<?php
/**
 * DokuWiki Plugin sqlite (Helper Component)
 *
 * @license GPL 2 http://www.gnu.org/licenses/gpl-2.0.html
 * @author  Andreas Gohr <gohr@cosmocode.de>
 */

// must be run within Dokuwiki
if (!defined('DOKU_INC')) die();

if (!defined('DOKU_LF')) define('DOKU_LF', "\n");
if (!defined('DOKU_TAB')) define('DOKU_TAB', "\t");
if (!defined('DOKU_PLUGIN')) define('DOKU_PLUGIN',DOKU_INC.'lib/plugins/');

if (!defined('DOKU_EXT_SQLITE')) define('DOKU_EXT_SQLITE', 'sqlite');
if (!defined('DOKU_EXT_PDO')) define('DOKU_EXT_PDO', 'pdo');

require_once(DOKU_PLUGIN.'sqlite/classes/adapter.php');

class helper_plugin_sqlite extends DokuWiki_Plugin {
    var $adapter = null;


    public function getInfo() {
        return confToHash(dirname(__FILE__).'plugin.info.txt');
    }

    /**
     * Keep separate instances for every call to keep database connections
     */
    public function isSingleton() {
        return false;
    }

    /**
     * constructor
     */
    public function helper_plugin_sqlite(){

      if(!$this->adapter)
      {
        if($this->existsPDOSqlite()){
            require_once(DOKU_PLUGIN.'sqlite/classes/adapter_pdosqlite.php');
            $this->adapter = new helper_plugin_sqlite_adapter_pdosqlite();
        }
      }

      if(!$this->adapter)
      {
        if($this->existsSqlite2()){
            require_once(DOKU_PLUGIN.'sqlite/classes/adapter_sqlite2.php');
            $this->adapter = new helper_plugin_sqlite_adapter_sqlite2();
        }
      }

      if(!$this->adapter)
      {
        msg('SQLite & PDO SQLite support missing in this PHP install - plugin will not work',-1);
      }
    }


    /**
     * check availabilty of PHPs sqlite extension (for sqlite2 support)
     */
    public function existsSqlite2(){
        if (!extension_loaded('sqlite')) {
            $prefix = (PHP_SHLIB_SUFFIX === 'dll') ? 'php_' : '';
            if(function_exists('dl')) @dl($prefix . 'sqlite.' . PHP_SHLIB_SUFFIX);
        }

        return function_exists('sqlite_open');
    }

    /**
     * check availabilty of PHP PDO sqlite3
     */
    public function existsPDOSqlite(){
        if (!extension_loaded('pdo_sqlite')) {
            $prefix = (PHP_SHLIB_SUFFIX === 'dll') ? 'php_' : '';
            if(function_exists('dl')) @dl($prefix . 'pdo_sqlite.' . PHP_SHLIB_SUFFIX);
        }

        if(class_exists('pdo')){
            foreach(PDO::getAvailableDrivers() as $driver){
                if($driver=='sqlite'){
                    return true;
                }
            }
        }
        return false;
    }

    /**
     * Initializes and opens the database
     *
     * Needs to be called right after loading this helper plugin
     *
     * @param string $dbname
     * @param string $updatedir - Database update infos
     * @return bool
     */
    public function init($dbname,$updatedir){

        $init = null; // set by initdb()
        if(!$this->adapter->initdb($dbname,$init)) return false;

        return $this->_updatedb($init,$updatedir);
    }

    /**
     * Return the current Database Version
     */
    private function _currentDBversion(){
        $sql = "SELECT val FROM opts WHERE opt = 'dbversion';";
        $res = $this->query($sql);
        if(!$res) return false;
        $row = $this->res2row($res,0);
        return (int) $row['val'];
    }

    /**
     * Update the database if needed
     *
     * @param bool   $init      - true if this is a new database to initialize
     * @param string $updatedir - Database update infos
     * @return bool
     */
    private function _updatedb($init,$updatedir)
    {
        if($init){

            $current = 0;
        }else{
            $current = $this->_currentDBversion();
            if(!$current){
                msg("SQLite: no DB version found. '".$this->adapter->getDbname()."' DB probably broken.",-1);
                return false;
            }
        }

        // in case of init, add versioning table
        if($init){
            if(!$this->_runupdatefile(dirname(__FILE__).'/db.sql',0)){
                  msg("SQLite: '".$this->adapter->getDbname()."' database upgrade failed for version ", -1);
                return false;
            }
        }

        $latest  = (int) trim(io_readFile($updatedir.'/latest.version'));

        // all up to date?
        if($current >= $latest) return true;
        for($i=$current+1; $i<=$latest; $i++){
            $file = sprintf($updatedir.'/update%04d.sql',$i);
            if(file_exists($file)){
                if(!$this->_runupdatefile($file,$i)){
                    msg("SQLite: '".$this->adapter->getDbname()."' database upgrade failed for version ".$i, -1);
                    return false;
                }
            }
        }
        return true;
    }

