-- ============================================================
-- Migration 006: Referral System Tables
-- All tables in public schema (cross-tenant, like billing)
-- ============================================================

-- 1. Referral codes — one per tenant, auto-generated on registration
CREATE TABLE IF NOT EXISTS public.referral_codes (
  id         UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  tenant_id  VARCHAR(100) NOT NULL UNIQUE,
  user_id    VARCHAR(100) NOT NULL,
  code       VARCHAR(20)  NOT NULL UNIQUE,
  click_count INT         NOT NULL DEFAULT 0,
  created_at TIMESTAMPTZ  NOT NULL DEFAULT NOW(),
  updated_at TIMESTAMPTZ  NOT NULL DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_referral_codes_code ON public.referral_codes (code);
CREATE INDEX IF NOT EXISTS idx_referral_codes_tenant ON public.referral_codes (tenant_id);

-- 2. Referral relationships — tracks who referred whom (tenant level)
CREATE TABLE IF NOT EXISTS public.referral_relationships (
  id                  UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  referrer_tenant_id  VARCHAR(100) NOT NULL,
  referred_tenant_id  VARCHAR(100) NOT NULL UNIQUE,  -- one referrer per tenant
  referral_code       VARCHAR(20)  NOT NULL,
  level               INT          NOT NULL DEFAULT 1,  -- 1=direct, 2=indirect
  status              VARCHAR(20)  NOT NULL DEFAULT 'PENDING',
  registered_at       TIMESTAMPTZ  NOT NULL DEFAULT NOW(),
  activated_at        TIMESTAMPTZ,
  rewarded_at         TIMESTAMPTZ
);

CREATE INDEX IF NOT EXISTS idx_referral_rel_referrer ON public.referral_relationships (referrer_tenant_id);
CREATE INDEX IF NOT EXISTS idx_referral_rel_status   ON public.referral_relationships (status);
CREATE INDEX IF NOT EXISTS idx_referral_rel_referred  ON public.referral_relationships (referred_tenant_id);

-- 3. Referral rewards — credit records for each tenant
CREATE TABLE IF NOT EXISTS public.referral_rewards (
  id                       UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  beneficiary_tenant_id    VARCHAR(100) NOT NULL,
  referral_relationship_id UUID         NOT NULL REFERENCES public.referral_relationships(id),
  reward_type              VARCHAR(20)  NOT NULL,   -- CREDIT | PERCENTAGE
  trigger_type             VARCHAR(20)  NOT NULL,   -- FIRST_PAYMENT | RECURRING
  amount_cents             INT          NOT NULL,
  status                   VARCHAR(20)  NOT NULL DEFAULT 'PENDING',
  invoice_id               VARCHAR(100),
  source_invoice_id        VARCHAR(100),
  recurring_month          INT,
  expires_at               TIMESTAMPTZ,
  created_at               TIMESTAMPTZ  NOT NULL DEFAULT NOW(),
  applied_at               TIMESTAMPTZ
);

CREATE INDEX IF NOT EXISTS idx_referral_rewards_beneficiary ON public.referral_rewards (beneficiary_tenant_id, status);
CREATE INDEX IF NOT EXISTS idx_referral_rewards_relationship ON public.referral_rewards (referral_relationship_id);

-- 4. Referral stats — denormalized cache per tenant
CREATE TABLE IF NOT EXISTS public.referral_stats (
  tenant_id             VARCHAR(100) PRIMARY KEY,
  direct_count          INT NOT NULL DEFAULT 0,
  active_count          INT NOT NULL DEFAULT 0,
  total_credit_earned   INT NOT NULL DEFAULT 0,
  total_credit_applied  INT NOT NULL DEFAULT 0,
  pending_credit        INT NOT NULL DEFAULT 0,
  updated_at            TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- 5. Processed events — idempotency for Redis Stream consumers
CREATE TABLE IF NOT EXISTS public.referral_processed_events (
  id           UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  event_id     VARCHAR(255) NOT NULL UNIQUE,
  event_type   VARCHAR(100) NOT NULL,
  processed_at TIMESTAMPTZ  NOT NULL DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_referral_processed_events_event_id ON public.referral_processed_events (event_id);