<?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/>.

require_once '../../../config.php';
require_once $CFG->libdir.'/gradelib.php';
require_once $CFG->dirroot.'/grade/lib.php';
require_once $CFG->dirroot.'/grade/report/overview/lib.php';

$courseid = required_param('id', PARAM_INT);
$userid   = optional_param('userid', $USER->id, PARAM_INT);

$PAGE->set_url(new moodle_url('/grade/report/overview/index.php', array('id'=>$courseid)));

/// basic access checks
if (!$course = $DB->get_record('course', array('id' => $courseid))) {
    print_error('nocourseid');
}
require_login($course);

$context = get_context_instance(CONTEXT_COURSE, $course->id);
$systemcontext = get_context_instance(CONTEXT_SYSTEM);
require_capability('gradereport/overview:view', $context);

if (empty($userid)) {
    require_capability('moodle/grade:viewall', $systemcontext);

} else {
    if (!$DB->get_record('user', array('id'=>$userid, 'deleted'=>0)) or isguestuser($userid)) {
        print_error('invaliduserid');
    }
}

$access = false;
if (has_capability('moodle/grade:viewall', $systemcontext)) {
    //ok - can view all course grades
    $access = true;

} else if ($userid == $USER->id and has_capability('moodle/grade:viewall', $context)) {
    //ok - can view any own grades
    $access = true;

} else if ($userid == $USER->id and has_capability('moodle/grade:view', $context) and $course->showgrades) {
    //ok - can view own course grades
    $access = true;

} else if (has_capability('moodle/grade:viewall', get_context_instance(CONTEXT_USER, $userid)) and $course->showgrades) {
    // ok - can view grades of this user- parent most probably
    $access = true;
}

if (!$access) {
    // no access to grades!
    print_error('nopermissiontoviewgrades', 'error',  $CFG->wwwroot.'/course/view.php?id='.$courseid);
}

/// return tracking object
$gpr = new grade_plugin_return(array('type'=>'report', 'plugin'=>'overview', 'courseid'=>$course->id, 'userid'=>$userid));

/// last selected report session tracking
if (!isset($USER->grade_last_report)) {
    $USER->grade_last_report = array();
}
$USER->grade_last_report[$course->id] = 'overview';

//first make sure we have proper final grades - this must be done before constructing of the grade tree
grade_regrade_final_grades($courseid);

if (has_capability('moodle/grade:viewall', $systemcontext)) { //Admins will see all student reports
    // please note this would be extremely slow if we wanted to implement this properly for all teachers
    $groupmode    = groups_get_course_groupmode($course);   // Groups are being used
    $currentgroup = groups_get_course_group($course, true);

    if (!$currentgroup) {      // To make some other functions work better later
        $currentgroup = NULL;
    }

    $isseparategroups = ($course->groupmode == SEPARATEGROUPS and !has_capability('moodle/site:accessallgroups', $context));

    if ($isseparategroups and (!$currentgroup)) {
        // no separate group access, can view only self
        $userid = $USER->id;
        $user_selector = false;
    } else {
        $user_selector = true;
    }

    if (empty($userid)) {
        // Add tabs
        print_grade_page_head($courseid, 'report', 'overview');

        groups_print_course_menu($course, $gpr->get_return_url('index.php?id='.$courseid, array('userid'=>0)));

        if ($user_selector) {
            $renderer = $PAGE->get_renderer('gradereport_overview');
            echo $renderer->graded_users_selector('overview', $course, $userid, $currentgroup, false);
        }
        // do not list all users

    } else { // Only show one user's report
        $report = new grade_report_overview($userid, $gpr, $context);
        print_grade_page_head($courseid, 'report', 'overview', get_string('pluginname', 'gradereport_overview'). ' - '.fullname($report->user));
        groups_print_course_menu($course, $gpr->get_return_url('index.php?id='.$courseid, array('userid'=>0)));

        if ($user_selector) {
            $renderer = $PAGE->get_renderer('gradereport_overview');
            echo $renderer->graded_users_selector('overview', $course, $userid, $currentgroup, false);
        }

        if ($currentgroup and !groups_is_member($currentgroup, $userid)) {
            echo $OUTPUT->notification(get_string('groupusernotmember', 'error'));
        } else {
            if ($report->fill_table()) {
                echo '<br />'.$report->print_table(true);
            }
        }
    }
} else { //Non-admins will see just their own report

    // Create a report instance
    $report = new grade_report_overview($userid, $gpr, $context);

    // print the page
    print_grade_page_head($courseid, 'report', 'overview', get_string('pluginname', 'gradereport_overview'). ' - '.fullname($report->user));

    if ($report->fill_table()) {
        echo '<br />'.$report->print_table(true);
    }
}

echo $OUTPUT->footer();


