/*
 * CMapGenerator.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 "CMapGenerator.h"

#include "../mapping/CMap.h"
#include "../mapping/MapFormat.h"
#include "../VCMI_Lib.h"
#include "../texts/CGeneralTextHandler.h"
#include "../CRandomGenerator.h"
#include "../entities/faction/CTownHandler.h"
#include "../entities/faction/CFaction.h"
#include "../mapObjectConstructors/AObjectTypeHandler.h"
#include "../mapObjectConstructors/CObjectClassesHandler.h"
#include "../mapping/CMapEditManager.h"
#include "../CArtHandler.h"
#include "../CHeroHandler.h"
#include "../constants/StringConstants.h"
#include "../filesystem/Filesystem.h"
#include "CZonePlacer.h"
#include "TileInfo.h"
#include "Zone.h"
#include "Functions.h"
#include "RmgMap.h"
#include "threadpool/ThreadPool.h"
#include "modificators/ObjectManager.h"
#include "modificators/TreasurePlacer.h"
#include "modificators/RoadPlacer.h"

#include <vstd/RNG.h>

VCMI_LIB_NAMESPACE_BEGIN

CMapGenerator::CMapGenerator(CMapGenOptions& mapGenOptions, IGameCallback * cb, int RandomSeed) :
	mapGenOptions(mapGenOptions), randomSeed(RandomSeed),
	monolithIndex(0),
	rand(std::make_unique<CRandomGenerator>(RandomSeed))
{
	loadConfig();
	mapGenOptions.finalize(*rand);
	map = std::make_unique<RmgMap>(mapGenOptions, cb);
	placer = std::make_shared<CZonePlacer>(*map);
}

int CMapGenerator::getRandomSeed() const
{
	return randomSeed;
}

void CMapGenerator::loadConfig()
{
	JsonNode randomMapJson(JsonPath::builtin("config/randomMap.json"));

	config.shipyardGuard = randomMapJson["waterZone"]["shipyard"]["value"].Integer();
	for(auto & treasure : randomMapJson["waterZone"]["treasure"].Vector())
	{
		config.waterTreasure.emplace_back(treasure["min"].Integer(), treasure["max"].Integer(), treasure["density"].Integer());
	}
	config.mineExtraResources = randomMapJson["mines"]["extraResourcesLimit"].Integer();
	config.minGuardStrength = randomMapJson["minGuardStrength"].Integer();
	config.defaultRoadType = randomMapJson["defaultRoadType"].String();
	config.secondaryRoadType = randomMapJson["secondaryRoadType"].String();
	config.treasureValueLimit = randomMapJson["treasureValueLimit"].Integer();
	for(auto & i : randomMapJson["prisons"]["experience"].Vector())
		config.prisonExperience.push_back(i.Integer());
	for(auto & i : randomMapJson["prisons"]["value"].Vector())
		config.prisonValues.push_back(i.Integer());
	for(auto & i : randomMapJson["scrolls"]["value"].Vector())
		config.scrollValues.push_back(i.Integer());
	for(auto & i : randomMapJson["pandoras"]["creaturesValue"].Vector())
		config.pandoraCreatureValues.push_back(i.Integer());
	for(auto & i : randomMapJson["quests"]["value"].Vector())
		config.questValues.push_back(i.Integer());
	for(auto & i : randomMapJson["quests"]["rewardValue"].Vector())
		config.questRewardValues.push_back(i.Integer());
	config.pandoraMultiplierGold = randomMapJson["pandoras"]["valueMultiplierGold"].Integer();
	config.pandoraMultiplierExperience = randomMapJson["pandoras"]["valueMultiplierExperience"].Integer();
	config.pandoraMultiplierSpells = randomMapJson["pandoras"]["valueMultiplierSpells"].Integer();
	config.pandoraSpellSchool = randomMapJson["pandoras"]["valueSpellSchool"].Integer();
	config.pandoraSpell60 = randomMapJson["pandoras"]["valueSpell60"].Integer();
	config.singleThread = randomMapJson["singleThread"].Bool();
}

const CMapGenerator::Config & CMapGenerator::getConfig() const
{
	return config;
}

