/*
 * 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/.
 */

// Makre usre the Molten include is first!
#include <MoltenVK/mvk_vulkan.h>
#include <vulkan/vulkan_metal.h>

#include "ArSessionArKitInternal.h"
#include "ArFrameArKit.h"
#include "ArTrackingStateConverter.h"
#include "Base/Logger.hpp"
#include "IO/AppFolders.hpp"
#include "Vulkan/Renderer.hpp"
#include "Vulkan/Scene/VulkanTexture.hpp"
#include <sstream>

#import <ARKit/ARSession.h>
#import <ARKit/ARFrame.h>
#import <ARKit/ARConfiguration.h>
#import <ARKit/ARCamera.h>
#import <ARKit/ARKit.h>
#import <AVFoundation/AVCaptureDevice.h>
#import <CoreVideo/CoreVideo.h>
#import "ArKitDelegate.h"

#define VALIDATE_SESSION(s) if(s != m_arSession) { Logger::AR->warn("ARSession does not match."); return; }

namespace OpenVulkano::AR::ArKit
{
	namespace
	{
		std::string SupportedVideoFormatsToString()
		{
			std::stringstream ss("[ ");
			auto vidFormats = [ARWorldTrackingConfiguration supportedVideoFormats];
			for (ARVideoFormat* format: vidFormats)
			{
				if (ss.tellp() > std::streampos(5)) ss << ", ";
				ss << format.imageResolution.width << 'x' << format.imageResolution.height;
				ss << '@' << format.framesPerSecond;
				if (@available(iOS 16.0, *))
				{
					if (format.videoHDRSupported) ss << "_HDR";
					if (format.isRecommendedForHighResolutionFrameCapturing) ss << "_HdCaptureRecommended";
				}
			}
			ss << " ]";
			return ss.str();
		}

		void LogFormat(std::string_view formatUsage, ARVideoFormat* format)
		{
			bool hdr = false, hdCapture = false;
			if (@available(iOS 16.0, *))
			{
				hdr = format.videoHDRSupported;
				hdCapture = format.isRecommendedForHighResolutionFrameCapturing;
			}
			Logger::AR->info("{}: {}x{}@{}{}{}", formatUsage,
							 format.imageResolution.width, format.imageResolution.height, format.framesPerSecond,
							 hdr ? " HDR" : "", hdCapture ? " HdCaptureRecommended" : "");
		}
	}

	ArSessionArKitInternal::ArSessionArKitInternal(const ArSessionConfig& config)
			: m_frameId(0)
	{
		m_arKitDelegate = [[ArKitDelegate alloc] initWithFrameHandler:this];
		m_arConfig = [ARWorldTrackingConfiguration new];
		if (config.enableDepth)
		{
			m_arConfig.frameSemantics = ARFrameSemanticSceneDepth;
		}
		if (config.sceneReconstruction)
		{
			m_arConfig.sceneReconstruction = ARSceneReconstructionMesh;
		}
		m_arConfig.planeDetection = config.planeDetection ? (ARPlaneDetectionVertical | ARPlaneDetectionHorizontal) : ARPlaneDetectionNone;
		m_arConfig.autoFocusEnabled = config.autoFocus;

		// Set video format
		{
			Logger::AR->debug("Supported Video Formats: {}", SupportedVideoFormatsToString());
			//TODO handle ar video format in settings
			if (@available(iOS 16.0, *))
			{
				if (config.preferHDR) m_arConfig.videoFormat = [ARWorldTrackingConfiguration recommendedVideoFormatForHighResolutionFrameCapturing];
				//TODO resolution handling
			}
			LogFormat("Using video format", m_arConfig.videoFormat);
			metadata.imageResolution = { m_arConfig.videoFormat.imageResolution.width, m_arConfig.videoFormat.imageResolution.height };
			metadata.frameRate = m_arConfig.videoFormat.framesPerSecond;
		}

		m_arSession = [ARSession new];
		m_arSession.delegate = m_arKitDelegate;

		running = false;
	}

	ArSessionArKitInternal::~ArSessionArKitInternal()
	{
		Stop();
		[m_arSession release];
		[m_arConfig release];
		[m_arKitDelegate release];
	}

	void ArSessionArKitInternal::SetRenderer(IRenderer* renderer)
	{
		if (renderer)
			m_textureCache.Init(renderer);
		else
			m_textureCache.Close();
	}

