#include <QPainter>
#include <QCache>
#include "common/programpaths.h"
#include "map/mapsforgemap.h"
#include "map/textpathitem.h"
#include "map/textpointitem.h"
#include "rastertile.h"

using namespace Mapsforge;

static const Style& style()
{
	static Style s(ProgramPaths::renderthemeFile());
	return s;
}

static qreal area(const QPainterPath &polygon)
{
	qreal area = 0;

	for (int i = 0; i < polygon.elementCount(); i++) {
		int j = (i + 1) % polygon.elementCount();
		area += polygon.elementAt(i).x * polygon.elementAt(j).y;
		area -= polygon.elementAt(i).y * polygon.elementAt(j).x;
	}
	area /= 2.0;

	return area;
}

static QPointF centroid(const QPainterPath &polygon)
{
	qreal cx = 0, cy = 0;
	qreal factor = 1.0 / (6.0 * area(polygon));

	for (int i = 0; i < polygon.elementCount(); i++) {
		int j = (i + 1) % polygon.elementCount();
		qreal f = (polygon.elementAt(i).x * polygon.elementAt(j).y
		  - polygon.elementAt(j).x * polygon.elementAt(i).y);
		cx += (polygon.elementAt(i).x + polygon.elementAt(j).x) * f;
		cy += (polygon.elementAt(i).y + polygon.elementAt(j).y) * f;
	}

	return QPointF(cx * factor, cy * factor);
}

void RasterTile::processPoints(QList<TextItem*> &textItems)
{
	const Style &s = style();
	QList<const Style::TextRender*> labels(s.pointLabels(_zoom));
	QList<const Style::Symbol*> symbols(s.symbols(_zoom));

	for (int i = 0; i < _points.size(); i++) {
		const MapData::Point &point = _points.at(i);
		const QString *label = point.label.isEmpty() ? 0 : &(point.label);
		const Style::TextRender *ti = 0;
		const Style::Symbol *si = 0;

		if (label) {
			for (int i = 0; i < labels.size(); i++) {
				const Style::TextRender *ri = labels.at(i);
				if (ri->rule().match(point.tags)) {
					ti = ri;
					break;
				}
			}
		}

		for (int i = 0; i < symbols.size(); i++) {
			const Style::Symbol *ri = symbols.at(i);
			if (ri->rule().match(point.tags)) {
				si = ri;
				break;
			}
		}

		if (!ti && !si)
			continue;

		const QImage *img = si ? &si->img() : 0;
		const QFont *font = ti ? &ti->font() : 0;
		const QColor *color = ti ? &ti->fillColor() : 0;

		TextPointItem *item = new TextPointItem(
		  ll2xy(point.coordinates).toPoint(), label, font, img, color, 0, false);
		if (item->isValid() && !item->collides(textItems))
			textItems.append(item);
		else
			delete item;

	}
}

void RasterTile::processAreaNames(const QRect &tileRect,
  QList<TextItem*> &textItems)
{
	const Style &s = style();
	QList<const Style::TextRender*> instructions(s.areaLabels(_zoom));
	QSet<QString> set;

	for (int i = 0; i < instructions.size(); i++) {
		const Style::TextRender *ri = instructions.at(i);

		for (int j = 0; j < _paths.size(); j++) {
			const MapData::Path &path = _paths.at(j);

			if (!path.closed || path.label.isEmpty())
				continue;
			if (!path.path.elementCount())
				continue;
			if (set.contains(path.label))
				continue;
			if (!ri->rule().match(path.closed, path.tags))
				continue;

			QPointF pos = path.labelPos.isNull()
			  ? centroid(path.path) : ll2xy(path.labelPos);

			TextPointItem *item = new TextPointItem(pos.toPoint(), &path.label,
			  &ri->font(), 0, &ri->fillColor(), 0, false);
			if (item->isValid() && tileRect.contains(item->boundingRect().toRect())
			  && !item->collides(textItems)) {
				textItems.append(item);
				set.insert(path.label);
			} else
				delete item;
		}
	}
}

void RasterTile::processStreetNames(const QRect &tileRect,
  QList<TextItem*> &textItems)
{
	const Style &s = style();
	QList<const Style::TextRender*> instructions(s.pathLabels(_zoom));

	for (int i = 0; i < instructions.size(); i++) {
		const Style::TextRender *ri = instructions.at(i);

		for (int j = 0; j < _paths.size(); j++) {
			MapData::Path &path = _paths[j];

			if (path.label.isEmpty())
				continue;
			if (!path.path.elementCount())
				continue;
			if (!ri->rule().match(path.closed, path.tags))
				continue;

