// Copyright Epic Games, Inc. All Rights Reserved.

#include "up_cmd.h"

#include <zencore/compactbinary.h>
#include <zencore/compactbinaryutil.h>
#include <zencore/filesystem.h>
#include <zencore/fmtutils.h>
#include <zencore/logging.h>
#include <zencore/process.h>
#include <zencore/timer.h>
#include <zenutil/zenserverprocess.h>

#include <memory>

namespace zen {

UpCommand::UpCommand()
{
	m_Options.add_option("", "p", "port", "Host port", cxxopts::value(m_Port)->default_value("0"), "<hostport>");
	m_Options.add_option("", "b", "base-dir", "Parent folder of server executable", cxxopts::value(m_ProgramBaseDir), "<directory>");
	m_Options
		.add_option("", "c", "show-console", "Open a console window for the zenserver process", cxxopts::value(m_ShowConsole), "<console>");
	m_Options.add_option("",
						 "l",
						 "show-log",
						 "Show the output log of the zenserver process after successful start",
						 cxxopts::value(m_ShowLog),
						 "<showlog>");
}

UpCommand::~UpCommand() = default;

void
UpCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
{
	using namespace std::literals;

	ZEN_UNUSED(GlobalOptions);

	if (!ParseOptions(argc, argv))
	{
		return;
	}

	if (m_ShowConsole && m_ShowLog)
	{
		throw OptionParseException("'--show-console' conficts with '--show-log'", m_Options.help());
	}

	{
		ZenServerState State;
		if (State.InitializeReadOnly())
		{
			struct EntryInfo
			{
				uint32_t Pid		   = 0;
				uint16_t DesiredPort   = 0;
				uint16_t EffectivePort = 0;
			};
			std::vector<EntryInfo> RunningEntries;
			State.Snapshot([&RunningEntries, DesiredPort = this->m_Port](const zen::ZenServerState::ZenServerEntry& Entry) {
				if (DesiredPort == 0 || Entry.DesiredListenPort.load() == DesiredPort)
				{
					RunningEntries.push_back(EntryInfo{.Pid			  = Entry.Pid.load(),
													   .DesiredPort	  = Entry.DesiredListenPort.load(),
													   .EffectivePort = Entry.EffectiveListenPort.load()});
				}
			});
			if (RunningEntries.size() > 0)
			{
				ZEN_CONSOLE("Zen server already running with base port {}. First instance at port {}, pid {}",
							RunningEntries[0].DesiredPort,
							RunningEntries[0].EffectivePort,
							RunningEntries[0].Pid);
				return;
			}
		}
	}

	if (m_ProgramBaseDir.empty())
	{
		std::filesystem::path ExePath = zen::GetRunningExecutablePath();
		m_ProgramBaseDir			  = ExePath.parent_path();
	}
	ZenServerEnvironment ServerEnvironment;
	ServerEnvironment.Initialize(m_ProgramBaseDir);
	ZenServerInstance Server(ServerEnvironment);
	std::string		  ServerArguments = GlobalOptions.PassthroughCommandLine;
	if ((m_Port != 0) && (ServerArguments.find("--port"sv) == std::string::npos))
	{
		ServerArguments.append(fmt::format(" --port {}", m_Port));
	}
	Server.SpawnServer(ServerArguments, m_ShowConsole, /*WaitTimeoutMs*/ 0);

	int Timeout = 10000;

	if (!Server.WaitUntilReady(Timeout))
	{
		if (Server.IsRunning())
		{
			ZEN_CONSOLE_WARN("Zen server launch failed (timed out), terminating");
			Server.Terminate();
			if (!m_ShowConsole)
			{
				ZEN_CONSOLE("{}", Server.GetLogOutput());
			}
			throw std::runtime_error("Zen server launch failed (timed out), launched process was terminated");
		}
		int ServerExitCode = Server.Shutdown();
		if (!m_ShowConsole)
		{
			ZEN_CONSOLE("{}", Server.GetLogOutput());
		}
		if (ServerExitCode != 0)
		{
			throw ErrorWithReturnCode(
				fmt::format("Zen server failed to get to a ready state and exited with return code {}", ServerExitCode),
				ServerExitCode);
		}
	}
	else
	{
		if (m_ShowLog)
		{
			ZEN_CONSOLE("{}", Server.GetLogOutput());
		}
		else
		{
			ZEN_CONSOLE("Zen server up");
		}
	}
}

//////////////////////////////////////////////////////////////////////////

AttachCommand::AttachCommand()
{
	m_Options.add_option("", "p", "port", "Host port", cxxopts::value(m_Port)->default_value("8558"), "<hostport>");
	m_Options.add_option("lifetime", "", "owner-pid", "Specify owning process id", cxxopts::value(m_OwnerPid), "<identifier>");
	m_Options.add_option("", "", "data-dir", "Path to data directory to inspect for running server", cxxopts::value(m_DataDir), "<file>");
}

