<?php

class Qs_Debug extends Qs_Db_Obj
{
    protected static $_instance;
    protected $_tableAlias = 'Log';
    protected $_errorReporting = E_ALL;
    protected $_previousErrorReporting = E_ALL;
    protected $_idSession;
    protected $_startTime;
    protected $_count;
    protected $_writed = false;
    protected $_writeLog = true;
    protected $_options = array();
    protected $_logBacktrace = false;
    protected $_root;
    
    protected function _init()
    {
        set_exception_handler(array($this, 'exceptionHandler'));
        if ($this->_writeLog) {
            $this->_startTime = date('Y-m-d H:i:s');
        }
        $this->_idSession = Zend_Session::getId();
        $this->_clearOldHistory();
        return $this;
    }
    
    public function getOption($name)
    {
        if (isset($this->_options[$name])) {
            return $this->_options[$name];
        }
        return null;
    }
    
    public function setLogBacktrace($flag)
    {
        $this->_logBacktrace = (bool) $flag;
    }
    
    public function setWriteLog($flag)
    {
        $this->_writeLog = (bool) $flag;
    }

    /**
     * @return Qs_Debug
     * @throws Qs_Exception
     */
    public static function getInstance()
    {
        if (null === Qs_Debug::$_instance) {
            if (!Zend_Registry::isRegistered('config')) {
                throw new Qs_Exception('Config is not registered in Zend_Registry');
            }
            Qs_Debug::$_instance = new Qs_Debug(Zend_Registry::get('config')->debug);
        }
        return Qs_Debug::$_instance;
    }
    
    public function setErrorReporting($errorReporting)
    {
        $this->_previousErrorReporting = $this->_errorReporting;
        $this->_errorReporting = $errorReporting;
        error_reporting($errorReporting);
        set_error_handler(array($this, 'errorHandler'), $this->_errorReporting);
    }
    
    public function getErrorReporting()
    {
        return $this->_errorReporting;
    }
    
    public function restoreErrorReporting()
    {
        $this->_errorReporting = $this->_previousErrorReporting;
        set_error_handler(array($this, 'errorHandler'), $this->_errorReporting);
    }
    
    protected function _clearOldHistory()
    {
        if ($this->_writeLog) {
            if ($this->_count > $this->getOption('clearOverflow')) {
                $select = $this->_db->select();
                $select->from($this->_tableName, 'id')
                       ->order('id DESC')
                       ->limit(1, $this->getOption('clearLimit') - 1);
                if (false !== ($maxId = $this->_db->fetchOne($select))) {
                    $this->_db->delete($this->_tableName, 'id < ' . $this->_db->quote($maxId, Qs_Db::INT_TYPE));
                }
            }
        }
    }
    
    public function errorHandler($errNo, $errMsg, $filename, $linenNum, $errContext)
    {
        // Ignore warnings and notices from lib/Zend
        if (in_array($errNo, array(E_WARNING, E_NOTICE)) && false !== strpos($filename, '/Zend/')) {
            return true;
        }
        $this->_writeLog([
            //Деякі меседжі містять в собі шляхи до файлів
            'message'       => $this->_filterFilePaths($errMsg),
            'errorNumber'   => $errNo,
            'file'          => $this->_filterFilePaths($filename),
            'line'          => $linenNum,
        ]);
        return true;
    }
    
    public static function log($message, $errNo = E_WARNING)
    {
        Qs_Debug::getInstance()->errorHandler($errNo, $message, null, null, null);
    }

    public static function logStdError($message)
    {
        if (false !== ($handle = fopen('php://stderr', 'w'))) {
            fwrite($handle, $message);
            fclose($handle);
        }
    }
    
    protected function _writeLog(array $data)
    {
        if (!$this->_writeLog) {
            return false;
        }
        if (!isset($data['message'])) {
            return false;
        }
        if (!isset($data['errorNumber'])) {
            $data['errorNumber'] = 0;
        }
        ksort($data);
        $uid = md5(implode('', $data));
        $data = array_merge($data, [
            'uid'           => $uid,
            'backtrace'     => $this->_logBacktrace ? gzcompress(serialize(Qs_Debug::_getBackTrace()), 9) : null,
            'ip'            => $_SERVER['REMOTE_ADDR'],
            'count'         => new Zend_Db_Expr('count + 1'),
            'idSession'     => $this->_idSession,
            'serverName'    => $_SERVER['SERVER_NAME'],
            'url'           => (string)Qs_Request::getUrl(),
            'added'         => date('Y-m-d H:i:s'),
        ]);
        $db = Qs_Db::getInstance();
        $table = Qs_Db::getTableName('Log');
        $updated = $db->update($table, $data, $db->quoteInto('uid = ?', $uid));
        if (!$updated) {
            $data['count'] = 1;
            $db->insert($table, $data);
        }
        $this->_writed = true;
        return true;
    }

