/*******************************************************************************
 * Copyright (c) 2009, 2018 STMicroelectronics and others.
 * 
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *    Marzia Maugeri <marzia.maugeri@st.com> - initial API and implementation
 *******************************************************************************/
package org.eclipse.linuxtools.dataviewers.charts.provider;

import java.util.List;

import org.eclipse.linuxtools.dataviewers.abstractviewers.ISTDataViewersField;
import org.eclipse.linuxtools.dataviewers.piechart.PieChart;
import org.eclipse.linuxtools.internal.dataviewers.charts.Activator;
import org.eclipse.linuxtools.internal.dataviewers.charts.view.ChartView;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.widgets.Display;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.PlatformUI;
import org.swtchart.Chart;
import org.swtchart.IAxis;
import org.swtchart.IBarSeries;
import org.swtchart.ISeries.SeriesType;
import org.swtchart.ITitle;
import org.swtchart.LineStyle;

/**
 * A utility class that handles the charts creation (pie chart and bar chart)
 */
public final class ChartFactory {

    private ChartFactory() {}

    /**
     * Produces a pie chart from the input objects.
     *
     * @param objects
     *            the input data
     * @param nameField
     *            the field used to get the labels of the objects (colored parts in the pie).
     * @param valFields
     *            the field providing the values for the pie parts.
     * @param title Title of the chart.
     * @return a new pie chart
     */
    public static Chart producePieChart(Object[] objects, ISTDataViewersField nameField,
            List<IChartField> valFields, String title) {

        ChartView view;
        try {
            final Color WHITE = PlatformUI.getWorkbench().getDisplay().getSystemColor(SWT.COLOR_WHITE);
            final Color BLACK = PlatformUI.getWorkbench().getDisplay().getSystemColor(SWT.COLOR_BLACK);
            final Color GRAD = PlatformUI.getWorkbench().getDisplay().getSystemColor(SWT.COLOR_WIDGET_BACKGROUND);

            view = (ChartView) PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage()
                    .showView(ChartView.VIEW_ID, String.valueOf(ChartView.getSecId()), IWorkbenchPage.VIEW_ACTIVATE);
            PieChart chart = new PieChart(view.getParent(), SWT.NONE);

            chart.setBackground(WHITE);
            chart.setBackgroundInPlotArea(GRAD);

            chart.getTitle().setText(title);
            chart.getTitle().setForeground(BLACK);

            chart.getLegend().setPosition(SWT.RIGHT);

            String[] valueLabels = new String[objects.length];
            for (int i = 0; i < objects.length; i++) {
                valueLabels[i] = nameField.getValue(objects[i]);
            }

            // pie chart data is grouped by columns
            // row size is the number of pie charts
            // column size is the number of data per pie chart
            double[][] doubleValues = new double[objects.length][valFields.size()];

            // data
            for (int i = 0; i < valFields.size(); i++) {
                for (int j = 0; j < objects.length; j++) {
                    Number num = valFields.get(i).getNumber(objects[j]);
                    double longVal = num.doubleValue();
                    doubleValues[j][i] = longVal + 1;
                }
            }

            chart.addPieChartSeries(valueLabels, doubleValues);
            chart.getAxisSet().adjustRange();

            return chart;
        } catch (PartInitException e) {
            Activator.getDefault().getLog().log(e.getStatus());
        }
        return null;
    }

    /**
     * Produces a 2D bar chart from the input objects.
     *
     * @param objects
     *            the input data
     * @param nameField
     *            the field used to get the labels of the objects (the labels of the series groups).
     * @param valFields
     *            the fields providing the values for the different bars in a series group.
     * @param title Title of the chart.
     * @param horizontal
     *            if true the bars are displayed horizontally, else vertically.
     * @return a new 2D bar chart
     */

    public static Chart produceBarChart(Object[] objects, final ISTDataViewersField nameField,
            List<IChartField> valFields, String title, boolean horizontal) {
        ChartView view;
        try {
            final Color WHITE = PlatformUI.getWorkbench().getDisplay().getSystemColor(SWT.COLOR_WHITE);
            final Color BLACK = PlatformUI.getWorkbench().getDisplay().getSystemColor(SWT.COLOR_BLACK);
            final Color GRAD = PlatformUI.getWorkbench().getDisplay().getSystemColor(SWT.COLOR_WIDGET_BACKGROUND);

            view = (ChartView) PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage()
                    .showView(ChartView.VIEW_ID, String.valueOf(ChartView.getSecId()), IWorkbenchPage.VIEW_ACTIVATE);
            Chart chart = new Chart(view.getParent(), SWT.NONE);

            chart.setBackground(WHITE);
            chart.setBackgroundInPlotArea(GRAD);

            chart.getTitle().setText(title);
            chart.getTitle().setForeground(BLACK);

            // this is correct (refers to orientation of x-axis, not bars)
            if (horizontal) {
                chart.setOrientation(SWT.VERTICAL);
            } else {
                chart.setOrientation(SWT.HORIZONTAL);
            }

            chart.getLegend().setPosition(SWT.RIGHT);

            String[] textLabels = new String[objects.length];
            for (int i = 0; i < objects.length; i++) {
                textLabels[i] = nameField.getValue(objects[i]);
            }

            // x-axis
            IAxis xAxis = chart.getAxisSet().getXAxis(0);
            xAxis.getGrid().setStyle(LineStyle.NONE);
            xAxis.getTick().setForeground(BLACK);
            ITitle xTitle = xAxis.getTitle();
            xTitle.setForeground(BLACK);
            xTitle.setText(nameField.getColumnHeaderText());
            xAxis.setCategorySeries(textLabels);
            xAxis.enableCategory(true);

            // y-axis
            IAxis yAxis = chart.getAxisSet().getYAxis(0);
            yAxis.getGrid().setStyle(LineStyle.NONE);
            yAxis.getTick().setForeground(BLACK);
            yAxis.getTitle().setVisible(false);

            // data
            for (IChartField field : valFields) {
                final IBarSeries bs = (IBarSeries) chart.getSeriesSet().createSeries(SeriesType.BAR,
                        field.getColumnHeaderText());
                bs.setBarColor(new Color(Display.getDefault(), getRC(), getRC(), getRC()));
                double[] doubleValues = new double[objects.length];

                for (int i = 0; i < objects.length; i++) {
                    Number num = field.getNumber(objects[i]);
                    double longVal = num.doubleValue();
                    doubleValues[i] = longVal;
                }

                bs.setYSeries(doubleValues);
            }

            chart.getAxisSet().adjustRange();

            return chart;
        } catch (PartInitException e) {
            Activator.getDefault().getLog().log(e.getStatus());
        }
        return null;
    }

    private static int getRC() {
        return (int) (Math.random() * 255);
    }
}
