<?php

    // THESE CONSTANTS ARE USED FOR THE REPORTING PAGE.

    define('STATS_REPORT_LOGINS',1); // double impose logins and unqiue logins on a line graph. site course only.
    define('STATS_REPORT_READS',2); // double impose student reads and teacher reads on a line graph. 
    define('STATS_REPORT_WRITES',3); // double impose student writes and teacher writes on a line graph.
    define('STATS_REPORT_ACTIVITY',4); // 2+3 added up, teacher vs student.
    define('STATS_REPORT_ACTIVITYBYROLE',5); // all activity, reads vs writes, seleted by role.
    
    // user level stats reports.
    define('STATS_REPORT_USER_ACTIVITY',7);
    define('STATS_REPORT_USER_ALLACTIVITY',8);
    define('STATS_REPORT_USER_LOGINS',9);
    define('STATS_REPORT_USER_VIEW',10);  // this is the report you see on the user profile.

    // admin only ranking stats reports
    define('STATS_REPORT_ACTIVE_COURSES',11);
    define('STATS_REPORT_ACTIVE_COURSES_WEIGHTED',12);
    define('STATS_REPORT_PARTICIPATORY_COURSES',13);
    define('STATS_REPORT_PARTICIPATORY_COURSES_RW',14);

    // start after 0 = show dailies.
    define('STATS_TIME_LASTWEEK',1);
    define('STATS_TIME_LAST2WEEKS',2);
    define('STATS_TIME_LAST3WEEKS',3);
    define('STATS_TIME_LAST4WEEKS',4);

    // start after 10 = show weeklies
    define('STATS_TIME_LAST2MONTHS',12);

    define('STATS_TIME_LAST3MONTHS',13);
    define('STATS_TIME_LAST4MONTHS',14);
    define('STATS_TIME_LAST5MONTHS',15);
    define('STATS_TIME_LAST6MONTHS',16);

    // start after 20 = show monthlies
    define('STATS_TIME_LAST7MONTHS',27);
    define('STATS_TIME_LAST8MONTHS',28);
    define('STATS_TIME_LAST9MONTHS',29);
    define('STATS_TIME_LAST10MONTHS',30);
    define('STATS_TIME_LAST11MONTHS',31);
    define('STATS_TIME_LASTYEAR',32);

    // different modes for what reports to offer
    define('STATS_MODE_GENERAL',1);
    define('STATS_MODE_DETAILED',2);
    define('STATS_MODE_RANKED',3); // admins only - ranks courses

    // return codes - whether to rerun
    define('STATS_RUN_COMPLETE',1);
    define('STATS_RUN_ABORTED',0);

function stats_cron_daily () {
    global $CFG;
    
    if (empty($CFG->enablestats)) {
        return STATS_RUN_ABORTED;
    }

    if (!$timestart = stats_get_start_from('daily')) {
        return STATS_RUN_ABORTED;
    }


    $midnight = stats_getmidnight(time());
    
    // check to make sure we're due to run, at least one day after last run
    if (isset($CFG->statslastdaily) and ((time() - 24*60*60) < $CFG->statslastdaily)) {
        return STATS_RUN_ABORTED;
    }

    mtrace("Running daily statistics gathering...");
    set_config('statslastdaily',time());

    $return = STATS_RUN_COMPLETE; // optimistic

    static $daily_modules;
    
    if (empty($daily_modules)) {
        $daily_modules = array();
        $mods = get_records("modules");
        foreach ($mods as $mod) {
            $file = $CFG->dirroot.'/mod/'.$mod->name.'/lib.php';
            if (!is_readable($file)) {
                continue;
            }
            require_once($file);
            $fname = $mod->name.'_get_daily_stats';
            if (function_exists($fname)) {
                $daily_modules[$mod] = $fname;
            }
        }
    }

    $nextmidnight = stats_get_next_dayend($timestart);

    if (!$courses = get_records('course','','','','id,1')) {
        return STATS_RUN_ABORTED;
    }
    
    $days = 0;
    mtrace("starting at $timestart");
    while ($midnight > $nextmidnight && $timestart < $nextmidnight) {

        $timesql = " (l.time > $timestart AND l.time < $nextmidnight) ";
        begin_sql();
        foreach ($courses as $course) {
            //do this first.
            if ($course->id == SITEID) {
                $stat = new StdClass;
                $stat->courseid = $course->id;
                $stat->timeend = $nextmidnight;
                $stat->roleid = 0; // all users
                $stat->stattype = 'logins';
                $sql = 'SELECT count(l.id) FROM '.$CFG->prefix.'log l WHERE l.action = \'login\' AND '.$timesql;
                $stat->stat1 = count_records_sql($sql);
                $sql = 'SELECT COUNT(DISTINCT(l.userid)) FROM '.$CFG->prefix.'log l WHERE l.action = \'login\' AND '.$timesql;
                $stat->stat2 = count_records_sql($sql);
                insert_record('stats_daily',$stat,false); // don't worry about the return id, we don't need it.

                // and now user logins...
                $sql = 'SELECT l.userid,count(l.id) as count FROM '.$CFG->prefix.'log l WHERE action = \'login\' AND '.$timesql.' GROUP BY userid';
                
                if ($logins = get_records_sql($sql)) {
                    foreach ($logins as $l) {
                        $stat->statsreads = $l->count;
                        $stat->userid = $l->userid;
                        $stat->timeend = $nextmidnight;
                        $stat->courseid = SITEID;
                        $stat->statswrites = 0;
                        $stat->stattype = 'logins';
                        $stat->roleid = 0;
                        insert_record('stats_user_daily',$stat,false);
                    }
                }
            }

            $context = get_context_instance(CONTEXT_COURSE, $course->id); 
            if (!$roles = get_roles_on_exact_context($context)) {
                // no roles.. nothing to log.
                continue;
            }
            
            $primary_roles = sql_primary_role_subselect();  // In dmllib.php
            foreach ($roles as $role) {
                // ENROLMENT FIRST....
                // ALL users with this role...
                $stat = new StdClass;
                $stat->courseid = $course->id;
                $stat->roleid = $role->id;
                $stat->timeend = $nextmidnight;
                $stat->stattype = 'enrolments';
                $sql = 'SELECT COUNT(DISTINCT prs.userid) FROM ('.$primary_roles.') prs WHERE prs.primary_roleid='.$role->id.
                    ' AND prs.courseid='.$course->id.' AND prs.contextlevel = '.CONTEXT_COURSE;
                $stat->stat1 = count_records_sql($sql);               
                
                $sql = 'SELECT COUNT(DISTINCT prs.userid) FROM ('.$primary_roles.') prs 
                        INNER JOIN '.$CFG->prefix.'log l ON (prs.userid=l.userid AND l.course=prs.courseid) 
                        WHERE prs.primary_roleid='.$role->id.' AND prs.courseid='.$course->id.' 
                        AND prs.contextlevel = '.CONTEXT_COURSE.' AND '.$timesql;

                $stat->stat2 = count_records_sql($sql);               
                insert_record('stats_daily',$stat,false); // don't worry about the return id, we don't need it.

