException = false)
    {
        try {
            $this->checkLogin();

            if ($this->user->uid == $ownUid || $this->user->hasPermission(User::PERMISSION_EDIT_TOPIC)) {
                return true;
            } else {
                throw new bbsException('您没有权限删除当前楼层。', 403);
            }
        } catch (Exception $e) {
            if ($noException) {
                return false;
            } else {
                throw $e;
            }
        }
    }

    /**
     * 检查用户是否可沉帖
     */
    public function canSink($ownUid, $noException = false)
    {
        try {
            $this->checkLogin();

            if ($this->user->uid == $ownUid || $this->user->hasPermission(User::PERMISSION_EDIT_TOPIC)) {
                return true;
            } else {
                throw new bbsException('您没有权限下沉该帖。', 403);
            }
        } catch (Exception $e) {
            if ($noException) {
                return false;
            } else {
                throw $e;
            }
        }
    }

    /**
     * 检查板块是否可以发帖
     */
    public function canCreateTopic($fid)
    {
        $sql = 'SELECT notopic FROM ' . DB_A . 'bbs_forum_meta WHERE id=?';
        $rs = $this->db->prepare($sql);
        $rs->execute([$fid]);

        if (!$rs) {
            return false;
        }

        if (!($data = $rs->fetch(db::num))) {
            return false;
        }

        return 0 == $data[0];
    }

    /**
     * 发帖
     *
     * 参数：
     *     $fid        论坛id
     *     $title      帖子标题
     *     $content    帖子内容
     */
    public function newTopic($fid, $title, $content)
    {
        try {
            global $PAGE;
            $time = $_SERVER['REQUEST_TIME'];

            //发帖权限检查
            $this->checkLogin();

            //版块有效性检查
            $sql = 'SELECT id,name,notopic FROM ' . DB_A . 'bbs_forum_meta WHERE id=?';
            $rs = $this->db->prepare($sql);
            if (!$rs) throw new bbsException('数据库错误，论坛元数据表（' . DB_A . 'bbs_forum_meta）异常！', 500);
            $rs->bindParam(1, $fid);
            $rs->execute();
            $data = $rs->fetch();
            if (!$data)
                throw new bbsException('版块id' . $fid . '不存在，请重新选择。', 404);
            if ($data['notopic'])
                throw new bbsException('版块 ' . $data['name'] . ' 禁止发帖，请重新选择。', 403);

            //标题处理
            $title = mb_substr(trim($title), 0, 50, 'utf-8');
            //内容处理
            $ubb = new ubbparser;
            $data = $ubb->parse($content, true);
            //写主题数据
            $rs = $this->db->insert('bbs_topic_content', 'ctime,mtime,content,uid,topic_id,reply_id', $time, $time, $data, $this->user->uid, 0, 0);
            if (!$rs)
                throw new bbsException('数据库错误，主题内容（' . DB_A . 'bbs_topic_content）写入失败！', 500);
            $content_id = $this->db->lastInsertId();

            //写主题标题
            $rs = $this->db->insert('bbs_topic_meta', 'forum_id,content_id,title,uid,ctime,mtime', $fid, $content_id, $title, $this->user->uid, $time, $time);

            if (!$rs) {
                $this->db->delete('bbs_topic_content', 'WHERE id=?', $content_id);
                throw new bbsException('数据库错误，主题标题（' . DB_A . 'bbs_topic_meta）写入失败！', 500);
            }

            $topic_id = $this->db->lastInsertId();
            $this->db->update('bbs_topic_content', 'topic_id=? WHERE id=?', $topic_id, $content_id);

            //注册at消息
            $this->user->regAt("帖子“{$title}”中", "bbs.topic.{$topic_id}.{\$BID}", mb_substr($content, 0, 200, 'utf-8'));

            //更新发帖版块的改动时间
            $this->updateForumTime($fid);

            return $topic_id;
        } catch (exception $e) {
            throw $e;
        }
    }

