#include "viewercontainer.h"

#include <QWidget>
#include <QResizeEvent>
#include <QScrollBar>
#include <QVBoxLayout>

#include "viewerwidget.h"
#include "panels/viewer.h"
#include "project/sequence.h"
#include "debug.h"

// enforces aspect ratio
ViewerContainer::ViewerContainer(QWidget *parent) :
	QScrollArea(parent),
	fit(true),
	child(nullptr)
{
	setFrameShadow(QFrame::Plain);
	setFrameShape(QFrame::NoFrame);

	area = new QWidget(this);
	area->move(0, 0);
	setWidget(area);

	child = new ViewerWidget(area);
	child->container = this;
}

ViewerContainer::~ViewerContainer() {
	delete child;
	delete area;
}

void ViewerContainer::dragScrollPress(const QPoint &p) {
	drag_start_x = p.x();
	drag_start_y = p.y();
	horiz_start = horizontalScrollBar()->value();
	vert_start = verticalScrollBar()->value();
}

void ViewerContainer::dragScrollMove(const QPoint &p) {
	int true_x = p.x() + (horiz_start - horizontalScrollBar()->value());
	int true_y = p.y() + (vert_start - verticalScrollBar()->value());

	horizontalScrollBar()->setValue(horizontalScrollBar()->value() + (drag_start_x - true_x));
	verticalScrollBar()->setValue(verticalScrollBar()->value() + (drag_start_y - true_y));

	drag_start_x = true_x;
	drag_start_y = true_y;
}

void ViewerContainer::adjust() {
	if (viewer->seq != nullptr) {
		if (child->waveform) {
			child->move(0, 0);
			child->resize(size());
		} else if (fit) {
			double aspect_ratio = double(viewer->seq->width)/double(viewer->seq->height);

			int widget_x = 0;
			int widget_y = 0;
			int widget_width = width();
			int widget_height = height();
			double widget_ar = double(widget_width) / double(widget_height);

			bool widget_is_wider_than_sequence = widget_ar > aspect_ratio;

			if (widget_is_wider_than_sequence) {
				widget_width = widget_height * aspect_ratio;
				widget_x = (width() / 2) - (widget_width / 2);
			} else {
				widget_height = widget_width / aspect_ratio;
				widget_y = (height() / 2) - (widget_height / 2);
			}

			child->move(widget_x, widget_y);
			child->resize(widget_width, widget_height);

			zoom = double(widget_width) / double(viewer->seq->width);
		} else {
			int zoomed_width = double(viewer->seq->width)*zoom;
			int zoomed_height = double(viewer->seq->height)*zoom;
			int zoomed_x = 0;
			int zoomed_y = 0;

			if (zoomed_width < width()) zoomed_x = (width()>>1)-(zoomed_width>>1);
			if (zoomed_height < height()) zoomed_y = (height()>>1)-(zoomed_height>>1);

			child->move(zoomed_x, zoomed_y);
			child->resize(zoomed_width, zoomed_height);
		}
	}
	area->resize(qMax(width(), child->width()), qMax(height(), child->height()));
}

void ViewerContainer::resizeEvent(QResizeEvent *event) {
	event->accept();
	adjust();
}