<?php

function serendipity_db_logmsg($msgstr) {
    $fp = @fopen('sqlite.log', 'a');
    fwrite($fp, '[' . date('d.m.Y H:i') . '] ' . $msgstr . "\n\n");
    fclose($fp);
}

/**
 * Parse result arrays into expected format for further operations
 *
 * SQLite does not support to return "e.entryid" within a $row['entryid'] return.
 * So this function manually iteratse through all result rows and rewrites 'X.yyyy' to 'yyyy'.
 * Yeah. This sucks. Don't tell me!
 *
 * @access private
 * @param  resource    The row resource handle
 * @param  int          Bitmask to tell whether to fetch numerical/associative arrays
 * @return array        Propper array containing the resource results
 */
function serendipity_db_sqlite_fetch_array($row, $type = PDO::FETCH_ASSOC)
{
    static $search  = array('%00',  '%25');
    static $replace = array("\x00", '%');

    if (!is_array($row)) {
        return $row;
    }

    /* strip any slashes, correct fieldname */
    $newrow = array();
    foreach ($row AS $i => $v) {
        // TODO: If a query of the format 'SELECT a.id, b.text FROM table' is used,
        //       the sqlite extension will give us key indizes 'a.id' and 'b.text'
        //       instead of just 'id' and 'text' like in mysql/postgresql extension.
        //       To fix that, we use a preg-regex; but that is quite performance costy.
        //       Either we always need to use 'SELECT a.id AS id, b.text AS text' in query,
        //       or the sqlite extension may get fixed. :-)
        $newrow[preg_replace('@^.+\.(.*)@', '\1', $i)] = str_replace($search, $replace, $v);
    }

    return $newrow;
}

/**
 * Tells the DB Layer to start a DB transaction.
 *
 * @access public
 */

function serendipity_db_begin_transaction(){
    global $serendipity;
    $serendipity['dbConn']->beginTransaction();
}

/**
 * Tells the DB Layer to end a DB transaction.
 *
 * @access public
 * @param  boolean  If true, perform the query. If false, rollback.
 */
function serendipity_db_end_transaction($commit){
    global $serendipity;
    if ($commit){
        $serendipity['dbConn']->commit();
    }else{
        $serendipity['dbConn']->rollback();
    }
}

/**
 * Assemble and return SQL condition for a "IN (...)" clause
 *
 * @access public
 * @param  string   table column name
 * @param  array    referenced array of values to search for in the "IN (...)" clause
 * @param  string   condition of how to associate the different input values of the $search_ids parameter
 * @return string   resulting SQL string
 */
function serendipity_db_in_sql($col, &$search_ids, $type = ' OR ') {
    $sql = array();
    if (!is_array($search_ids)) {
        return false;
    }

    foreach($search_ids AS $id) {
        $sql[] = $col . ' = ' . $id;
    }

    $cond = '(' . implode($type, $sql) . ')';
    return $cond;
}

/**
 * Connect to the configured Database
 *
 * @access public
 * @return  resource   connection handle
 */
function serendipity_db_connect() {
    global $serendipity;

    $serendipity['dbConn'] = new PDO(
                                 'sqlite:' . (defined('S9Y_DATA_PATH') ? S9Y_DATA_PATH : $serendipity['serendipityPath']) . $serendipity['dbName'] . '.db'
                             );

    return $serendipity['dbConn'];
}

function serendipity_db_reconnect() {
}

/**
 * Returns a escaped string, so that it can be safely included in a SQL string encapsulated within quotes, without allowing SQL injection.
 *
 * @access  public
 * @param   string   input string
 * @return  string   output string
 */
function serendipity_db_escape_string($string) {
    global $serendipity;
    return substr($serendipity['dbConn']->quote($string), 1, -1);
}

/**
 * Returns the option to a LIMIT SQL statement, because it varies across DB systems
 *
 * @access public
 * @param  int      Number of the first row to return data from
 * @param  int      Number of rows to return
 * @return string   SQL string to pass to a LIMIT statement
 */
function serendipity_db_limit($start, $offset) {
    return $start . ', ' . $offset;
}