//must be instantiated in .cpp file for access to complete types of all member fields
CMapGenerator::~CMapGenerator() = default;

const CMapGenOptions& CMapGenerator::getMapGenOptions() const
{
	return mapGenOptions;
}

void CMapGenerator::initQuestArtsRemaining()
{
	//TODO: Move to QuestArtifactPlacer?
	for (auto artID : VLC->arth->getDefaultAllowed())
	{
		auto art = artID.toArtifact();
		//Don't use parts of combined artifacts
		if (art->aClass == CArtifact::ART_TREASURE && VLC->arth->legalArtifact(art->getId()) && art->getPartOf().empty())
			questArtifacts.push_back(art->getId());
	}
}

std::unique_ptr<CMap> CMapGenerator::generate()
{
	Load::Progress::reset();
	Load::Progress::setupStepsTill(5, 30);
	try
	{
		addHeaderInfo();
		map->initTiles(*this, *rand);
		Load::Progress::step();
		initQuestArtsRemaining();
		genZones();
		Load::Progress::step();
		map->getMap(this).calculateGuardingGreaturePositions(); //clear map so that all tiles are unguarded
		map->addModificators();
		Load::Progress::step(3);
		fillZones();
		//updated guarded tiles will be calculated in CGameState::initMapObjects()
		map->getZones().clear();

		// undo manager keeps pointers to object that might be removed during gameplay. Remove them to prevent any hanging pointer after gameplay
		map->getEditManager()->getUndoManager().clearAll();
	}
	catch (rmgException &e)
	{
		logGlobal->error("Random map generation received exception: %s", e.what());
		throw;
	}
	Load::Progress::finish();

	map->mapInstance->creationDateTime = std::time(nullptr);
	map->mapInstance->author = MetaString::createFromTextID("core.genrltxt.740");
	const auto * mapTemplate = mapGenOptions.getMapTemplate();
	if(mapTemplate)
		map->mapInstance->mapVersion = MetaString::createFromRawString(mapTemplate->getName());

	return std::move(map->mapInstance);
}

std::string CMapGenerator::getMapDescription() const
{
	assert(map);

	const std::string waterContentStr[3] = { "none", "normal", "islands" };
	const std::string monsterStrengthStr[3] = { "weak", "normal", "strong" };

	int monsterStrengthIndex = mapGenOptions.getMonsterStrength() - EMonsterStrength::GLOBAL_WEAK; //does not start from 0
	const auto * mapTemplate = mapGenOptions.getMapTemplate();

	if(!mapTemplate)
		throw rmgException("Map template for Random Map Generator is not found. Could not start the game.");

    std::stringstream ss;
    ss << boost::str(boost::format(std::string("Map created by the Random Map Generator.\nTemplate was %s, size %dx%d") +
        ", levels %d, players %d, computers %d, water %s, monster %s, VCMI map") % mapTemplate->getName() %
		map->width() % map->height() % static_cast<int>(map->levels()) % static_cast<int>(mapGenOptions.getHumanOrCpuPlayerCount()) %
		static_cast<int>(mapGenOptions.getCompOnlyPlayerCount()) % waterContentStr[mapGenOptions.getWaterContent()] %
		monsterStrengthStr[monsterStrengthIndex]);

	for(const auto & pair : mapGenOptions.getPlayersSettings())
	{
		const auto & pSettings = pair.second;
		if(pSettings.getPlayerType() == EPlayerType::HUMAN)
		{
			ss << ", " << GameConstants::PLAYER_COLOR_NAMES[pSettings.getColor().getNum()] << " is human";
		}
		if(pSettings.getStartingTown() != FactionID::RANDOM)
		{
			ss << ", " << GameConstants::PLAYER_COLOR_NAMES[pSettings.getColor().getNum()]
			   << " town choice is " << (*VLC->townh)[pSettings.getStartingTown()]->getNameTranslated();
		}
	}

	return ss.str();
}

void CMapGenerator::addPlayerInfo()
{
	// Teams are already configured in CMapGenOptions. However, it's not the case when it comes to map editor

	std::set<TeamID> teamsTotal;

	if (mapGenOptions.arePlayersCustomized())
	{
		// Simply copy existing settings set in GUI

		for (const auto & player : mapGenOptions.getPlayersSettings())
		{
			PlayerInfo playerInfo;
			playerInfo.team = player.second.getTeam();
			if (player.second.getPlayerType() == EPlayerType::COMP_ONLY)
			{
				playerInfo.canHumanPlay = false;
			}
			else
			{
				playerInfo.canHumanPlay = true;
			}
			map->getMap(this).players[player.first.getNum()] = playerInfo;
			teamsTotal.insert(player.second.getTeam());
		}
	}
	else
	{
		// Assign standard teams (in map editor)

		// Calculate which team numbers exist

		enum ETeams {CPHUMAN = 0, CPUONLY = 1, AFTER_LAST = 2}; // Used as a kind of a local named array index, so left as enum, not enum class
		std::array<std::list<int>, 2> teamNumbers;
		
		int teamOffset = 0;
		int playerCount = 0;
		int teamCount = 0;

