// Copyright 2018 The SwiftShader Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "VkQueue.hpp"

#include "VkCommandBuffer.hpp"
#include "VkFence.hpp"
#include "VkSemaphore.hpp"
#include "VkStringify.hpp"
#include "VkStructConversion.hpp"
#include "VkTimelineSemaphore.hpp"
#include "Device/Renderer.hpp"
#include "WSI/VkSwapchainKHR.hpp"

#include "marl/defer.h"
#include "marl/scheduler.h"
#include "marl/thread.h"
#include "marl/trace.h"

#include <cstring>

namespace vk {

Queue::Queue(Device *device, marl::Scheduler *scheduler)
    : device(device)
{
	queueThread = std::thread(&Queue::taskLoop, this, scheduler);
}

Queue::~Queue()
{
	Task task;
	task.type = Task::KILL_THREAD;
	pending.put(task);

	queueThread.join();
	ASSERT_MSG(pending.count() == 0, "queue has work after worker thread shutdown");

	garbageCollect();
}

VkResult Queue::submit(uint32_t submitCount, SubmitInfo *pSubmits, Fence *fence)
{
	garbageCollect();

	Task task;
	task.submitCount = submitCount;
	task.pSubmits = pSubmits;
	if(fence)
	{
		task.events = fence->getCountedEvent();
		task.events->add();
	}

	pending.put(task);

	return VK_SUCCESS;
}

void Queue::submitQueue(const Task &task)
{
	if(renderer == nullptr)
	{
		renderer.reset(new sw::Renderer(device));
	}

	for(uint32_t i = 0; i < task.submitCount; i++)
	{
		SubmitInfo &submitInfo = task.pSubmits[i];
		for(uint32_t j = 0; j < submitInfo.waitSemaphoreCount; j++)
		{
			if(auto *sem = DynamicCast<TimelineSemaphore>(submitInfo.pWaitSemaphores[j]))
			{
				ASSERT(j < submitInfo.waitSemaphoreValueCount);
				sem->wait(submitInfo.pWaitSemaphoreValues[j]);
			}
			else if(auto *sem = DynamicCast<BinarySemaphore>(submitInfo.pWaitSemaphores[j]))
			{
				sem->wait(submitInfo.pWaitDstStageMask[j]);
			}
			else
			{
				UNSUPPORTED("Unknown semaphore type");
			}
		}

		{
			CommandBuffer::ExecutionState executionState;
			executionState.renderer = renderer.get();
			executionState.events = task.events.get();
			for(uint32_t j = 0; j < submitInfo.commandBufferCount; j++)
			{
				Cast(submitInfo.pCommandBuffers[j])->submit(executionState);
			}
		}

		for(uint32_t j = 0; j < submitInfo.signalSemaphoreCount; j++)
		{
			if(auto *sem = DynamicCast<TimelineSemaphore>(submitInfo.pSignalSemaphores[j]))
			{
				ASSERT(j < submitInfo.signalSemaphoreValueCount);
				sem->signal(submitInfo.pSignalSemaphoreValues[j]);
			}
			else if(auto *sem = DynamicCast<BinarySemaphore>(submitInfo.pSignalSemaphores[j]))
			{
				sem->signal();
			}
			else
			{
				UNSUPPORTED("Unknown semaphore type");
			}
		}
	}

	if(task.pSubmits)
	{
		toDelete.put(task.pSubmits);
	}

	if(task.events)
	{
		// TODO: fix renderer signaling so that work submitted separately from (but before) a fence
		// is guaranteed complete by the time the fence signals.
		renderer->synchronize();
		task.events->done();
	}
}

void Queue::taskLoop(marl::Scheduler *scheduler)
{
	marl::Thread::setName("Queue<%p>", this);
	scheduler->bind();
	defer(scheduler->unbind());

	while(true)
	{
		Task task = pending.take();

		switch(task.type)
		{
		case Task::KILL_THREAD:
			ASSERT_MSG(pending.count() == 0, "queue has remaining work!");
			return;
		case Task::SUBMIT_QUEUE:
			submitQueue(task);
			break;
		default:
			UNREACHABLE("task.type %d", static_cast<int>(task.type));
			break;
		}
	}
}

VkResult Queue::waitIdle()
{
	// Wait for task queue to flush.
	auto event = std::make_shared<sw::CountedEvent>();
	event->add();  // done() is called at the end of submitQueue()

	Task task;
	task.events = event;
	pending.put(task);

	event->wait();

	garbageCollect();

	return VK_SUCCESS;
}

void Queue::garbageCollect()
{
	while(true)
	{
		auto v = toDelete.tryTake();
		if(!v.second) { break; }
		SubmitInfo::Release(v.first);
	}
}

#ifndef __ANDROID__
VkResult Queue::present(const VkPresentInfoKHR *presentInfo)
{
	// This is a hack to deal with screen tearing for now.
	// Need to correctly implement threading using VkSemaphore
	// to get rid of it. b/132458423
	waitIdle();

	// Note: VkSwapchainPresentModeInfoEXT can be used to override the present mode, but present
	// mode is currently ignored by SwiftShader.

	for(uint32_t i = 0; i < presentInfo->waitSemaphoreCount; i++)
	{
		auto *semaphore = vk::DynamicCast<BinarySemaphore>(presentInfo->pWaitSemaphores[i]);
		semaphore->wait();
	}

	const auto *presentFences = vk::GetExtendedStruct<VkSwapchainPresentFenceInfoEXT>(presentInfo->pNext, VK_STRUCTURE_TYPE_SWAPCHAIN_PRESENT_FENCE_INFO_EXT);

	VkResult commandResult = VK_SUCCESS;

	for(uint32_t i = 0; i < presentInfo->swapchainCount; i++)
	{
		auto *swapchain = vk::Cast(presentInfo->pSwapchains[i]);
		VkResult perSwapchainResult = swapchain->present(presentInfo->pImageIndices[i]);

		if(presentInfo->pResults)
		{
			presentInfo->pResults[i] = perSwapchainResult;
		}

		// Keep track of the worst result code. VK_SUBOPTIMAL_KHR is a success code so it should
		// not override failure codes, but should not get replaced by a VK_SUCCESS result itself.
		if(perSwapchainResult != VK_SUCCESS)
		{
			if(commandResult == VK_SUCCESS || commandResult == VK_SUBOPTIMAL_KHR)
			{
				commandResult = perSwapchainResult;
			}
		}

		// The wait semaphores and the swapchain are no longer accessed
		if(presentFences)
		{
			vk::Cast(presentFences->pFences[i])->complete();
		}
	}

	return commandResult;
}
#endif

void Queue::beginDebugUtilsLabel(const VkDebugUtilsLabelEXT *pLabelInfo)
{
	// Optional debug label region
}

void Queue::endDebugUtilsLabel()
{
	// Close debug label region opened with beginDebugUtilsLabel()
}

void Queue::insertDebugUtilsLabel(const VkDebugUtilsLabelEXT *pLabelInfo)
{
	// Optional single debug label
}

}  // namespace vk