/**
 * Return a LIMIT SQL option to the DB Layer as a full LIMIT statement
 *
 * @access public
 * @param   SQL string of a LIMIT option
 * @return  SQL string containing a full LIMIT statement
 */
function serendipity_db_limit_sql($limitstring) {
    return ' LIMIT ' . $limitstring;
}

/**
 * Returns the number of affected rows of a SQL query
 *
 * @access public
 * @return int      Number of affected rows
 */
function serendipity_db_affected_rows() {
    global $serendipity;
    return $serendipity['dbSth']->rowCount();
}

/**
 * Returns the number of updated rows in a SQL query
 *
 * @access public
 * @return int  Number of updated rows
 */
function serendipity_db_updated_rows() {
    global $serendipity;
    // it is unknown whether pg_affected_rows returns number of rows
    //  UPDATED or MATCHED on an UPDATE statement.
    return $serendipity['dbSth']->rowCount();
}

/**
 * Returns the number of matched rows in a SQL query
 *
 * @access public
 * @return int  Number of matched rows
 */
function serendipity_db_matched_rows() {
    global $serendipity;
    // it is unknown whether pg_affected_rows returns number of rows
    //  UPDATED or MATCHED on an UPDATE statement.
    return $serendipity['dbSth']->rowCount();
}

/**
 * Returns the latest INSERT_ID of an SQL INSERT INTO command, for auto-increment columns
 *
 * @access public
 * @param  string   Name of the table to get a INSERT ID for
 * @param  string   Name of the column to get a INSERT ID for
 * @return int      Value of the auto-increment column
 */
function serendipity_db_insert_id($table = '', $id = '') {
    global $serendipity;
    return $serendipity['dbConn']->lastInsertId();
}

/**
 * Perform a DB Layer SQL query.
 *
 * This function returns values dependin on the input parameters and the result of the query.
 * It can return:
 *   false or a string if there was an error (depends on $expectError),
 *   true if the query succeeded but did not generate any rows
 *   array of field values if it returned a single row and $single is true
 *   array of array of field values if it returned row(s) [stacked array]
 *
 * @access public
 * @param   string      SQL query to execute
 * @param   boolean     Toggle whether the expected result is a single row (TRUE) or multiple rows (FALSE). This affects whether the returned array is 1 or 2 dimensional!
 * @param   string      Result type of the array indexing. Can be one of "assoc" (associative), "num" (numerical), "both" (numerical and associative, default)
 * @param   boolean     If true, errors will be reported. If false, errors will be ignored.
 * @param   string      A possible array key name, so that you can control the multi-dimensional mapping of an array by the key column
 * @param   string      A possible array field name, so that you can control the multi-dimensional mapping of an array by the key column and the field value.
 * @param   boolean     If true, the executed SQL error is known to fail, and should be disregarded (errors can be ignroed on DUPLICATE INDEX queries and the likes)
 * @return  mixed       Returns the result of the SQL query, depending on the input parameters
 */
function &serendipity_db_query($sql, $single = false, $result_type = "both", $reportErr = false, $assocKey = false, $assocVal = false, $expectError = false) {
    global $serendipity;
    $type_map = array(
                         'assoc' => PDO::FETCH_ASSOC,
                         'num'   => PDO::FETCH_NUM,
                         'both'  => PDO::FETCH_BOTH,
                         'true'  => true,
                         'false' => false
    );

    //serendipity_db_logmsg('SQLQUERY: ' . $sql);
    if (!$expectError && ($reportErr || !$serendipity['production'])) {
        $serendipity['dbSth'] = $serendipity['dbConn']->prepare($sql);
    } else {
        $serendipity['dbSth'] = $serendipity['dbConn']->prepare($sql);
    }

    if (!$serendipity['dbSth']) {
        if (!$expectError && !$serendipity['production']) {
            print "<span class='msg_error'>Error in $sql</span>";
            print $serendipity['dbConn']->errorInfo() . "<BR/>\n";
            if (function_exists('debug_backtrace')) {
                highlight_string(var_export(debug_backtrace(), 1));
            }
            print "<pre>$sql</pre>";
        }
        return $type_map['false'];
    }

