/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

#include "PerformanceInfo.hpp"
#include "Base/FrameMetadata.hpp"
#include "Base/Utils.hpp"
#include "Host/SystemInfo.hpp"
#include "Math/ByteSize.hpp"
#include "ImGuiExtensions/ImGuiTextFmt.hpp"
#include "ImGuiExtensions/ImGuiPlotTwoLines.hpp"

#include <assert.h>

namespace OpenVulkano::Scene::UI
{
	namespace
	{
		float FrameCollectionValuesGetter(void *data, int index)
		{
			auto frameCollection = reinterpret_cast<FrameTimeCollection *>(data);
			float value = frameCollection->m_frameTimes[index];
			float result = value / frameCollection->m_maxValue * 100;
			return result;
		}

		float RamValuesGetter(void *data, int index)
		{
			auto queue = reinterpret_cast<std::deque<float> *>(data);
			float used = (*queue)[index];
			float max = SystemInfo::GetAppRamMax();
			float percentage = used / max * 100;
			return percentage;
		}

	}

	void PerformanceInfo::UpdateQueues()
	{
		m_frameCollection.m_frameTimes.push_back(static_cast<float>(CURRENT_FRAME.frameTime));
		while(m_frameCollection.m_frameTimes.size() > m_windowSize)
			m_frameCollection.m_frameTimes.pop_front();

		float maxFrameTime = FLT_MIN;
		for(auto value : m_frameCollection.m_frameTimes)
		{
			if(value > maxFrameTime)
				maxFrameTime = value;
		}
		m_frameCollection.m_maxValue = maxFrameTime;

		m_ramUsed.push_back(static_cast<float>(SystemInfo::GetAppRamUsed()));
		while(m_ramUsed.size() > m_windowSize)
			m_ramUsed.pop_front();
	}

	void PerformanceInfo::BeginDraw()
	{
		bool alwaysShow = true;
		ImGui::Begin("Performance Info", &alwaysShow);
	}

	void PerformanceInfo::Draw()
	{
		UpdateQueues();
		assert(m_frameCollection.m_frameTimes.size() == m_ramUsed.size());

		ImGui::Text("Last Frame Time(wrt max): %f s", m_frameCollection.m_frameTimes.back());
		ImGui::Text("Last FPS: %f", 1 / m_frameCollection.m_frameTimes.back());
		ImGui::SliderInt("Window Size", &m_windowSize, 10, 1000);
		ImGui::TextFmt("RAM: {} / {}, Free: {}", ByteSize(m_ramUsed.back()), ByteSize(SystemInfo::GetAppRamMax()), ByteSize(SystemInfo::GetAppRamAvailable()));

		ImVec2 availableSize = ImGui::GetContentRegionAvail();
		float scaleMin = 0.01;
		float scaleMax = 100;
		ImGui::PlotTwoLines("",
			&FrameCollectionValuesGetter, &m_frameCollection, "Frame Time",
			&RamValuesGetter, &m_ramUsed, "RAM",
			(int)m_ramUsed.size(),
			scaleMin, scaleMax, availableSize);
	}

	void PerformanceInfo::EndDraw()
	{
		ImGui::End();
	}
}