    /**
     * Remove objects instances from array
     * (раніше приймав занчення по посиланню, в РНР 5.4 вилізла проблема, debug_backtrace повертає масив з посиланнями
     * на об'єкти, тому зміни в $array моломи сайт)
     * @param array $array
     * @return array
     */
    protected static function _removeObjects(array $array)
    {
        $result = array();
        foreach ($array as $key => $value) {
            if (is_array($value)) {
                $result[$key] = Qs_Debug::_removeObjects($value);
            } else if (is_object($value)) {
                $result[$key] = get_class($value) . ' Object';
            } else {
                $result[$key] = $value;
            }
        }
        return $result;
    }
    
    protected static function _getBackTrace()
    {
        $backtrace = debug_backtrace();
        array_shift($backtrace);
        array_shift($backtrace);
        array_shift($backtrace);
        $backtrace = Qs_Debug::_removeObjects($backtrace);
        return $backtrace;
    }
   
    public function getDebugInformation()
    {
        if (!$this->_writeLog || !$this->_writed) {
            return array();
        }
        $select = $this->_db->select();
        $select->from($this->_getPair(), array('added', 'errorNumber', 'message', 'file', 'line'));
        $select->where("`{$this->_tableAlias}`.`added` >= " . $this->_db->quote($this->_startTime));
        $select->where("`{$this->_tableAlias}`.`idSession` = " . $this->_db->quote($this->_idSession));
        $select->order($this->_tableAlias . '.id');
        $list = $this->_db->fetchAll($select);
        return $list;
    }
    
    public static function getExceptionMessage(Exception $exception)
    {
        $firstTracePoint = current($exception->getTrace());
        $html = '<br />'
              . '<b>' . $firstTracePoint['class'] . $firstTracePoint['type'] . $firstTracePoint['function'] . '</b>'
              . ' uncaught exception '
              . 'in ' . $exception->getFile() . ' on line <b>' . $exception->getLine() . ''
              . '<br/>'
              . '<span style="color:#DD0000"><b>' . nl2br(strip_tags($exception->getMessage())) . '</b></span>'
              . '<br />';
        if ($exception instanceof Zend_Db_Statement_Exception
            && false !== ($lastQueryProfile = Qs_Db::getInstance()->getProfiler()->getLastQueryProfile())
        ) {
            if (Qs_Request::isXmlHttpRequest()) {
                $html .= "\nLast Query:\n" . Qs_SqlFormatter::format($lastQueryProfile->getQuery(), false);
            } else {
                $html .= '<br/>Last query:<hr/>' . Qs_SqlFormatter::format($lastQueryProfile->getQuery());
            }
        }
        return $html;
    }

    public static function getExceptionPlainMessage(Exception $exception)
    {
        $firstTracePoint = current($exception->getTrace());
        $text = $firstTracePoint['class'] . $firstTracePoint['type'] . $firstTracePoint['function'] . ' '
              . 'uncaught exception in ' . $exception->getFile() . ' on line ' . $exception->getLine() . ' - '
              . strip_tags($exception->getMessage());
        if ($exception instanceof Zend_Db_Statement_Exception
            && false !== ($lastQueryProfile = Qs_Db::getInstance()->getProfiler()->getLastQueryProfile())
        ) {
            $text .= '. Last query: ' . $lastQueryProfile->getQuery();
        }
        return $text;
    }

    /**
     * @param Exception $exception
     * @return string
     */
    public static function getExceptionBacktrace($exception)
    {
        $debugBacktrace = $exception->getTrace();
        $debugBacktrace = Qs_Debug::_removeObjects($debugBacktrace);
        return '<b>BACKTRACE</b><br /><pre>' . print_r($debugBacktrace, true) . '</pre>';
    }
    
    protected function _sendExceptionNotification($exception)
    {
        $message   = Qs_Debug::getExceptionMessage($exception);
        $backtrace = Qs_Debug::getExceptionBacktrace($exception);
        $html = $message
              . '<hr />'
              . '<b>URL</b>: <a href="' . Qs_Request::getUrl() . '">' . Qs_Request::getUrl() . '</a>';
        foreach (array('_GET', '_POST', '_COOKIE', '_SERVER', '_ENV') as $name) {
          $html .= '<hr /><b>$' . $name . '</b><br /><pre>' . htmlspecialchars(print_r($GLOBALS[$name], true)) . '</pre>';
        }
        $html .= '<hr />' . $backtrace;
        $notifyEmails = $this->getOption('notifyEmails');
        if (is_array($notifyEmails) && !empty($notifyEmails)) {
            $headers = 'From: debug@' . $_SERVER['SERVER_NAME'] . "\n"
                     . 'Reply-To: no-reply@' . $_SERVER['SERVER_NAME'] . "\n"
                     . 'Content-Type: text/html' . "\n"
                     . 'X-Mailer: PHP/' . phpversion();
            foreach ($notifyEmails as $email) {
                mail($email, 'Error Dump from ' . $_SERVER['SERVER_NAME'], $html, $headers);
            }
        }
        return $this;
    }

    protected function _filterFilePaths($file)
    {
        if (!$this->_root) {
            $this->_root = dirname(BASE_PATH);
        }
        return str_replace($this->_root . '/', '', $file);
    }

    /**
     * @param Exception $exception
     */
    public function exceptionHandler($exception)
    {
        self::logStdError('QSF Exception: ' . self::getExceptionPlainMessage($exception));
        $message   = Qs_Debug::getExceptionMessage($exception);
        $backtrace = Qs_Debug::getExceptionBacktrace($exception);
        $this->_sendExceptionNotification($exception);
        $this->_writeLog([
            'message'       => $exception->getMessage(),
            'exceptionCode' => $exception->getCode(),
            'file'          => $this->_filterFilePaths($exception->getFile()),
            'line'          => $exception->getLine(),
        ]);
        if (Qs_Constant::get('DEBUG')) {
            die($message . '<hr/>' . $backtrace);
        }
        die('Internal error');
    }
    
    public static function processException($exception)
    {
        Qs_Debug::getInstance()->exceptionHandler($exception);
    }

    public static function dumpSql($sql)
    {
        echo Qs_SqlFormatter::format('' . $sql);
    }
}