		// FIXME: Player can be any color, not just 0
		for (int i = CPHUMAN; i < AFTER_LAST; ++i)
		{
			if (i == CPHUMAN)
			{
				playerCount = mapGenOptions.getHumanOrCpuPlayerCount();
				teamCount = mapGenOptions.getTeamCount();
			}
			else
			{
				playerCount = mapGenOptions.getCompOnlyPlayerCount();
				teamCount = mapGenOptions.getCompOnlyTeamCount();
			}

			if(playerCount == 0)
			{
				continue;
			}
			int playersPerTeam = playerCount / (teamCount == 0 ? playerCount : teamCount);
			int teamCountNorm = teamCount;
			if(teamCountNorm == 0)
			{
				teamCountNorm = playerCount;
			}
			for(int j = 0; j < teamCountNorm; ++j)
			{
				for(int k = 0; k < playersPerTeam; ++k)
				{
					teamNumbers[i].push_back(j + teamOffset);
				}
			}
			for(int j = 0; j < playerCount - teamCountNorm * playersPerTeam; ++j)
			{
				teamNumbers[i].push_back(j + teamOffset);
			}
			teamOffset += teamCountNorm;
		}
		logGlobal->info("Current player settings size: %d",  mapGenOptions.getPlayersSettings().size());

		// Team numbers are assigned randomly to every player
		//TODO: allow to customize teams in rmg template
		for(const auto & pair : mapGenOptions.getPlayersSettings())
		{
			const auto & pSettings = pair.second;
			PlayerInfo player;
			player.canComputerPlay = true;
			int j = (pSettings.getPlayerType() == EPlayerType::COMP_ONLY) ? CPUONLY : CPHUMAN;
			if (j == CPHUMAN)
			{
				player.canHumanPlay = true;
			}

			if(pSettings.getTeam() != TeamID::NO_TEAM)
			{
				player.team = pSettings.getTeam();
			}
			else
			{
				if (teamNumbers[j].empty())
				{
					logGlobal->error("Not enough places in team for %s player", ((j == CPUONLY) ? "CPU" : "CPU or human"));
					assert (teamNumbers[j].size());
				}
				auto itTeam = RandomGeneratorUtil::nextItem(teamNumbers[j], *rand);
				player.team = TeamID(*itTeam);
				teamNumbers[j].erase(itTeam);
			}
			teamsTotal.insert(player.team);
			map->getMap(this).players[pSettings.getColor().getNum()] = player;
		}

		logGlobal->info("Current team count: %d", teamsTotal.size());

	}
	// FIXME: 0
	// Can't find info for player 0 (starting zone)
	// Can't find info for player 1 (starting zone)

	map->getMap(this).howManyTeams = teamsTotal.size();
}

void CMapGenerator::genZones()
{
	placer->placeZones(rand.get());
	placer->assignZones(rand.get());

	logGlobal->info("Zones generated successfully");
}

void CMapGenerator::addWaterTreasuresInfo()
{
	if (!getZoneWater())
		return;

	//add treasures on water
	for (const auto& treasureInfo : getConfig().waterTreasure)
	{
		getZoneWater()->addTreasureInfo(treasureInfo);
	}
}

void CMapGenerator::fillZones()
{
	addWaterTreasuresInfo();

	logGlobal->info("Started filling zones");

	size_t numZones = map->getZones().size();

	//we need info about all town types to evaluate dwellings and pandoras with creatures properly
	//place main town in the middle

	Load::Progress::setupStepsTill(numZones, 50);
	for (const auto& it : map->getZones())
	{
		it.second->initFreeTiles();
		it.second->initModificators();
		Progress::Progress::step();
	}

	std::vector<std::shared_ptr<Zone>> treasureZones;

	TModificators allJobs;
	for (auto& it : map->getZones())
	{
		allJobs.splice(allJobs.end(), it.second->getModificators());
	}

	Load::Progress::setupStepsTill(allJobs.size(), 240);

	if (config.singleThread) //No thread pool, just queue with deterministic order
	{
		while (!allJobs.empty())
		{
			for (auto it = allJobs.begin(); it != allJobs.end();)
			{
				if ((*it)->isReady())
				{
					auto jobCopy = *it;
					jobCopy->run();
					Progress::Progress::step(); //Update progress bar
					allJobs.erase(it);
					break; //Restart from the first job
				}
				else
				{
					++it;
				}
			}
		}
	}
	else
	{
		ThreadPool pool;
		std::vector<boost::future<void>> futures;
		//At most one Modificator can run for every zone
		pool.init(std::min<int>(boost::thread::hardware_concurrency(), numZones));

		while (!allJobs.empty())
		{
			for (auto it = allJobs.begin(); it != allJobs.end();)
			{
				if ((*it)->isFinished())
				{
					it = allJobs.erase(it);
					Progress::Progress::step();
				}
				else if ((*it)->isReady())
				{
					auto jobCopy = *it;
					futures.emplace_back(pool.async([this, jobCopy]() -> void
						{
							jobCopy->run();
							Progress::Progress::step(); //Update progress bar
						}
					));
					it = allJobs.erase(it);
				}
				else
				{
					++it;
				}
			}
		}

