Feature: Configurable subsidy duration

1 files changed, 21 insertions, 9 deletions

diff --git a/src/subsidy.cpp b/src/subsidy.cpp
index 14679e4dc..8800da1bd 100644
--- a/src/subsidy.cpp
+++ b/src/subsidy.cpp
@@ -41,7 +41,7 @@ void Subsidy::AwardTo(CompanyID company)
 	assert(!this->IsAwarded());
 
 	this->awarded = company;
-	this->remaining = SUBSIDY_CONTRACT_MONTHS;
+	this->remaining = _settings_game.difficulty.subsidy_duration * MONTHS_IN_YEAR;
 
 	char company_name[MAX_LENGTH_COMPANY_NAME_CHARS * MAX_CHAR_LENGTH];
 	SetDParam(0, company);
@@ -50,7 +50,7 @@ void Subsidy::AwardTo(CompanyID company)
 	char *cn = stredup(company_name);
 
 	/* Add a news item */
-	std::pair<NewsReferenceType, NewsReferenceType> reftype = SetupSubsidyDecodeParam(this, false);
+	std::pair<NewsReferenceType, NewsReferenceType> reftype = SetupSubsidyDecodeParam(this, SubsidyDecodeParamType::NewsAwarded);
 	InjectDParam(1);
 
 	SetDParamStr(0, cn);
@@ -69,17 +69,21 @@ void Subsidy::AwardTo(CompanyID company)
 /**
  * Setup the string parameters for printing the subsidy at the screen, and compute the news reference for the subsidy.
  * @param s %Subsidy being printed.
- * @param mode Unit of cargo used, \c true means general name, \c false means singular form.
+ * @param mode Type of subsidy news message to decide on parameter format.
  * @return Reference of the subsidy in the news system.
  */
-std::pair<NewsReferenceType, NewsReferenceType> SetupSubsidyDecodeParam(const Subsidy *s, bool mode)
+std::pair<NewsReferenceType, NewsReferenceType> SetupSubsidyDecodeParam(const Subsidy *s, SubsidyDecodeParamType mode)
 {
 	NewsReferenceType reftype1 = NR_NONE;
 	NewsReferenceType reftype2 = NR_NONE;
 
-	/* if mode is false, use the singular form */
+	/* Choose whether to use the singular or plural form of the cargo name based on how we're printing the subsidy */
 	const CargoSpec *cs = CargoSpec::Get(s->cargo_type);
-	SetDParam(0, mode ? cs->name : cs->name_single);
+	if (mode == SubsidyDecodeParamType::Gui || mode == SubsidyDecodeParamType::NewsWithdrawn) {
+		SetDParam(0, cs->name);
+	} else {
+		SetDParam(0, cs->name_single);
+	}
 
 	switch (s->src_type) {
 		case ST_INDUSTRY:
@@ -107,6 +111,11 @@ std::pair<NewsReferenceType, NewsReferenceType> SetupSubsidyDecodeParam(const Su
 	}
 	SetDParam(5, s->dst);
 
+	/* If the subsidy is being offered or awarded, the news item mentions the subsidy duration. */
+	if (mode == SubsidyDecodeParamType::NewsOffered || mode == SubsidyDecodeParamType::NewsAwarded) {
+		SetDParam(7, _settings_game.difficulty.subsidy_duration);
+	}
+
 	return std::pair<NewsReferenceType, NewsReferenceType>(reftype1, reftype2);
 }
 
@@ -216,7 +225,7 @@ void CreateSubsidy(CargoID cid, SourceType src_type, SourceID src, SourceType ds
 	s->remaining = SUBSIDY_OFFER_MONTHS;
 	s->awarded = INVALID_COMPANY;
 
-	std::pair<NewsReferenceType, NewsReferenceType> reftype = SetupSubsidyDecodeParam(s, false);
+	std::pair<NewsReferenceType, NewsReferenceType> reftype = SetupSubsidyDecodeParam(s, SubsidyDecodeParamType::NewsOffered);
 	AddNewsItem(STR_NEWS_SERVICE_SUBSIDY_OFFERED, NT_SUBSIDIES, NF_NORMAL, reftype.first, s->src, reftype.second, s->dst);
 	SetPartOfSubsidyFlag(s->src_type, s->src, POS_SRC);
 	SetPartOfSubsidyFlag(s->dst_type, s->dst, POS_DST);
@@ -491,13 +500,13 @@ void SubsidyMonthlyLoop()
 	for (Subsidy *s : Subsidy::Iterate()) {
 		if (--s->remaining == 0) {
 			if (!s->IsAwarded()) {
-				std::pair<NewsReferenceType, NewsReferenceType> reftype = SetupSubsidyDecodeParam(s, true);
+				std::pair<NewsReferenceType, NewsReferenceType> reftype = SetupSubsidyDecodeParam(s, SubsidyDecodeParamType::NewsWithdrawn);
 				AddNewsItem(STR_NEWS_OFFER_OF_SUBSIDY_EXPIRED, NT_SUBSIDIES, NF_NORMAL, reftype.first, s->src, reftype.second, s->dst);
 				AI::BroadcastNewEvent(new ScriptEventSubsidyOfferExpired(s->index));
 				Game::NewEvent(new ScriptEventSubsidyOfferExpired(s->index));
 			} else {
 				if (s->awarded == _local_company) {
-					std::pair<NewsReferenceType, NewsReferenceType> reftype = SetupSubsidyDecodeParam(s, true);
+					std::pair<NewsReferenceType, NewsReferenceType> reftype = SetupSubsidyDecodeParam(s, SubsidyDecodeParamType::NewsWithdrawn);
 					AddNewsItem(STR_NEWS_SUBSIDY_WITHDRAWN_SERVICE, NT_SUBSIDIES, NF_NORMAL, reftype.first, s->src, reftype.second, s->dst);
 				}
 				AI::BroadcastNewEvent(new ScriptEventSubsidyExpired(s->index));
@@ -510,6 +519,9 @@ void SubsidyMonthlyLoop()
 
 	if (modified) {
 		RebuildSubsidisedSourceAndDestinationCache();
+	} else if (_settings_game.difficulty.subsidy_duration == 0) {
+		/* If subsidy duration is set to 0, subsidies are disabled, so bail out. */
+		return;
 	} else if (_settings_game.linkgraph.distribution_pax != DT_MANUAL &&
 			   _settings_game.linkgraph.distribution_mail != DT_MANUAL &&
 			   _settings_game.linkgraph.distribution_armoured != DT_MANUAL &&