/**

 * Relational pipes

 * Copyright © 2018 František Kučera (Frantovo.cz, GlobalCode.info)

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program. If not, see <http://www.gnu.org/licenses/>.

 */

#pragma once

#include <iostream>

#include <QWidget>

#include <QGridLayout>

#include <QLabel>

#include <QChart>

#include <QChartView>

#include <QStackedBarSeries>

#include <QBarCategoryAxis>

#include <QVBarModelMapper>

#include <relpipe/reader/typedefs.h>

#include <relpipe/reader/TypeId.h>

#include <relpipe/reader/handlers/AttributeMetadata.h>

#include "RelpipeTableModel.h"

using namespace relpipe::reader;

using namespace relpipe::reader::handlers;

QT_CHARTS_USE_NAMESPACE

class RelpipeChartWidget : public QWidget {

	Q_OBJECT

private:

	RelpipeTableModel* model;

	QGridLayout* layout;

	QChart* chart;

	QChartView* chartView;

	QVBarModelMapper* mapper;

	QStackedBarSeries* series;

	QBarCategoryAxis* axis;

	boolean_t isNumeric(TypeId typeId) {

		return typeId == TypeId::INTEGER;

	}

	int firstValueColumn() {

		int first = lastValueColumn();

		for (int i = first; i > 0; i--) if (isNumeric(model->attributeType(i))) first = i; else break;

		return first;

	}

	int lastValueColumn() {

		return model->columnCount() - 1;

	}

public:

	RelpipeChartWidget(RelpipeTableModel* model, QWidget* parent = Q_NULLPTR) : model(model), QWidget(parent) {

		layout = new QGridLayout();

		setLayout(layout);

	}

	void endOfRelation() {

		if (hasChartData()) {

			chart = new QChart();

			chartView = new QChartView(chart, this);

			mapper = new QVBarModelMapper(chartView);

			series = new QStackedBarSeries(mapper);

			mapper->setFirstBarSetColumn(firstValueColumn());

			mapper->setLastBarSetColumn(lastValueColumn());

			mapper->setSeries(series);

			mapper->setModel(model);

			axis = new QBarCategoryAxis(chartView);

			for (int i = 0; i < model->rowCount(); i++) axis->append(model->data(model->index(i, 0)).toString());

			chart->addSeries(series);

			chart->createDefaultAxes();

			chart->setAxisX(axis, series);

			layout->addWidget(chartView);

		} else {

			layout->addWidget(new QLabel("This relation can't be displayed as a chart.", this));

		}

	}

	/**

	 * @return whether drawing a chart makes sense for this relation

	 */

	boolean_t hasChartData() {

		return model->columnCount() >= 2 // first = category, last = numeric value

				&& isNumeric(model->attributeType(lastValueColumn())); // at least the last attribute must be numeric

	}

};