    /*更新发帖版块及其父版块的改动时间*/
    protected function updateForumTime($fid)
    {
        $forums = $this->fatherForumMeta($fid, 'id');
        $sql = 'UPDATE ' . DB_A . 'bbs_forum_meta SET mtime=? WHERE id=?';
        $rs = $this->db->prepare($sql);
        $time = $_SERVER['REQUEST_TIME'];

        $rs->bindValue(1, $time);

        unset($forums[0]);

        foreach ($forums as $forum) {
            $rs->bindValue(2, $forum['id']);
            $rs->execute();
        }
    }

    /**
     * 新回复
     */
    public function newReply($reply_id, $content)
    {
        global $PAGE;

        $this->checkLogin();
        $data = $this->topicContent($reply_id, 'topic_id');
        if (!$data)
            throw new bbsException('帖子内容 id=' . $reply_id . ' 不存在！', 404);
        $topic_id = $data['topic_id'];
        //内容处理
        $ubb = new ubbparser;
        $data = $ubb->parse($content, true);
        //写回复数据
        $time = $_SERVER['REQUEST_TIME'];
        $floor = $this->db->query('SELECT max(floor) FROM ' . DB_A . 'bbs_topic_content WHERE topic_id=?', $topic_id);
        $floor = $floor->fetch(db::num);
        $rs = $this->db->insert('bbs_topic_content', 'ctime,mtime,content,uid,topic_id,reply_id,floor', $time, $time, $data, $this->user->uid, $topic_id, $reply_id, $floor[0] + 1);

        //注册at消息
        $topicTitle = $this->topicMeta($topic_id, 'title');
        $this->user->regAt("帖子“{$topicTitle['title']}”的回复中", "bbs.topic.{$topic_id}.{\$BID}", mb_substr($content, 0, 200, 'utf-8'));

        $sql = 'UPDATE ' . DB_A . 'bbs_topic_meta SET mtime=? WHERE id=?';
        $this->db->query($sql, $_SERVER['REQUEST_TIME'], $topic_id);

        return $rs ? true : false;
    }

    /**
     * 更改帖子标题
     */
    public function updateTopicTitle($topicId, $newTitle)
    {
        $title = mb_substr(trim($newTitle), 0, 50, 'utf-8');

        $sql = 'UPDATE ' . DB_A . 'bbs_topic_meta SET title=?,mtime=? WHERE id=?';

        $ok = $this->db->query($sql, $title, $_SERVER['REQUEST_TIME'], $topicId);

        if (!$ok) {
            throw new bbsException('修改失败，数据库错误');
        }
    }

    /**
     * 下沉帖子
     */
    public function sinkTopic($topicId)
    {
        $sql = 'UPDATE ' . DB_A . 'bbs_topic_meta SET level=? WHERE id=?';

        $ok = $this->db->query($sql, -1, $topicId);

        if (!$ok) {
            throw new bbsException('修改失败，数据库错误');
        }
    }

    /**
     * 删除帖子标题
     */
    public function deleteTopicTitle($topicId)
    {
        $title = '【管理员删除了该帖】';

        $sql = 'UPDATE ' . DB_A . 'bbs_topic_meta SET title=?,locked=?,level=? WHERE id=?';

        $ok = $this->db->query($sql, $title, 1, -1, $topicId);

        if (!$ok) {
            throw new bbsException('修改失败，数据库错误');
        }
    }

    /**
     * 更改帖子/回复内容
     */
    public function updateTopicContent($contentId, $newContent)
    {
        $ubb = new ubbparser;
        $data = is_array($newContent) ? serialize($newContent) : $ubb->parse($newContent, true);
        $sql = 'UPDATE ' . DB_A . 'bbs_topic_content SET content=?,mtime=? WHERE id=?';
        $ok = $this->db->query($sql, $data, $_SERVER['REQUEST_TIME'], $contentId);

        if (!$ok) {
            throw new bbsException('修改失败，数据库错误');
        }

        //若未修改，则部分服务器会报错，故注释
        /*if ($ok->rowCount() == 0) {
            throw new bbsException('修改失败，楼层不存在！');
        }*/