                // ACTIVITY
                
                $stat = new StdClass;
                $stat->courseid = $course->id;
                $stat->roleid = $role->id;
                $stat->timeend = $nextmidnight;
                $stat->stattype = 'activity';
                
                $sql = 'SELECT COUNT(DISTINCT l.id) FROM ('.$primary_roles.') prs 
                        INNER JOIN '.$CFG->prefix.'log l ON (prs.userid=l.userid
                        AND l.course=prs.courseid) WHERE prs.primary_roleid='.$role->id.' 
                        AND prs.courseid='.$course->id.' AND prs.contextlevel = '.CONTEXT_COURSE.'
                         AND '.$timesql.' '.stats_get_action_sql_in('view');
                $stat->stat1 = count_records_sql($sql);       

                $sql = 'SELECT COUNT(DISTINCT l.id) FROM ('.$primary_roles.') prs 
                        INNER JOIN '.$CFG->prefix.'log l ON (prs.userid=l.userid  AND l.course=prs.courseid) 
                        WHERE prs.primary_roleid='.$role->id.' AND prs.courseid='.$course->id.' 
                        AND prs.contextlevel = '.CONTEXT_COURSE.' AND '.$timesql.' '.stats_get_action_sql_in('post');
                $stat->stat2 = count_records_sql($sql);       

                insert_record('stats_daily',$stat,false); // don't worry about the return id, we don't need it.
            }
            
            $users = stats_get_course_users($course,$timesql);
            foreach ($users as $user) {
                stats_do_daily_user_cron($course,$user,$user->primaryrole,$timesql,$nextmidnight,$daily_modules);
            }
        }
        commit_sql();
        $timestart = $nextmidnight;
        $nextmidnight = stats_get_next_dayend($nextmidnight);
        $days++;

        if (!stats_check_runtime()) {
            mtrace("Stopping early! reached maxruntime");
            $return = STATS_RUN_ABORTED;
            break;
        }
    }
    mtrace("got up to ".$timestart);
    mtrace("Completed $days days");
    return $return;

}


function stats_cron_weekly () {

    global $CFG;

    if (empty($CFG->enablestats)) {
        STATS_RUN_ABORTED;
    }

    if (!$timestart = stats_get_start_from('weekly')) {
        return STATS_RUN_ABORTED;
    }
    
    // check to make sure we're due to run, at least one week after last run
    $sunday = stats_get_base_weekly(); 

    if (isset($CFG->statslastweekly) and ((time() - (7*24*60*60)) <= $CFG->statslastweekly)) {
        return STATS_RUN_ABORTED;
    }

    mtrace("Running weekly statistics gathering...");
    set_config('statslastweekly',time());

    $return = STATS_RUN_COMPLETE; // optimistic

    static $weekly_modules;
    
    if (empty($weekly_modules)) {
        $weekly_modules = array();
        $mods = get_records("modules");
        foreach ($mods as $mod) {
            $file = $CFG->dirroot.'/mod/'.$mod->name.'/lib.php';
            if (!is_readable($file)) {
                continue;
            }
            require_once($file);
            $fname = $mod->name.'_get_weekly_stats';
            if (function_exists($fname)) {
                $weekly_modules[$mod] = $fname;
            }
        }
    }

    $nextsunday = stats_get_next_weekend($timestart);

    if (!$courses = get_records('course','','','','id,1')) {
        return STATS_RUN_ABORTED;
    }
    
    $weeks = 0;
    mtrace("starting at $timestart");
    while ($sunday > $nextsunday && $timestart < $nextsunday) {

        $timesql = " (timeend > $timestart AND timeend < $nextsunday) ";
        begin_sql();
        foreach ($courses as $course) {
            
            // enrolment first
            $sql = 'SELECT roleid, ceil(avg(stat1)) AS stat1, ceil(avg(stat2)) AS stat2
                    FROM '.$CFG->prefix.'stats_daily 
                    WHERE courseid = '.$course->id.' AND '.$timesql.' AND stattype = \'enrolments\'
                    GROUP BY roleid';
            
            if ($rolestats = get_records_sql($sql)) {
                foreach ($rolestats as $stat) {
                    $stat->courseid = $course->id;
                    $stat->timeend = $nextsunday;
                    $stat->stattype = 'enrolments';
                    
                    insert_record('stats_weekly',$stat,false); // don't worry about the return id, we don't need it.
                }
            }
            
            // activity
            $sql = 'SELECT roleid, sum(stat1) AS stat1, sum(stat2) as stat2
                    FROM '.$CFG->prefix.'stats_daily 
                    WHERE courseid = '.$course->id.' AND '.$timesql.' AND stattype = \'activity\'
                    GROUP BY roleid';
            
            if ($rolestats = get_records_sql($sql)) {
                foreach ($rolestats as $stat) {
                    $stat->courseid = $course->id;
                    $stat->timeend = $nextsunday;
                    $stat->stattype = 'activity';
                    unset($stat->id);
                    
                    insert_record('stats_weekly',$stat,false); // don't worry about the return id, we don't need it.
                }
            }
            
            // logins
            if ($course->id == SITEID) {
                $sql = 'SELECT sum(stat1) AS stat1
                    FROM '.$CFG->prefix.'stats_daily 
                    WHERE courseid = '.$course->id.' AND '.$timesql.' AND stattype = \'logins\'';
                
                if ($stat = get_record_sql($sql)) {
                    if (empty($stat->stat1)) {
                        $stat->stat1 = 0;
                    }
                    $stat->courseid = $course->id;
                    $stat->roleid = 0;
                    $stat->timeend = $nextsunday;
                    $stat->stattype = 'logins';
                    $sql = 'SELECT COUNT(DISTINCT(l.userid)) FROM '.$CFG->prefix.'log l WHERE l.action = \'login\' AND '
                        .str_replace('timeend','time',$timesql);
                    $stat->stat2 = count_records_sql($sql);
                    
                    insert_record('stats_weekly',$stat,false); // don't worry about the return id, we don't need it.
                }
            }

