SappAddressDecimal.java

/**
 * Copyright (c) 2010-2016 by the respective copyright holders.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.openhab.binding.sapp.internal.model;

import java.math.BigDecimal;
import java.math.MathContext;
import java.math.RoundingMode;

import org.openhab.binding.sapp.internal.configs.SappBindingConfigUtils;

/**
 * Decimal Address model
 *
 * @author Paolo Denti
 * @since 1.8.0
 *
 */
public class SappAddressDecimal extends SappAddress {

    private int originalMinScale;
    private int originalMaxScale;
    private int minScale;
    private int maxScale;

    /**
     * Constructor
     */
    public SappAddressDecimal(String pnmasId, SappAddressType addressType, int address, String subAddress, int minScale,
            int maxScale) {
        super(pnmasId, addressType, address, subAddress);

        setOriginalScale(subAddress);
        if (minScale != maxScale) { // check against bad parameters, division by zero
            this.minScale = minScale;
            this.maxScale = maxScale;
        } else {
            this.minScale = originalMinScale;
            this.maxScale = originalMaxScale;
        }
    }

    /**
     * Constructor
     */
    public SappAddressDecimal(String pnmasId, SappAddressType addressType, int address, String subAddress) {
        super(pnmasId, addressType, address, subAddress);

        setOriginalScale(subAddress);
        this.minScale = originalMinScale;
        this.maxScale = originalMaxScale;
    }

    /**
     * minScale getter
     */
    public int getMinScale() {
        return minScale;
    }

    /**
     * maxScale getter
     */
    public int getMaxScale() {
        return maxScale;
    }

    /**
     * originalMinScale getter
     */
    public int getOriginalMinScale() {
        return originalMinScale;
    }

    /**
     * originalMaxScale getter
     */
    public int getOriginalMaxScale() {
        return originalMaxScale;
    }

    private void setOriginalScale(String subAddress) {

        if (subAddress.equals(SappBindingConfigUtils.WORD_MASK_U)
                || subAddress.equals(SappBindingConfigUtils.WORD_MASK_S)) {
            originalMinScale = 0;
            originalMaxScale = 0xFFFF;
        } else if (subAddress.equals(SappBindingConfigUtils.LOW_MASK_U)
                || subAddress.equals(SappBindingConfigUtils.LOW_MASK_S)) {
            originalMinScale = 0;
            originalMaxScale = 0x00FF;
        } else if (subAddress.equals(SappBindingConfigUtils.HIGH_MASK_U)
                || subAddress.equals(SappBindingConfigUtils.HIGH_MASK_S)) {
            originalMinScale = 0;
            originalMaxScale = 0x00FF;
        } else {
            originalMinScale = 0;
            originalMaxScale = 0x0001;
        }
    }

    /**
     * returns the scaled value with respect to the original scale
     */
    public BigDecimal scaledValue(int value, String subAddress) {
        BigDecimal toScaleValue = new BigDecimal(value);

        if (subAddress.equals(SappBindingConfigUtils.WORD_MASK_S) && value > 0x7FFF) {
            toScaleValue = (toScaleValue.subtract(new BigDecimal(0xFFFF))).subtract(BigDecimal.ONE);
        } else if (subAddress.equals(SappBindingConfigUtils.LOW_MASK_S) && value > 0x7F) {
            toScaleValue = (toScaleValue.subtract(new BigDecimal(0xFF))).subtract(BigDecimal.ONE);
        } else if (subAddress.equals(SappBindingConfigUtils.HIGH_MASK_S) && value > 0x7F) {
            toScaleValue = (toScaleValue.subtract(new BigDecimal(0xFF))).subtract(BigDecimal.ONE);
        }

        BigDecimal originalScale = new BigDecimal(originalMaxScale - originalMinScale);
        BigDecimal scale = new BigDecimal(maxScale - minScale);

        return toScaleValue.subtract(new BigDecimal(originalMinScale)).multiply(scale)
                .divide(originalScale, MathContext.DECIMAL128).add(new BigDecimal(minScale));
    }

    /**
     * converts a scaled value back to the original scale
     */
    public int backScaledValue(BigDecimal value) {

        BigDecimal originalScale = new BigDecimal(originalMaxScale - originalMinScale);
        BigDecimal scale = new BigDecimal(maxScale - minScale);

        return value.subtract(new BigDecimal(minScale)).multiply(originalScale).divide(scale, MathContext.DECIMAL128)
                .add(new BigDecimal(originalMinScale)).round(new MathContext(0, RoundingMode.HALF_EVEN)).intValue();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String toString() {
        return String.format("[ %s:%s:%d:%s:%d:%d ]", getPnmasId(), getAddressType(), getAddress(), getSubAddress(),
                minScale, maxScale);
    }
}