        $sql = 'UPDATE ' . DB_A . 'bbs_topic_meta SET mtime=? WHERE id = (SELECT topic_id FROM ' . DB_A . 'bbs_topic_content WHERE id=?)';
        $this->db->query($sql, $_SERVER['REQUEST_TIME'], $contentId);
    }

    /**
     * 删除帖子/回复内容
     */
    public function deleteTopicContent($contentId, $deleteNotice)
    {
        $ubb = new ubbparser;
        $data = is_array($deleteNotice) ? serialize($deleteNotice) : $ubb->parse($deleteNotice, true);
        $sql = 'UPDATE ' . DB_A . 'bbs_topic_content SET content=?,locked=? WHERE id=?';
        $ok = $this->db->query($sql, $data, 1, $contentId);

        if (!$ok) {
            throw new bbsException('删除失败，数据库错误');
        }
    }


    /**
     * 获取版块元信息
     */
    public function forumMeta($forum_id, $fetch = '*')
    {
        $rs = $this->db->select($fetch, 'bbs_forum_meta', 'WHERE id=?', $forum_id);
        if (!$rs)
            throw new bbsException('数据库错误，表' . DB_A . 'bbs_forum_meta不可读', 500);
        return $rs->fetch();
    }

    /**
     * 获取版块的子版块数量
     */
    public function childForumCount($forum_id)
    {
        $rs = $this->db->select('count(*)', 'bbs_forum_meta', 'WHERE parent_id=?', $forum_id);
        if (!$rs)
            throw new bbsException('数据库错误，表' . DB_A . 'bbs_forum_meta不可读', 500);
        $rs = $rs->fetch(db::num);
        return $rs[0];
    }

    /**
     * 获取子版块元信息
     *
     * level为0时递归获取所有子版块
     */
    public function childForumMeta($fid, $fetch = '*', $level = 1)
    {
        $fetch .= ',id';

        $rs = $this->db->select($fetch, 'bbs_forum_meta', 'WHERE parent_id=? ORDER BY mtime DESC', $fid);
        if (!$rs) throw new Exception('数据库错误，表' . DB_A . 'bbs_forum_meta不可读', 500);
        $forum = $rs->fetchAll();

        if ($level > 1 || $level == 0) {
            foreach ($forum as &$v) {
                $v['child'] = $this->childForumMeta($v['id'], $fetch, $level == 0 ? 0 : $level - 1);
            }
        }

        return $forum;
    }

    /**
     * 获取子版块id数组（递归获取所有子版块id，包括其自身）
     */
    public function childForumId($fid, &$result = [])
    {
        $result[] = (int)$fid;

        $rs = $this->db->select('id', 'bbs_forum_meta', 'WHERE parent_id=?', $fid);

        if (!$rs) {
            throw new Exception('数据库错误，表' . DB_A . 'bbs_forum_meta不可读', 500);
        }

        $forum = $rs->fetchAll(db::num);

        foreach ($forum as $v) {
            $this->childForumId($v[0], $result);
        }

        return $result;
    }

    /**
     * 获取逗号分隔的子版块id列表
     */
    protected function childForumIdList($fid)
    {
        return implode(',', $this->childForumId($fid));
    }

    /**
     * 获取父版块元信息
     */
    public function fatherForumMeta($fid, $fetch = '*')
    {
        $fetch .= ',parent_id';
        $fIndex = array();
        $parent_id = $fid;
        if ($fid == 0) { //id为0的是根节点
            return null;
        } else do {
            $meta = $this->forumMeta($parent_id, $fetch);
            $fIndex[] = $meta;
            if (!$meta)
                throw new bbsException('版块 id=' . $parent_id . ' 不存在！', 1404);
            $parent_id = $meta['parent_id'];
        } while ($parent_id != 0); //遍历到父版块是根节点时结束
        $fIndex[] = array(
            'id' => 0,
            'name' => '',
        );
        $fIndex = array_reverse($fIndex);
        return $fIndex;
    }

