// Fill out your copyright notice in the Description page of Project Settings.


#include "Game/ShooterGameMode.h"
#include "Logging/LogMacros.h"
#include "Logging/StructuredLog.h"

#if WITH_GAMELIFT
#include "GameLiftServerSDK.h"
#endif

DEFINE_LOG_CATEGORY(LogShooterGameMode)

namespace GameLiftValidators {
	const FRegexPattern FleetIdPattern(TEXT("^[a-z]*fleet-[a-zA-Z0-9\\-]+$"));
	const int32 FleetIdLengthMin = 1;
	const int32 FleetIdLengthMax = 128;
	const FString ServerRegionPattern(TEXT("^[a-z]{2}-[a-z]+-[0-9]$"));
	const int32 ServerRegionLengthMin = 3;
	const int32 ServerRegionLengthMax = 16;
	const FString WebSocketUrlPattern(TEXT("^(ws|wss):\\/\\/([0-9a-zA-Z.-]+)(:([1-9][0-9]{0,4}))?(\\/.*)?$"));
	const int32 WebSocketUrlLengthMin = 1;
	const int32 WebSocketUrlLengthMax = 128;
	const FString AuthTokenPattern(TEXT("^[A-Za-z0-9+/=]+$"));
	const int32 AuthTokenLengthMin = 20;
	const int32 AuthTokenLengthMax = 2048;
	const FString HostIdPattern(TEXT("^[a-z]*host-[a-zA-Z0-9\\-]+$"));
	const int32 HostIdLengthMin = 1;
	const int32 HostIdLengthMax = 128;
	const int32 ServerPortMin = 1026;
	const int32 ServerPortMax = 60000;
	const int32 WebSocketPortMin = 1;
	const int32 WebSocketPortMax = 60000;
	
	bool IsStringValid(const FString& Value, const FRegexPattern* OptionalPattern, const int32 Min, const int32 Max)
	{
		if (Value.IsEmpty()) return false;
		
		if (OptionalPattern)
		{
			return FRegexMatcher(*OptionalPattern, Value).FindNext() &&
				Value.Len() >= Min &&
				Value.Len() <= Max;
		}
		else
		{
			return Value.Len() >= Min && Value.Len() <= Max;
		}
	}
	
	bool IsNumberValid(const int32 Value, const int32 Min, const int32 Max)
	{
		return Value >= Min && Value <= Max;
	}
}

AShooterGameMode::AShooterGameMode()
{
	UE_LOG(LogShooterGameMode, Log, TEXT("Initializing ShooterGameMode..."));
}

void AShooterGameMode::BeginPlay()
{
	Super::BeginPlay();
	
#if WITH_GAMELIFT
	InitGameLift();
#endif
}

void AShooterGameMode::InitGame(const FString& MapName, const FString& Options, FString& ErrorMessage)
{
	Super::InitGame(MapName, Options, ErrorMessage);
	
	UE_LOG(LogShooterGameMode, Log, TEXT("[%s] Parsing CLI"), *FDateTime::UtcNow().ToString(TEXT("%Y%m%d-%H%M%S")));
	CachedCommandLine = FCommandLine::Get();
	
	//  Parsing of Command Line
	GameLiftConfig.bDebugMode = FParse::Param(*CachedCommandLine, TEXT("Debug"));
	
	if (GameLiftConfig.bDebugMode)
	{
		UE_LOG(LogShooterGameMode, Log, TEXT("Debug mode: ENABLED"));
#if UE_BUILD_DEBUG
		UE_LOG(LogShooterGameMode, Log, TEXT("Command Line Arguments: %s"), *CachedCommandLine);
#endif
	}
	
	GameLiftConfig.ServerPort = GetConfiguredOrDefaultPort();
	GameLiftConfig.bIsAnywhereFleet = FParse::Param(*CachedCommandLine, TEXT("glAnywhere"));
	
	if (GameLiftConfig.bIsAnywhereFleet)
	{
		UE_LOGFMT(LogShooterGameMode, Log, "GameLift Anywhere Fleet Command Line Parsing");
		UE_LOGFMT(LogShooterGameMode, Log, "======Command Line Parameters======");
		
		UE_LOGFMT(LogShooterGameMode, Log, "===================================");
	}
	else
	{
		
