/*
 * 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 "ArSessionPlayback.hpp"
#include "ArFramePlayback.hpp"
#include "Base/Logger.hpp"
#include <filesystem>

namespace OpenVulkano::AR::Playback
{
	ArSessionPlayback::ArSessionPlayback(const std::string& recordingPath, bool autoAdvance)
		: ArSession(ArSessionMetadata(recordingPath)), recordingPath(recordingPath), autoAdvance(autoAdvance), playbackReader(recordingPath)
	{
		capabilities = ArSessionCapabilities(metadata.type, ArSessionType::PLAYBACK, false, metadata.depthFormat != ArDepthFormat::UNAVAILABLE);
		constants = { Math::Matrix4f(1), metadata.confidenceRange };

		m_playbackReaderThread = std::thread([this](){ReadWorker();});
	}

	ArSessionPlayback::~ArSessionPlayback()
	{
		Stop();
		if (m_playbackReaderThread.joinable()) m_playbackReaderThread.join();
	}

	void ArSessionPlayback::Start()
	{
		running = true;
		m_frameConsumed = true;
	}

	void ArSessionPlayback::Stop()
	{
		running = false;
		OnStopped();
	}

	void ArSessionPlayback::Pause()
	{
		running = false;
	}

	std::shared_ptr<ArFrame> ArSessionPlayback::GetFrame()
	{
		while(IsRunning() && m_frameConsumed) { std::this_thread::yield(); }
		auto frame = m_nextFrame;
		m_nextFrame = nullptr;
		m_frameConsumed = true;
		return frame;
	}

	ArType ArSessionPlayback::GetArType()
	{
		return capabilities.GetArType();
	}

	void ArSessionPlayback::ReadWorker()
	{
		while (playbackReader.HasNext() && IsRunning())
		{
			while (!m_frameConsumed) { std::this_thread::yield(); }
			try
			{
				std::shared_ptr<ArFrame> frame = std::make_shared<ArFramePlayback>(shared_from_this(), playbackReader);
				lastTimestamp = frame->GetTimestamp();
				m_nextFrame = frame;
				m_frameConsumed = false;
				//TODO try to keep original frame timing

				// Trigger events
				OnNewFrameAvailable();
				OnNewFrame(frame);
				OnNewCameraTransformation(frame->GetCameraTransformation());
				if (OnNewCameraViewMatrix.HasHandlers())
				{
					auto view = frame->GetCameraViewForCurrentDeviceOrientation();
					OnNewCameraViewMatrix(view);
				}
			}
			catch (const std::exception& e)
			{
				Logger::AR->error("Failed to read AR frame: {}", e.what());
			}
		}
		Stop();
		OnSessionInterruptionChange(true);
	}
}