<?php

class XMLConnection
{
    public $phptype = 'myxml';
    public $caseFolding = true;
    public $xmldoc = null;
    public $xmlFile = '';

    /**
     * XMLConnection
     *
     * @param string $file
     * @return void
     */
    public function __construct($file)
    {
        $this->xmldoc = new Xml_Document();
        $this->xmldoc->parseXmlFile($file);
        $this->xmlFile = $file;
    }

    /**
     * &query
     * Actualy the only one supported query is simple SELECT.
     *
     * @param string $sql
     * @return object(XMLResult) $result
     */
    public function &query($sql)
    {
        if (! isset($this->xmldoc)) {
            $err = new DB_Error("Error: Closed xmlConnection.");
            return $err;
        }
        if (1 === preg_match('/^\s*SELECT\s+([\w\W]+?)(?:\s+FROM\s+`?([^`]+?)`?)(?:\s+WHERE\s+([\w\W]+?))?(?:\s+GROUP\s+BY\s+([\w\W]+?))?(?:\s+ORDER\s+BY\s+([\w\W]+?))?(?:\s+BETWEEN\s+([\w\W]+?)\s+AND\s+([\w\W]+?))?(?:\s+LIMIT\s+(\d+)\s*,\s*(\d+))?\s*$/im', $sql, $matches)) {
            $sqlColumns = $matches[1];
            $sqlFrom = isset($matches[2]) ? $matches[2] : '';
            $sqlWhere = isset($matches[3]) ? $matches[3] : '';
            $sqlGroupBy = isset($matches[4]) ? $matches[4] : '';
            $sqlOrderBy = isset($matches[5]) ? $matches[5] : '';
            $sqlLowLimit = isset($matches[8]) ? $matches[8] : '';
            $sqlHighLimit = isset($matches[9]) ? $matches[9] : '';
            /* Start Block: Fields list */
            $count = preg_match_all('/\s*(\*|[\w\.]+)(?:\s+AS\s+([\w\.]+))?/im', $sqlColumns, $match, PREG_PATTERN_ORDER | PREG_OFFSET_CAPTURE);
            $fieldsList = array();
            for ($r = 0; $r < $count; $r ++) {
                $name = (is_array($match[2][$r]) && $match[2][$r][0] !== '') ? $match[2][$r][0] : $match[1][$r][0];
                $fieldsList[$name] = $match[1][$r][0];
            }
            /* End Block */
            /* Start Block: Order list */
            $count = preg_match_all('/\s*(\*|[\w\.]+)(\s+ASC|\s+DESC)?\s*,?/im', $sqlOrderBy, $match, PREG_PATTERN_ORDER | PREG_OFFSET_CAPTURE);
            $orderList = array();
            for ($r = $count - 1; $r >= 0; $r --) {
                $direction = (is_array($match[2][$r]) && $match[2][$r][0] !== '') ? $match[2][$r][0] : 'ASC';
                $direction = strtoupper($direction);
                $orderList[$match[1][$r][0]] = $direction;
            }
            /* End Block */
            $xmlFrom = '/' . str_replace('.', '/', $sqlFrom);
            $node = $this->xmldoc->findNode($xmlFrom);
            if (! isset($node)) {
                //$err = new DB_Error( "$xmlFrom node not found in $dsn." );
                throw new Exception("$xmlFrom node not found in " . $this->xmlFile . ".");
                return $err;
            } else {
                $res = $this->fetchChildren($node);
            }
            /* Start Block: WHERE*/
            if ($sqlWhere !== '') {
                /*Start Block: Replace the operator */
                $blocks = preg_split('/("(?:(?:[^"]|"")*)"|\'(?:(?:[^\']|\'\')*)\')/im', $sqlWhere, - 1, PREG_SPLIT_DELIM_CAPTURE);
                $sqlWhere = '';
                for ($r = 0; $r < sizeof($blocks); $r ++) {
                    if (($r % 2) === 0) {
                        $blocks[$r] = str_replace('=', '==', $blocks[$r]);
                        $blocks[$r] = str_replace('<>', '!=', $blocks[$r]);
                        $blocks[$r] = str_replace('AND', '&&', $blocks[$r]);
                        $blocks[$r] = str_replace('and', '&&', $blocks[$r]);
                        $blocks[$r] = str_replace('OR', '||', $blocks[$r]);
                        $blocks[$r] = str_replace('or', '||', $blocks[$r]);
                        $blocks[$r] = str_replace('NOT', '!', $blocks[$r]);
                        $blocks[$r] = str_replace('not', '!', $blocks[$r]);
                        $blocks[$r] = preg_replace('/\b[a-zA-Z_][\w\.]*\b/im', '$res[$r][\'$0\']', $blocks[$r]);