	}
	
}

void AShooterGameMode::InitGame_original(const FString& MapName, const FString& Options, FString& ErrorMessage)
{
	Super::InitGame(MapName, Options, ErrorMessage);
	
	UE_LOG(LogShooterGameMode, Log, TEXT("[%s] Parsing CLI"), *FDateTime::UtcNow().ToString(TEXT("%Y%m%d-%H%M%S")));
	CachedCommandLine = FCommandLine::Get();
	bool bIsCriticalError = false;
	
	if (bDebugMode)
	{
		UE_LOG(LogShooterGameMode, Log, TEXT("Debug mode: ENABLED"));
#if UE_BUILD_DEBUG		
		UE_LOG(LogShooterGameMode, Log, TEXT("Command Line Arguments: %s"), *CachedCommandLine);
#endif
	}
	
	ServerPort = GetConfiguredOrDefaultPort();
	
	bIsAnywhereFleet = FParse::Param(*CachedCommandLine, TEXT("glAnywhere"));
	if (bIsAnywhereFleet)
	{
		UE_LOG(LogShooterGameMode, Log, TEXT("GameLift Anywhere Fleet Command Line Parsing"));
		UE_LOG(LogShooterGameMode, Log, TEXT("======Command Line Parameters======"));
		
		if (!FParse::Value(*CachedCommandLine, TEXT("fleetID="), FleetId))
		{
			UE_LOG(LogShooterGameMode, Error, TEXT("FleetId Missing in Command Line"));
			bIsCriticalError = true;
		}
		else
		{
			UE_LOG(LogShooterGameMode, Log, TEXT("Fleet ID: %s"), *FleetId);
		}
		
		if (!FParse::Value(*CachedCommandLine, TEXT("authtoken="), AuthToken))
		{
			UE_LOG(LogShooterGameMode, Error, TEXT("AuthToken Missing in Command Line"));
			bIsCriticalError = true;
		}
		else
		{
			if (bDebugMode)
			{
				FString TokenHash = GetSHA256Hash(AuthToken);
				UE_LOG(LogShooterGameMode, Log, TEXT("AuthToken: %s"), *TokenHash);
			}
			else
			{
				UE_LOG(LogShooterGameMode, Log, TEXT("AuthToken Length: %d"), AuthToken.Len());
			}
		}
		if (!FParse::Value(*CachedCommandLine, TEXT("hostId="), HostId))
		{
			UE_LOG(LogShooterGameMode, Error, TEXT("HostId Missing in Command Line"));
			bIsCriticalError = true;
		}
		else
		{
			UE_LOG(LogShooterGameMode, Log, TEXT("Host ID: %s"), *HostId);
		}
		if (!FParse::Value(*CachedCommandLine, TEXT("websocketUrl="), WebSocketUrl))
		{
			UE_LOG(LogShooterGameMode, Error, TEXT("WebSocketUrl Missing in Command Line"));
			bIsCriticalError = true;
		}
		else
		{
			UE_LOG(LogShooterGameMode, Log, TEXT("Websocket URL: %s"), *WebSocketUrl);
			
			bool bValidWebSocket = WebSocketUrl.StartsWith(TEXT("wss://")) || WebSocketUrl.StartsWith(TEXT("ws://"));

			if (bValidWebSocket)
			{
				int32 ColonPos = WebSocketUrl.Find(TEXT(":"), ESearchCase::CaseSensitive);
				int32 SlashPos = WebSocketUrl.Find(TEXT("/"), ESearchCase::CaseSensitive, ESearchDir::FromStart, ColonPos + 1);
    
				int32 ParsedPort = 443;  // Default wss
				if (WebSocketUrl.StartsWith(TEXT("ws://"))) ParsedPort = 80;
    
				if (ColonPos != INDEX_NONE && SlashPos != INDEX_NONE)
				{
					FString PortStr = WebSocketUrl.Mid(ColonPos + 1, SlashPos - ColonPos - 1);
					int32 ExplicitPort = FCString::Atoi(*PortStr);
					if (ExplicitPort > 1024 && ExplicitPort <= 65535)  // Privileged ports OK for servers
					{
						ParsedPort = ExplicitPort;
					}
					else
					{
						bValidWebSocket = false;  // Invalid explicit port
					}
				}
    