            $users = stats_get_course_users($course,$timesql);
            foreach ($users as $user) {
                stats_do_aggregate_user_cron($course,$user,$user->primaryrole,$timesql,$nextsunday,'weekly',$weekly_modules);
            }
        }
        stats_do_aggregate_user_login_cron($timesql,$nextsunday,'weekly');
        commit_sql();
        $timestart = $nextsunday;
        $nextsunday = stats_get_next_weekend($nextsunday);
        $weeks++;

        if (!stats_check_runtime()) {
            mtrace("Stopping early! reached maxruntime");
            $return = STATS_RUN_ABORTED;
            break;
        }
    }
    mtrace("got up to ".$timestart);
    mtrace("Completed $weeks weeks");
    return $return;
}
    

function stats_cron_monthly () {
    global $CFG;

    if (empty($CFG->enablestats)) {
        return STATS_RUN_ABORTED;
    }

    if (!$timestart = stats_get_start_from('monthly')) {
        return STATS_RUN_ABORTED;
    }
    
    // check to make sure we're due to run, at least one month after last run
    $monthend = stats_get_base_monthly();
    
    if (isset($CFG->statslastmonthly) and ((time() - (31*24*60*60)) <= $CFG->statslastmonthly)) {
        return STATS_RUN_ABORTED;
    }
    
    mtrace("Running monthly statistics gathering...");
    set_config('statslastmonthly',time());

    $return = STATS_RUN_COMPLETE; // optimistic

    static $monthly_modules;
    
    if (empty($monthly_modules)) {
        $monthly_modules = array();
        $mods = get_records("modules");
        foreach ($mods as $mod) {
            $file = $CFG->dirroot.'/mod/'.$mod->name.'/lib.php';
            if (!is_readable($file)) {
                continue;
            }
            require_once($file);
            $fname = $mod->name.'_get_monthly_stats';
            if (function_exists($fname)) {
                $monthly_modules[$mod] = $fname;
            }
        }
    }
    
    $nextmonthend = stats_get_next_monthend($timestart);

    if (!$courses = get_records('course','','','','id,1')) {
        return STATS_RUN_ABORTED;
    }
    
    $months = 0;
    mtrace("starting from $timestart");
    while ($monthend > $nextmonthend && $timestart < $nextmonthend) {

        $timesql = " (timeend > $timestart AND timeend < $nextmonthend) ";
        begin_sql();
        foreach ($courses as $course) {
            
            // enrolment first
            $sql = 'SELECT roleid, ceil(avg(stat1)) AS stat1, ceil(avg(stat2)) AS stat2
                    FROM '.$CFG->prefix.'stats_daily 
                    WHERE courseid = '.$course->id.' AND '.$timesql.' AND stattype = \'enrolments\'
                    GROUP BY roleid';
            
            if ($rolestats = get_records_sql($sql)) {
                foreach ($rolestats as $stat) {
                    $stat->courseid = $course->id;
                    $stat->timeend = $nextmonthend;
                    $stat->stattype = 'enrolments';
                    
                    insert_record('stats_monthly',$stat,false); // don't worry about the return id, we don't need it.
                }
            }
            
            // activity
            $sql = 'SELECT roleid, sum(stat1) AS stat1, sum(stat2) as stat2
                    FROM '.$CFG->prefix.'stats_daily 
                    WHERE courseid = '.$course->id.' AND '.$timesql.' AND stattype = \'activity\'
                    GROUP BY roleid';
            
            if ($rolestats = get_records_sql($sql)) {
                foreach ($rolestats as $stat) {
                    $stat->courseid = $course->id;
                    $stat->timeend = $nextmonthend;
                    $stat->stattype = 'activity';
                    unset($stat->id);
                    
                    insert_record('stats_monthly',$stat,false); // don't worry about the return id, we don't need it.
                }
            }
            
            // logins
            if ($course->id == SITEID) {
                $sql = 'SELECT sum(stat1) AS stat1
                    FROM '.$CFG->prefix.'stats_daily 
                    WHERE courseid = '.$course->id.' AND '.$timesql.' AND stattype = \'logins\'';
                
                if ($stat = get_record_sql($sql)) {
                    if (empty($stat->stat1)) {
                        $stat->stat1 = 0;
                    }
                    $stat->courseid = $course->id;
                    $stat->roleid = 0;
                    $stat->timeend = $nextmonthend;
                    $stat->stattype = 'logins';
                    $sql = 'SELECT COUNT(DISTINCT(l.userid)) FROM '.$CFG->prefix.'log l WHERE l.action = \'login\' AND '
                        .str_replace('timeend','time',$timesql);
                    $stat->stat2 = count_records_sql($sql);
                    
                    insert_record('stats_monthly',$stat,false); // don't worry about the return id, we don't need it.
                }
            }

            $users = stats_get_course_users($course,$timesql);
            foreach ($users as $user) {
                stats_do_aggregate_user_cron($course,$user,$user->primaryrole,$timesql,$nextmonthend,'monthly',$monthly_modules);
            }

        }
        stats_do_aggregate_user_login_cron($timesql,$nextmonthend,'monthly');
        commit_sql();
        $timestart = $nextmonthend;
        $nextmonthend = stats_get_next_monthend($timestart);
        $months++;
        if (!stats_check_runtime()) {
            mtrace("Stopping early! reached maxruntime");
            break;
            $return = STATS_RUN_ABORTED;
        }
    }
    mtrace("got up to $timestart");
    mtrace("Completed $months months");
    return $return;
}

function stats_get_start_from($str) {
    global $CFG;

    // if it's not our first run, just return the most recent.
    if ($timeend = get_field_sql('SELECT timeend FROM '.$CFG->prefix.'stats_'.$str.' ORDER BY timeend DESC')) {
        return $timeend;
    }
    
    // decide what to do based on our config setting (either all or none or a timestamp)
    $function = 'stats_get_base_'.$str;
    switch ($CFG->statsfirstrun) {
        case 'all': 
            return $function(get_field_sql('SELECT time FROM '.$CFG->prefix.'log ORDER BY time'));
            break;
        case 'none': 
            return $function(strtotime('-1 day',time()));
            break;
        default:
            if (is_numeric($CFG->statsfirstrun)) {
                return $function(time() - $CFG->statsfirstrun);
            }
            return false;
            break;
    }
}

function stats_get_base_daily($time=0) {
    if (empty($time)) {
        $time = time();
    }
    return stats_getmidnight($time);
}

function stats_get_base_weekly($time=0) {
    if (empty($time)) {
        $time = time();
    }
    // if we're currently a monday, last monday will take us back a week
    $str = 'last monday';
    if (date('D',$time) == 'Mon')
        $str = 'now';

    return stats_getmidnight(strtotime($str,$time));
}

function stats_get_base_monthly($time=0) {
    if (empty($time)) {
        $time = time();
    }
    return stats_getmidnight(strtotime(date('1-M-Y',$time)));
}

function stats_get_next_monthend($lastmonth) {
    return stats_getmidnight(strtotime(date('1-M-Y',$lastmonth).' +1 month'));
}

function stats_get_next_weekend($lastweek) {
    return stats_getmidnight(strtotime('+1 week',$lastweek));
}

function stats_get_next_dayend($lastday) {
    return stats_getmidnight(strtotime('+1 day',$lastday));
}

function stats_clean_old() {
    mtrace("Running stats cleanup tasks... ");
    // delete dailies older than 2 months (to be safe)
    $deletebefore = stats_get_next_monthend(strtotime('-2 months',time()));
    delete_records_select('stats_daily',"timeend < $deletebefore");
    delete_records_select('stats_user_daily',"timeend < $deletebefore");
    
