/* 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 "ShaderSelector.h"

#include "Display.h"
#include "VFileDevice.h"

#include <QCheckBox>
#include <QDoubleSpinBox>
#include <QFileDialog>
#include <QFormLayout>
#include <QGridLayout>
#include <QSpinBox>

extern "C" {
#include "platform/video-backend.h"

#if !defined(_WIN32) || defined(USE_EPOXY)
#include "platform/opengl/gles2.h"
#endif
}

using namespace QGBA;

ShaderSelector::ShaderSelector(Display* display, QWidget* parent)
	: QDialog(parent)
	, m_display(display)
{
	m_ui.setupUi(this);

	refreshShaders();

	connect(m_ui.load, SIGNAL(clicked()), this, SLOT(selectShader()));
	connect(m_ui.unload, SIGNAL(clicked()), this, SLOT(clearShader()));
}

ShaderSelector::~ShaderSelector() {
	clear();
}

void ShaderSelector::clear() {
	m_ui.shaderName->setText(tr("No shader active"));
	m_ui.description->clear();
	m_ui.author->clear();

	while (QWidget* page = m_ui.passes->widget(0)) {
		m_ui.passes->removeTab(0);
		delete page;
	}
}

void ShaderSelector::selectShader() {
#ifdef QT_SHADER_DIR
	QFileDialog dialog(nullptr, tr("Load shader"), QT_SHADER_DIR, tr("%1 Shader (%.shader)").arg(projectName));
#else
	QString path = QCoreApplication::applicationDirPath();
#ifdef Q_OS_MAC
	path += QLatin1String("/../Resources");
#endif
	path += QLatin1String("/shaders");
	QFileDialog dialog(nullptr, tr("Load shader"), path, tr("%1 Shader (%.shader)").arg(projectName));
#endif
	dialog.setFileMode(QFileDialog::Directory);
	dialog.exec();
	QStringList names = dialog.selectedFiles();
	if (names.count() == 1) {
		loadShader(names[0]);
		refreshShaders();
	}
}

void ShaderSelector::loadShader(const QString& path) {
	VDir* shader = VFileDevice::openDir(path);
	if (!shader) {
		shader = VFileDevice::openArchive(path);
	}
	if (!shader) {
		return;
	}
	m_display->setShaders(shader);
	shader->close(shader);
	// TODO: Config
}

void ShaderSelector::clearShader() {
	m_display->clearShaders();
	refreshShaders();
	// TODO: Config
}

void ShaderSelector::refreshShaders() {
	clear();
	m_shaders = m_display->shaders();
	if (!m_shaders) {
		return;
	}
	if (m_shaders->name) {
		m_ui.shaderName->setText(m_shaders->name);
	} else {
		m_ui.shaderName->setText(tr("No shader loaded"));
	}
	if (m_shaders->description) {
		m_ui.description->setText(m_shaders->description);
	} else {
		m_ui.description->clear();
	}
	if (m_shaders->author) {
		m_ui.author->setText(tr("by %1").arg(m_shaders->author));
	} else {
		m_ui.author->clear();
	}

#if !defined(_WIN32) || defined(USE_EPOXY)
	m_ui.passes->addTab(makePage(static_cast<GBAGLES2Shader*>(m_shaders->preprocessShader)), tr("Preprocessing"));
	GBAGLES2Shader* shaders = static_cast<GBAGLES2Shader*>(m_shaders->passes);
	for (size_t p = 0; p < m_shaders->nPasses; ++p) {
		QWidget* page = makePage(&shaders[p]);
		if (page) {
			m_ui.passes->addTab(page, tr("Pass %1").arg(p + 1));
		}
	}
#endif
}

void ShaderSelector::addUniform(QGridLayout* settings, float* value, float min, float max, int y, int x) {
	QDoubleSpinBox* f = new QDoubleSpinBox;
	f->setDecimals(3);
	if (min < max) {
		f->setMinimum(min);
		f->setMaximum(max);
	}
	f->setValue(*value);
	f->setSingleStep(0.001);
	f->setAccelerated(true);
	settings->addWidget(f, y, x);
	connect(f, static_cast<void (QDoubleSpinBox::*)(double)>(&QDoubleSpinBox::valueChanged), [value](double v) {
		*value = v;
		// TODO: Config
	});
}

void ShaderSelector::addUniform(QGridLayout* settings, int* value, int min, int max, int y, int x) {
	QSpinBox* i = new QSpinBox;
	if (min < max) {
		i->setMinimum(min);
		i->setMaximum(max);
	}
	i->setValue(*value);
	i->setSingleStep(1);
	i->setAccelerated(true);
	settings->addWidget(i, y, x);
	connect(i, static_cast<void (QSpinBox::*)(int)>(&QSpinBox::valueChanged), [value](int v) {
		*value = v;
		// TODO: Config
	});
}