                        $blocks[$r] = preg_replace('/\$res\[\$r\]\[\'(like)\'\]/im', '$1', $blocks[$r]);
                    }
                    $sqlWhere .= $blocks[$r];
                }
                $sqlWhere = preg_replace_callback('/(.+)\s+like\s+("(?:(?:[^"]|"")*)"|\'(?:(?:[^\']|\'\')*)\')/im', array('XMLConnection','sqlWhereLike'
                ), $sqlWhere);
                $sqlWhere = preg_replace_callback('/"(?:(?:[^"]|"")*)"|\'(?:(?:[^\']|\'\')*)\'/im', array('XMLConnection','sqlString'
                ), $sqlWhere);
                $newRes = array();
                for ($r = 0; $r < sizeof($res); $r ++) {
                    $evalWhere = false;
                    @eval('$evalWhere = ' . $sqlWhere . ';');
                    if ($evalWhere) {
                        $newRes[] = $res[$r];
                    }
                }
                $res = $newRes;
            }
            /* End Block */
            /* Start Block: Expands the resultant data according to fill an array
             *              with the required fields in the query.
             */
            for ($r = 0; $r < sizeof($res); $r ++) {
                $res[$r] = $this->expandFields($res[$r], $fieldsList);
            }
            /* End Block */
            /* Start Block: ORDER BY*/
            foreach ($orderList as $field => $direction) {
                for ($i = 0; $i < sizeof($res); $i ++) {
                    for ($j = $i + 1; $j < sizeof($res); $j ++) {
                        $condition = ($direction === 'ASC') ? ($res[$j] < $res[$i]) : ($res[$j] > $res[$i]);
                        if ($condition) {
                            $swap = $res[$i];
                            $res[$i] = $res[$j];
                            $res[$j] = $swap;
                        }
                    }
                }
            }
            /* End Block */
            /* Start Block: Apply limits */
            if ($sqlLowLimit != '' && $sqlHighLimit != '') {
                $sqlLowLimit = (int) $sqlLowLimit;
                $sqlHighLimit = (int) $sqlHighLimit;
                $res = array_slice($res, $sqlLowLimit, $sqlHighLimit);
            }
            /* End Block */
            $result = new XMLResult($res);
            return $result;
        } elseif (1 === preg_match('/^\s*DELETE\s+FROM\s+`?([^`]+?)`?(?:\s+WHERE\s+([\w\W]+?))?\s*$/im', $sql, $matches)) {
            $sqlFrom = isset($matches[1]) ? $matches[1] : '';
            $sqlWhere = isset($matches[2]) ? $matches[2] : '1';
            /* Start Block: WHERE*/
            /*Start Block: Replace the operator */
            $blocks = preg_split('/("(?:(?:[^"]|"")*)"|\'(?:(?:[^\']|\'\')*)\')/im', $sqlWhere, - 1, PREG_SPLIT_DELIM_CAPTURE);
            $sqlWhere = '';
            for ($r = 0; $r < sizeof($blocks); $r ++) {
                if (($r % 2) === 0) {
                    $blocks[$r] = str_replace('=', '==', $blocks[$r]);
                    $blocks[$r] = str_replace('<>', '!=', $blocks[$r]);
                    $blocks[$r] = str_replace('AND', '&&', $blocks[$r]);
                    $blocks[$r] = str_replace('and', '&&', $blocks[$r]);
                    $blocks[$r] = str_replace('OR', '||', $blocks[$r]);
                    $blocks[$r] = str_replace('or', '||', $blocks[$r]);
                    $blocks[$r] = str_replace('NOT', '!', $blocks[$r]);
                    $blocks[$r] = str_replace('not', '!', $blocks[$r]);
                    $blocks[$r] = preg_replace('/\b[a-zA-Z_][\w\.]*\b/im', '$res[$r][\'$0\']', $blocks[$r]);
                    $blocks[$r] = preg_replace('/\$res\[\$r\]\[\'(like)\'\]/im', '$1', $blocks[$r]);
                }
                $sqlWhere .= $blocks[$r];
            }
            /* End Block */
            $sqlWhere = preg_replace_callback('/(.+)\s+like\s+("(?:(?:[^"]|"")*)"|\'(?:(?:[^\']|\'\')*)\')/im', array('XMLConnection','sqlWhereLike'
            ), $sqlWhere);
            $sqlWhere = preg_replace_callback('/"(?:(?:[^"]|"")*)"|\'(?:(?:[^\']|\'\')*)\'/im', array('XMLConnection','sqlString'
            ), $sqlWhere);

