+std::string TariffImpl::TariffChangeIsAllowed(const Tariff & to, time_t currentTime) const
+{
+time_t timeout = GetChangePolicyTimeout();
+if (currentTime > timeout && timeout != 0)
+ return "";
+switch (GetChangePolicy())
+ {
+ case Tariff::ALLOW:
+ return "";
+ case Tariff::TO_CHEAP:
+ if (to.GetFee() < GetFee())
+ return "";
+ else
+ return "New tariff '" + to.GetName() + "' is more expensive than current tariff '" + GetName() + "'. The policy is '" + Tariff::toString(GetChangePolicy()) + "'.";
+ case Tariff::TO_EXPENSIVE:
+ if (to.GetFee() >= GetFee())
+ return "";
+ else
+ return "New tariff '" + to.GetName() + "' is more cheap than current tariff '" + GetName() + "'. The policy is '" + Tariff::toString(GetChangePolicy()) + "'.";
+ case Tariff::DENY:
+ return "Current tariff '" + GetName() + "', new tariff '" + to.GetName() + "'. The policy is '" + Tariff::toString(GetChangePolicy()) + "'.";
+ }
+return "";
+}
+//-----------------------------------------------------------------------------