//========================================================================
// BaseGameLogic.cpp : defines game logic class
//
// Part of the GameCode4 Application
//
// GameCode4 is the sample application that encapsulates much of the source code
// discussed in "Game Coding Complete - 4th Edition" by Mike McShaffry and David
// "Rez" Graham, published by Charles River Media. 
// ISBN-10: 1133776574 | ISBN-13: 978-1133776574
//
// If this source code has found it's way to you, and you think it has helped you
// in any way, do the authors a favor and buy a new copy of the book - there are 
// detailed explanations in it that compliment this code well. Buy a copy at Amazon.com
// by clicking here: 
//    http://www.amazon.com/gp/product/1133776574/ref=olp_product_details?ie=UTF8&me=&seller=
//
// There's a companion web site at http://www.mcshaffry.com/GameCode/
// 
// The source code is managed and maintained through Google Code: 
//    http://code.google.com/p/gamecode4/
//
// (c) Copyright 2012 Michael L. McShaffry and David Graham
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser GPL v3
// as published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See 
// http://www.gnu.org/licenses/lgpl-3.0.txt for more details.
//
// You should have received a copy of the GNU Lesser GPL v3
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
//========================================================================

#include "../Unix/GameCodeStd.h"

#include "../EventManager/Events.h"				// only for EvtData_Game_State
#include "../ResourceCache/XmlResource.h"
#include "../UserInterface/HumanView.h"  // [rez] not ideal, but the loading sequence needs to know if this is a human view

#include "BaseGameLogic.h"

//========================================================================
//
// LevelManager implementation
//
//========================================================================

bool LevelManager::Initialize(std::vector<std::string> &levels)
{
	std::vector<std::string>::iterator i = levels.begin();
	while (i != levels.end())
	{
		m_Levels.push_back(*i);
		++i;
	}
	return true;
}




//========================================================================
//
// BaseGameLogic implementation
//
//========================================================================

BaseGameLogic::BaseGameLogic()
{
	m_Lifetime              = 0;
	m_State                 = BGS_Initializing;
	m_bProxy                = false;
	m_ExpectedPlayers       = 0;
	m_ExpectedRemotePlayers = 0;
	m_ExpectedAI            = 0;
	m_HumanPlayersAttached  = 0;
	m_AIPlayersAttached     = 0;
	m_HumanGamesLoaded      = 0;

	m_pLevelManager = GCC_NEW LevelManager;
	// GCC_ASSERT(m_pProcessManager && m_pLevelManager);

	// TODO(munnellg) - book passes levels directly, but my compiler doesn't like that. Find out why
	std::vector<std::string> levels = g_pApp->m_ResCache->Match("world/*.xml");
	m_pLevelManager->Initialize(levels);
}

BaseGameLogic::~BaseGameLogic()
{
	// MrMike: 12-Apr-2009 
	//   Added this to explicitly remove views from the game logic list.
	while (!m_gameViews.empty())
		m_gameViews.pop_front();

	SAFE_DELETE(m_pLevelManager);
	// SAFE_DELETE(m_pProcessManager);
	SAFE_DELETE(m_pActorFactory);

	// destroy all actors
	for (auto it = m_actors.begin(); it != m_actors.end(); ++it)
		it->second->Destroy();
	m_actors.clear();

	// IEventManager::Get()->VRemoveListener(MakeDelegate(this, &BaseGameLogic::RequestDestroyActorDelegate), EvtData_Request_Destroy_Actor::sk_EventType);
}

bool BaseGameLogic::Init(void)
{
    m_pActorFactory = VCreateActorFactory();
    // m_pPathingGraph.reset(CreatePathingGraph());

    // IEventManager::Get()->VAddListener(MakeDelegate(this, &BaseGameLogic::RequestDestroyActorDelegate), EvtData_Request_Destroy_Actor::sk_EventType);

    return true;
}

bool BaseGameLogic::VLoadGame(const char* levelResource)
{
	// Grab the root XML node
	TiXmlElement* pRoot = XmlResourceLoader::LoadAndReturnRootXmlElement(levelResource);
	if (!pRoot)
	{
		GCC_ERROR("Failed to find level resource file: " + std::string(levelResource));
		return false;
	}

	// pre and post load scripts
	const char* preLoadScript = NULL;
	const char* postLoadScript = NULL;

	// parse the pre & post script attributes
	TiXmlElement* pScriptElement = pRoot->FirstChildElement("Script");
	if (pScriptElement)
	{
		preLoadScript = pScriptElement->Attribute("preLoad");
		postLoadScript = pScriptElement->Attribute("postLoad");
	}

	// load the pre-load script if there is one
	if (preLoadScript)
	{
		Resource resource(preLoadScript);
		std::shared_ptr<ResHandle> pResourceHandle = g_pApp->m_ResCache->GetHandle(&resource);
	}