            /*Start Block: Removing fields */
            $xmlFrom = '/' . str_replace('.', '/', $sqlFrom);
            $node = $this->xmldoc->findNode($xmlFrom);
            if (! isset($node)) {
                $err = new DB_Error("$xmlFrom node not found!.");
                return $err;
            } else {
                $res = $this->fetchChildren($node);
            }
            $newRes = array();
            for ($r = 0; $r < sizeof($res); $r ++) {
                $evalWhere = false;
                @eval('$evalWhere = ' . $sqlWhere . ';');
                if ($evalWhere) {
                    unset($node->children[$r]);
                    $newRes[] = $res[$r];
                }
            }
            //Re-index
            $node->children = array_values($node->children);
            /* End Block */
            $this->xmldoc->save($this->xmlFile);
            $result = new XMLResult($newRes);
            return $result;
        } elseif (1 === preg_match('/^\s*INSERT\s+INTO\s+`?([^`]+?)`?\s*\(([\w\W]+?)\)\s+VALUES\s*\(([\w\W]+?)\)\s*$/im', $sql, $matches)) {
            $sqlFrom = isset($matches[1]) ? $matches[1] : '';
            $sqlColumns = isset($matches[2]) ? $matches[2] : '1';
            $sqlValues = isset($matches[3]) ? $matches[3] : '1';
            $xmlFrom = '/' . str_replace('.', '/', $sqlFrom);
            $node = $this->xmldoc->findNode($xmlFrom);
            /* Start Block: Fields list */
            $count = preg_match_all('/([\w\.]+)/im', $sqlColumns, $match, PREG_PATTERN_ORDER | PREG_OFFSET_CAPTURE);
            $fieldsList = array();
            for ($r = 0; $r < $count; $r ++) {
                $fieldsList[] = $match[1][$r][0];
            }
            /* End Block */
            /* Start Block: Fields Values */
            $count = preg_match_all('/("(?:(?:[^"]|"")*)"|\'(?:(?:[^\']|\'\')*)\'|\d+)/im', $sqlValues, $match, PREG_PATTERN_ORDER | PREG_OFFSET_CAPTURE);
            $fieldsValues = array();
            for ($r = 0; $r < $count; $r ++) {
                if (substr($match[1][$r][0], 0, 1) === '"') {
                    $match[1][$r][0] = substr($match[1][$r][0], 1, - 1);
                    $match[1][$r][0] = str_replace('""', '"', $match[1][$r][0]);
                    $match[1][$r][0] = str_replace("''", "'", $match[1][$r][0]);
                }
                if (substr($match[1][$r][0], 0, 1) === "'") {
                    $match[1][$r][0] = substr($match[1][$r][0], 1, - 1);
                    $match[1][$r][0] = str_replace("''", "'", $match[1][$r][0]);
                    $match[1][$r][0] = str_replace('""', '"', $match[1][$r][0]);
                }
                $fieldsValues[$fieldsList[$r]] = $match[1][$r][0];
            }
            /* End Block */
            $AAA = getNames($this->xmldoc->children[0]->children);
            $this->insertRow($node, $fieldsValues);
            $DDD = getNames($this->xmldoc->children[0]->children);
            $this->xmldoc->save($this->xmlFile);
            $result = new XMLResult(array($fieldsValues
            ));
            return $result;
        } elseif (1 === preg_match('/^\s*UPDATE\s+`?([^`]+?)`?\s+SET\s+((?:(?:[a-z][\w\.]*)\s*=\s*(?:"(?:(?:[^"]|"")*)"|\'(?:(?:[^\']|\'\')*)\'|\d+)\s*(?:,\s*)?)+)(?:\s+WHERE\s+([\w\W]+?))?\s*$/im', $sql, $matches)) {
            $sqlFrom = isset($matches[1]) ? $matches[1] : '';
            $sqlColumns = isset($matches[2]) ? $matches[2] : '';
            $sqlWhere = isset($matches[3]) ? $matches[3] : '1';
