/* Copyright (c) 2013-2015 Jeffrey Pfau
 *
 * 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 http://mozilla.org/MPL/2.0/. */
#include "DisplayQt.h"

#include "CoreController.h"

#include <QPainter>

#include <mgba/core/core.h>
#include <mgba/core/thread.h>
#include <mgba-util/math.h>

using namespace QGBA;

DisplayQt::DisplayQt(QWidget* parent)
	: Display(parent)
{
}

void DisplayQt::startDrawing(std::shared_ptr<CoreController> controller) {
	QSize size = controller->screenDimensions();
	m_width = size.width();
	m_height = size.height();
	m_backing = std::move(QImage());
	m_oldBacking = std::move(QImage());
	m_isDrawing = true;
	m_context = controller;
}

void DisplayQt::stopDrawing() {
	m_isDrawing = false;
	m_context.reset();
}

void DisplayQt::lockAspectRatio(bool lock) {
	Display::lockAspectRatio(lock);
	update();
}

void DisplayQt::lockIntegerScaling(bool lock) {
	Display::lockIntegerScaling(lock);
	update();
}

void DisplayQt::interframeBlending(bool lock) {
	Display::interframeBlending(lock);
	update();
}

void DisplayQt::filter(bool filter) {
	Display::filter(filter);
	update();
}

void DisplayQt::framePosted() {
	update();
	const color_t* buffer = m_context->drawContext();
	if (const_cast<const QImage&>(m_backing).bits() == reinterpret_cast<const uchar*>(buffer)) {
		return;
	}
	m_oldBacking = m_backing;
#ifdef COLOR_16_BIT
#ifdef COLOR_5_6_5
	m_backing = QImage(reinterpret_cast<const uchar*>(buffer), m_width, m_height, QImage::Format_RGB16);
#else
	m_backing = QImage(reinterpret_cast<const uchar*>(buffer), m_width, m_height, QImage::Format_RGB555);
#endif
#else
	m_backing = QImage(reinterpret_cast<const uchar*>(buffer), m_width, m_height, QImage::Format_ARGB32);
	m_backing = m_backing.convertToFormat(QImage::Format_RGB32);
#endif
#ifndef COLOR_5_6_5
	m_backing = m_backing.rgbSwapped();
#endif
}

void DisplayQt::resizeContext() {
	if (!m_context) {
		return;
	}
	QSize size = m_context->screenDimensions();
	if (m_width != size.width() || m_height != size.height()) {
		m_width = size.width();
		m_height = size.height();
		m_oldBacking = std::move(QImage());
		m_backing = std::move(QImage());
	}
}

void DisplayQt::paintEvent(QPaintEvent*) {
	QPainter painter(this);
	painter.fillRect(QRect(QPoint(), size()), Qt::black);
	if (isFiltered()) {
		painter.setRenderHint(QPainter::SmoothPixmapTransform);
	}
	QSize s = size();
	QSize ds = s;
	if (isAspectRatioLocked()) {
		if (s.width() * m_height > s.height() * m_width) {
			ds.setWidth(s.height() * m_width / m_height);
		} else if (s.width() * m_height < s.height() * m_width) {
			ds.setHeight(s.width() * m_height / m_width);
		}
	}
	if (isIntegerScalingLocked()) {
		ds.setWidth(ds.width() - ds.width() % m_width);
		ds.setHeight(ds.height() - ds.height() % m_height);
	}
	QPoint origin = QPoint((s.width() - ds.width()) / 2, (s.height() - ds.height()) / 2);
	QRect full(origin, ds);

	if (hasInterframeBlending()) {
		painter.drawImage(full, m_oldBacking, QRect(0, 0, m_width, m_height));
		painter.setOpacity(0.5);
	}
	painter.drawImage(full, m_backing, QRect(0, 0, m_width, m_height));
	painter.setOpacity(1);
	messagePainter()->paint(&painter);
}