    // delete weeklies older than 8 months (to be safe)
    $deletebefore = stats_get_next_monthend(strtotime('-8 months',time()));
    delete_records_select('stats_weekly',"timeend < $deletebefore");
    delete_records_select('stats_user_weekly',"timeend < $deletebefore");

    // don't delete monthlies
}

function stats_get_parameters($time,$report,$courseid,$mode,$roleid=0) {
    global $CFG,$db;
    if ($time < 10) { // dailies
        // number of days to go back = 7* time
        $param->table = 'daily';
        $param->timeafter = strtotime("-".($time*7)." days",stats_get_base_daily());
    } elseif ($time < 20) { // weeklies
        // number of weeks to go back = time - 10 * 4 (weeks) + base week
        $param->table = 'weekly';
        $param->timeafter = strtotime("-".(($time - 10)*4)." weeks",stats_get_base_weekly());
    } else { // monthlies.
        // number of months to go back = time - 20 * months + base month
        $param->table = 'monthly';
        $param->timeafter = strtotime("-".($time - 20)." months",stats_get_base_monthly());
    }

    $param->extras = '';

    // compatibility - if we're in postgres, cast to real for some reports.
    $real = '';
    if ($CFG->dbfamily == 'postgres') {
        $real = '::real';
    }

    switch ($report) {
    // ******************** STATS_MODE_GENERAL ******************** //
    case STATS_REPORT_LOGINS:
        $param->fields = 'timeend,sum(stat1) as line1,sum(stat2) as line2';
        $param->fieldscomplete = true;
        $param->stattype = 'logins';
        $param->line1 = get_string('statslogins');
        $param->line2 = get_string('statsuniquelogins');
        if ($courseid == SITEID) {
            $param->extras = 'GROUP BY timeend';
        }
        break;

    case STATS_REPORT_READS:
        $param->fields = $db->Concat('timeend','roleid').' AS uniqueid, timeend, roleid, stat1 as line1';
        $param->fieldscomplete = true; // set this to true to avoid anything adding stuff to the list and breaking complex queries.
        $param->aggregategroupby = 'roleid';
        $param->stattype = 'activity';
        $param->crosstab = true;
        $param->extras = 'GROUP BY timeend,roleid,stat1';
        if ($courseid == SITEID) {
            $param->fields = $db->Concat('timeend','roleid').' AS uniqueid, timeend, roleid, sum(stat1) as line1';
            $param->extras = 'GROUP BY timeend,roleid';
        }
        break;

    case STATS_REPORT_WRITES: 
        $param->fields = $db->Concat('timeend','roleid').' AS uniqueid, timeend, roleid, stat2 as line1';
        $param->fieldscomplete = true; // set this to true to avoid anything adding stuff to the list and breaking complex queries.
        $param->aggregategroupby = 'roleid';
        $param->stattype = 'activity';
        $param->crosstab = true;
        $param->extras = 'GROUP BY timeend,roleid,stat2';
        if ($courseid == SITEID) {
            $param->fields = $db->Concat('timeend','roleid').' AS uniqueid, timeend, roleid, sum(stat2) as line1';
            $param->extras = 'GROUP BY timeend,roleid';
        }
        break;

    case STATS_REPORT_ACTIVITY:
        $param->fields = $db->Concat('timeend','roleid').' AS uniqueid, timeend, roleid, sum(stat1+stat2) as line1';
        $param->fieldscomplete = true; // set this to true to avoid anything adding stuff to the list and breaking complex queries.
        $param->aggregategroupby = 'roleid';
        $param->stattype = 'activity';
        $param->crosstab = true;
        $param->extras = 'GROUP BY timeend,roleid';
        if ($courseid == SITEID) {
            $param->extras = 'GROUP BY timeend,roleid';
        }
        break;

    case STATS_REPORT_ACTIVITYBYROLE;
        $param->fields = 'stat1 AS line1, stat2 AS line2';
        $param->stattype = 'activity';
        $rolename = get_field('role','name','id',$roleid);
        $param->line1 = $rolename . get_string('statsreads');
        $param->line2 = $rolename . get_string('statswrites');
        if ($courseid == SITEID) {
            $param->extras = 'GROUP BY timeend';
        }
        break;

    // ******************** STATS_MODE_DETAILED ******************** //
    case STATS_REPORT_USER_ACTIVITY:
        $param->fields = 'statsreads as line1, statswrites as line2';
        $param->line1 = get_string('statsuserreads');
        $param->line2 = get_string('statsuserwrites');
        $param->stattype = 'activity';
        break;

    case STATS_REPORT_USER_ALLACTIVITY:
        $param->fields = 'statsreads+statswrites as line1';
        $param->line1 = get_string('statsuseractivity');
        $param->stattype = 'activity';
        break;

    case STATS_REPORT_USER_LOGINS:
        $param->fields = 'statsreads as line1';
        $param->line1 = get_string('statsuserlogins');
        $param->stattype = 'logins';
        break;

    case STATS_REPORT_USER_VIEW:
        $param->fields = 'statsreads as line1, statswrites as line2, statsreads+statswrites as line3';
        $param->line1 = get_string('statsuserreads');
        $param->line2 = get_string('statsuserwrites');
        $param->line3 = get_string('statsuseractivity');
        $param->stattype = 'activity';
        break;