QWidget* ShaderSelector::makePage(GBAGLES2Shader* shader) {
	if (!shader->nUniforms) {
		return nullptr;
	}
	QWidget* page = new QWidget;
	QFormLayout* layout = new QFormLayout;
	page->setLayout(layout);
	for (size_t u = 0 ; u < shader->nUniforms; ++u) {
		QGridLayout* settings = new QGridLayout;
		GBAGLES2Uniform* uniform = &shader->uniforms[u];
		switch (uniform->type) {
		case GL_FLOAT:
			addUniform(settings, &uniform->value.f, uniform->min.f, uniform->max.f, 0, 0);
			break;
		case GL_FLOAT_VEC2:
			addUniform(settings, &uniform->value.fvec2[0], uniform->min.fvec2[0], uniform->max.fvec2[0], 0, 0);
			addUniform(settings, &uniform->value.fvec2[1], uniform->min.fvec2[1], uniform->max.fvec2[1], 0, 1);
			break;
		case GL_FLOAT_VEC3:
			addUniform(settings, &uniform->value.fvec3[0], uniform->min.fvec3[0], uniform->max.fvec3[0], 0, 0);
			addUniform(settings, &uniform->value.fvec3[1], uniform->min.fvec3[1], uniform->max.fvec3[1], 0, 1);
			addUniform(settings, &uniform->value.fvec3[2], uniform->min.fvec3[2], uniform->max.fvec3[2], 0, 2);
			break;
		case GL_FLOAT_VEC4:
			addUniform(settings, &uniform->value.fvec4[0], uniform->min.fvec4[0], uniform->max.fvec4[0], 0, 0);
			addUniform(settings, &uniform->value.fvec4[1], uniform->min.fvec4[1], uniform->max.fvec4[1], 0, 1);
			addUniform(settings, &uniform->value.fvec4[2], uniform->min.fvec4[2], uniform->max.fvec4[2], 0, 2);
			addUniform(settings, &uniform->value.fvec4[3], uniform->min.fvec4[3], uniform->max.fvec4[3], 0, 3);
			break;
		case GL_INT:
			addUniform(settings, &uniform->value.i, uniform->min.i, uniform->max.i, 0, 0);
			break;
		case GL_INT_VEC2:
			addUniform(settings, &uniform->value.ivec2[0], uniform->min.ivec2[0], uniform->max.ivec2[0], 0, 0);
			addUniform(settings, &uniform->value.ivec2[1], uniform->min.ivec2[1], uniform->max.ivec2[1], 0, 1);
			break;
		case GL_INT_VEC3:
			addUniform(settings, &uniform->value.ivec3[0], uniform->min.ivec3[0], uniform->max.ivec3[0], 0, 0);
			addUniform(settings, &uniform->value.ivec3[1], uniform->min.ivec3[1], uniform->max.ivec3[1], 0, 1);
			addUniform(settings, &uniform->value.ivec3[2], uniform->min.ivec3[2], uniform->max.ivec3[2], 0, 2);
			break;
		case GL_INT_VEC4:
			addUniform(settings, &uniform->value.ivec4[0], uniform->min.ivec4[0], uniform->max.ivec4[0], 0, 0);
			addUniform(settings, &uniform->value.ivec4[1], uniform->min.ivec4[1], uniform->max.ivec4[1], 0, 1);
			addUniform(settings, &uniform->value.ivec4[2], uniform->min.ivec4[2], uniform->max.ivec4[2], 0, 2);
			addUniform(settings, &uniform->value.ivec4[3], uniform->min.ivec4[3], uniform->max.ivec4[3], 0, 3);
			break;
		}
		layout->addRow(shader->uniforms[u].readableName, settings);
	}
	return page;
}