<?php
/* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
# ***** BEGIN LICENSE BLOCK *****
# This file is part of Plume Framework, a simple PHP Application Framework.
# Copyright (C) 2001-2007 Loic d'Anterroches and contributors.
#
# Plume Framework is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# Plume Framework is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#
# ***** END LICENSE BLOCK ***** */

/**
 * PostgreSQL connection class
 */
class Pluf_DB_PostgreSQL
{
    /**
     * The connection resource.
     */
    public $con_id;

    /**
     * The prefix for the table names.
     */
    public $pfx = '';

    /**
     * Debug mode.
     */
    private $debug = false;

    /** 
     * The last query, set with debug(). Used when an error is
     * returned. 
     */
    public $lastquery = '';

    /**
     * Name of the engine.
     */
    public $engine = 'PostgreSQL';

    /**
     * Used by the model to convert the values from and to the
     * database.
     *
     * @see Pluf_DB_defaultTypecast
     */
    public $type_cast = array();

    /**
     * Current query cursor.
     */
    private $cur = null;

    /**
     * Current search path.
     */
    public $search_path = 'public';

    function __construct($user, $pwd, $server, $dbname, $pfx='', $debug=false)
    {
        Pluf::loadFunction('Pluf_DB_defaultTypecast');
        $this->type_cast = Pluf_DB_defaultTypecast();
        $this->type_cast['Pluf_DB_Field_Boolean'] =
            array('Pluf_DB_PostgreSQL_BooleanFromDb', 'Pluf_DB_BooleanToDb');
        $this->type_cast['Pluf_DB_Field_Compressed'] = 
            array('Pluf_DB_PostgreSQL_CompressedFromDb', 'Pluf_DB_PostgreSQL_CompressedToDb');

        $this->debug('* POSTGRESQL CONNECT');
        $cstring = '';
        if ($server) {
            $cstring .= 'host='.$server.' ';
        }
        $cstring .= 'dbname='.$dbname.' user='.$user;
        if ($pwd) {
            $cstring .= ' password='.$pwd;
        }
        $this->debug = $debug;
        $this->pfx = $pfx;
        $this->cur = null; 
        $this->con_id = @pg_connect($cstring);
        if (!$this->con_id) {
            throw new Exception($this->getError());
        }
    }


    /**
     * Get the version of the PostgreSQL server.
     *
     * Requires PostgreSQL 7.4 or later.
     *
     * @return string Version string
     */
    function getServerInfo()
    {
        $ver = pg_version($this->con_id);
        return $ver['server'];
    }

    /**
     * Log the queries. Keep track of the last query and if in debug mode
     * keep track of all the queries in 
     * $GLOBALS['_PX_debug_data']['sql_queries']
     *
     * @param string Query to keep track
     * @return bool true
     */
    function debug($query)
    {
        $this->lastquery = $query;
        if (!$this->debug) return true;
        if (!isset($GLOBALS['_PX_debug_data']['sql_queries'])) 
            $GLOBALS['_PX_debug_data']['sql_queries'] = array();
        $GLOBALS['_PX_debug_data']['sql_queries'][] = $query;
        return true;
    }

    function close()
    {
        if ($this->con_id) {
            pg_close($this->con_id);
            return true;
        } else {
            return false;
        }
    }

    function select($query)
    {
        $this->debug($query);
        $this->cur = @pg_query($this->con_id, $query);
        if (!$this->cur) {
            throw new Exception($this->getError());
        }
        $res = array();
        while ($row = pg_fetch_assoc($this->cur)) {
            $res[] = $row;
        }
        @pg_free_result($this->cur);
        $this->cur = null;
        return $res;
    }

    function execute($query)
    {
        $this->debug($query);
        $this->cur = @pg_query($this->con_id, $query);
        if (!$this->cur) {
            throw new Exception($this->getError());
        }
        return true;
    }

    function getLastID()
    {
        $this->debug('* GET LAST ID');
        $res = $this->select('SELECT lastval() AS last_id');
        return (int) $res[0]['last_id'];
    }

    /**
     * Returns a string ready to be used in the exception.
     *
     * @return string Error string
     */
    function getError()
    {
        if ($this->cur) {
            return pg_result_error($this->cur).' - '.$this->lastquery;
        }
        if ($this->con_id) {
            return pg_last_error($this->con_id).' - '.$this->lastquery;
        } else {
            return pg_last_error().' - '.$this->lastquery;
        }
    }

    function esc($str)
    {
        return '\''.pg_escape_string($this->con_id, $str).'\'';
    }

    /**
     * Set the current search path.
     */
    function setSearchPath($search_path='public')
    {
        if (preg_match('/[^\w\s\,]/', $search_path)) {
            throw new Exception('The search path: "'.$search_path.'" is not valid.');            
        }
        $this->execute('SET search_path TO '.$search_path);
        $this->search_path = $search_path;
        return true;
    }

    /**
     * Quote the column name.
     *
     * @param string Name of the column
     * @return string Escaped name
     */
    function qn($col)
    {
        return '"'.$col.'"';
    }

    /**
     * Start a transaction.
     */
    function begin()
    {
        $this->execute('BEGIN');
    }

    /**
     * Commit a transaction.
     */
    function commit()
    {
        $this->execute('COMMIT');
    }

    /**
     * Rollback a transaction.
     */
    function rollback()
    {
        $this->execute('ROLLBACK');
    }

    function __toString()
    {
        return '<Pluf_DB_PostgreSQL('.$this->con_id.')>';
    }
}

function Pluf_DB_PostgreSQL_BooleanFromDb($val) 
{
    if (!$val) {
        return false;
    }
    return (strtolower(substr($val, 0, 1)) == 't');
}

function Pluf_DB_PostgreSQL_CompressedToDb($val, $con) 
{
    if (is_null($val)) {
        return 'NULL';
    }
    return "'".pg_escape_bytea(gzdeflate($val, 9))."'";
}

function Pluf_DB_PostgreSQL_CompressedFromDb($val)
{
    return ($val) ? gzinflate(pg_unescape_bytea($val)) : $val;
}