            $count = preg_match_all('/([a-z][\w\.]*)\s*=\s*("(?:(?:[^"]|"")*)"|\'(?:(?:[^\']|\'\')*)\'|\d+)/im', $sqlColumns, $match, PREG_PATTERN_ORDER | PREG_OFFSET_CAPTURE);
            $fieldsValues = array();
            for ($r = 0; $r < $count; $r ++) {
                if (substr($match[2][$r][0], 0, 1) === '"') {
                    $match[2][$r][0] = substr($match[2][$r][0], 1, - 1);
                    $match[2][$r][0] = str_replace('""', '"', $match[2][$r][0]);
                    $match[2][$r][0] = str_replace("''", "'", $match[2][$r][0]);
                }
                if (substr($match[2][$r][0], 0, 1) === "'") {
                    $match[2][$r][0] = substr($match[2][$r][0], 1, - 1);
                    $match[2][$r][0] = str_replace("''", "'", $match[2][$r][0]);
                    $match[2][$r][0] = str_replace('""', '"', $match[2][$r][0]);
                }
                $fieldsValues[$match[1][$r][0]] = $match[2][$r][0];
            }
            /* Start Block: WHERE*/
            /*Start Block: Replace the operator */
            $blocks = preg_split('/("(?:(?:[^"]|"")*)"|\'(?:(?:[^\']|\'\')*)\')/im', $sqlWhere, - 1, PREG_SPLIT_DELIM_CAPTURE);
            $sqlWhere = '';
            for ($r = 0; $r < sizeof($blocks); $r ++) {
                if (($r % 2) === 0) {
                    $blocks[$r] = str_replace('=', '==', $blocks[$r]);
                    $blocks[$r] = str_replace('<>', '!=', $blocks[$r]);
                    $blocks[$r] = str_replace('AND', '&&', $blocks[$r]);
                    $blocks[$r] = str_replace('and', '&&', $blocks[$r]);
                    $blocks[$r] = str_replace('OR', '||', $blocks[$r]);
                    $blocks[$r] = str_replace('or', '||', $blocks[$r]);
                    $blocks[$r] = str_replace('NOT', '!', $blocks[$r]);
                    $blocks[$r] = str_replace('not', '!', $blocks[$r]);
                    $blocks[$r] = preg_replace('/\b[a-zA-Z_][\w\.]*\b/im', '$res[$r][\'$0\']', $blocks[$r]);
                    $blocks[$r] = preg_replace('/\$res\[\$r\]\[\'(like)\'\]/im', '$1', $blocks[$r]);
                }
                $sqlWhere .= $blocks[$r];
            }
            /* End Block */
            $sqlWhere = preg_replace_callback('/(.+)\s+like\s+("(?:(?:[^"]|"")*)"|\'(?:(?:[^\']|\'\')*)\')/im', array('XMLConnection','sqlWhereLike'
            ), $sqlWhere);
            $sqlWhere = preg_replace_callback('/"(?:(?:[^"]|"")*)"|\'(?:(?:[^\']|\'\')*)\'/im', array('XMLConnection','sqlString'
            ), $sqlWhere);
            /*Start Block: Removing fields */
            $xmlFrom = '/' . str_replace('.', '/', $sqlFrom);
            $node = $this->xmldoc->findNode($xmlFrom);
            if (! isset($node)) {
                $err = new DB_Error("$xmlFrom node not found in $dsn.");
                return $err;
            } else {
                $res = $this->fetchChildren($node);
            }
            $newRes = array();
            for ($r = 0; $r < sizeof($res); $r ++) {
                $evalWhere = false;
                @eval('$evalWhere = ' . $sqlWhere . ';');
                if ($evalWhere) {
                    $this->updateRow($node->children[$r], $fieldsValues);
                    $newRes[] = array_merge($res[$r], $fieldsValues);
                }
            }
            /* End Block */
            $nodeTEST = $this->xmldoc->findNode($xmlFrom);
            $this->xmldoc->save($this->xmlFile);
            $result = new XMLResult($newRes);
            return $result;
        } else {
            echo($sql);
            $err = new DB_Error("SQL Query is not well formed.");
            return $err;
        }
    }

