<?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($CFG->dirroot.'/grade/export/lib.php');

class grade_export_txt extends grade_export {

    public $plugin = 'txt';

    public $separator; // default separator

    public function grade_export_txt($course, $groupid=0, $itemlist='', $export_feedback=false, $updatedgradesonly = false, $displaytype = GRADE_DISPLAY_TYPE_REAL, $decimalpoints = 2, $separator='comma') {
        $this->grade_export($course, $groupid, $itemlist, $export_feedback, $updatedgradesonly, $displaytype, $decimalpoints);
        $this->separator = $separator;
    }

    public function __construct($course, $groupid=0, $itemlist='', $export_feedback=false, $updatedgradesonly = false, $displaytype = GRADE_DISPLAY_TYPE_REAL, $decimalpoints = 2, $separator='comma') {
        parent::__construct($course, $groupid, $itemlist, $export_feedback, $updatedgradesonly, $displaytype, $decimalpoints);
        $this->separator = $separator;
    }

    public function get_export_params() {
        $params = parent::get_export_params();
        $params['separator'] = $this->separator;
        return $params;
    }

    public function print_grades() {
        global $CFG;

        $export_tracking = $this->track_exports();

        $strgrades = get_string('grades');

        switch ($this->separator) {
            case 'comma':
                $separator = ",";
                break;
            case 'tab':
            default:
                $separator = "\t";
        }

        /// Print header to force download
        if (strpos($CFG->wwwroot, 'https://') === 0) { //https sites - watch out for IE! KB812935 and KB316431
            @header('Cache-Control: max-age=10');
            @header('Expires: '. gmdate('D, d M Y H:i:s', 0) .' GMT');
            @header('Pragma: ');
        } else { //normal http - prevent caching at all cost
            @header('Cache-Control: private, must-revalidate, pre-check=0, post-check=0, max-age=0');
            @header('Expires: '. gmdate('D, d M Y H:i:s', 0) .' GMT');
            @header('Pragma: no-cache');
        }
        header("Content-Type: application/download\n");
        $shortname = format_string($this->course->shortname, true, array('context' => get_context_instance(CONTEXT_COURSE, $this->course->id)));
        $downloadfilename = clean_filename("$shortname $strgrades");
        header("Content-Disposition: attachment; filename=\"$downloadfilename.txt\"");

/// Print names of all the fields
        echo get_string("firstname").$separator.
             get_string("lastname").$separator.
             get_string("idnumber").$separator.
             get_string("institution").$separator.
             get_string("department").$separator.
             get_string("email");

        foreach ($this->columns as $grade_item) {
            echo $separator.$this->format_column_name($grade_item);

            /// add a feedback column
            if ($this->export_feedback) {
                echo $separator.$this->format_column_name($grade_item, true);
            }
        }
        echo "\n";

/// Print all the lines of data.
        $geub = new grade_export_update_buffer();
        $gui = new graded_users_iterator($this->course, $this->columns, $this->groupid);
        $gui->init();
        while ($userdata = $gui->next_user()) {

            $user = $userdata->user;

            echo $user->firstname.$separator.$user->lastname.$separator.$user->idnumber.$separator.$user->institution.$separator.$user->department.$separator.$user->email;

            foreach ($userdata->grades as $itemid => $grade) {
                if ($export_tracking) {
                    $status = $geub->track($grade);
                }

                echo $separator.$this->format_grade($grade);

                if ($this->export_feedback) {
                    echo $separator.$this->format_feedback($userdata->feedbacks[$itemid]);
                }
            }
            echo "\n";
        }
        $gui->close();
        $geub->close();

        exit;
    }
}