    // ******************** STATS_MODE_RANKED ******************** //
    case STATS_REPORT_ACTIVE_COURSES: 
        $param->fields = 'sum(stat1+stat2) AS line1';
        $param->stattype = 'activity';
        $param->orderby = 'line1 DESC';
        $param->line1 = get_string('activity');
        $param->graphline = 'line1';
        break;

    case STATS_REPORT_ACTIVE_COURSES_WEIGHTED:
        $threshold = 0;
        if (!empty($CFG->statsuserthreshold) && is_numeric($CFG->statsuserthreshold)) {
            $threshold = $CFG->statsuserthreshold;
        }
        $param->fields = '';
        $param->sql = 'SELECT activity.courseid, activity.all_activity AS line1, enrolments.highest_enrolments AS line2,
                        activity.all_activity / enrolments.highest_enrolments as line3 
                       FROM (
                            SELECT courseid, sum(stat1+stat2) AS all_activity 
                            FROM '.$CFG->prefix.'stats_'.$param->table.'
                            WHERE stattype=\'activity\' AND timeend >= '.$param->timeafter.'
                            GROUP BY courseid
                       ) activity
                       INNER JOIN 
                            (
                            SELECT courseid, max(stat1) AS highest_enrolments 
                            FROM '.$CFG->prefix.'stats_'.$param->table.'
                            WHERE stattype=\'enrolments\' AND timeend >= '.$param->timeafter.'
                            GROUP BY courseid
                      ) enrolments
                      ON (activity.courseid = enrolments.courseid)
                      WhERE enrolments.highest_enrolments > '.$threshold.'
                      ORDER BY line3 DESC';
        $param->line1 = get_string('activity');
        $param->line2 = get_string('users');
        $param->line3 = get_string('activityweighted');
        $param->graphline = 'line3';
        break;

    case STATS_REPORT_PARTICIPATORY_COURSES:
        $threshold = 0;
        if (!empty($CFG->statsuserthreshold) && is_numeric($CFG->statsuserthreshold)) {
            $threshold = $CFG->statsuserthreshold;
        }
        $param->fields = '';
        $param->sql = 'SELECT courseid, ceil(avg(all_enrolments)) as line1,
                         ceil(avg(active_enrolments)) as line2, avg(proportion_active) AS line3 
                       FROM (
                           SELECT courseid, timeend, sum(stat2) as active_enrolments, 
                              sum(stat1) as all_enrolments, sum(stat2)'.$real.'/sum(stat1)'.$real.' as proportion_active 
                           FROM '.$CFG->prefix.'stats_'.$param->table.' WHERE stattype=\'enrolments\' 
                           GROUP BY courseid, timeend
                           HAVING sum(stat1) > '.$threshold.'
                       ) aq 
                       WHERE timeend >= '.$param->timeafter.'
                       GROUP BY courseid
                       ORDER BY line3 DESC';

        $param->line1 = get_string('users');
        $param->line2 = get_string('activeusers');
        $param->line3 = get_string('participationratio');
        $param->graphline = 'line3';
        break;

    case STATS_REPORT_PARTICIPATORY_COURSES_RW:
        $param->fields = '';
        $param->sql =  'SELECT courseid, sum(views) AS line1, sum(posts) AS line2,
                           avg(proportion_active) AS line3
                         FROM (
                           SELECT courseid, timeend,sum(stat1) as views, sum(stat2) AS posts,
                            sum(stat2)'.$real.'/sum(stat1)'.$real.' as proportion_active 
                           FROM '.$CFG->prefix.'stats_'.$param->table.' WHERE stattype=\'activity\' 
                           GROUP BY courseid, timeend
                           HAVING sum(stat1) > 0
                       ) aq 
                       WHERE timeend >= '.$param->timeafter.'
                       GROUP BY courseid
                       ORDER BY line3 DESC';
        $param->line1 = get_string('views');
        $param->line2 = get_string('posts');
        $param->line3 = get_string('participationratio');
        $param->graphline = 'line3';
        break;
    }

    /*
    if ($courseid == SITEID && $mode != STATS_MODE_RANKED) { // just aggregate all courses.
        $param->fields = preg_replace('/(?:sum)([a-zA-Z0-9+_]*)\W+as\W+([a-zA-Z0-9_]*)/i','sum($1) as $2',$param->fields);
        $param->extras = ' GROUP BY timeend'.((!empty($param->aggregategroupby)) ? ','.$param->aggregategroupby : '');
    }
    */
    //TODO must add the SITEID reports to the rest of the reports.
    return $param;
} 

function stats_get_view_actions() {
    return array('view','view all','history');
}

function stats_get_post_actions() {
    return array('add','delete','edit','add mod','delete mod','edit section'.'enrol','loginas','new','unenrol','update','update mod');
}

function stats_get_action_sql_in($str) {
    global $CFG;
    
    $mods = get_records('modules');
    $function = 'stats_get_'.$str.'_actions';
    $actions = $function();
    foreach ($mods as $mod) {
        $file = $CFG->dirroot.'/mod/'.$mod->name.'/lib.php';
        if (!is_readable($file)) {
            continue;
        }
        require_once($file);
        $function = $mod->name.'_get_'.$str.'_actions';
        if (function_exists($function)) {
            $actions = array_merge($actions,$function());
        }
    }
    $actions = array_unique($actions);
    if (empty($actions)) {
        return ' ';
    } else if (count($actions) == 1) {
        return ' AND l.action = '.array_pop($actions).' ';
    } else {
        return ' AND l.action IN (\''.implode('\',\'',$actions).'\') ';
    }
}


function stats_get_course_users($course,$timesql) {
    global $CFG;
    
    $timesql = str_replace('timeend','l.time',$timesql);

    $sql = "SELECT userid, primaryrole FROM (
                SELECT active_course_users.userid,
                    (SELECT roleid FROM {$CFG->prefix}role_assignments outer_r_a INNER JOIN {$CFG->prefix}role outer_r ON outer_r_a.roleid=outer_r.id
                        INNER JOIN {$CFG->prefix}context c ON outer_r_a.contextid = c.id
                        WHERE c.instanceid=".$course->id." AND c.contextlevel = ".CONTEXT_COURSE." AND outer_r_a.userid=active_course_users.userid
                        AND NOT EXISTS (SELECT 1 FROM {$CFG->prefix}role_assignments inner_r_a
                            INNER JOIN {$CFG->prefix}role inner_r ON inner_r_a.roleid = inner_r.id
                            WHERE inner_r.sortorder < outer_r.sortorder
                            AND inner_r_a.userid = outer_r_a.userid
                            AND inner_r_a.contextid = outer_r_a.contextid
                        )
                    ) AS primaryrole
                    FROM (SELECT DISTINCT userid FROM {$CFG->prefix}log l WHERE course=".$course->id." AND ".$timesql." )
                    active_course_users
                ) foo WHERE primaryrole IS NOT NULL";
    if (!$users = get_records_sql($sql)) {
        $users = array();
    } 

    return $users;

}

function stats_do_daily_user_cron($course,$user,$roleid,$timesql,$timeend,$mods) {

    global $CFG;

    $stat = new StdClass;
    $stat->userid   = $user->userid;
    $stat->roleid   = $roleid;
    $stat->courseid = $course->id;
    $stat->stattype = 'activity';
    $stat->timeend  = $timeend;
    
