#include <td/simulation/ServerSimulation.h>

namespace td {
namespace sim {

ServerSimulation::ServerSimulation(game::World& a_World, std::uint64_t a_StepTime) :
	m_World(a_World), m_StepTime(a_StepTime), m_CurrentTime(0), m_History(std::numeric_limits<StepTime>::max()) {}

protocol::packets::LockStepsPacket ServerSimulation::Update() {
	std::lock_guard<std::mutex> lock(m_Mutex);

	m_World.Tick(m_History[m_CurrentTime], FpFloat(m_StepTime) / FpFloat(1000));
	m_CurrentTime++;

	return MakePacket();
}

protocol::packets::LockStepsPacket ServerSimulation::MakePacket() {
	std::array<protocol::LockStep, LOCKSTEP_BUFFER_SIZE> nextSteps;
	std::copy(m_History.begin() + m_CurrentTime, m_History.begin() + m_CurrentTime + nextSteps.size(), nextSteps.begin());
	return {m_CurrentTime, std::move(nextSteps)};
}

template <typename T>
void AddToCommandHistory(protocol::LockStep& a_LockStep, const T& a_Cmd) {
	a_LockStep.push_back({std::make_shared<T>(a_Cmd)});
}

void ServerSimulation::Handle(const protocol::commands::SpawnTroopCommand& a_SpawnTroop) {
	std::lock_guard<std::mutex> lock(m_Mutex);
	AddToCommandHistory(m_History[m_CurrentTime + LOCKSTEP_BUFFER_SIZE], a_SpawnTroop);
}

void ServerSimulation::Handle(const protocol::commands::PlaceTowerCommand& a_PlaceTower) {
	std::lock_guard<std::mutex> lock(m_Mutex);
	AddToCommandHistory(m_History[m_CurrentTime + LOCKSTEP_BUFFER_SIZE], a_PlaceTower);
}

protocol::packets::LockStepResponsePacket ServerSimulation::GetResponse(
	const protocol::packets::LockStepRequestPacket& a_Missing) const {
	std::map<StepTime, protocol::LockStep> result;

	for (StepTime step : a_Missing->m_Missing) {
		result.emplace(step, m_History[step]);
	}

	return {result};
}

std::vector<protocol::LockStep> ServerSimulation::GetFirstLocksteps() {
	std::vector<protocol::LockStep> result;
	if (m_CurrentTime <= LOCKSTEP_BUFFER_SIZE)
		return result;

	result.reserve(m_CurrentTime);
	result.insert(result.begin(), m_History.begin(), m_History.begin() + m_CurrentTime);
	return result;
}


}  // namespace sim
}  // namespace td