-- Durable, recipient-safe notification model. The legacy notifications table is
-- intentionally retained for rollback and audit during the migration window.

CREATE TYPE "NotificationRecipientType" AS ENUM ('EMPLOYEE', 'RENTER');
CREATE TYPE "NotificationDeliveryStatus" AS ENUM ('PENDING', 'QUEUED', 'SENT', 'DELIVERED', 'FAILED', 'SKIPPED', 'DEAD_LETTER');
CREATE TYPE "NotificationOutboxStatus" AS ENUM ('PENDING', 'PUBLISHED', 'FAILED');

CREATE TABLE "notification_events" (
  "id" TEXT NOT NULL,
  "companyId" TEXT NOT NULL,
  "type" "NotificationType" NOT NULL,
  "templateKey" TEXT,
  "locale" TEXT NOT NULL DEFAULT 'en',
  "title" TEXT NOT NULL,
  "body" TEXT NOT NULL,
  "data" JSONB,
  "sourceType" TEXT NOT NULL,
  "sourceId" TEXT NOT NULL,
  "idempotencyKey" TEXT NOT NULL,
  "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,

  CONSTRAINT "notification_events_pkey" PRIMARY KEY ("id"),
  CONSTRAINT "notification_events_companyId_fkey" FOREIGN KEY ("companyId") REFERENCES "companies"("id") ON DELETE CASCADE ON UPDATE CASCADE
);

CREATE TABLE "notification_recipients" (
  "id" TEXT NOT NULL,
  "notificationEventId" TEXT NOT NULL,
  "recipientType" "NotificationRecipientType" NOT NULL,
  "employeeId" TEXT,
  "renterId" TEXT,
  "readAt" TIMESTAMP(3),
  "archivedAt" TIMESTAMP(3),
  "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,

  CONSTRAINT "notification_recipients_pkey" PRIMARY KEY ("id"),
  CONSTRAINT "notification_recipients_notificationEventId_fkey" FOREIGN KEY ("notificationEventId") REFERENCES "notification_events"("id") ON DELETE CASCADE ON UPDATE CASCADE,
  CONSTRAINT "notification_recipients_employeeId_fkey" FOREIGN KEY ("employeeId") REFERENCES "employees"("id") ON DELETE CASCADE ON UPDATE CASCADE,
  CONSTRAINT "notification_recipients_renterId_fkey" FOREIGN KEY ("renterId") REFERENCES "renters"("id") ON DELETE CASCADE ON UPDATE CASCADE,
  CONSTRAINT "notification_recipients_exactly_one_identity_chk" CHECK (
    (CASE WHEN "employeeId" IS NULL THEN 0 ELSE 1 END) +
    (CASE WHEN "renterId" IS NULL THEN 0 ELSE 1 END) = 1
  ),
  CONSTRAINT "notification_recipients_type_identity_chk" CHECK (
    ("recipientType" = 'EMPLOYEE' AND "employeeId" IS NOT NULL AND "renterId" IS NULL) OR
    ("recipientType" = 'RENTER' AND "renterId" IS NOT NULL AND "employeeId" IS NULL)
  )
);

CREATE TABLE "notification_deliveries" (
  "id" TEXT NOT NULL,
  "notificationRecipientId" TEXT NOT NULL,
  "channel" "NotificationChannel" NOT NULL,
  "status" "NotificationDeliveryStatus" NOT NULL DEFAULT 'PENDING',
  "attemptCount" INTEGER NOT NULL DEFAULT 0,
  "lastAttemptAt" TIMESTAMP(3),
  "nextAttemptAt" TIMESTAMP(3),
  "provider" TEXT,
  "providerMessageId" TEXT,
  "failureCode" TEXT,
  "failureReason" TEXT,
  "preferenceDecision" TEXT,
  "sentAt" TIMESTAMP(3),
  "deliveredAt" TIMESTAMP(3),
  "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
  "updatedAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,

  CONSTRAINT "notification_deliveries_pkey" PRIMARY KEY ("id"),
  CONSTRAINT "notification_deliveries_notificationRecipientId_fkey" FOREIGN KEY ("notificationRecipientId") REFERENCES "notification_recipients"("id") ON DELETE CASCADE ON UPDATE CASCADE
);

CREATE TABLE "notification_outbox" (
  "id" TEXT NOT NULL,
  "notificationEventId" TEXT NOT NULL,
  "status" "NotificationOutboxStatus" NOT NULL DEFAULT 'PENDING',
  "payload" JSONB NOT NULL,
  "publishedAt" TIMESTAMP(3),
  "failureReason" TEXT,
  "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
  "updatedAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,

  CONSTRAINT "notification_outbox_pkey" PRIMARY KEY ("id"),
  CONSTRAINT "notification_outbox_notificationEventId_fkey" FOREIGN KEY ("notificationEventId") REFERENCES "notification_events"("id") ON DELETE CASCADE ON UPDATE CASCADE
);

CREATE TABLE "company_notification_preferences" (
  "id" TEXT NOT NULL,
  "companyId" TEXT NOT NULL,
  "notificationType" "NotificationType" NOT NULL,
  "channel" "NotificationChannel" NOT NULL,
  "enabled" BOOLEAN NOT NULL DEFAULT true,

  CONSTRAINT "company_notification_preferences_pkey" PRIMARY KEY ("id"),
  CONSTRAINT "company_notification_preferences_companyId_fkey" FOREIGN KEY ("companyId") REFERENCES "companies"("id") ON DELETE CASCADE ON UPDATE CASCADE
);

CREATE UNIQUE INDEX "notification_events_companyId_idempotencyKey_key" ON "notification_events"("companyId", "idempotencyKey");
CREATE INDEX "notification_events_companyId_type_createdAt_idx" ON "notification_events"("companyId", "type", "createdAt");
CREATE INDEX "notification_recipients_employeeId_readAt_createdAt_idx" ON "notification_recipients"("employeeId", "readAt", "createdAt");
CREATE INDEX "notification_recipients_renterId_readAt_createdAt_idx" ON "notification_recipients"("renterId", "readAt", "createdAt");
CREATE INDEX "notification_recipients_notificationEventId_idx" ON "notification_recipients"("notificationEventId");
CREATE UNIQUE INDEX "notification_deliveries_notificationRecipientId_channel_key" ON "notification_deliveries"("notificationRecipientId", "channel");
CREATE INDEX "notification_deliveries_channel_status_nextAttemptAt_idx" ON "notification_deliveries"("channel", "status", "nextAttemptAt");
CREATE INDEX "notification_outbox_status_createdAt_idx" ON "notification_outbox"("status", "createdAt");
CREATE UNIQUE INDEX "company_notification_preferences_companyId_notificationType_channel_key" ON "company_notification_preferences"("companyId", "notificationType", "channel");