Advanced Data Visualization

@Route("politician-dashboard")
public class PoliticianDashboardView extends VerticalLayout {

    private Chart createVotingTrendChart(List<VotingRecord> records) {
        Chart chart = new Chart(ChartType.LINE);
        Configuration conf = chart.getConfiguration();
        conf.setTitle("Voting Participation Over Time");

        XAxis xAxis = new XAxis();
        xAxis.setType(AxisType.DATETIME);
        conf.addxAxis(xAxis);

        YAxis yAxis = new YAxis();
        yAxis.setTitle("Participation %");
        yAxis.setMin(0);
        yAxis.setMax(100);
        conf.addyAxis(yAxis);

        DataSeries series = new DataSeries("Attendance");
        for (VotingRecord record : records) {
            series.add(new DataSeriesItem(
                record.getDate().toInstant(),
                record.getParticipationRate()
            ));
        }
        conf.addSeries(series);

        return chart;
    }
}

public final class SwedishPartyColors {
    // Official Swedish party colors for consistent visualization
    public static final String SOCIALDEMOKRATERNA = "#ED1B34";  // S - Red
    public static final String MODERATERNA = "#52BDEC";         // M - Blue
    public static final String SVERIGEDEMOKRATERNA = "#DDDD00"; // SD - Yellow
    public static final String CENTERPARTIET = "#009933";       // C - Green
    public static final String VANSTERPARTIET = "#DA291C";      // V - Dark Red
    public static final String KRISTDEMOKRATERNA = "#000077";   // KD - Dark Blue
    public static final String LIBERALERNA = "#006AB3";         // L - Light Blue
    public static final String MILJOPARTIET = "#83CF39";        // MP - Light Green

    private SwedishPartyColors() {}
}

// Annotate significant events on time series
private void addAnnotations(Configuration conf, List<PoliticalEvent> events) {
    PlotBand[] bands = events.stream()
        .filter(e -> e.getSignificance() > 0.7)
        .map(e -> {
            PlotBand band = new PlotBand();
            band.setFrom(e.getStartDate().toEpochMilli());
            band.setTo(e.getEndDate().toEpochMilli());
            band.setColor(new SolidColor(255, 200, 200, 0.3));
            band.setLabel(new Label(e.getDescription()));
            return band;
        })
        .toArray(PlotBand[]::new);

    conf.getxAxis().setPlotBands(bands);
}

private DataSeries calculateMovingAverage(List<DataPoint> data, int window) {
    DataSeries maSeries = new DataSeries("Moving Avg (" + window + "d)");
    maSeries.setPlotOptions(new PlotOptionsLine());

    for (int i = window - 1; i < data.size(); i++) {
        double sum = 0;
        for (int j = i - window + 1; j <= i; j++) {
            sum += data.get(j).getValue();
        }
        maSeries.add(new DataSeriesItem(
            data.get(i).getTimestamp(), sum / window
        ));
    }
    return maSeries;
}

chart.getElement().setAttribute("aria-label",
    "Line chart showing voting participation trend for " + politicianName);
chart.getElement().setAttribute("role", "img");