// Copyright 2015 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include <mutex>

#include "VideoCommon/AsyncRequests.h"
#include "VideoCommon/Fifo.h"
#include "VideoCommon/RenderBase.h"
#include "VideoCommon/VideoBackendBase.h"
#include "VideoCommon/VideoCommon.h"

AsyncRequests AsyncRequests::s_singleton;

AsyncRequests::AsyncRequests()
: m_enable(false), m_passthrough(true)
{
}

void AsyncRequests::PullEventsInternal()
{
	std::unique_lock<std::mutex> lock(m_mutex);
	m_empty.store(true);

	while (!m_queue.empty())
	{
		Event e = m_queue.front();

		// try to merge as many efb pokes as possible
		// it's a bit hacky, but some games render a complete frame in this way
		if ((e.type == Event::EFB_POKE_COLOR || e.type == Event::EFB_POKE_Z))
		{
			m_merged_efb_pokes.clear();
			Event first_event = m_queue.front();
			EFBAccessType t = first_event.type == Event::EFB_POKE_COLOR ? POKE_COLOR : POKE_Z;

			do
			{
				e = m_queue.front();

				EfbPokeData d;
				d.data = e.efb_poke.data;
				d.x = e.efb_poke.x;
				d.y = e.efb_poke.y;
				m_merged_efb_pokes.push_back(d);

				m_queue.pop();
			} while(!m_queue.empty() && m_queue.front().type == first_event.type);

			lock.unlock();
			g_renderer->PokeEFB(t, m_merged_efb_pokes.data(), m_merged_efb_pokes.size());
			lock.lock();
			continue;
		}

		lock.unlock();
		HandleEvent(e);
		lock.lock();

		m_queue.pop();
	}

	if (m_wake_me_up_again)
	{
		m_wake_me_up_again = false;
		m_cond.notify_all();
	}
}

void AsyncRequests::PushEvent(const AsyncRequests::Event& event, bool blocking)
{
	std::unique_lock<std::mutex> lock(m_mutex);

	if (m_passthrough)
	{
		HandleEvent(event);
		return;
	}

	m_empty.store(false);
	m_wake_me_up_again |= blocking;

	if (!m_enable)
		return;

	m_queue.push(event);

	Fifo::RunGpu();
	if (blocking)
	{
		m_cond.wait(lock, [this]{return m_queue.empty();});
	}
}

void AsyncRequests::SetEnable(bool enable)
{
	std::unique_lock<std::mutex> lock(m_mutex);
	m_enable = enable;

	if (!enable)
	{
		// flush the queue on disabling
		while (!m_queue.empty())
			m_queue.pop();
		if (m_wake_me_up_again)
			m_cond.notify_all();
	}
}

void AsyncRequests::HandleEvent(const AsyncRequests::Event& e)
{
	EFBRectangle rc;
	switch (e.type)
	{
		case Event::EFB_POKE_COLOR:
			{
				EfbPokeData poke = { e.efb_poke.x, e.efb_poke.y, e.efb_poke.data };
				g_renderer->PokeEFB(POKE_COLOR, &poke, 1);
			}
			break;

		case Event::EFB_POKE_Z:
			{
				EfbPokeData poke = { e.efb_poke.x, e.efb_poke.y, e.efb_poke.data };
				g_renderer->PokeEFB(POKE_Z, &poke, 1);
			}
			break;

		case Event::EFB_PEEK_COLOR:
			*e.efb_peek.data = g_renderer->AccessEFB(PEEK_COLOR, e.efb_peek.x, e.efb_peek.y, 0);
			break;

		case Event::EFB_PEEK_Z:
			*e.efb_peek.data = g_renderer->AccessEFB(PEEK_Z, e.efb_peek.x, e.efb_peek.y, 0);
			break;

		case Event::SWAP_EVENT:
			Renderer::Swap(e.swap_event.xfbAddr, e.swap_event.fbWidth, e.swap_event.fbStride, e.swap_event.fbHeight, rc);
			break;

		case Event::BBOX_READ:
			*e.bbox.data = g_renderer->BBoxRead(e.bbox.index);
			break;

		case Event::PERF_QUERY:
			g_perf_query->FlushResults();
			break;

	}
}

void AsyncRequests::SetPassthrough(bool enable)
{
	std::unique_lock<std::mutex> lock(m_mutex);
	m_passthrough = enable;
}

