-- Migration 032: Create/update stores, employees, redemptions tables
-- Date: 2026-02-22

-- ============================================================
-- 1. ALTER stores table: add level and parent_id columns
-- ============================================================
DO $$
BEGIN
  IF NOT EXISTS (
    SELECT 1 FROM information_schema.columns
    WHERE table_name = 'stores' AND column_name = 'level'
  ) THEN
    ALTER TABLE stores ADD COLUMN level VARCHAR(50) NOT NULL DEFAULT 'store';
  END IF;

  IF NOT EXISTS (
    SELECT 1 FROM information_schema.columns
    WHERE table_name = 'stores' AND column_name = 'parent_id'
  ) THEN
    ALTER TABLE stores ADD COLUMN parent_id UUID NULL;
  END IF;
END $$;

-- Index for parent_id on stores
CREATE INDEX IF NOT EXISTS idx_stores_parent ON stores (parent_id);

-- Self-referencing FK (store hierarchy)
DO $$
BEGIN
  IF NOT EXISTS (
    SELECT 1 FROM information_schema.table_constraints
    WHERE constraint_name = 'fk_stores_parent' AND table_name = 'stores'
  ) THEN
    ALTER TABLE stores ADD CONSTRAINT fk_stores_parent
      FOREIGN KEY (parent_id) REFERENCES stores(id) ON DELETE SET NULL;
  END IF;
END $$;

-- ============================================================
-- 2. CREATE employees table
-- ============================================================
CREATE TABLE IF NOT EXISTS employees (
  id          UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  issuer_id   UUID NOT NULL REFERENCES issuers(id) ON DELETE CASCADE,
  store_id    UUID NULL REFERENCES stores(id) ON DELETE SET NULL,
  name        VARCHAR(100) NOT NULL,
  phone       VARCHAR(20),
  role        VARCHAR(50) NOT NULL DEFAULT 'staff',
  status      VARCHAR(20) NOT NULL DEFAULT 'active',
  created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_employees_issuer ON employees (issuer_id);
CREATE INDEX IF NOT EXISTS idx_employees_store ON employees (store_id);

-- ============================================================
-- 3. CREATE redemptions table
-- ============================================================
CREATE TABLE IF NOT EXISTS redemptions (
  id          UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  coupon_id   UUID NOT NULL REFERENCES coupons(id) ON DELETE CASCADE,
  issuer_id   UUID NOT NULL REFERENCES issuers(id) ON DELETE CASCADE,
  user_id     UUID NOT NULL,
  store_id    UUID NULL REFERENCES stores(id) ON DELETE SET NULL,
  method      VARCHAR(20) NOT NULL,
  amount      NUMERIC(12,2) NOT NULL,
  status      VARCHAR(20) NOT NULL DEFAULT 'completed',
  created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_redemptions_coupon ON redemptions (coupon_id);
CREATE INDEX IF NOT EXISTS idx_redemptions_issuer ON redemptions (issuer_id);
CREATE INDEX IF NOT EXISTS idx_redemptions_user ON redemptions (user_id);
CREATE INDEX IF NOT EXISTS idx_redemptions_store ON redemptions (store_id);
CREATE INDEX IF NOT EXISTS idx_redemptions_created ON redemptions (created_at);

-- ============================================================
-- 4. Update trigger for employees.updated_at
-- ============================================================
CREATE OR REPLACE FUNCTION update_updated_at_column()
RETURNS TRIGGER AS $$
BEGIN
  NEW.updated_at = NOW();
  RETURN NEW;
END;
$$ LANGUAGE plpgsql;

DROP TRIGGER IF EXISTS trg_employees_updated_at ON employees;
CREATE TRIGGER trg_employees_updated_at
  BEFORE UPDATE ON employees
  FOR EACH ROW
  EXECUTE FUNCTION update_updated_at_column();