    public function newTopicList($size = 20, $offset = 0, $where = '')
    {
        $rs = $this->db->select('id as topic_id', 'bbs_topic_meta', $where . ' ORDER BY level DESC, mtime DESC LIMIT ?,?', $offset, $size);
        if (!$rs) throw new Exception('数据库错误，表' . DB_A . 'bbs_topic_meta不可读', 500);
        $topic = $rs->fetchAll();
        foreach ($topic as &$v) {
            $v += (array)$this->topicMeta($v['topic_id']);
            $v['uinfo'] = new userinfo;
            $v['uinfo']->uid($v['uid']);
        }
        return $topic;
    }

    public function newTopicForum($size = 10, $topicSize = 3)
    {
        $rs = $this->db->select('id,name', 'bbs_forum_meta', 'ORDER BY mtime DESC LIMIT ?', $size);
        if (!$rs) throw new Exception('数据库错误，表' . DB_A . 'bbs_forum_meta不可读', 500);
        $forum = $rs->fetchAll();
        foreach ($forum as &$v) {
            $v['topic_count'] = $this->topicCount($v['id']);
            $rs = $this->db->select('id as topic_id', 'bbs_topic_meta', 'WHERE forum_id=? ORDER BY level DESC, mtime DESC LIMIT ?', $v['id'], $topicSize);
            if (!$rs) throw new Exception('数据库错误，表' . DB_A . 'bbs_topic_meta不可读', 500);
            $v['topic'] = $rs->fetchAll();
            foreach ($v['topic'] as &$vt) {
                $vt += (array)$this->topicMeta($vt['topic_id']);
                $vt['uinfo'] = new userinfo;
                $vt['uinfo']->uid($vt['uid']);
            }
        }
        return $forum;
    }

    /**
     * 获取版块下的帖子总数
     */
    public function topicCount($forum_id)
    {
        if ($forum_id != 0) {
            $where = 'WHERE forum_id IN (' . $this->childForumIdList($forum_id) . ')';
        }

        $rs = $this->db->select('count(*)', 'bbs_topic_meta', $where);
        if (!$rs)
            throw new bbsException('数据库错误，表' . DB_A . 'bbs_topic_meta不可读', 500);
        $rs = $rs->fetch(db::num);
        return $rs[0];
    }

    /**
     * 获取版块下的帖子id
     */
    public function topicList($forum_id, $page, $size, $orderBy = 'mtime')
    {
        if ($forum_id != 0) {
            $where = 'WHERE `forum_id` IN (' . $this->childForumIdList($forum_id) . ') ';
        }

        $rs = $this->db->select('id as topic_id', 'bbs_topic_meta', $where . 'ORDER BY `level` DESC, `' . $orderBy . '` DESC LIMIT ?,?', $page, $size);

        if (!$rs)
            throw new bbsException('数据库错误，表' . DB_A . 'bbs_topic_meta不可读', 500);
        return $rs->fetchAll();
    }

    /**
     * 获取帖子所属的版块
     *
     * @return 数组，所属版块的列表，可能为空
     */
    public function findTopicForum($tid)
    {
        $rs = $this->db->select('forum_id', 'bbs_topic_meta', 'WHERE id=?', $tid);
        if (!$rs)
            throw new bbsException('数据库错误，表' . DB_A . 'bbs_topic_meta不可读', 500);
        $result = $rs->fetchAll(db::num);
        return array_column($result, 0);
    }

    /**
     * 获取帖子元信息
     */
    public function topicMeta($topic_id, $fetch = '*')
    {
        $rs = $this->db->select($fetch, 'bbs_topic_meta', 'WHERE id=?', $topic_id);
        if (!$rs)
            throw new bbsException('数据库错误，表' . DB_A . 'bbs_topic_meta不可读', 500);
        return $rs->fetch();
    }