	Scene::Texture* ArSessionArKitInternal::MakeTexture(ArFrame* frame)
	{
		if (!m_textureCache) [[unlikely]]
			throw std::runtime_error("No renderer set for which to produce textures");
		ArFrameArKit* arFrame = static_cast<ArFrameArKit*>(frame);
		ARFrame* arKitFrame = arFrame->GetArKitFrame();
		return m_textureCache.Get(arKitFrame.capturedImage, MTLPixelFormatR8Unorm);
	}

	void ArSessionArKitInternal::ReturnTexture(Scene::Texture* texture)
	{
		m_textureCache.ReturnTexture(texture);
	}

	void ArSessionArKitInternal::Start()
	{
		[m_arSession runWithConfiguration:m_arConfig];
		running = true;
	}

	void ArSessionArKitInternal::Stop()
	{
		if (m_lockedConfiguration)
		{
			m_lockedConfiguration = false;
			[[ARWorldTrackingConfiguration configurableCaptureDeviceForPrimaryCamera] unlockForConfiguration];
		}
		OnStopped();
		[m_arSession pause];
/*#if (__cplusplus >= 202002L)
		m_frame = nullptr;
#else*/
		m_frame.Access()->reset();
//#endif
		running = false;
	}

	void ArSessionArKitInternal::Pause()
	{
		ArSession::Pause();
	}

	double timestamp = 0;

	std::shared_ptr<ArFrame> ArSessionArKitInternal::GetFrame()
	{
		if (GetRecorder().GetRecordingMode() == RecordingMode::FRAME_REQUEST)
			GetRecorder().Save(m_frame);
		return m_frame;
	}

	void ArSessionArKitInternal::RequestHighResolutionFrame()
	{
		if (@available(iOS 16.0, *)) {
			[m_arSession captureHighResolutionFrameWithCompletion:^(ARFrame * _Nullable frame, NSError * _Nullable error) {
				if (frame)
				{
					std::shared_ptr<ArFrame> arFrame = std::make_shared<ArFrameArKit>(frame, shared_from_this());
					arFrame->MarkHighRes();
					OnNewFrameHighResolution(arFrame);
				}
				else
				{
					Logger::AR->warn("Failed to perform high resolution still frame capture: {}", [[error description] UTF8String]);
				}
			}];
		}
		else
		{
			Logger::AR->warn("Failed to perform high resolution still frame capture: requires iOS 16 or later!");
		}
	}
	
	void ArSessionArKitInternal::LockExposureTime(bool locked)
	{
		AVCaptureDevice* dev = [ARWorldTrackingConfiguration configurableCaptureDeviceForPrimaryCamera];
		if (!m_lockedConfiguration) m_lockedConfiguration |=[dev lockForConfiguration:nil];
		[dev setExposureMode: locked ? AVCaptureExposureModeLocked : AVCaptureExposureModeContinuousAutoExposure];
	}
	
	void ArSessionArKitInternal::LockWhitebalance(bool locked)
	{
		AVCaptureDevice* dev = [ARWorldTrackingConfiguration configurableCaptureDeviceForPrimaryCamera];
		if (!m_lockedConfiguration) m_lockedConfiguration |=[dev lockForConfiguration:nil];
		[dev setWhiteBalanceMode: locked ? AVCaptureWhiteBalanceModeLocked : AVCaptureWhiteBalanceModeContinuousAutoWhiteBalance];
	}
	
	void ArSessionArKitInternal::SetFlashlightOn(bool on)
	{
		AVCaptureDevice* dev = [ARWorldTrackingConfiguration configurableCaptureDeviceForPrimaryCamera];
		if (!m_lockedConfiguration) m_lockedConfiguration |=[dev lockForConfiguration:nil];
		[dev setTorchMode: on ? AVCaptureTorchModeOn : AVCaptureTorchModeOff];
	}


	// AR Kit delegate events
	void ArSessionArKitInternal::OnArNewFrame(ARSession* session, ARFrame* frame)
	{
		VALIDATE_SESSION(session);

		std::shared_ptr<ArFrame> arFrame = std::make_shared<ArFrameArKit>(frame, shared_from_this());

		OnNewFrame(arFrame);
		OnNewCameraTransformation(arFrame->GetCameraTransformation());
		if (OnNewCameraViewMatrix.HasHandlers())
		{
			auto view = arFrame->GetCameraViewForCurrentDeviceOrientation();
			OnNewCameraViewMatrix(view);
		}
		OnNewFrameAvailable();
		m_frame = arFrame;
	}

	void ArSessionArKitInternal::OnArSessionInterruptedChanged(ARSession* session, bool interrupted)
	{
		VALIDATE_SESSION(session);
		Logger::AR->info("Ar session {}", interrupted ? "interrupted" : "resumed");
		OnSessionInterruptionChange.NotifyAll(interrupted);
	}

	void ArSessionArKitInternal::OnArSessionFailed(ARSession* session, NSError* error)
	{
		VALIDATE_SESSION(session);
		Logger::AR->warn("Ar session failed, description: {}", [[error description] UTF8String]);
		std::string failReason = [[error localizedDescription] UTF8String];
		OnSessionFailed(failReason);
	}

	void ArSessionArKitInternal::OnArCameraTrackingChange(ARSession* session, ARCamera* camera)
	{
		VALIDATE_SESSION(session);
		auto trackingState = GetArTrackingState(camera);
		Logger::AR->info("Ar session tracking state changed: {}", trackingState.GetName());
		OnTrackingStateChanged(trackingState);
	}

	void ArSessionArKitInternal::OnArAnchorsUpdate(NSArray<__kindof ARAnchor*>* anchors)
	{
		Logger::AR->info("Anchors updated.");
		OnAnchorsUpdated();
	}

	bool ArSessionArKitInternal::ArShouldAttemptRelocalization()
	{
		return shouldAttemptRelocalization;
	}
}