--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/ai/api/ai_subsidy.cpp	Fri Apr 25 00:22:41 2008 +0000
@@ -0,0 +1,94 @@
+/* $Id$ */
+
+/** @file ai_subsidy.cpp Implementation of AISubsidy. */
+
+#include "ai_subsidy.hpp"
+#include "ai_error.hpp"
+#include "ai_company.hpp"
+#include "ai_date.hpp"
+#include "../../openttd.h"
+#include "../../economy_func.h"
+#include "../../station_base.h"
+#include "../../cargotype.h"
+
+/* static */ bool AISubsidy::IsValidSubsidy(SubsidyID subsidy_id)
+{
+	return subsidy_id < lengthof(_subsidies) && _subsidies[subsidy_id].cargo_type != CT_INVALID;
+}
+
+/* static */ bool AISubsidy::IsAwarded(SubsidyID subsidy_id)
+{
+	if (!IsValidSubsidy(subsidy_id)) return false;
+
+	return _subsidies[subsidy_id].age >= 12;
+}
+
+/* static */ AICompany::CompanyIndex AISubsidy::GetAwardedTo(SubsidyID subsidy_id)
+{
+	if (!IsAwarded(subsidy_id)) return AICompany::INVALID_COMPANY;
+
+	return (AICompany::CompanyIndex)((byte)GetStation(_subsidies[subsidy_id].from)->owner);
+}
+
+/* static */ int32 AISubsidy::GetExpireDate(SubsidyID subsidy_id)
+{
+	if (!IsValidSubsidy(subsidy_id)) return -1;
+
+	int year = AIDate::GetYear(AIDate::GetCurrentDate());
+	int month = AIDate::GetMonth(AIDate::GetCurrentDate());
+
+	if (IsAwarded(subsidy_id)) {
+		month += 24 - _subsidies[subsidy_id].age;
+	} else {
+		month += 12 - _subsidies[subsidy_id].age;
+	}
+
+	year += month / 12;
+	month = month % 12;
+
+	return AIDate::GetDate(year, month, 1);
+}
+
+/* static */ CargoID AISubsidy::GetCargoType(SubsidyID subsidy_id)
+{
+	if (!IsValidSubsidy(subsidy_id)) return CT_INVALID;
+
+	return _subsidies[subsidy_id].cargo_type;
+}
+
+/* static */ bool AISubsidy::SourceIsTown(SubsidyID subsidy_id)
+{
+	if (!IsValidSubsidy(subsidy_id) || IsAwarded(subsidy_id)) return false;
+
+	return GetCargo(GetCargoType(subsidy_id))->town_effect == TE_PASSENGERS ||
+	       GetCargo(GetCargoType(subsidy_id))->town_effect == TE_MAIL;
+}
+
+/* static */ int32 AISubsidy::GetSource(SubsidyID subsidy_id)
+{
+	if (!IsValidSubsidy(subsidy_id)) return INVALID_STATION;
+
+	return _subsidies[subsidy_id].from;
+}
+
+/* static */ bool AISubsidy::DestinationIsTown(SubsidyID subsidy_id)
+{
+	if (!IsValidSubsidy(subsidy_id) || IsAwarded(subsidy_id)) return false;
+
+	switch (GetCargo(GetCargoType(subsidy_id))->town_effect) {
+		case TE_PASSENGERS:
+		case TE_MAIL:
+		case TE_GOODS:
+		case TE_FOOD:
+			return true;
+		default:
+			return false;
+	}
+}
+
+/* static */ int32 AISubsidy::GetDestination(SubsidyID subsidy_id)
+{
+	if (!IsValidSubsidy(subsidy_id)) return INVALID_STATION;
+
+	return _subsidies[subsidy_id].to;
+}