AttachCommand::~AttachCommand() = default;

void
AttachCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
{
	ZEN_UNUSED(GlobalOptions);

	if (!ParseOptions(argc, argv))
	{
		return;
	}

	ZenServerState Instance;
	Instance.Initialize();
	Instance.Sweep();
	ZenServerState::ZenServerEntry* Entry = Instance.Lookup(m_Port);

	if (!m_DataDir.empty())
	{
		if (!IsFile(m_DataDir / ".lock"))
		{
			throw std::runtime_error(fmt::format("Lock file does not exist in directory '{}'", m_DataDir));
		}
		CbValidateError ValidateResult = CbValidateError::None;
		if (CbObject LockFileObject =
				ValidateAndReadCompactBinaryObject(IoBufferBuilder::MakeFromFile(m_DataDir / ".lock"), ValidateResult);
			ValidateResult == CbValidateError::None && LockFileObject)
		{
			LockFileInfo Info = ReadLockFilePayload(LockFileObject);
			std::string	 Reason;
			if (!ValidateLockFileInfo(Info, Reason))
			{
				throw std::runtime_error(fmt::format("Lock file in directory '{}' is not valid. Reason: '{}'", m_DataDir, Reason));
			}
			Entry = Instance.LookupByEffectivePort(Info.EffectiveListenPort);
		}
		else
		{
			throw std::runtime_error(
				fmt::format("Lock file in directory '{}' is malformed. Reason: '{}'", m_DataDir, ToString(ValidateResult)));
		}
	}

	if (!Entry)
	{
		throw std::runtime_error("No zen server instance to add sponsor process to");
	}

	// Sponsor processes are checked every second, so 2 second wait time should be enough
	if (!Entry->AddSponsorProcess(m_OwnerPid, 2000))
	{
		throw std::runtime_error("Unable to add sponsor process to running zen server instance");
	}

	ZEN_CONSOLE("Added sponsor process {} to running instance {} on port {}", m_OwnerPid, Entry->Pid.load(), m_Port);
}

//////////////////////////////////////////////////////////////////////////

DownCommand::DownCommand()
{
	m_Options.add_option("", "p", "port", "Host port", cxxopts::value(m_Port)->default_value("0"), "<hostport>");
	m_Options.add_option("", "a", "all", "Shut down all running zen server instances", cxxopts::value(m_All), "");
	m_Options.add_option("", "f", "force", "Force terminate if graceful shutdown fails", cxxopts::value(m_ForceTerminate), "<force>");
	m_Options.add_option("", "b", "base-dir", "Parent folder of server executable", cxxopts::value(m_ProgramBaseDir), "<directory>");
	m_Options.add_option("", "", "data-dir", "Path to data directory to inspect for running server", cxxopts::value(m_DataDir), "<file>");
}

DownCommand::~DownCommand() = default;

bool
DownCommand::ShutdownEntry(ZenServerState& Instance, ZenServerState::ZenServerEntry* Entry)
{
	int			   EntryPort		= (int)Entry->DesiredListenPort.load();
	const uint32_t ServerProcessPid = Entry->Pid.load();
	try
	{
		ZenServerEnvironment ServerEnvironment;
		ServerEnvironment.Initialize(m_ProgramBaseDir);
		ZenServerInstance Server(ServerEnvironment);
		Server.AttachToRunningServer(EntryPort);

		ZEN_CONSOLE("attached to server on port {} (pid {}), requesting shutdown", EntryPort, ServerProcessPid);

		std::error_code Ec;
		if (Server.SignalShutdown(Ec) && !Ec)
		{
			Stopwatch Timer;
			while (Timer.GetElapsedTimeMs() < 10000)
			{
				if (Server.WaitUntilExited(100, Ec) && !Ec)
				{
					ZEN_CONSOLE("shutdown complete");
					return true;
				}
				else if (Ec)
				{
					ZEN_CONSOLE("Waiting for server on port {} (pid {}) failed. Reason: '{}'", EntryPort, ServerProcessPid, Ec.message());
				}
			}
		}
		else if (Ec)
		{
			ZEN_CONSOLE_WARN("Requesting shutdown of server on port {} failed. Reason: '{}'", EntryPort, Ec.message());
		}
	}
	catch (const std::exception& Ex)
	{
		ZEN_DEBUG("Exception caught when requesting shutdown: {}", Ex.what());
	}

	// Since we cannot obtain a handle to the process we are unable to block on the process
	// handle to determine when the server has shut down. Thus we signal that we would like
	// a shutdown via the shutdown flag and the check if the entry is still running.

