CREATE TABLE messages (
    id INT AUTO_INCREMENT PRIMARY KEY,
    user_id INT NOT NULL,
    message TEXT NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    is_deleted BOOLEAN DEFAULT FALSE,
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
    INDEX idx_created_at (created_at)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50) UNIQUE NOT NULL,
    password VARCHAR(255) NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    last_login TIMESTAMP NULL,
    login_attempts INT DEFAULT 0,
    last_attempt TIMESTAMP NULL,
    is_blocked BOOLEAN DEFAULT FALSE,
    INDEX idx_username (username)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE user_blocks (
    id INT AUTO_INCREMENT PRIMARY KEY,
    blocker_id INT NOT NULL,
    blocked_id INT NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (blocker_id) REFERENCES users(id) ON DELETE CASCADE,
    FOREIGN KEY (blocked_id) REFERENCES users(id) ON DELETE CASCADE,
    UNIQUE KEY unique_block (blocker_id, blocked_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE activity_log (
    id INT AUTO_INCREMENT PRIMARY KEY,
    user_id INT,
    action VARCHAR(50) NOT NULL,
    ip_address VARCHAR(45),
    user_agent TEXT,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE SET NULL,
    INDEX idx_created_at (created_at)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE sessions (
    id VARCHAR(128) PRIMARY KEY,
    user_id INT NOT NULL,
    ip_address VARCHAR(45),
    user_agent TEXT,
    last_activity TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
    INDEX idx_last_activity (last_activity)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE rate_limits (
    id INT AUTO_INCREMENT PRIMARY KEY,
    ip_address VARCHAR(45) NOT NULL,
    action VARCHAR(50) NOT NULL,
    attempts INT DEFAULT 1,
    last_attempt TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    UNIQUE KEY unique_ip_action (ip_address, action),
    INDEX idx_last_attempt (last_attempt)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE csrf_tokens (
    id INT AUTO_INCREMENT PRIMARY KEY,
    user_id INT NOT NULL,
    token VARCHAR(64) NOT NULL,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    expires_at TIMESTAMP NOT NULL,
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
    UNIQUE KEY unique_token (token),
    INDEX idx_expires_at (expires_at)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE registrations (
    id INT AUTO_INCREMENT PRIMARY KEY,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    INDEX idx_created_at (created_at)
);