-- Create vouchers table
CREATE TABLE IF NOT EXISTS vouchers (
    id INT AUTO_INCREMENT PRIMARY KEY,
    code VARCHAR(50) UNIQUE NOT NULL,
    discount_amount DECIMAL(15, 2) NOT NULL,
    is_used TINYINT(1) DEFAULT 0,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    expires_at TIMESTAMP NULL
);

-- Update sales table to track point redemption and voucher usage
ALTER TABLE sales ADD COLUMN IF NOT EXISTS points_redeemed INT DEFAULT 0;
ALTER TABLE sales ADD COLUMN IF NOT EXISTS voucher_id INT NULL;
ALTER TABLE sales ADD CONSTRAINT fk_sale_voucher FOREIGN KEY (voucher_id) REFERENCES vouchers(id);