    /**
     * Updates the database structure using the given file to
     * the given version.
     */
    private function _runupdatefile($file,$version){
        $sql  = io_readFile($file,false);

        $sql = explode(";",$sql);
        array_unshift($sql,'BEGIN TRANSACTION');
        array_push($sql,"INSERT OR REPLACE INTO opts (val,opt) VALUES ($version,'dbversion')");
        array_push($sql,"COMMIT TRANSACTION");

        foreach($sql as $s){
            $s = preg_replace('!^\s*--.*$!m', '', $s);
            $s = trim($s);
            if(!$s) continue;


            $res = $this->query("$s;");
            if ($res === false) {
                if($this->adapter->getName() == DOKU_EXT_SQLITE)
                {
                    sqlite_query($this->db, 'ROLLBACK TRANSACTION');
                }
                return false;
            }
        }

        return ($version == $this->_currentDBversion());
    }

    /**
     * Dump db into a file in meta directory
     *
     */
     public function dumpDatabase($dbname){
        global $conf;

        $res = $this->query("SELECT name,sql FROM sqlite_master WHERE type='table'");
        $tables = $this->res2arr($res);

        $filename = 'dumpfile_'.$dbname.'.sql';
        if($fp = fopen($conf['metadir'].'/'.$filename, 'w')){

            fwrite($fp, 'BEGIN TRANSACTION;'."\n");

            foreach($tables as $table){

                fwrite($fp, $table['sql'].";\n");

                $sql = "SELECT * FROM ".$table['name'];
                $res = $this->query($sql);

                while($row = $this->res_fetch_array($res)){

                    $line = 'INSERT INTO '.$table['name'].' VALUES(';
                    foreach($row as $no_entry => $entry){
                        if($no_entry!==0){
                            $line .= ',';
                        }

                        if(is_null($entry)){
                            $line .= 'NULL';
                        }elseif(!is_numeric($entry)){
                            $line .= $this->quote_string($entry);
                        }else{
                            //FIXME extra leading zeros are truncated e.g 1.300 (thousand three hunderd)-> 1.3
                            $line .= $entry;
                        }
                    }
                    $line .= ');'."\n";

                    fwrite($fp, $line);
                }
            }

            $res = $this->query("SELECT name,sql FROM sqlite_master WHERE type='index'");
            $indexes = $this->res2arr($res);
            foreach($indexes as $index){
                fwrite($fp, $index['sql'].";\n");
            }

            fwrite($fp, 'COMMIT;'."\n");

            fclose($fp);
            return true;
        }else{
            msg('Dumping "'.hsc($dbname).'" has failed. Could not open '.$filename);
            return false;
        }
    }

    /**
     * Registers a User Defined Function for use in SQL statements
     */
    public function create_function($function_name,$callback,$num_args){
        $this->adapter->create_function($function_name,$callback,$num_args);
    }

    /**
     * Execute a query with the given parameters.
     *
     * Takes care of escaping
     *
     * @internal param string $sql - the statement
     * @internal param $arguments ...
     * @return bool|\SQLiteResult
     */
    public function query(){
        // get function arguments
        $args = func_get_args();

        return $this->adapter->query($args);
    }

    /**
     * Join the given values and quote them for SQL insertion
     */
    public function quote_and_join($vals,$sep=',') {
        return $this->adapter->quote_and_join($vals,$sep);
    }

    /**
     * Run sqlite_escape_string() on the given string and surround it
     * with quotes
     */
    public function quote_string($string){
        return $this->adapter->quote_string($string);
    }

    /**
     * Escape string for sql
     */
    public function escape_string($str){
        return $this->adapter->escape_string($str);
    }

    /**
     * Returns a complete result set as array
     */
    public function res2arr($res, $assoc = true){
        return $this->adapter->res2arr($res, $assoc);
    }

    /**
     * Return the wanted row from a given result set as
     * associative array
     */
    public function res2row($res,$rownum=0){
        return $this->adapter->res2row($res,$rownum);
    }

    /**
     * Return the first value from the first row.
     */
    public function res2single($res){
        return $this->adapter->res2single($res);
    }

     /**
     * fetch the next row as zero indexed array
     */
    public function res_fetch_array($res){
        return $this->adapter->res_fetch_array($res);
    }


    /**
     * fetch the next row as assocative array
     */
    public function res_fetch_assoc($res){
        return $this->adapter->res_fetch_assoc($res);
    }

    /**
     * Count the number of records in result
     *
     * This function is really inperformant in PDO and should be avoided!
     */
    public function res2count($res) {
        return $this->adapter->res2count($res);
    }

    /**
    * Count the number of records changed last time
    */
    public function countChanges($db, $res){
        return $this->adapter->countChanges($db, $res);
    }

}