<?php
header('Content-Type: application/json');
require_once __DIR__ . '/../db/config.php';

if (!isset($_GET['course_id'])) {
    echo json_encode(['error' => 'Course ID is required.']);
    exit;
}

$courseId = filter_input(INPUT_GET, 'course_id', FILTER_VALIDATE_INT);

if ($courseId === false) {
    echo json_encode(['error' => 'Invalid Course ID.']);
    exit;
}

try {
    $pdo = db();
    $stmt = $pdo->prepare("SELECT * FROM courses WHERE id = ?");
    $stmt->execute([$courseId]);
    $course = $stmt->fetch();

    if ($course) {
        echo json_encode($course);
    } else {
        echo json_encode(['error' => 'Course not found.']);
    }
} catch (PDOException $e) {
    echo json_encode(['error' => 'Database error: ' . $e->getMessage()]);
}