<?php
require_once('../../config.php');
require_once($CFG->libdir . '/adminlib.php');
require_once($CFG->libdir . '/gradelib.php');
require_once($CFG->libdir . '/tablelib.php');
require_once($CFG->libdir . '/formslib.php');
require_once($CFG->dirroot . '/user/selector/lib.php');
require_once('classes/user_selector.php');
require_once('classes/usergrades_form.php');
require_once('vendor/autoload.php');

use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;

admin_externalpage_setup('report_usergrades_details', '', null, '', array('capability' => 'report/usergrades:view'));

// Instantiate the form
$mform = new usergrades_form();

// Check if form data is submitted
if ($data = $mform->get_data()) {
    $userid = $data->userid;

    if (!empty($userid)) {
        $user = $DB->get_record('user', array('id' => $userid), '*', MUST_EXIST);
        $courses = enrol_get_users_courses($user->id, true);
        $questions = $DB->get_records('question');

        if (isset($data->exportxls)) { // Assume a form field named 'exportxls' for Excel export action
            // Create a new Spreadsheet object
            $spreadsheet = new Spreadsheet();
            $sheet = $spreadsheet->getActiveSheet();
            $row = 1;

            // Add the user details
            $sheet->setCellValue('A' . $row, get_string('username', 'report_usergrades'));
            $sheet->setCellValue('B' . $row, $user->username);
            $row++;
            $sheet->setCellValue('A' . $row, get_string('firstname', 'report_usergrades'));
            $sheet->setCellValue('B' . $row, $user->firstname);
            $row++;
            $sheet->setCellValue('A' . $row, get_string('lastname', 'report_usergrades'));
            $sheet->setCellValue('B' . $row, $user->lastname);
            $row++;
            $sheet->setCellValue('A' . $row, get_string('email', 'report_usergrades'));
            $sheet->setCellValue('B' . $row, $user->email);
            $row += 2; // Extra space before courses

            // Start iterating the courses
            foreach ($courses as $course) {
                $sheet->setCellValue('A' . $row, get_string('course', 'report_usergrades') . ': ' . $course->fullname);
                $row++;

                $quizzes = $DB->get_records('quiz', array('course' => $course->id));

                if ($quizzes) {
                    foreach ($quizzes as $quiz) {
                        $quiz_attempts = $DB->get_records('quiz_attempts', array('quiz' => $quiz->id, 'userid' => $user->id));

                        if ($quiz_attempts) {
                            $sheet->setCellValue('A' . $row, get_string('quiz', 'report_usergrades') . ': ' . $quiz->name);
                            $row++;

                            foreach ($quiz_attempts as $attempt) {
                                $sheet->setCellValue('A' . $row, get_string('attempt', 'report_usergrades') . ' ' . $attempt->attempt);
                                $row++;

                                $sheet->setCellValue('A' . $row, get_string('question', 'report_usergrades'));
                                $sheet->setCellValue('B' . $row, get_string('response', 'report_usergrades'));
                                $sheet->setCellValue('C' . $row, get_string('grade', 'report_usergrades'));
                                $row++;

                                $question_usages = $DB->get_records('question_usages', array('id' => $attempt->uniqueid));

                                foreach ($question_usages as $question_usage) {
                                    $question_attempts = $DB->get_records('question_attempts', array('questionusageid' => $question_usage->id));

                                    foreach ($question_attempts as $question_attempt) {
                                        $question = $questions[$question_attempt->questionid];
                                        $response = $question_attempt->responsesummary;

                                        $question_grades = $DB->get_records('question_attempt_steps', array('questionattemptid' => $question_attempt->id));

                                        foreach ($question_grades as $question_grade) {
                                            if ($question_grade->fraction) {
                                                $sheet->setCellValue('A' . $row, $question->name . ': ' . $question->questiontext);
                                                $sheet->setCellValue('B' . $row, $response);
                                                $sheet->setCellValue('C' . $row, $question_grade->fraction);
                                                $row++;
                                            }
                                        }
                                    }
                                }

