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

#include <zenutil/consul.h>

#include <zencore/except_fmt.h>
#include <zencore/fmtutils.h>
#include <zencore/logging.h>
#include <zencore/process.h>
#include <zencore/string.h>
#include <zencore/timer.h>

#include <fmt/format.h>

namespace zen::consul {

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

struct ConsulProcess::Impl
{
	Impl(std::string_view BaseUri) : m_HttpClient(BaseUri) {}
	~Impl() = default;

	void SpawnConsulAgent()
	{
		if (m_ProcessHandle.IsValid())
		{
			return;
		}

		CreateProcOptions Options;
		Options.Flags |= CreateProcOptions::Flag_Windows_NewProcessGroup;

		CreateProcResult Result = CreateProc("consul" ZEN_EXE_SUFFIX_LITERAL, "consul" ZEN_EXE_SUFFIX_LITERAL " agent -dev", Options);

		if (Result)
		{
			m_ProcessHandle.Initialize(Result);

			Stopwatch Timer;

			// Poll to check when the agent is ready

			do
			{
				Sleep(100);
				HttpClient::Response Resp = m_HttpClient.Get("v1/status/leader");
				if (Resp)
				{
					ZEN_INFO("Consul agent started successfully (waited {})", NiceTimeSpanMs(Timer.GetElapsedTimeMs()));

					return;
				}
			} while (Timer.GetElapsedTimeMs() < 10000);
		}

		// Report failure!

		ZEN_WARN("Consul agent failed to start within timeout period");
	}

	void StopConsulAgent()
	{
		if (!m_ProcessHandle.IsValid())
		{
			return;
		}

		// This waits for the process to exit and also resets the handle
		m_ProcessHandle.Kill();
	}

private:
	ProcessHandle m_ProcessHandle;
	HttpClient	  m_HttpClient;
};

ConsulProcess::ConsulProcess() : m_Impl(std::make_unique<Impl>("http://localhost:8500/"))
{
}

ConsulProcess::~ConsulProcess()
{
}

void
ConsulProcess::SpawnConsulAgent()
{
	m_Impl->SpawnConsulAgent();
}

void
ConsulProcess::StopConsulAgent()
{
	m_Impl->StopConsulAgent();
}

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

ConsulClient::ConsulClient(std::string_view BaseUri) : m_HttpClient(BaseUri)
{
}

ConsulClient::~ConsulClient()
{
}

void
ConsulClient::SetKeyValue(std::string_view Key, std::string_view Value)
{
	IoBuffer			 ValueBuffer = IoBufferBuilder::MakeFromMemory(MakeMemoryView(Value));
	HttpClient::Response Result =
		m_HttpClient.Put(fmt::format("v1/kv/{}", Key), ValueBuffer, {{"Content-Type", "text/plain"}, {"Accept", "application/json"}});
	if (!Result)
	{
		throw runtime_error("ConsulClient::SetKeyValue() failed to set key '{}' ({})", Key, Result.ErrorMessage(""));
	}
}

std::string
ConsulClient::GetKeyValue(std::string_view Key)
{
	HttpClient::Response Result = m_HttpClient.Get(fmt::format("v1/kv/{}?raw", Key));
	if (!Result)
	{
		throw runtime_error("ConsulClient::GetKeyValue() failed to get key '{}' ({})", Key, Result.ErrorMessage(""));
	}
	return Result.ToText();
}

void
ConsulClient::DeleteKey(std::string_view Key)
{
	HttpClient::Response Result = m_HttpClient.Delete(fmt::format("v1/kv/{}", Key));
	if (!Result)
	{
		throw runtime_error("ConsulClient::DeleteKey() failed to delete key '{}' ({})", Key, Result.ErrorMessage(""));
	}
}

}  // namespace zen::consul