			TextPathItem *item = new TextPathItem(path.path,
			  &path.label, tileRect, &ri->font(), &ri->fillColor(),
			  &ri->strokeColor());
			if (item->isValid() && !item->collides(textItems))
				textItems.append(item);
			else
				delete item;
		    }
	}
}

void RasterTile::drawTextItems(QPainter *painter,
  const QList<TextItem*> &textItems)
{
	for (int i = 0; i < textItems.size(); i++)
		textItems.at(i)->paint(painter);
}

QPainterPath RasterTile::painterPath(const Polygon &polygon) const
{
	QPainterPath path;

	for (int i = 0; i < polygon.size(); i++) {
		const QVector<Coordinates> &subpath = polygon.at(i);

		path.moveTo(ll2xy(subpath.first()));
		for (int j = 1; j < subpath.size(); j++)
			path.lineTo(ll2xy(subpath.at(j)));
	}

	return path;
}

QVector<RasterTile::PathInstruction> RasterTile::pathInstructions()
{
	QCache<Key, QVector<const Style::PathRender *> > cache(1024);
	QVector<PathInstruction> instructions;
	const Style &s = style();

	for (int i = 0 ; i < _paths.size(); i++) {
		MapData::Path &path = _paths[i];

		Key key(_zoom, path.closed, path.tags);
		QVector<const Style::PathRender*> *cached = cache.object(key);
		if (!cached) {
			QVector<const Style::PathRender*> *ri
			  = new QVector<const Style::PathRender*>();
			s.match(_zoom, path.closed, path.tags, ri);
			for (int j = 0; j < ri->size(); j++)
				instructions.append(PathInstruction(ri->at(j), &path));
			cache.insert(key, ri);
		} else {
			for (int j = 0; j < cached->size(); j++)
				instructions.append(PathInstruction(cached->at(j), &path));
		}
	}

	std::sort(instructions.begin(), instructions.end());

	return instructions;
}

void RasterTile::drawPaths(QPainter *painter)
{
	QVector<PathInstruction> instructions(pathInstructions());
	const Style::PathRender *lri = 0;

	QPixmap layer(_pixmap.size());
	layer.fill(Qt::transparent);

	QPainter lp(&layer);
	lp.setRenderHint(QPainter::Antialiasing);
	lp.translate(-_xy.x(), -_xy.y());
	lp.setCompositionMode(QPainter::CompositionMode_Source);

	for (int i = 0; i < instructions.size(); i++) {
		PathInstruction &is = instructions[i];
		const Style::PathRender *ri = is.render();

		if (lri && ri != lri) {
			painter->drawPixmap(_xy, layer);
			lp.fillRect(QRect(_xy, _pixmap.size()), Qt::transparent);
		}
		lri = ri;

		if (!is.path()->path.elementCount())
			is.path()->path = painterPath(is.path()->poly);

		lp.setPen(ri->pen(_zoom));
		lp.setBrush(ri->brush());
		lp.drawPath(is.path()->path);
	}

	painter->drawPixmap(_xy, layer);
}

void RasterTile::render()
{
	std::sort(_points.begin(), _points.end());

	QList<TextItem*> textItems;
	QRect tileRect(_xy, _pixmap.size());

	_pixmap.fill(Qt::transparent);

	QPainter painter(&_pixmap);
	painter.setRenderHint(QPainter::Antialiasing);
	painter.translate(-_xy.x(), -_xy.y());

	drawPaths(&painter);

	processPoints(textItems);
	processAreaNames(tileRect, textItems);
	processStreetNames(tileRect, textItems);
	drawTextItems(&painter, textItems);

	//painter.setPen(Qt::red);
	//painter.setBrush(Qt::NoBrush);
	//painter.drawRect(QRect(_xy, _pixmap.size()));

	qDeleteAll(textItems);
}