	// load all initial actors
	TiXmlElement* pActorsNode = pRoot->FirstChildElement("StaticActors");
	if (pActorsNode)
	{
		for (TiXmlElement* pNode = pActorsNode->FirstChildElement(); pNode; pNode = pNode->NextSiblingElement())
		{
			const char* actorResource = pNode->Attribute("resource");

			StrongActorPtr pActor = VCreateActor(actorResource, pNode);
			if (pActor)
			{
				// fire an event letting everyone else know that we created a new actor
				std::shared_ptr<EvtData_New_Actor> pNewActorEvent(GCC_NEW EvtData_New_Actor(pActor->GetId()));
				IEventManager::Get()->VQueueEvent(pNewActorEvent);
			}
		}
	}

	// initialize all human views
	for (auto it = m_gameViews.begin(); it != m_gameViews.end(); ++it)
	{
		std::shared_ptr<IGameView> pView = *it;
		if (pView->VGetType() == GameView_Human)
		{
			std::shared_ptr<HumanView> pHumanView = static_pointer_cast<HumanView, IGameView>(pView);
			pHumanView->LoadGame(pRoot);
		}
	}

    // register script events from the engine
	//   [mrmike] this was moved to the constructor post-press, since this function can be called when new levels are loaded by the game or editor
    // RegisterEngineScriptEvents();

    // call the delegate load function
    if (!VLoadGameDelegate(pRoot))
        return false;  // no error message here because it's assumed VLoadGameDelegate() kicked out the error

    // load the post-load script if there is one
    if (postLoadScript)
    {
        Resource resource(postLoadScript);
        std::shared_ptr<ResHandle> pResourceHandle = g_pApp->m_ResCache->GetHandle(&resource);  // this actually loads the XML file from the zip file
    }

	// trigger the Environment Loaded Game event - only then can player actors and AI be spawned!
	if (m_bProxy)
	{
		std::shared_ptr<EvtData_Remote_Environment_Loaded> pNewGameEvent(GCC_NEW EvtData_Remote_Environment_Loaded);
		IEventManager::Get()->VTriggerEvent(pNewGameEvent);
	}
	else
	{
		std::shared_ptr<EvtData_Environment_Loaded> pNewGameEvent(GCC_NEW EvtData_Environment_Loaded);
		IEventManager::Get()->VTriggerEvent(pNewGameEvent);
	}
	return true;
}

void BaseGameLogic::VSetProxy() 
{
	m_bProxy = true; 

	// IEventManager::Get()->VAddListener(MakeDelegate(this, &BaseGameLogic::RequestNewActorDelegate), EvtData_Request_New_Actor::sk_EventType);

	// m_pPhysics.reset(CreateNullPhysics());
}

StrongActorPtr BaseGameLogic::VCreateActor(
		const std::string &actorResource,
		TiXmlElement* overrides,
		std::optional<const glm::mat4> initialTransform,
		const ActorId serversActorId
) {
	
	GCC_ASSERT(m_pActorFactory);
	if (!m_bProxy && serversActorId != INVALID_ACTOR_ID)
		return StrongActorPtr();

	if (m_bProxy && serversActorId == INVALID_ACTOR_ID)
		return StrongActorPtr();

	StrongActorPtr pActor = m_pActorFactory->CreateActor(actorResource.c_str(), overrides, initialTransform, serversActorId);
	if (pActor)
	{
		m_actors.insert(std::make_pair(pActor->GetId(), pActor));
		if (!m_bProxy && (m_State==BGS_SpawningPlayersActors || m_State==BGS_Running))
		{
			std::shared_ptr<EvtData_Request_New_Actor> pNewActor(GCC_NEW EvtData_Request_New_Actor(actorResource, initialTransform, pActor->GetId()));
			IEventManager::Get()->VTriggerEvent(pNewActor);
		}
		return pActor;
	}
	else
	{
		return StrongActorPtr();
	}
}

void BaseGameLogic::VDestroyActor(const ActorId actorId)
{
	std::shared_ptr<EvtData_Destroy_Actor> pEvent(GCC_NEW EvtData_Destroy_Actor(actorId));
	IEventManager::Get()->VTriggerEvent(pEvent);

	auto findIt = m_actors.find(actorId);
	if (findIt != m_actors.end())
	{
		findIt->second->Destroy();
		m_actors.erase(findIt);
	}
}

