-- Лояльность и промокоды
ALTER TABLE users ADD COLUMN IF NOT EXISTS loyalty_points INTEGER NOT NULL DEFAULT 0
  CHECK (loyalty_points >= 0);

CREATE TABLE IF NOT EXISTS promo_codes (
  id SERIAL PRIMARY KEY,
  code TEXT NOT NULL UNIQUE,
  description TEXT NOT NULL DEFAULT '',
  discount_type TEXT NOT NULL CHECK (discount_type IN ('percent', 'fixed')),
  discount_value INTEGER NOT NULL CHECK (discount_value > 0),
  starts_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  expires_at TIMESTAMPTZ NOT NULL,
  min_order_cents INTEGER NOT NULL DEFAULT 0 CHECK (min_order_cents >= 0),
  max_uses INTEGER CHECK (max_uses IS NULL OR max_uses > 0),
  use_count INTEGER NOT NULL DEFAULT 0 CHECK (use_count >= 0),
  active BOOLEAN NOT NULL DEFAULT true,
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_promo_codes_active ON promo_codes (active, expires_at);

ALTER TABLE orders ADD COLUMN IF NOT EXISTS subtotal_cents INTEGER;
ALTER TABLE orders ADD COLUMN IF NOT EXISTS discount_cents INTEGER NOT NULL DEFAULT 0;
ALTER TABLE orders ADD COLUMN IF NOT EXISTS promo_code_id INTEGER REFERENCES promo_codes(id);
ALTER TABLE orders ADD COLUMN IF NOT EXISTS loyalty_points_used INTEGER NOT NULL DEFAULT 0;
ALTER TABLE orders ADD COLUMN IF NOT EXISTS loyalty_points_earned INTEGER NOT NULL DEFAULT 0;

UPDATE orders SET subtotal_cents = total_cents WHERE subtotal_cents IS NULL;