    $sql = 'SELECT COUNT(l.id) FROM '.$CFG->prefix.'log l WHERE l.userid = '.$user->userid
        .' AND  l.course = '.$course->id
        .' AND '.$timesql .' '.stats_get_action_sql_in('view');

    $stat->statsreads  = count_records_sql($sql);
    
    $sql = 'SELECT COUNT(l.id) FROM '.$CFG->prefix.'log l WHERE l.userid = '.$user->userid
        .' AND l.course = '.$course->id
        .' AND '.$timesql.' '.stats_get_action_sql_in('post');

    $stat->statswrites = count_records_sql($sql);
                
    insert_record('stats_user_daily',$stat,false);

    // now ask the modules if they want anything.
    foreach ($mods as $mod => $fname) {
        mtrace('  doing daily statistics for '.$mod->name);
        $fname($course,$user,$timeend,$roleid);
    }
}

function stats_do_aggregate_user_cron($course,$user,$roleid,$timesql,$timeend,$timestr,$mods) {

    global $CFG;

    $stat = new StdClass;
    $stat->userid   = $user->userid;
    $stat->roleid   = $roleid;
    $stat->courseid = $course->id;
    $stat->stattype = 'activity';
    $stat->timeend  = $timeend;

    $sql = 'SELECT sum(statsreads) as statsreads, sum(statswrites) as statswrites FROM '.$CFG->prefix.'stats_user_daily WHERE courseid = '.$course->id.' AND '.$timesql
        ." AND roleid=".$roleid." AND userid = ".$stat->userid." AND stattype='activity'"; // add on roleid in case they have teacher and student records.
    
    $r = get_record_sql($sql);
    $stat->statsreads = (empty($r->statsreads)) ? 0 : $r->statsreads;
    $stat->statswrites = (empty($r->statswrites)) ? 0 : $r->statswrites;
    
    insert_record('stats_user_'.$timestr,$stat,false);

    // now ask the modules if they want anything.
    foreach ($mods as $mod => $fname) {
        mtrace('  doing '.$timestr.' statistics for '.$mod->name);
        $fname($course,$user,$timeend,$roleid);
    }
}

function stats_do_aggregate_user_login_cron($timesql,$timeend,$timestr) {
    global $CFG;
    
    $sql = 'SELECT userid,roleid,sum(statsreads) as statsreads, sum(statswrites) as writes FROM '.$CFG->prefix.'stats_user_daily WHERE stattype = \'logins\' AND '.$timesql.' GROUP BY userid,roleid';
    
    if ($users = get_records_sql($sql)) {
        foreach ($users as $stat) {
            $stat->courseid = SITEID;
            $stat->timeend = $timeend;
            $stat->stattype = 'logins';
            
            insert_record('stats_user_'.$timestr,$stat,false);
        }
    }
}


function stats_get_time_options($now,$lastweekend,$lastmonthend,$earliestday,$earliestweek,$earliestmonth) {

    $now = stats_get_base_daily(time());
    // it's really important that it's TIMEEND in the table. ie, tuesday 00:00:00 is monday night.
    // so we need to take a day off here (essentially add a day to $now
    $now += 60*60*24;

    $timeoptions = array();

    if ($now - (60*60*24*7) >= $earliestday) {
        $timeoptions[STATS_TIME_LASTWEEK] = get_string('numweeks','moodle',1);
    }
    if ($now - (60*60*24*14) >= $earliestday) {
        $timeoptions[STATS_TIME_LAST2WEEKS] = get_string('numweeks','moodle',2);
    }
    if ($now - (60*60*24*21) >= $earliestday) {
        $timeoptions[STATS_TIME_LAST3WEEKS] = get_string('numweeks','moodle',3); 
    }
    if ($now - (60*60*24*28) >= $earliestday) {
        $timeoptions[STATS_TIME_LAST4WEEKS] = get_string('numweeks','moodle',4);// show dailies up to (including) here.
    }
    if ($lastweekend - (60*60*24*56) >= $earliestweek) {
        $timeoptions[STATS_TIME_LAST2MONTHS] = get_string('nummonths','moodle',2);
    }
    if ($lastweekend - (60*60*24*84) >= $earliestweek) {
        $timeoptions[STATS_TIME_LAST3MONTHS] = get_string('nummonths','moodle',3);
    }
    if ($lastweekend - (60*60*24*112) >= $earliestweek) {
        $timeoptions[STATS_TIME_LAST4MONTHS] = get_string('nummonths','moodle',4);
    }
    if ($lastweekend - (60*60*24*140) >= $earliestweek) {
        $timeoptions[STATS_TIME_LAST5MONTHS] = get_string('nummonths','moodle',5);
    }
    if ($lastweekend - (60*60*24*168) >= $earliestweek) {
        $timeoptions[STATS_TIME_LAST6MONTHS] = get_string('nummonths','moodle',6); // show weeklies up to (including) here
    }
    if (strtotime('-7 months',$lastmonthend) >= $earliestmonth) {
        $timeoptions[STATS_TIME_LAST7MONTHS] = get_string('nummonths','moodle',7);
    }
    if (strtotime('-8 months',$lastmonthend) >= $earliestmonth) {
        $timeoptions[STATS_TIME_LAST8MONTHS] = get_string('nummonths','moodle',8);
    }
    if (strtotime('-9 months',$lastmonthend) >= $earliestmonth) {
        $timeoptions[STATS_TIME_LAST9MONTHS] = get_string('nummonths','moodle',9);
    }
    if (strtotime('-10 months',$lastmonthend) >= $earliestmonth) {
        $timeoptions[STATS_TIME_LAST10MONTHS] = get_string('nummonths','moodle',10);
    }
    if (strtotime('-11 months',$lastmonthend) >= $earliestmonth) {
        $timeoptions[STATS_TIME_LAST11MONTHS] = get_string('nummonths','moodle',11);
    }
    if (strtotime('-1 year',$lastmonthend) >= $earliestmonth) {
        $timeoptions[STATS_TIME_LASTYEAR] = get_string('lastyear');
    }

    return $timeoptions;
}

function stats_get_report_options($courseid,$mode) {
    global $CFG;
    
