TSubgoal CollectRes::whatToDoToTrade()
{
std::vector<const IMarket *> markets;
std::vector<const CGObjectInstance *> visObjs;
ai->retrieveVisitableObjs(visObjs, true);
for (const CGObjectInstance * obj : visObjs)
{
if (const IMarket * m = IMarket::castFrom(obj, false))
{
if (obj->ID == Obj::TOWN && obj->tempOwner == ai->playerID && m->allowsTrade(EMarketMode::RESOURCE_RESOURCE))
markets.push_back(m);
else if (obj->ID == Obj::TRADING_POST)
markets.push_back(m);
}
}
boost::sort(markets, [](const IMarket * m1, const IMarket * m2) -> bool
{
return m1->getMarketEfficiency() < m2->getMarketEfficiency();
});
markets.erase(boost::remove_if(markets, [](const IMarket * market) -> bool
{
if (!(market->o->ID == Obj::TOWN && market->o->tempOwner == ai->playerID))
{
if (!ai->isAccessible(market->o->visitablePos()))
return true;
}
return false;
}), markets.end());
if (!markets.size())
{
for (const CGTownInstance * t : cb->getTownsInfo())
{
if (cb->canBuildStructure(t, BuildingID::MARKETPLACE) == EBuildingState::ALLOWED)
return sptr(BuildThis(BuildingID::MARKETPLACE, t).setpriority(2));
}
}
else
{
const IMarket * m = markets.back();
//attempt trade at back (best prices)
int howManyCanWeBuy = 0;
for (Res::ERes i = Res::WOOD; i <= Res::GOLD; vstd::advance(i, 1))
{
if (i == resID)
continue;
int toGive = -1, toReceive = -1;
m->getOffer(i, resID, toGive, toReceive, EMarketMode::RESOURCE_RESOURCE);
assert(toGive > 0 && toReceive > 0);
howManyCanWeBuy += toReceive * (ai->ah->freeResources()[i] / toGive);
}
if (howManyCanWeBuy >= value)
{
auto backObj = cb->getTopObj(m->o->visitablePos()); //it'll be a hero if we have one there; otherwise marketplace
assert(backObj);
auto objid = m->o->id.getNum();
if (backObj->tempOwner != ai->playerID) //top object not owned
{
return sptr(VisitObj(objid)); //just go there
}
else //either it's our town, or we have hero there
{
return sptr(Trade(resID, value, objid).setisElementar(true)); //we can do this immediately
}
}
}
return sptr(Invalid()); //cannot trade
}
