-- ============================================================
-- Migration 010: Notification Campaigns + Read Event Log
-- Phase 3: Campaign scheduling + analytics
-- ============================================================

-- 1. Notification campaigns
--    A campaign is a scheduled or recurring notification push job
CREATE TABLE IF NOT EXISTS public.notification_campaigns (
  id             UUID         PRIMARY KEY DEFAULT gen_random_uuid(),
  name           VARCHAR(200) NOT NULL,
  description    TEXT,
  status         VARCHAR(20)  NOT NULL DEFAULT 'DRAFT',
  -- DRAFT | SCHEDULED | RUNNING | COMPLETED | CANCELLED | FAILED

  -- Linked notification template (optional: can create ad-hoc body)
  notification_id UUID        REFERENCES public.notifications(id) ON DELETE SET NULL,

  -- Schedule
  schedule_type  VARCHAR(20)  NOT NULL DEFAULT 'ONCE',
  -- ONCE | RECURRING
  scheduled_at   TIMESTAMPTZ,          -- for ONCE: exact send time
  cron_expr      VARCHAR(100),          -- for RECURRING: cron expression
  timezone       VARCHAR(50)  NOT NULL DEFAULT 'UTC',
  next_run_at    TIMESTAMPTZ,           -- computed by scheduler
  last_run_at    TIMESTAMPTZ,

  -- Execution stats
  target_count   INT          NOT NULL DEFAULT 0,   -- estimated / actual target size
  sent_count     INT          NOT NULL DEFAULT 0,
  read_count     INT          NOT NULL DEFAULT 0,

  created_by     VARCHAR(100),
  created_at     TIMESTAMPTZ  NOT NULL DEFAULT NOW(),
  updated_at     TIMESTAMPTZ  NOT NULL DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_campaigns_status       ON public.notification_campaigns (status);
CREATE INDEX IF NOT EXISTS idx_campaigns_scheduled_at ON public.notification_campaigns (scheduled_at)
  WHERE status IN ('SCHEDULED', 'RUNNING');
CREATE INDEX IF NOT EXISTS idx_campaigns_next_run     ON public.notification_campaigns (next_run_at)
  WHERE status = 'SCHEDULED';

-- 2. Campaign execution log
--    Records each run of a campaign (for RECURRING campaigns, one row per run)
CREATE TABLE IF NOT EXISTS public.campaign_execution_log (
  id             UUID         PRIMARY KEY DEFAULT gen_random_uuid(),
  campaign_id    UUID         NOT NULL REFERENCES public.notification_campaigns(id) ON DELETE CASCADE,
  notification_id UUID        REFERENCES public.notifications(id) ON DELETE SET NULL,
  started_at     TIMESTAMPTZ  NOT NULL DEFAULT NOW(),
  finished_at    TIMESTAMPTZ,
  status         VARCHAR(20)  NOT NULL DEFAULT 'RUNNING',
  -- RUNNING | COMPLETED | FAILED
  target_count   INT          NOT NULL DEFAULT 0,
  sent_count     INT          NOT NULL DEFAULT 0,
  error          TEXT
);

CREATE INDEX IF NOT EXISTS idx_cel_campaign ON public.campaign_execution_log (campaign_id);

-- 3. Notification delivery event log
--    Detailed per-notification read events (for analytics / funnel)
CREATE TABLE IF NOT EXISTS public.notification_event_log (
  id               UUID         PRIMARY KEY DEFAULT gen_random_uuid(),
  notification_id  UUID         NOT NULL REFERENCES public.notifications(id) ON DELETE CASCADE,
  campaign_id      UUID         REFERENCES public.notification_campaigns(id) ON DELETE SET NULL,
  event_type       VARCHAR(30)  NOT NULL,
  -- DELIVERED | READ | CLICKED | DISMISSED
  user_id          VARCHAR(100) NOT NULL,
  tenant_id        VARCHAR(100) NOT NULL,
  occurred_at      TIMESTAMPTZ  NOT NULL DEFAULT NOW(),
  metadata         JSONB        DEFAULT '{}'::jsonb
);

CREATE INDEX IF NOT EXISTS idx_nel_notification ON public.notification_event_log (notification_id);
CREATE INDEX IF NOT EXISTS idx_nel_campaign     ON public.notification_event_log (campaign_id) WHERE campaign_id IS NOT NULL;
CREATE INDEX IF NOT EXISTS idx_nel_user         ON public.notification_event_log (user_id);
CREATE INDEX IF NOT EXISTS idx_nel_occurred     ON public.notification_event_log (occurred_at);