    $reportoptions = array();

    switch ($mode) {
    case STATS_MODE_GENERAL:
        $reportoptions[STATS_REPORT_ACTIVITY] = get_string('statsreport'.STATS_REPORT_ACTIVITY);
        if ($courseid != SITEID && $context = get_context_instance(CONTEXT_COURSE, $courseid)) {
            $sql = 'SELECT r.id,r.name FROM '.$CFG->prefix.'role r JOIN '.$CFG->prefix.'stats_daily s ON s.roleid = r.id WHERE s.courseid = '.$courseid;
            if ($roles = get_records_sql($sql)) {
                foreach ($roles as $role) {
                    $reportoptions[STATS_REPORT_ACTIVITYBYROLE.$role->id] = get_string('statsreport'.STATS_REPORT_ACTIVITYBYROLE). ' '.$role->name;
                }
            }
        }
        $reportoptions[STATS_REPORT_READS] = get_string('statsreport'.STATS_REPORT_READS);
        $reportoptions[STATS_REPORT_WRITES] = get_string('statsreport'.STATS_REPORT_WRITES);
        if ($courseid == SITEID) {
            $reportoptions[STATS_REPORT_LOGINS] = get_string('statsreport'.STATS_REPORT_LOGINS);
        }
        
        break;
    case STATS_MODE_DETAILED:
        $reportoptions[STATS_REPORT_USER_ACTIVITY] = get_string('statsreport'.STATS_REPORT_USER_ACTIVITY);
        $reportoptions[STATS_REPORT_USER_ALLACTIVITY] = get_string('statsreport'.STATS_REPORT_USER_ALLACTIVITY);
        if (has_capability('moodle/site:viewreports', get_context_instance(CONTEXT_SYSTEM, SITEID))) {
            $site = get_site();
            $reportoptions[STATS_REPORT_USER_LOGINS] = get_string('statsreport'.STATS_REPORT_USER_LOGINS);
        }
        break;
    case STATS_MODE_RANKED:
        if (has_capability('moodle/site:viewreports', get_context_instance(CONTEXT_SYSTEM, SITEID))) {
            $reportoptions[STATS_REPORT_ACTIVE_COURSES] = get_string('statsreport'.STATS_REPORT_ACTIVE_COURSES);
            $reportoptions[STATS_REPORT_ACTIVE_COURSES_WEIGHTED] = get_string('statsreport'.STATS_REPORT_ACTIVE_COURSES_WEIGHTED);
            $reportoptions[STATS_REPORT_PARTICIPATORY_COURSES] = get_string('statsreport'.STATS_REPORT_PARTICIPATORY_COURSES);
            $reportoptions[STATS_REPORT_PARTICIPATORY_COURSES_RW] = get_string('statsreport'.STATS_REPORT_PARTICIPATORY_COURSES_RW);
        }
     break;
    }
  
    return $reportoptions;
}

function stats_fix_zeros($stats,$timeafter,$timestr,$line2=true,$line3=false) {

    if (empty($stats)) {
        return;
    }

    $timestr = str_replace('user_','',$timestr); // just in case.
    $fun = 'stats_get_base_'.$timestr;
    
    $now = $fun();

    $times = array();
    // add something to timeafter since it is our absolute base
    $actualtimes = array();
    foreach ($stats as $s) {
        $actualtimes[] = $s->timeend;
    }

    $timeafter = array_pop(array_values($actualtimes));

    while ($timeafter < $now) {
        $times[] = $timeafter;
        if ($timestr == 'daily') {
            $timeafter = stats_get_next_dayend($timeafter);
        } else if ($timestr == 'weekly') {
            $timeafter = stats_get_next_weekend($timeafter);
        } else if ($timestr == 'monthly') {
            $timeafter = stats_get_next_monthend($timeafter);
        } else {
            return $stats; // this will put us in a never ending loop.
        }
    }

    foreach ($times as $count => $time) {
        if (!in_array($time,$actualtimes) && $count != count($times) -1) {
            $newobj = new StdClass;
            $newobj->timeend = $time;
            $newobj->id = 0;
            $newobj->roleid = 0;
            $newobj->line1 = 0;
            if (!empty($line2)) {
                $newobj->line2 = 0;
            }
            if (!empty($line3)) {
                $newobj->line3 = 0;
            }
            $newobj->zerofixed = true;
            $stats[] = $newobj;
        }
    }
    
    usort($stats,"stats_compare_times");
    return $stats;

}

// helper function to sort arrays by $obj->timeend
function stats_compare_times($a,$b) {
   if ($a->timeend == $b->timeend) {
       return 0;
   }
   return ($a->timeend > $b->timeend) ? -1 : 1;
}

function stats_check_runtime() {
    global $CFG;
    
    if (empty($CFG->statsmaxruntime)) {
        return true;
    }
    
    if ((time() - $CFG->statsrunning) < $CFG->statsmaxruntime) {
        return true;
    }
    
    return false; // we've gone over! 
        
}

function stats_check_uptodate($courseid=0) {
    global $CFG;

    if (empty($courseid)) {
        $courseid = SITEID;
    }

    $latestday = stats_get_start_from('daily');

    if ((time() - 60*60*24*2) < $latestday) { // we're ok
        return NULL;
    }

    $a = new object();
    $a->daysdone = get_field_sql("SELECT count(distinct(timeend)) from {$CFG->prefix}stats_daily");

    // how many days between the last day and now?
    $a->dayspending = ceil((stats_get_base_daily() - $latestday)/(60*60*24));

    if ($a->dayspending == 0 && $a->daysdone != 0) {
        return NULL; // we've only just started...
    }

    //return error as string
    return get_string('statscatchupmode','error',$a);
}


// copied from usergetmidnight, but we ignore dst
function stats_getmidnight($date, $timezone=99) {
    $timezone = get_user_timezone_offset($timezone);
    $userdate = getdate($date);
    return make_timestamp($userdate['year'], $userdate['mon'], $userdate['mday'], 0, 0, 0, $timezone,false ); // ignore dst for this.
}

function stats_getdate($time, $timezone=99) {

    $timezone = get_user_timezone_offset($timezone);

    if (abs($timezone) > 13) {    // Server time
        return getdate($time);
    }

    // There is no gmgetdate so we use gmdate instead
    $time += intval((float)$timezone * HOURSECS);
    $datestring = strftime('%S_%M_%H_%d_%m_%Y_%w_%j_%A_%B', $time);
    list(
        $getdate['seconds'],
        $getdate['minutes'],
        $getdate['hours'],
        $getdate['mday'],
        $getdate['mon'],
        $getdate['year'],
        $getdate['wday'],
        $getdate['yday'],
        $getdate['weekday'],
        $getdate['month']
    ) = explode('_', $datestring);

    return $getdate;
}


function stats_upgrade_for_roles_wrapper() {
    global $CFG;
    if (!empty($CFG->statsrolesupgraded)) {
        return true;
    }

    $result = begin_sql();
    
    $result = $result && stats_upgrade_user_table_for_roles('daily');
    $result = $result && stats_upgrade_user_table_for_roles('weekly');
    $result = $result && stats_upgrade_user_table_for_roles('monthly');
    
