function uniq(values) {
  return Array.from(new Set((values ?? []).filter(Boolean)));
}

async function resolveRecipientsForAssignee(tx, params) {
  if (params.assigneeId) {
    return [params.assigneeId];
  }

  if (params.assigneeRole) {
    const rows = await tx.employeeRole.findMany({
      where: {
        role_code: params.assigneeRole,
        employee: {
          status: "active",
        },
      },
      select: {
        employee_id: true,
      },
    });

    return rows.map((row) => row.employee_id);
  }

  return [];
}

async function createNotifications(tx, input) {
  const recipientIds = uniq(input.recipientEmployeeIds);
  if (recipientIds.length === 0) {
    return { count: 0 };
  }

  const title = String(input.title ?? "").slice(0, 200);
  const body = input.body != null ? String(input.body).slice(0, 5000) : null;
  const type = String(input.type ?? "").slice(0, 64);
  const targetType = input.targetType != null ? String(input.targetType).slice(0, 64) : null;

  return tx.notification.createMany({
    data: recipientIds.map((recipientId) => ({
      recipient_employee_id: recipientId,
      type,
      title,
      body,
      target_type: targetType,
      target_id: input.targetId ?? null,
    })),
  });
}

async function createNotificationsWithRecords(tx, input) {
  const recipientIds = uniq(input.recipientEmployeeIds);
  if (recipientIds.length === 0) {
    return [];
  }

  const title = String(input.title ?? '').slice(0, 200);
  const body = input.body != null ? String(input.body).slice(0, 5000) : null;
  const type = String(input.type ?? '').slice(0, 64);
  const targetType = input.targetType != null ? String(input.targetType).slice(0, 64) : null;

  const created = [];
  for (const recipientId of recipientIds) {
    created.push(
      await tx.notification.create({
        data: {
          recipient_employee_id: recipientId,
          type,
          title,
          body,
          target_type: targetType,
          target_id: input.targetId ?? null,
        },
      }),
    );
  }

  return created;
}

module.exports = {
  createNotifications,
  createNotificationsWithRecords,
  resolveRecipientsForAssignee,
};