<?php
require_once 'config.php';

try {
    $pdo = db();
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    // Create courses table
    $sql_courses = "CREATE TABLE IF NOT EXISTS courses (
        id INT AUTO_INCREMENT PRIMARY KEY,
        name VARCHAR(255) NOT NULL,
        teacher_id INT NOT NULL,
        FOREIGN KEY (teacher_id) REFERENCES users(id)
    )";
    $pdo->exec($sql_courses);
    echo "Table 'courses' created successfully.\n";

    // Create enrollments table
    $sql_enrollments = "CREATE TABLE IF NOT EXISTS enrollments (
        id INT AUTO_INCREMENT PRIMARY KEY,
        student_id INT NOT NULL,
        course_id INT NOT NULL,
        FOREIGN KEY (student_id) REFERENCES users(id),
        FOREIGN KEY (course_id) REFERENCES courses(id)
    )";
    $pdo->exec($sql_enrollments);
    echo "Table 'enrollments' created successfully.\n";

    // Create activities table
    $sql_activities = "CREATE TABLE IF NOT EXISTS activities (
        id INT AUTO_INCREMENT PRIMARY KEY,
        enrollment_id INT NOT NULL,
        activity_name VARCHAR(255) NOT NULL,
        grade INT,
        activity_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
        FOREIGN KEY (enrollment_id) REFERENCES enrollments(id)
    )";
    $pdo->exec($sql_activities);
    echo "Table 'activities' created successfully.\n";

    // Sample Data
    // Hash a default password
    $password = password_hash('password', PASSWORD_DEFAULT);

    // Truncate tables before inserting sample data to avoid duplicates on re-run
    $pdo->exec("SET FOREIGN_KEY_CHECKS = 0");
    $pdo->exec("TRUNCATE TABLE activities");
    $pdo->exec("TRUNCATE TABLE enrollments");
    $pdo->exec("TRUNCATE TABLE courses");
    $pdo->exec("TRUNCATE TABLE users");
    $pdo->exec("SET FOREIGN_KEY_CHECKS = 1");
    echo "Tables truncated successfully.\n";

    // Insert a teacher
    $pdo->exec("INSERT INTO users (email, password, role) VALUES ('teacher@example.com', '$password', 'teacher')");
    $teacher_id = $pdo->lastInsertId();
    echo "Sample teacher inserted.\n";

    // Insert courses for the teacher
    $stmt = $pdo->prepare("INSERT INTO courses (name, teacher_id) VALUES (?, ?)");
    $stmt->execute(['Algebra 101', $teacher_id]);
    $course1_id = $pdo->lastInsertId();
    $stmt->execute(['History of Algebra', $teacher_id]);
    $course2_id = $pdo->lastInsertId();
    echo "Sample courses inserted.\n";

    // Insert students
    $stmt = $pdo->prepare("INSERT INTO users (email, password, role) VALUES (?, ?, ?)");
    $stmt->execute(['student1@example.com', $password, 'student']);
    $student1_id = $pdo->lastInsertId();
    $stmt->execute(['student2@example.com', $password, 'student']);
    $student2_id = $pdo->lastInsertId();
    echo "Sample students inserted.\n";

    // Enroll students in courses
    $stmt = $pdo->prepare("INSERT INTO enrollments (student_id, course_id) VALUES (?, ?)");
    $stmt->execute([$student1_id, $course1_id]);
    $enrollment1_id = $pdo->lastInsertId();
    $stmt->execute([$student2_id, $course1_id]);
    $enrollment2_id = $pdo->lastInsertId();
    $stmt->execute([$student1_id, $course2_id]);
    $enrollment3_id = $pdo->lastInsertId();
    echo "Students enrolled in courses.\n";

    // Add student activities
    $stmt = $pdo->prepare("INSERT INTO activities (enrollment_id, activity_name, grade) VALUES (?, ?, ?)");
    $stmt->execute([$enrollment1_id, 'Homework 1', 95]);
    $stmt->execute([$enrollment1_id, 'Quiz 1', 88]);
    $stmt->execute([$enrollment2_id, 'Homework 1', 72]);
    $stmt->execute([$enrollment3_id, 'Research Paper', 92]);
    echo "Student activities added.\n";


} catch (PDOException $e) {
    die("ERROR: Could not able to execute script. " . $e->getMessage());
}

unset($pdo);
?>