    $result = $result && stats_upgrade_table_for_roles('daily');
    $result = $result && stats_upgrade_table_for_roles('weekly');
    $result = $result && stats_upgrade_table_for_roles('monthly');

    
    $result = $result && commit_sql();

    if (!empty($result)) {
        set_config('statsrolesupgraded',time());
    }

    return $result;
}

/**
 * Upgrades a prefix_stats_user_* table for the new role based permission
 * system.
 *
 * @param string $period  daily, weekly or monthly: the stat period to upgrade
 * @return boolean @todo maybe something else (error message) depending on
 * how this will be called.
 */
function stats_upgrade_user_table_for_roles ($period) {
    global $CFG;
    static $teacher_role_id, $student_role_id;

    if (!in_array($period, array('daily', 'weekly', 'monthly'))) {
        error_log('stats upgrade:  invalid period: ' . $period);
        return false;
    }

    if (!$teacher_role_id) {
        $role            = get_roles_with_capability('moodle/legacy:editingteacher', CAP_ALLOW);
        $role            = array_keys($role);
        $teacher_role_id = $role[0];
        $role            = get_roles_with_capability('moodle/legacy:student', CAP_ALLOW);
        $role            = array_keys($role);
        $student_role_id = $role[0];
    }

    if (empty($teacher_role_id) || empty($student_role_id)) {
        error_log("Couldn't find legacy roles for teacher or student");
        return false;
    }

    $status = true;

    $status = $status && execute_sql("UPDATE {$CFG->prefix}stats_user_{$period}
        SET roleid = $teacher_role_id
        WHERE roleid = 1");
    $status = $status && execute_sql("UPDATE {$CFG->prefix}stats_user_{$period}
        SET roleid = $student_role_id
        WHERE roleid = 2");

    return $status;
}

/**
 * Upgrades a prefix_stats_* table for the new role based permission system.
 *
 * @param string $period  daily, weekly or monthly: the stat period to upgrade
 * @return boolean        @todo depends on how this will be called
 */
function stats_upgrade_table_for_roles ($period) {
    global $CFG;
    static $teacher_role_id, $student_role_id;

    if (!in_array($period, array('daily', 'weekly', 'monthly'))) {
        return false;
    }
    
    if (!$teacher_role_id) {
        $role            = get_roles_with_capability('moodle/legacy:teacher', CAP_ALLOW);
        $role            = array_keys($role);
        $teacher_role_id = $role[0];
        $role            = get_roles_with_capability('moodle/legacy:student', CAP_ALLOW);
        $role            = array_keys($role);
        $student_role_id = $role[0];
    }

    if (empty($teacher_role_id) || empty($student_role_id)) {
        error_log("Couldn't find legacy roles for teacher or student");
        return false;
    }

    execute_sql("CREATE TABLE {$CFG->prefix}stats_{$period}_tmp AS
        SELECT * FROM {$CFG->prefix}stats_{$period}");

    $table = new XMLDBTable('stats_' . $period);
    if (!drop_table($table)) {
        return false;
    }

    // Create a new stats table
    // @todo this definition I have made blindly by looking at how definitions are
    // made, it needs work to make sure it works properly
    require_once("$CFG->libdir/xmldb/classes/XMLDBTable.class.php");

    $table = new XMLDBTable('stats_' . $period);
    $table->addFieldInfo('id', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED,
        XMLDB_NOTNULL, XMLDB_SEQUENCE, null, null, null);

    $table->addFieldInfo('courseid', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED,
        XMLDB_NOTNULL, null, null, null, null);

    $table->addFieldInfo('roleid', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED,
        XMLDB_NOTNULL, null, null, null, null);
    $table->addFieldInfo('timeend', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED,
        XMLDB_NOTNULL, null, null, null, null);
    $table->addFieldInfo('stattype', XMLDB_TYPE_CHAR, '20', null, XMLDB_NOTNULL,
        null, XMLDB_ENUM, array('enrolments', 'activity', 'logins'), 'activity');
    $table->addFieldInfo('stat1', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED,
        XMLDB_NOTNULL, null, null, null, null);
    $table->addFieldInfo('stat2', XMLDB_TYPE_INTEGER, '10', XMLDB_UNSIGNED,
        XMLDB_NOTNULL, null, null, null, null);

    /// Adding keys to table stats_daily
    $table->addKeyInfo('primary', XMLDB_KEY_PRIMARY, array('id'));

    /// Adding indexes to table stats_daily
    $table->addIndexInfo('courseid', XMLDB_INDEX_NOTUNIQUE, array('courseid'));
    $table->addIndexInfo('timeend', XMLDB_INDEX_NOTUNIQUE, array('timeend'));
    $table->addIndexInfo('roleid', XMLDB_INDEX_NOTUNIQUE, array('roleid'));

    if (!create_table($table)) {
        return false;
    }

    //
    // Now insert the data from the temporary table into the new one
    //

    // Student enrolments
    execute_sql("INSERT INTO {$CFG->prefix}stats_{$period}
       (courseid, roleid, timeend, stattype, stat1, stat2)
       SELECT courseid, $student_role_id, timeend, 'enrolments', students, activestudents
       FROM {$CFG->prefix}stats_{$period}_tmp");

    // Teacher enrolments
    execute_sql("INSERT INTO {$CFG->prefix}stats_{$period}
       (courseid, roleid, timeend, stattype, stat1, stat2)
       SELECT courseid, $teacher_role_id, timeend, 'enrolments', teachers, activeteachers
       FROM {$CFG->prefix}stats_{$period}_tmp");

    // Student activity
    execute_sql("INSERT INTO {$CFG->prefix}stats_{$period}
       (courseid, roleid, timeend, stattype, stat1, stat2)
       SELECT courseid, $student_role_id, timeend, 'activity', studentreads, studentwrites
       FROM {$CFG->prefix}stats_{$period}_tmp");

    // Teacher activity
    execute_sql("INSERT INTO {$CFG->prefix}stats_{$period}
       (courseid, roleid, timeend, stattype, stat1, stat2)
       SELECT courseid, $teacher_role_id, timeend, 'activity', teacherreads, teacherwrites
       FROM {$CFG->prefix}stats_{$period}_tmp");

    // Logins
    execute_sql("INSERT INTO {$CFG->prefix}stats_{$period}
       (courseid, roleid, timeend, stattype, stat1, stat2)
       SELECT courseid, 0, timeend, 'logins', logins, uniquelogins
       FROM {$CFG->prefix}stats_{$period}_tmp WHERE courseid = ".SITEID);

    // Drop the temporary table
    $table = new XMLDBTable('stats_' . $period . '_tmp');
    if (!drop_table($table)) {
        return false;
    }

    return true;
}

?>