                                $total_grade = $DB->get_record('quiz_grades', array('quiz' => $quiz->id, 'userid' => $user->id));
                                $sheet->setCellValue('A' . $row, get_string('totalgrade', 'report_usergrades') . ': ' . $total_grade->grade . ' / ' . $quiz->grade);
                                $row += 2; // Extra space before next attempt or quiz
                            }
                        }
                    }
                }
                $row += 2; // Extra space between courses
            }

            // Create writer and output the file
            $writer = new Xlsx($spreadsheet);
            $filename = 'user_grades_' . $user->id . '.xlsx';

            // Redirect output to a client’s web browser (Excel2007)
            header('Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
            header('Content-Disposition: attachment;filename="' . $filename . '"');
            header('Cache-Control: max-age=0');

            $writer->save('php://output');
            exit();
        } else {
            // HTML output if not exporting
            echo $OUTPUT->header();
            echo $OUTPUT->heading(get_string('usergradesreport', 'report_usergrades'));

            echo $OUTPUT->heading(get_string('userdetails', 'report_usergrades'), 3);

            $user_table = new html_table();
            $user_table->head = array(get_string('field', 'report_usergrades'), get_string('value', 'report_usergrades'));
            $user_table->data[] = array(get_string('username', 'report_usergrades'), $user->username);
            $user_table->data[] = array(get_string('firstname', 'report_usergrades'), $user->firstname);
            $user_table->data[] = array(get_string('lastname', 'report_usergrades'), $user->lastname);
            $user_table->data[] = array(get_string('email', 'report_usergrades'), $user->email);

            echo html_writer::table($user_table);

            foreach ($courses as $course) {
                echo $OUTPUT->heading($course->fullname, 3);

                $quizzes = $DB->get_records('quiz', array('course' => $course->id));

                if ($quizzes) {
                    echo $OUTPUT->heading(get_string('quizzes', 'report_usergrades'), 4);

                    foreach ($quizzes as $quiz) {
                        $quiz_questions = $DB->get_records('quiz_slots', array('quizid' => $quiz->id));
                        $quiz_attempts = $DB->get_records('quiz_attempts', array('quiz' => $quiz->id, 'userid' => $user->id));

                        if ($quiz_attempts) {
                            echo $OUTPUT->heading($quiz->name, 5);

                            foreach ($quiz_attempts as $attempt) {
                                echo $OUTPUT->heading(get_string('attempt', 'report_usergrades') . ' ' . $attempt->attempt, 6);

                                $attempt_table = new html_table();
                                $attempt_table->head = array(get_string('question', 'report_usergrades'), get_string('response', 'report_usergrades'), get_string('grade', 'report_usergrades'));

                                $question_usages = $DB->get_records('question_usages', array('id' => $attempt->uniqueid));

                                foreach ($question_usages as $question_usage) {
                                    $question_attempts = $DB->get_records('question_attempts', array('questionusageid' => $question_usage->id));

                                    foreach ($question_attempts as $question_attempt) {
                                        $question = $questions[$question_attempt->questionid];
                                        $response = $question_attempt->responsesummary;

                                        $question_grades = $DB->get_records('question_attempt_steps', array('questionattemptid' => $question_attempt->id));

                                        foreach ($question_grades as $question_grade) {
                                            if ($question_grade->fraction) {
                                                $attempt_table->data[] = array($question->name . ': ' . $question->questiontext, $response, $question_grade->fraction);
                                            }
                                        }
                                    }
                                }

                                echo html_writer::table($attempt_table);

                                $total_grade = $DB->get_record('quiz_grades', array('quiz' => $quiz->id, 'userid' => $user->id));

                                echo $OUTPUT->heading(get_string('totalgrade', 'report_usergrades') . ': ' . $total_grade->grade . ' / ' . $quiz->grade, 6);
                            }
                        }
                    }
                }
            }
            echo $OUTPUT->footer();
        }
    } else {
        echo $OUTPUT->notification(get_string('nouserselected', 'report_usergrades'), 'notifyproblem');
    }
} else {
    // Show the form
    echo $OUTPUT->header();
    $mform->display();
    echo $OUTPUT->footer();
}