/*
* ExchangeSwapTownHeroes.cpp, part of VCMI engine
*
* Authors: listed in file AUTHORS in main folder
*
* License: GNU General Public License v2.0 or later
* Full text of license available in license.txt file, in main folder
*
*/
#include "StdInc.h"
#include "ExchangeSwapTownHeroes.h"
#include "ExecuteHeroChain.h"
#include "../VCAI.h"
#include "../FuzzyHelper.h"
#include "../AIhelper.h"
#include "../../../lib/mapping/CMap.h" //for victory conditions
#include "../../../lib/CPathfinder.h"
#include "../Engine/Nullkiller.h"

extern boost::thread_specific_ptr<CCallback> cb;
extern boost::thread_specific_ptr<VCAI> ai;
extern FuzzyHelper * fh;

using namespace Goals;

ExchangeSwapTownHeroes::ExchangeSwapTownHeroes(
	const CGTownInstance * town, 
	const CGHeroInstance * garrisonHero,
	HeroLockedReason lockingReason)
	:ElementarGoal(Goals::EXCHANGE_SWAP_TOWN_HEROES), town(town), garrisonHero(garrisonHero), lockingReason(lockingReason)
{
}

std::string ExchangeSwapTownHeroes::toString() const
{
	return "Exchange and swap heroes of " + town->name;
}

bool ExchangeSwapTownHeroes::operator==(const ExchangeSwapTownHeroes & other) const
{
	return town == other.town;
}

void ExchangeSwapTownHeroes::accept(VCAI * ai)
{
	if(!garrisonHero)
	{
		if(!town->garrisonHero)
			throw cannotFulfillGoalException("Invalid configuration. There is no hero in town garrison.");
		
		cb->swapGarrisonHero(town);
		ai->buildArmyIn(town);
		ai->nullkiller->unlockHero(town->visitingHero.get());
		logAi->debug("Extracted hero %s from garrison of %s", town->visitingHero->name, town->name);

		return;
	}

	if(town->visitingHero && town->visitingHero.get() != garrisonHero)
		cb->swapGarrisonHero(town);

	ai->makePossibleUpgrades(town);
	ai->moveHeroToTile(town->visitablePos(), garrisonHero);

	auto upperArmy = town->getUpperArmy();
	
	if(!town->garrisonHero && upperArmy->stacksCount() != 0)
	{
		// dismiss creatures we are not able to pick to be able to hide in garrison
		if(upperArmy->getArmyStrength() < 500 
			&& town->fortLevel() >= CGTownInstance::CITADEL)
		{
			for(auto slot : upperArmy->Slots())
			{
				cb->dismissCreature(upperArmy, slot.first);
			}

			cb->swapGarrisonHero(town);
		}
	}
	else
	{
		cb->swapGarrisonHero(town); // selected hero left in garrison with strongest army
	}

	ai->nullkiller->lockHero(garrisonHero, lockingReason);

	if(town->visitingHero && town->visitingHero != garrisonHero)
	{
		ai->nullkiller->unlockHero(town->visitingHero.get());
		ai->makePossibleUpgrades(town->visitingHero);
	}

	logAi->debug("Put hero %s to garrison of %s", garrisonHero->name, town->name);
}