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;
    }
}