<?php

// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.


/**
 * This file keeps track of upgrades to the lamslesson module
 *
 * Sometimes, changes between versions involve alterations to database
 * structures and other major things that may break installations. The upgrade
 * function in this file will attempt to perform all the necessary actions to
 * upgrade your older installation to the current version. If there's something
 * it cannot do itself, it will tell you what you need to do.  The commands in
 * here will all be database-neutral, using the functions defined in DLL libraries.
 *
 * @package   mod_lamslesson
 * @copyright 2011 LAMS Foundation - Ernie Ghiglione (ernieg@lamsfoundation.org) 
 * @license  http://www.gnu.org/licenses/gpl-2.0.html GNU GPL v2
 */

defined('MOODLE_INTERNAL') || die();

/**
 * xmldb_lamslesson_upgrade
 *
 * @param int $oldversion
 * @return bool
 */
function xmldb_lamslesson_upgrade($oldversion) {

    global $DB;

    $dbman = $DB->get_manager(); // loads ddl manager and xmldb classes

/// And upgrade begins here. For each one, you'll need one
/// block of code similar to the next one. Please, delete
/// this comment lines once this file start handling proper
/// upgrade code.

/// if ($oldversion < YYYYMMDD00) { //New version in version.php
///
/// }

/// Lines below (this included)  MUST BE DELETED once you get the first version
/// of your module ready to be installed. They are here only
/// for demonstrative purposes and to show how the lamslesson
/// iself has been upgraded.

/// For each upgrade block, the file lamslesson/version.php
/// needs to be updated . Such change allows Moodle to know
/// that this file has to be processed.

/// To know more about how to write correct DB upgrade scripts it's
/// highly recommended to read information available at:
///   http://docs.moodle.org/en/Development:XMLDB_Documentation
/// and to play with the XMLDB Editor (in the admin menu) and its
/// PHP generation posibilities.

/// First example, some fields were added to install.xml on 2007/04/01
    if ($oldversion < 2007040100) {

    /// Define field course to be added to lamslesson
        $table = new xmldb_table('lamslesson');
        $field = new xmldb_field('course', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, '0', 'id');

    /// Add field course
        if (!$dbman->field_exists($table, $field)) {
            $dbman->add_field($table, $field);
        }

    /// Define field intro to be added to lamslesson
        $table = new xmldb_table('lamslesson');
        $field = new xmldb_field('intro', XMLDB_TYPE_TEXT, 'medium', null, null, null, null,'name');

    /// Add field intro
        if (!$dbman->field_exists($table, $field)) {
            $dbman->add_field($table, $field);
        }

    /// Define field introformat to be added to lamslesson
        $table = new xmldb_table('lamslesson');
        $field = new xmldb_field('introformat', XMLDB_TYPE_INTEGER, '4', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, '0',
            'intro');

    /// Add field introformat
        if (!$dbman->field_exists($table, $field)) {
            $dbman->add_field($table, $field);
        }
    }

/// Second example, some hours later, the same day 2007/04/01
/// two more fields and one index were added to install.xml (note the micro increment
/// "01" in the last two digits of the version
    if ($oldversion < 2007040101) {

    /// Define field timecreated to be added to lamslesson
        $table = new xmldb_table('lamslesson');
        $field = new xmldb_field('timecreated', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, '0',
            'introformat');

    /// Add field timecreated
        if (!$dbman->field_exists($table, $field)) {
            $dbman->add_field($table, $field);
        }

    /// Define field timemodified to be added to lamslesson
        $table = new xmldb_table('lamslesson');
        $field = new xmldb_field('timemodified', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED, XMLDB_NOTNULL, null, '0',
            'timecreated');

    /// Add field timemodified
        if (!$dbman->field_exists($table, $field)) {
            $dbman->add_field($table, $field);
        }

    /// Define index course (not unique) to be added to lamslesson
        $table = new xmldb_table('lamslesson');
        $index = new xmldb_index('courseindex', XMLDB_INDEX_NOTUNIQUE, array('course'));

    /// Add index to course field
        if (!$dbman->index_exists($table, $index)) {
            $dbman->add_index($table, $index);
        }

    }

/// Third example, the next day, 2007/04/02 (with the trailing 00), some actions were performed to install.php,
/// related with the module
    if ($oldversion < 2007040200) {
    /// insert here code to perform some actions (same as in install.php)
    }

/// And that's all. Please, examine and understand the 3 example blocks above. Also
/// it's interesting to look how other modules are using this script. Remember that
/// the basic idea is to have "blocks" of code (each one being executed only once,
/// when the module version (version.php) is updated.

/// Lines above (this included) MUST BE DELETED once you get the first version of
/// yout module working. Each time you need to modify something in the module (DB
/// related, you'll raise the version and add one upgrade block here.

/// Final return of upgrade result (true, all went good) to Moodle.
    return true;
}