    /**
     * 增加帖子点击数
     */
    public function addTopicReadCount($tid)
    {
        $this->db->update('bbs_topic_meta', 'read_count=read_count+1 WHERE id=?', $tid);
    }

    /**
     * 获取帖子内容
     */
    public function topicContent($content_id, $fetch = '*')
    {
        $rs = $this->db->select($fetch, 'bbs_topic_content', 'WHERE id=?', $content_id);
        if (!$rs)
            throw new bbsException('数据库错误，表' . DB_A . 'bbs_topic_content不可读', 500);
        return $rs->fetch();
    }

    /**
     * 获取帖子楼层的内容
     */
    public function topicContents($topic_id, $page, $size, $fetch = '*')
    {
        if ($size < 1)
            $size = 1;
        if ($page < 1)
            $page = 1;
        $offset = ($page - 1) * $size;

        if ($this->user && $this->user->islogin && false == $this->user->getInfo('bbs.floorReverse')) {
            //正序排列楼层
            $rs = $this->db->select($fetch, 'bbs_topic_content', 'WHERE topic_id=? ORDER BY floor ASC LIMIT ?,?', $topic_id, $offset, $size);
            if (!$rs)
                throw new bbsException('数据库错误，表' . DB_A . 'bbs_topic_content不可读', 500);

            $data = $rs->fetchAll();

        } else {
            //倒序排列楼层
            if ($page == 1) {
                $size--;
            } else {
                $offset--;
            }

            $rs = $this->db->select($fetch, 'bbs_topic_content', 'WHERE topic_id=? AND floor!=0 ORDER BY floor DESC LIMIT ?,?', $topic_id, $offset, $size);

            if (!$rs)
                throw new bbsException('数据库错误，表' . DB_A . 'bbs_topic_content不可读', 500);

            $data = $rs->fetchAll();

            if ($page == 1) {
                $rs = $this->db->select($fetch, 'bbs_topic_content', 'WHERE topic_id=? AND floor=0', $topic_id);

                if (!$rs)
                    throw new bbsException('数据库错误，表' . DB_A . 'bbs_topic_content不可读', 500);

                array_unshift($data, $rs->fetch());
            }

        }

        return $data;
    }


    /**
     * 获取针对指定楼层的回复
     */
    public function topicReply($reply_id, $page, $size, $fetch = '*')
    {
        if ($size < 1)
            $size = 1;
        if ($page < 1)
            $page = 1;
        $offset = ($page - 1) * $size;
        $rs = $this->db->select($fetch, 'bbs_topic_content', 'WHERE reply_id=? ORDER BY floor ASC LIMIT ?,?', $reply_id, $offset, $size);
        if (!$rs)
            throw new bbsException('数据库错误，表' . DB_A . 'bbs_topic_content不可读', 500);
        return $rs->fetchAll();
    }

    /**
     * 获取指定楼层的回复数
     */
    public function topicReplyCount($reply_id)
    {
        $rs = $this->db->select('count(*)', 'bbs_topic_content', 'WHERE reply_id=?', $reply_id);
        if (!$rs)
            throw new bbsException('数据库错误，表' . DB_A . 'bbs_topic_content不可读', 500);
        $rs = $rs->fetch(db::num);
        return $rs[0];
    }

    /**
     * 获取帖子的总楼层数（包括楼主）
     */
    public function topicContentCount($topic_id)
    {
        $rs = $this->db->select('count(*)', 'bbs_topic_content', 'WHERE topic_id=?', $topic_id);
        if (!$rs)
            throw new bbsException('数据库错误，表' . DB_A . 'bbs_topic_content不可读', 500);
        $rs = $rs->fetch(db::num);
        return $rs[0];
    }

    /**
     * 创建板块
     */
    public function createForum($name, $parentId)
    {
        $rs = $this->db->insert('bbs_forum_meta', 'parent_id,name,mtime', $parentId, $name, time());
        if (!$rs)
            throw new bbsException('数据库错误，主题内容（' . DB_A . 'bbs_forum_meta）写入失败！', 500);
        return true;
    }

}