    /**
     * sqlLike
     *
     * @param string $a
     * @return void $b
     */
    public function sqlLike($a, $b)
    {
        $b = addcslashes($b, '[]()\/{}.?');
        $b = str_replace("%", '.*', $b);
        $b = '/^' . $b . '$/im';
        return preg_match($b, $a);
    }

    /**
     * expandFields
     *
     * @param string $resRow
     * @param string $fieldsList
     * @return array $res
     */
    public function expandFields($resRow, $fieldsList)
    {
        $res = array();
        foreach ($fieldsList as $key => $value) {
            if ($key === '*') {
                foreach ($resRow as $k => $v) {
                    $res[$k] = $v;
                }
            } else {
                $res[$key] = array_key_exists($value, $resRow) ? $resRow[$value] : null;
            }
        }
        return $res;
    }

    /**
     * fetchNode
     *
     * @param object &$node
     * @return array $res
     */
    public function fetchNode(&$node)
    {
        $res = array('XMLNODE_NAME' => $node->name,'XMLNODE_TYPE' => $node->type,'XMLNODE_VALUE' => $node->value
        );
        foreach ($node->attributes as $name => $value) {
            if ($this->caseFolding) {
                $name = strtoupper($name);
            }
            $res[$name] = $value;
        }
        return $res;
    }

    /**
     * fetchChildren
     *
     * @param string &$node
     * @return array $res
     */
    public function fetchChildren(&$node)
    {
        $res = array();
        foreach ($node->children as $name => $child) {
            $res[] = $this->fetchNode($child);
        }
        return $res;
    }

    /**
     * disconnect
     *
     * @return void
     */
    public function disconnect()
    {
        unset($this->xmldoc);
    }

    /**
     *
     * @param array $match
     * @return object(DB_Error) $err
     */
    public function sqlWhereLike($match)
    {
        switch (substr($match[2], 0, 1)) {
            case '"':
                return ' $this->sqlLike( ' . $match[1] . ', ' . $match[2] . ' ) ';
                break;
            case "'":
                return ' $this->sqlLike( ' . $match[1] . ', ' . $match[2] . ' ) ';
                break;
            default:
                $err = new DB_Error("XMLDB: Syntax error on $match[0]");
                die();
                return $err;
        }
    }

    /**
     * sqlString
     *
     * @param array $match
     * @return object(DB_Error) $err
     */
    public function sqlString($match)
    {
        switch (substr($match[0], 0, 1)) {
            case '"':
                $match[0] = substr($match[0], 1, - 1);
                $match[0] = str_replace('""', '"', $match[0]);
                $match[0] = str_replace("''", "'", $match[0]);
                $match[0] = addcslashes($match[0], '\\\'');
                return "'$match[0]'";
                break;
            case "'":
                $match[0] = substr($match[0], 1, - 1);
                $match[0] = str_replace("''", "'", $match[0]);
                $match[0] = str_replace('""', '"', $match[0]);
                $match[0] = addcslashes($match[0], '\\\'');
                return "'$match[0]'";
                break;
            default:
                $err = new DB_Error("XMLDB: Syntax error on $match[0]");
                die();
                return $err;
        }
    }

    /**
     * insertRow
     *
     * @param string &$node
     * @param object $values
     * @return void
     */
    public function insertRow(&$node, $values)
    {
        $attributes = array();
        foreach ($values as $field => $value) {
            switch ($field) {
                case 'XMLNODE_NAME':
                case 'XMLNODE_TYPE':
                case 'XMLNODE_VALUE':
                    break;
                default:
                    $attributes[strtolower($field)] = $value;
            }
        }
        $values['XMLNODE_NAME'] = ! isset($values['XMLNODE_NAME']) ? '' : $values['XMLNODE_NAME'];
        $values['XMLNODE_TYPE'] = ! isset($values['XMLNODE_TYPE']) ? 'open' : $values['XMLNODE_TYPE'];
        $values['XMLNODE_VALUE'] = ! isset($values['XMLNODE_VALUE']) ? '' : $values['XMLNODE_VALUE'];
        $node->addChildNode(new Xml_Node($values['XMLNODE_NAME'], $values['XMLNODE_TYPE'], $values['XMLNODE_VALUE'], $attributes));
    }

    /**
     * updateRow
     *
     * @param string &$node
     * @param object $values
     * @return void
     */
    public function updateRow(&$node, $values)
    {
        foreach ($values as $field => $value) {
            switch ($field) {
                case 'XMLNODE_NAME':
                    $node->name = $value;
                    break;
                case 'XMLNODE_TYPE':
                    $node->type = $value;
                    break;
                case 'XMLNODE_VALUE':
                    $node->value = $value;
                    break;
                default:
                    $node->attributes[strtolower($field)] = $value;
            }
        }
    }
}