    $serendipity['dbSth']->execute();

    if ($serendipity['dbSth'] === true) {
        return $type_map['true'];
    }

    $result_type = $type_map[$result_type];

    $rows = array();

    foreach($serendipity['dbSth']->fetchAll($result_type) AS $row) {
        $row = serendipity_db_sqlite_fetch_array($row, $result_type);
        if (!empty($assocKey)) {
            // You can fetch a key-associated array via the two function parameters assocKey and assocVal
            if (empty($assocVal)) {
                $rows[$row[$assocKey]] = $row;
            } else {
                $rows[$row[$assocKey]] = $row[$assocVal];
            }
        } else {
            $rows[] = $row;
        }
    }
    //serendipity_db_logmsg('SQLRESULT: ' . print_r($rows,true));

    if(count($rows) == 0) {
        if ($single) {
            return $type_map['false'];
        }
        return $type_map['true'];
    }
    if(count($rows) == 1 && $single) {
        return $rows[0];
    }
    return $rows;
}

/**
 * Prepares a Serendipty query input to fully valid SQL. Replaces certain "template" variables.
 *
 * @access public
 * @param  string   SQL query with template variables to convert
 * @return resource    SQL resource handle of the executed query
 */
function serendipity_db_schema_import($query) {
    static $search  = array('{AUTOINCREMENT}', '{PRIMARY}', '{UNSIGNED}', '{FULLTEXT}', '{BOOLEAN}', '{UTF_8}', '{TEXT}');
    static $replace = array('INTEGER AUTOINCREMENT', 'PRIMARY KEY', '', '', 'BOOLEAN NOT NULL', '', 'LONGTEXT');

    if (stristr($query, '{FULLTEXT_MYSQL}')) {
        return true;
    }

    $query = trim(str_replace($search, $replace, $query));
    $query = str_replace('INTEGER AUTOINCREMENT PRIMARY KEY', 'INTEGER PRIMARY KEY AUTOINCREMENT', $query);
    if ($query[0] == '@') {
        // Errors are expected to happen (like duplicate index creation)
        return serendipity_db_query(substr($query, 1), false, 'both', false, false, false, true);
    } else {
        return serendipity_db_query($query);
    }
}

/**
 * Try to connect to the configured Database (during installation)
 *
 * @access public
 * @param  array     input configuration array, holding the connection info
 * @param  array     referenced array which holds the errors that might be encountered
 * @return boolean   return true on success, false on error
 */
function serendipity_db_probe($hash, &$errs) {
    global $serendipity;

    if(!in_array('sqlite', PDO::getAvailableDrivers())) {
        $errs[] = 'PDO_SQLITE driver not available';
        return false;
    }

    $dbName = (isset($hash['sqlitedbName']) ? $hash['sqlitedbName'] : $hash['dbName']);
    if (defined('S9Y_DATA_PATH')) {
        // Shared installations!
        $dbfile = S9Y_DATA_PATH . $dbName . '.db';
    } else {
        $dbfile = $serendipity['serendipityPath'] . $dbName . '.db';
    }

    $serendipity['dbConn'] = new PDO(
                                 'sqlite:' . $dbfile
                             );

    if (!$serendipity['dbConn']) {
        $errs[] = "Unable to open \"$dbfile\" - check permissions (directory needs to be writeable for webserver)!";
        return false;
    }

    return true;
}

/**
 * Returns the SQL code used for concatenating strings
 *
 * @access public
 * @param  string   Input string/column to concatenate
 * @return string   SQL parameter
 */
function serendipity_db_concat($string) {
    return 'concat(' . $string . ')';
}

/* vim: set sts=4 ts=4 expandtab : */