				UE_LOG(LogShooterGameMode, Log, TEXT("WebSocket Parsed Port: %d"), ParsedPort);
			}

			if (!bValidWebSocket)
			{
				UE_LOG(LogShooterGameMode, Error, TEXT("Invalid WebSocketUrl: %s"), *WebSocketUrl);
				bIsCriticalError = true;
			}
		}
		if (ServerPort == 0)
		{
			UE_LOG(LogShooterGameMode, Error, TEXT("Invalid or Missing Server Port Number. Shutting Down."));
			bIsCriticalError = true;
		}
		else
		{
			UE_LOG(LogShooterGameMode, Log, TEXT("Port: %d"), ServerPort);
		}
		if (!FParse::Value(*CachedCommandLine, TEXT("serverRegion="), ServerRegion))
		{
			UE_LOG(LogShooterGameMode, Warning, TEXT("ServerRegion Missing in Command Line"));
		}
		else
		{
			UE_LOG(LogShooterGameMode, Log, TEXT(">>>Server Region: %s"), *ServerRegion);
		}
		
		UE_LOG(LogShooterGameMode, Log, TEXT("==================================="));
	}
	else
	{
		UE_LOG(LogShooterGameMode, Log, TEXT("GameLift EC2 Fleet"));
		if (ServerPort == 0)
		{
			UE_LOG(LogShooterGameMode, Error, TEXT("Invalid or Missing Server Port Number. Shutting Down."));
			bIsCriticalError = true;
		}
		else
		{
			UE_LOG(LogShooterGameMode, Log, TEXT("Port: %d"), ServerPort);
		}
	}
	
	if (bIsCriticalError)
	{
		UE_LOG(LogShooterGameMode, Error, TEXT("Critical Missing or Invalid Arguments in Command Line.   Shutting Down."));
		FPlatformMisc::RequestExit(true);
	}
	else
	{
		UE_LOG(LogShooterGameMode, Log, TEXT("Command Line Parsed Successfully."));
	}
	
	
}

int32 AShooterGameMode::GetConfiguredOrDefaultPort() const
{
	//  Default Unreal Engine listen/dedicated server port
	constexpr int32 DefaultPort = 7777;
	
	int32 CmdPort = DefaultPort;

	//  Check if a port was passed via command line: -port=xxxx
	
	if (FParse::Value(*CachedCommandLine, TEXT("port="), CmdPort) &&
		GameLiftValidators::IsNumberValid(CmdPort, GameLiftValidators::ServerPortMin, GameLiftValidators::ServerPortMax))
	{
		return CmdPort;
	}
	
	UE_LOGFMT(LogShooterGameMode, Warning, "Invalid/Missing port in command line - using {0}", DefaultPort);
	return DefaultPort;
}

FString AShooterGameMode::GetSHA256Hash(const FString& Input)
{
	FTCHARToUTF8 Utf8Input(Input);
	FSHA256Signature Hash;
	if (FPlatformMisc::GetSHA256Signature(reinterpret_cast<const uint8*>(Utf8Input.Get()), Utf8Input.Length(), Hash))
	{
		return Hash.ToString();
	}
	return FString::Printf(TEXT("Fail_%dbytes"), Input.Len());
}

bool AShooterGameMode::ParseAndOutputResult(const FString& InString, FString& OutValue, bool bRequired)
{
	//  Returns True if it is a critical error, returns false
	
	if (!FParse::Value(*InString, TEXT("hostId="), HostId))
	{
		UE_LOG(LogShooterGameMode, Error, TEXT("HostId Missing in Command Line"));
		return bRequired;
	}
	else
	{
		UE_LOG(LogShooterGameMode, Log, TEXT("Host ID: %s"), *HostId);
		return false;
	}
}

bool AShooterGameMode::ValidateFleetId(const FString& InFleetId)
{
//	FRegexMatcher Matcher(FleetIdPattern, InFleetId);
//	return Matcher.IsMatch() &&
//		InFleetId.Len() >= 10 &&
//		InFleetId.Len() < 128;
	return false;
}

void AShooterGameMode::InitGameLift()
{
#if WITH_GAMELIFT
	//TODO: Need to write later, working on parser first.
#else
	UE_LOGFMT(LogShooterGameMode, Warning, "GameLift  disabled");
#endif
}