package org.litesoft.GWT.client.widgets.sliderbar.client.presenter;

public class SliderBarCalculator {
    protected int maxValue;
    protected int absMaxLength;
    protected int minPosition, maxPosition;

    private int step;
    private double k;

    public int getMaxValue() {
        return maxValue;
    }

    public void setMaxValue( int maxValue ) {
        this.maxValue = maxValue;
    }

    public void setAbsMaxLength( int absMaxLength ) {
        this.absMaxLength = absMaxLength;
    }

    protected void processParams() {
        int usedAbsLength = absMaxLength;
        minPosition = 0;
        maxPosition = absMaxLength;
        if ( absMaxLength >= maxValue ) {
            usedAbsLength = absMaxLength - absMaxLength % maxValue;
            minPosition = (absMaxLength - usedAbsLength) / 2;
            maxPosition = minPosition + usedAbsLength;
        }
        step = usedAbsLength / maxValue;
        if ( step == 0 ) {
            step = 1;
        }
        k = (double) usedAbsLength / maxValue;
    }

    public int checkAbsPosition( int absPosition ) {
        if ( absPosition < minPosition ) {
            absPosition = minPosition;
        }
        if ( absPosition > maxPosition ) {
            absPosition = maxPosition;
        }
        return absPosition;
    }

    protected int clcValueByAbsPosition( int currentAbsPosition ) {
        currentAbsPosition = checkAbsPosition( currentAbsPosition ) - minPosition;
        int value = (int) Math.round( (currentAbsPosition / k) );
        return value;
    }

    protected int clcAbsPositionByValue( int value ) {
        int absPosition;
        if ( k >= 1 ) {
            absPosition = value * step;
        } else {
            absPosition = (int) Math.round( value * k );
        }
        return absPosition + minPosition;
    }
}