		//Wait for all the tasks
		for (auto& fut : futures)
		{
			fut.get();
		}
	}

	for (const auto& it : map->getZones())
	{
		if (it.second->getType() == ETemplateZoneType::TREASURE)
			treasureZones.push_back(it.second);
	}

	//find place for Grail
	if (treasureZones.empty())
	{
		for (const auto& it : map->getZones())
			if (it.second->getType() != ETemplateZoneType::WATER)
				treasureZones.push_back(it.second);
	}
	auto grailZone = *RandomGeneratorUtil::nextItem(treasureZones, *rand);

	map->getMap(this).grailPos = *RandomGeneratorUtil::nextItem(grailZone->freePaths()->getTiles(), *rand);
	map->getMap(this).reindexObjects();

	logGlobal->info("Zones filled successfully");

	Load::Progress::set(250);
}

void CMapGenerator::addHeaderInfo()
{
	auto& m = map->getMap(this);
	m.version = EMapFormat::VCMI;
	m.width = mapGenOptions.getWidth();
	m.height = mapGenOptions.getHeight();
	m.twoLevel = mapGenOptions.getHasTwoLevels();
	m.name.appendLocalString(EMetaText::GENERAL_TXT, 740);
	m.description.appendRawString(getMapDescription());
	m.difficulty = EMapDifficulty::NORMAL;
	addPlayerInfo();
	m.waterMap = (mapGenOptions.getWaterContent() != EWaterContent::EWaterContent::NONE);
	m.banWaterContent();
}

int CMapGenerator::getNextMonlithIndex()
{
	while (true)
	{
		if (monolithIndex >= VLC->objtypeh->knownSubObjects(Obj::MONOLITH_TWO_WAY).size())
			throw rmgException(boost::str(boost::format("There is no Monolith Two Way with index %d available!") % monolithIndex));
		else
		{
			//Skip modded Monoliths which can't beplaced on every terrain
			auto templates = VLC->objtypeh->getHandlerFor(Obj::MONOLITH_TWO_WAY, monolithIndex)->getTemplates();
			if (templates.empty() || !templates[0]->canBePlacedAtAnyTerrain())
			{
				monolithIndex++;
			}
			else
			{
				return monolithIndex++;
			}
		}
	}
}

std::shared_ptr<CZonePlacer> CMapGenerator::getZonePlacer() const
{
	return placer;
}

const std::vector<ArtifactID> & CMapGenerator::getAllPossibleQuestArtifacts() const
{
	return questArtifacts;
}

const std::vector<HeroTypeID> CMapGenerator::getAllPossibleHeroes() const
{
	auto isWaterMap = map->getMap(this).isWaterMap();
	//Skip heroes that were banned, including the ones placed in prisons
	std::vector<HeroTypeID> ret;

	for (HeroTypeID hero : map->getMap(this).allowedHeroes)
	{
		auto * h = dynamic_cast<const CHero*>(VLC->heroTypes()->getById(hero));
		if(h->onlyOnWaterMap && !isWaterMap)
			continue;

		if(h->onlyOnMapWithoutWater && isWaterMap)
			continue;

		bool heroUsedAsStarting = false;
		for (auto const & player : map->getMapGenOptions().getPlayersSettings())
		{
			if (player.second.getStartingHero() == hero)
			{
				heroUsedAsStarting = true;
				break;
			}
		}

		if (heroUsedAsStarting)
			continue;

		ret.push_back(hero);
	}
	return ret;
}

void CMapGenerator::banQuestArt(const ArtifactID & id)
{
	map->getMap(this).allowedArtifact.erase(id);
}

void CMapGenerator::unbanQuestArt(const ArtifactID & id)
{
	map->getMap(this).allowedArtifact.insert(id);
}

Zone * CMapGenerator::getZoneWater() const
{
	for(auto & z : map->getZones())
		if(z.second->getType() == ETemplateZoneType::WATER)
			return z.second.get();
	return nullptr;
}

VCMI_LIB_NAMESPACE_END