WeakActorPtr BaseGameLogic::VGetActor(const ActorId actorId)
{
	ActorMap::iterator findIt = m_actors.find(actorId);
	if (findIt != m_actors.end())
		return findIt->second;
	return WeakActorPtr();
}

void BaseGameLogic::VModifyActor(const ActorId actorId, TiXmlElement *override)
{
	GCC_ASSERT(m_pActorFactory);
	if (!m_pActorFactory)
		return;

	auto findIt = m_actors.find(actorId);
	if (findIt != m_actors.end())
	{
		m_pActorFactory->ModifyActor(findIt->second, override);
	}
}

void BaseGameLogic::VOnUpdate(float time, float elapsedTime)
{
	int deltaMilliseconds = int(elapsedTime * 1000.0f);
	m_Lifetime += elapsedTime;

	switch(m_State)
	{
		case BGS_Initializing:
		{
			// If we get to here we're ready to attach players
			VChangeState(BGS_MainMenu);
			break;
		}
		case BGS_MainMenu:
		{
			break;
		}
		case BGS_LoadingGameEnvironment:
		{
/***
			// [mrmike] This was modified a little from what you see in the book - VLoadGame() is now called from 
			//          BaseGameLogic::VChangeState()
			//
			if (!g_pApp->VLoadGame())
			{
				GCC_ERROR("The game failed to load.");
				g_pApp->AbortGame();
			}
***/
			break;
		}
		case BGS_WaitingForPlayersToLoadEnvironment:
		{
			if (m_ExpectedPlayers + m_ExpectedRemotePlayers <= m_HumanGamesLoaded)
			{
				VChangeState(BGS_SpawningPlayersActors);
			}
			break;
		}
		case BGS_SpawningPlayersActors:
		{
			VChangeState(BGS_Running);
			break;
		}
		case BGS_WaitingForPlayers:
		{
			if (m_ExpectedPlayers + m_ExpectedRemotePlayers == m_HumanPlayersAttached)
			{
				// The server sends us the level name as a part of the login message. 
				// We have to wait until it arrives before loading the level
				if (!g_pApp->m_Options.m_Level.empty())
				{
					VChangeState(BGS_LoadingGameEnvironment);
				}
			}
			break;
		}
		case BGS_Running:
		{
			// m_pProcessManager->UpdateProcesses(deltaMilliseconds);

			// if (m_pPhysics && !m_bProxy)
			// {
			// 	m_pPhysics->VOnUpdate(elapsedTime);
			// 	m_pPhysics->VSyncVisibleScene();
			// }
			break;
		}
		default:
			GCC_ERROR("Unrecognized state.");
	}

	// update all game views
	for (GameViewList::iterator it = m_gameViews.begin(); it != m_gameViews.end(); ++it)
	{
		(*it)->VOnUpdate(deltaMilliseconds);
	}

	// update game actors
	// for (ActorMap::const_iterator it = m_actors.begin(); it != m_actors.end(); ++it)
	// {
	// 	it->second->Update(deltaMilliseconds);
	// }
}

//
// BaseGameLogic::VChangeState				- Chapter 19, page 710
//
void BaseGameLogic::VChangeState(BaseGameState newState)
{
	// TODO(munnellg) - implement
	if (newState==BGS_WaitingForPlayers)
	{
		// Get rid of the Main Menu
		m_gameViews.pop_front();
		// Note: Split screen support would require this to change!
		m_ExpectedPlayers = 1;
		m_ExpectedRemotePlayers = g_pApp->m_Options.m_expectedPlayers - 1;
		m_ExpectedAI = g_pApp->m_Options.m_numAIs;

		if (!g_pApp->m_Options.m_gameHost.empty())
		{
			VSetProxy();
			m_ExpectedAI = 0;				// the server will create these
			m_ExpectedRemotePlayers = 0;	// the server will create these

			// TODO(munnellg) - implement
			// if (!g_pApp->AttachAsClient())
			// {
			// 	// Throw up a main menu
			// 	VChangeState(BGS_MainMenu);
			// 	return
			// }
		}
		// else if (m_ExpectedRemotePlayers > 0)
		// {
			// TODO(munnellg) - implement for network games		
		// }
	}
	else if (newState == BGS_LoadingGameEnvironment)
	{
		m_State = newState;
		if (!g_pApp->VLoadGame())
		{
			GCC_ERROR("The game failed to load.");
			g_pApp->AbortGame();
		}
		else
		{
			VChangeState(BGS_WaitingForPlayersToLoadEnvironment);			// we must wait for all human player to report their environments are loaded.
			return;
		}
	}
	m_State = newState;
}

// Chapter 19/20 refactor work
//   - move physics pointer into BaseGameLogic
//   - but make the inherited logic choose the implementation
void BaseGameLogic::VRenderDiagnostics() 
{
	if (m_RenderDiagnostics)
	{
		// TODO(munnellg) - uncomment this when we have physics
		// m_pPhysics->VRenderDiagnostics();
	}
}

void BaseGameLogic::VAddView(std::shared_ptr<IGameView> pView, ActorId actorId)
{
	// This makes sure that all views have a non-zero view id.
	int viewId = static_cast<int>(m_gameViews.size());
	m_gameViews.push_back(pView);
	pView->VOnAttach(viewId, actorId);
	pView->VOnRestore();
}

void BaseGameLogic::VRemoveView(std::shared_ptr<IGameView> pView)
{
	m_gameViews.remove(pView);
}


ActorFactory* BaseGameLogic::VCreateActorFactory(void)
{
    return GCC_NEW ActorFactory;
}