CREATE TABLE IF NOT EXISTS codes (
    id INT AUTO_INCREMENT PRIMARY KEY,
    code VARCHAR(64) UNIQUE NOT NULL,
    limit_send INT DEFAULT 1000,
    used_count INT DEFAULT 0,
    is_active TINYINT(1) DEFAULT 1,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    note VARCHAR(255) DEFAULT NULL
);

CREATE TABLE IF NOT EXISTS devices (
    id INT AUTO_INCREMENT PRIMARY KEY,
    code VARCHAR(64) NOT NULL,
    device_id VARCHAR(128) NOT NULL,
    last_active TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    UNIQUE KEY unique_device (code, device_id),
    INDEX (code)
);