CREATE DATABASE IF NOT EXISTS quiz_db;
USE quiz_db;

CREATE TABLE IF NOT EXISTS users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    index_number VARCHAR(50) NOT NULL UNIQUE,
    name VARCHAR(100) NOT NULL,
    institute_name VARCHAR(150) NOT NULL,
    is_admin TINYINT(1) DEFAULT 0,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE IF NOT EXISTS quizzes (
    id INT AUTO_INCREMENT PRIMARY KEY,
    title VARCHAR(255) NOT NULL,
    description TEXT,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE IF NOT EXISTS questions (
    id INT AUTO_INCREMENT PRIMARY KEY,
    quiz_id INT NOT NULL,
    question_text TEXT NOT NULL,
    option_a VARCHAR(255) NOT NULL,
    option_b VARCHAR(255) NOT NULL,
    option_c VARCHAR(255) NOT NULL,
    option_d VARCHAR(255) NOT NULL,
    correct_option VARCHAR(10) NOT NULL,
    FOREIGN KEY (quiz_id) REFERENCES quizzes(id) ON DELETE CASCADE
);

CREATE TABLE IF NOT EXISTS user_scores (
    id INT AUTO_INCREMENT PRIMARY KEY,
    user_id INT NOT NULL,
    quiz_id INT NOT NULL,
    score INT NOT NULL,
    total_questions INT NOT NULL,
    completed_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
    FOREIGN KEY (quiz_id) REFERENCES quizzes(id) ON DELETE CASCADE,
    UNIQUE KEY user_quiz (user_id, quiz_id)
);

CREATE TABLE IF NOT EXISTS user_answers (
    id INT AUTO_INCREMENT PRIMARY KEY,
    user_id INT NOT NULL,
    question_id INT NOT NULL,
    selected_option VARCHAR(10),
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
    FOREIGN KEY (question_id) REFERENCES questions(id) ON DELETE CASCADE,
    UNIQUE KEY user_question (user_id, question_id)
);

-- Insert a default admin user (index number: ADMIN)
INSERT IGNORE INTO users (index_number, name, institute_name, is_admin) VALUES ('ADMIN', 'System Admin', 'System', 1);