#include <STDInclude.hpp>
#include "RCon.hpp"

namespace Components
{
	std::unordered_map<std::uint32_t, int> RCon::RateLimit;

	RCon::Container RCon::RconContainer;
	Utils::Cryptography::ECC::Key RCon::RconKey;

	std::string RCon::Password;

	Dvar::Var RCon::RconPassword;
	Dvar::Var RCon::RconLogRequests;

	void RCon::AddCommands()
	{
		Command::Add("rcon", [](Command::Params* params)
		{
			if (params->size() < 2) return;

			const auto* operation = params->get(1);
			if (std::strcmp(operation, "login") == 0)
			{
				if (params->size() < 3) return;
				Password = params->get(2);
				return;
			}

			if (std::strcmp(operation, "logout") == 0)
			{
				Password.clear();
				return;
			}
				
			auto* addr = reinterpret_cast<Game::netadr_t*>(0xA5EA44);
			if (Password.empty())
			{
				Logger::Print("You need to be logged in and connected to a server!\n");
			}

			Network::Address target(addr);
			if (!target.isValid() || target.getIP().full == 0)
			{
				target = Party::Target();
			}

			if (target.isValid())
			{
				Network::SendCommand(target, "rcon", Password + " " + params->join(1));
				return;
			}

			Logger::Print("You are connected to an invalid server\n");
		});

		Command::Add("remoteCommand", [](Command::Params* params)
		{
			if (params->size() < 2) return;

			RconContainer.command = params->get(1);

			auto* addr = reinterpret_cast<Game::netadr_t*>(0xA5EA44);
			Network::Address target(addr);
			if (!target.isValid() || target.getIP().full == 0)
			{
				target = Party::Target();
			}

			if (target.isValid())
			{
				Network::SendCommand(target, "rconRequest");
			}
		});
	}

	bool RCon::RateLimitCheck(const Network::Address& address, const int time)
	{
		const auto ip = address.getIP();

		if (!RateLimit.contains(ip.full))
		{
			RateLimit[ip.full] = 0;
		}

		const auto lastTime = RateLimit[ip.full];

		// Only one request every 500ms
		if (lastTime && (time - lastTime) < 500)
		{
			return false; // Flooding
		}

		RateLimit[ip.full] = time;
		return true;
	}

	void RCon::RateLimitCleanup(const int time)
	{
		for (auto i = RateLimit.begin(); i != RateLimit.end();)
		{
			// No longer at risk of flooding, remove
			if ((time - i->second) > 500)
			{
				i = RateLimit.erase(i);
			}
			else
			{
				++i;
			}
		}
	}

	RCon::RCon()
	{
		AddCommands();

		if (!Dedicated::IsEnabled())
		{
			Network::OnClientPacket("rconAuthorization", [](const Network::Address& address, [[maybe_unused]] const std::string& data)
			{
				if (RconContainer.command.empty())
				{
					return;
				}

				const auto& key = CryptoKey::Get();
				const auto signedMsg = Utils::Cryptography::ECC::SignMessage(key, data);

				Proto::RCon::Command rconExec;
				rconExec.set_command(RconContainer.command);
				rconExec.set_signature(signedMsg);

				Network::SendCommand(address, "rconExecute", rconExec.SerializeAsString());
			});

			return;
		}

		// Load public key
		static std::uint8_t publicKey[] =
		{
			0x04, 0x01, 0x9D, 0x18, 0x7F, 0x57, 0xD8, 0x95, 0x4C, 0xEE, 0xD0, 0x21,
			0xB5, 0x00, 0x53, 0xEC, 0xEB, 0x54, 0x7C, 0x4C, 0x37, 0x18, 0x53, 0x89,
			0x40, 0x12, 0xF7, 0x08, 0x8D, 0x9A, 0x8D, 0x99, 0x9C, 0x79, 0x79, 0x59,
			0x6E, 0x32, 0x06, 0xEB, 0x49, 0x1E, 0x00, 0x99, 0x71, 0xCB, 0x4A, 0xE1,
			0x90, 0xF1, 0x7C, 0xB7, 0x4D, 0x60, 0x88, 0x0A, 0xB7, 0xF3, 0xD7, 0x0D,
			0x4F, 0x08, 0x13, 0x7C, 0xEB, 0x01, 0xFF, 0x00, 0x32, 0xEE, 0xE6, 0x23,
			0x07, 0xB1, 0xC2, 0x9E, 0x45, 0xD6, 0xD7, 0xBD, 0xED, 0x05, 0x23, 0xB5,
			0xE7, 0x83, 0xEF, 0xD7, 0x8E, 0x36, 0xDC, 0x16, 0x79, 0x74, 0xD1, 0xD5,
			0xBA, 0x2C, 0x4C, 0x28, 0x61, 0x29, 0x5C, 0x49, 0x7D, 0xD4, 0xB6, 0x56,
			0x17, 0x75, 0xF5, 0x2B, 0x58, 0xCD, 0x0D, 0x76, 0x65, 0x10, 0xF7, 0x51,
			0x69, 0x1D, 0xB9, 0x0F, 0x38, 0xF6, 0x53, 0x3B, 0xF7, 0xCE, 0x76, 0x4F,
			0x08
		};