	ZEN_CONSOLE("Requesting detached shutdown of server on port {}", EntryPort);
	Entry->SignalShutdownRequest();

	Stopwatch Timer;
	while (Timer.GetElapsedTimeMs() < 10000)
	{
		Instance.Sweep();
		Entry = Instance.Lookup(EntryPort);
		if (Entry == nullptr || Entry->Pid.load() != ServerProcessPid)
		{
			ZEN_CONSOLE("Shutdown complete");
			return true;
		}
		Sleep(100);
	}

	return false;
}

void
DownCommand::Run(const ZenCliOptions& GlobalOptions, int argc, char** argv)
{
	ZEN_UNUSED(GlobalOptions);

	if (!ParseOptions(argc, argv))
	{
		return;
	}

	if (m_ProgramBaseDir.empty())
	{
		std::filesystem::path ExePath = GetRunningExecutablePath();
		m_ProgramBaseDir			  = ExePath.parent_path();
	}

	// Discover executing instances
	ZenServerState Instance;
	Instance.Initialize();

	if (m_All)
	{
		struct EntryInfo
		{
			uint16_t Port = 0;
			uint32_t Pid  = 0;
		};
		std::vector<EntryInfo> Entries;
		Instance.Snapshot([&Entries](const ZenServerState::ZenServerEntry& Entry) {
			uint16_t Port = Entry.DesiredListenPort.load();
			uint32_t Pid  = Entry.Pid.load();
			if (Port != 0 && Pid != 0)
			{
				Entries.push_back({Port, Pid});
			}
		});

		if (Entries.empty())
		{
			ZEN_CONSOLE("No zen server instances to bring down");
			return;
		}

		int FailCount = 0;
		for (const EntryInfo& Info : Entries)
		{
			Instance.Sweep();
			ZenServerState::ZenServerEntry* Entry = Instance.Lookup(Info.Port);
			if (Entry && Entry->Pid.load() == Info.Pid)
			{
				if (!ShutdownEntry(Instance, Entry))
				{
					ZEN_CONSOLE_WARN("Failed to shutdown server on port {} (pid {})", Info.Port, Info.Pid);
					++FailCount;
				}
			}
		}

		if (FailCount > 0 && !m_ForceTerminate)
		{
			throw std::runtime_error(fmt::format("Failed to shutdown {} instance(s), use --force to hard terminate", FailCount));
		}
		return;
	}

	ZenServerState::ZenServerEntry* Entry = Instance.Lookup(m_Port);

	if (!m_DataDir.empty())
	{
		if (!IsFile(m_DataDir / ".lock"))
		{
			throw std::runtime_error(fmt::format("Lock file does not exist in directory '{}'", m_DataDir));
		}
		CbValidateError ValidateResult = CbValidateError::None;
		if (CbObject LockFileObject =
				ValidateAndReadCompactBinaryObject(IoBufferBuilder::MakeFromFile(m_DataDir / ".lock"), ValidateResult);
			ValidateResult == CbValidateError::None && LockFileObject)
		{
			LockFileInfo Info = ReadLockFilePayload(LockFileObject);
			std::string	 Reason;
			if (!ValidateLockFileInfo(Info, Reason))
			{
				throw std::runtime_error(fmt::format("Lock file in directory '{}' is not valid. Reason: '{}'", m_DataDir, Reason));
			}
			Entry = Instance.LookupByEffectivePort(Info.EffectiveListenPort);
		}
		else
		{
			throw std::runtime_error(
				fmt::format("Lock file in directory '{}' is malformed. Reason: '{}'", m_DataDir, ToString(ValidateResult)));
		}
	}

	if (Entry)
	{
		if (ShutdownEntry(Instance, Entry))
		{
			return;
		}
	}

	if (m_ForceTerminate)
	{
		// Try to find the running executable by path name
		std::filesystem::path ServerExePath = m_ProgramBaseDir / "zenserver" ZEN_EXE_SUFFIX_LITERAL;
		ProcessHandle		  RunningProcess;
		if (std::error_code Ec = FindProcess(ServerExePath, RunningProcess); !Ec, /*IncludeSelf*/ false)
		{
			ZEN_CONSOLE_WARN("Attempting hard terminate of zen process with pid ({})", RunningProcess.Pid());
			if (RunningProcess.Terminate(0))
			{
				ZEN_CONSOLE("Terminate complete");
				return;
			}
			throw std::runtime_error("Failed to terminate server, still running");
		}
		else
		{
			ZEN_CONSOLE_WARN("Failed to find process '{}', reason: {}", ServerExePath.string(), Ec.message());
		}
	}
	else if (Entry)
	{
		throw std::runtime_error(
			fmt::format("Failed to shutdown of server on port {}, use --force to hard terminate process", Entry->DesiredListenPort.load()));
	}

	ZEN_CONSOLE("No zen server to bring down");
}

}  // namespace zen