<?php
require_once '../../config/config.php';
header('Content-Type: application/json');

try {
    $exam_subject_id = isset($_GET['exam_subject_id']) ? (int)$_GET['exam_subject_id'] : 0;

    if ($exam_subject_id <= 0) {
        throw new Exception('Exam Subject ID is required');
    }

    $sql = "SELECT qp.pattern_id, 
                   qp.pattern_name, 
                   qp.total_marks,
                   COUNT(ps.section_id) as total_sections,
                   GROUP_CONCAT(
                       CONCAT(ps.section_name, ' (Q', ps.question_start_num, '-', ps.question_end_num, ' - ', ps.marks_per_question, ' marks)')
                       ORDER BY ps.question_start_num SEPARATOR ', '
                   ) as sections_info
            FROM question_patterns qp
            LEFT JOIN pattern_sections ps ON qp.pattern_id = ps.pattern_id
            WHERE qp.exam_subject_id = ?
            GROUP BY qp.pattern_id
            ORDER BY qp.pattern_name";

    $stmt = $pdo->prepare($sql);
    $stmt->execute([$exam_subject_id]);
    $data = $stmt->fetchAll(PDO::FETCH_ASSOC);

    echo json_encode([
        'status' => 'success',
        'data' => $data
    ]);

} catch (Exception $e) {
    echo json_encode([
        'status' => 'error',
        'message' => $e->getMessage()
    ]);
}
?>