		RconKey.set(std::string(reinterpret_cast<char*>(publicKey), sizeof(publicKey)));

		RconContainer.timestamp = 0;

		Scheduler::Once([]
		{
			RconPassword =  Dvar::Register<const char*>("rcon_password", "", Game::DVAR_NONE, "The password for rcon");
			RconLogRequests = Dvar::Register<bool>("rcon_log_requests", false, Game::DVAR_NONE, "Print remote commands in the output log");
		}, Scheduler::Pipeline::MAIN);

		Network::OnClientPacket("rcon", [](const Network::Address& address, [[maybe_unused]] const std::string& data)
		{
			const auto time = Game::Sys_Milliseconds();
			if (!RateLimitCheck(address, time))
			{
				return;
			}

			RateLimitCleanup(time);

			std::string data_ = data;
			Utils::String::Trim(data_);

			const auto pos = data.find_first_of(' ');
			if (pos == std::string::npos)
			{
				Logger::Print(Game::CON_CHANNEL_NETWORK, "Invalid RCon request from {}\n", address.getString());
				return;
			}

			auto password = data.substr(0, pos);
			auto command = data.substr(pos + 1);

			// B3 sends the password inside quotes :S
			if (!password.empty() && password[0] == '"' && password.back() == '"')
			{
				password.pop_back();
				password.erase(password.begin());
			}

			const auto svPassword = RconPassword.get<std::string>();

			if (svPassword.empty())
			{
				Logger::Print(Game::CON_CHANNEL_NETWORK, "RCon request from {} dropped. No password set!\n", address.getString());
				return;
			}

			if (svPassword != password)
			{
				Logger::Print(Game::CON_CHANNEL_NETWORK, "Invalid RCon password sent from {}\n", address.getString());
				return;
			}

			static std::string outputBuffer;
			outputBuffer.clear();

#ifndef DEBUG
			if (RconLogRequests.get<bool>())
#endif
			{
				Logger::Print(Game::CON_CHANNEL_NETWORK, "Executing RCon request from {}: {}\n", address.getString(), command);
			}

			Logger::PipeOutput([](const std::string& output)
			{
				outputBuffer.append(output);
			});

			Command::Execute(command, true);

			Logger::PipeOutput(nullptr);

			Network::SendCommand(address, "print", outputBuffer);
			outputBuffer.clear();
		});

		Network::OnClientPacket("rconRequest", [](const Network::Address& address, [[maybe_unused]] const std::string& data)
		{
			RconContainer.address = address;
			RconContainer.challenge = Utils::Cryptography::Rand::GenerateChallenge();
			RconContainer.timestamp = Game::Sys_Milliseconds();

			Network::SendCommand(address, "rconAuthorization", RconContainer.challenge);
		});

		Network::OnClientPacket("rconExecute", [](const Network::Address& address, [[maybe_unused]] const std::string& data)
		{
			if (address != RconContainer.address) return; // Invalid IP
			if (!RconContainer.timestamp || (Game::Sys_Milliseconds() - RconContainer.timestamp) > (1000 * 10)) return; // Timeout

			RconContainer.timestamp = 0;

			Proto::RCon::Command rconExec;
			rconExec.ParseFromString(data);

			if (!Utils::Cryptography::ECC::VerifyMessage(RconKey, RconContainer.challenge, rconExec.signature()))
			{
				return;
			}

			RconContainer.output.clear();
			Logger::PipeOutput([](const std::string& output)
			{
				RconContainer.output.append(output);
			});

			Command::Execute(rconExec.command(), true);

			Logger::PipeOutput(nullptr);

			Network::SendCommand(address, "print", RconContainer.output);
			RconContainer.output.clear();
		});
	}

	bool RCon::CryptoKey::LoadKey(Utils::Cryptography::ECC::Key& key)
	{
		std::string data;
		if (!Utils::IO::ReadFile("./private.key", &data))
		{
			return false;
		}

		key.deserialize(data);
		return key.isValid();
	}

	Utils::Cryptography::ECC::Key RCon::CryptoKey::GenerateKey()
	{
		auto key = Utils::Cryptography::ECC::GenerateKey(512);
		if (!key.isValid())
		{
			throw std::runtime_error("Failed to generate server key!");
		}

		if (!Utils::IO::WriteFile("./private.key", key.serialize()))
		{
			throw std::runtime_error("Failed to write server key!");
		}

		return key;
	}

	Utils::Cryptography::ECC::Key RCon::CryptoKey::LoadOrGenerateKey()
	{
		Utils::Cryptography::ECC::Key key;
		if (LoadKey(key))
		{
			return key;
		}

		return GenerateKey();
	}

	Utils::Cryptography::ECC::Key RCon::CryptoKey::GetKeyInternal()
	{
		auto key = LoadOrGenerateKey();
		Utils::IO::WriteFile("./public.key", key.getPublicKey());
		return key;
	}

	const Utils::Cryptography::ECC::Key& RCon::CryptoKey::Get()
	{
		static auto key = GetKeyInternal();
		return key;
	}
}