/*
* AIPathfinder.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 "AIPathfinder.h"
#include "AIPathfinderConfig.h"
#include "../../../CCallback.h"
#include "../../../lib/mapping/CMap.h"

std::vector<std::shared_ptr<AINodeStorage>> AIPathfinder::storagePool;
std::map<HeroPtr, std::shared_ptr<AINodeStorage>> AIPathfinder::storageMap;
boost::mutex AIPathfinder::storageMutex;

AIPathfinder::AIPathfinder(CPlayerSpecificInfoCallback * cb, VCAI * ai)
	:cb(cb), ai(ai)
{
}

void AIPathfinder::clear()
{
	boost::unique_lock<boost::mutex> storageLock(storageMutex);
	storageMap.clear();
}

void AIPathfinder::init()
{
	boost::unique_lock<boost::mutex> storageLock(storageMutex);
	storagePool.clear();
	storageMap.clear();
}

bool AIPathfinder::isTileAccessible(const HeroPtr & hero, const int3 & tile)
{
	boost::unique_lock<boost::mutex> storageLock(storageMutex);

	std::shared_ptr<AINodeStorage> nodeStorage = getOrCreateStorage(hero);

	return nodeStorage->isTileAccessible(tile, EPathfindingLayer::LAND)
		|| nodeStorage->isTileAccessible(tile, EPathfindingLayer::SAIL);
}

std::vector<AIPath> AIPathfinder::getPathInfo(HeroPtr hero, int3 tile)
{
	boost::unique_lock<boost::mutex> storageLock(storageMutex);

	std::shared_ptr<AINodeStorage> nodeStorage = getOrCreateStorage(hero);

	const TerrainTile * tileInfo = cb->getTile(tile, false);

	if(!tileInfo)
	{
		return std::vector<AIPath>();
	}

	return nodeStorage->getChainInfo(tile, !tileInfo->isWater());
}

std::shared_ptr<AINodeStorage> AIPathfinder::getOrCreateStorage(const HeroPtr & hero)
{
	std::shared_ptr<AINodeStorage> nodeStorage;

	if(!vstd::contains(storageMap, hero))
	{
		logAi->debug("Recalculate paths for %s", hero->name);

		if(storageMap.size() < storagePool.size())
		{
			nodeStorage = storagePool.at(storageMap.size());
		}
		else
		{
			nodeStorage = std::make_shared<AINodeStorage>(cb->getMapSize());
			storagePool.push_back(nodeStorage);
		}

		storageMap[hero] = nodeStorage;
		nodeStorage->setHero(hero.get());

		auto config = std::make_shared<AIPathfinding::AIPathfinderConfig>(cb, ai, nodeStorage);

		cb->calculatePaths(config, hero.get());
	}
	else
	{
		nodeStorage = storageMap.at(hero);
	}

	return nodeStorage;
}