// $Id$
// Author: Yves Lafon <ylafon@w3.org>
//
// (c) COPYRIGHT MIT, ERCIM and Keio University, 2013.
// Please first read the full copyright statement in file COPYRIGHT.html
package org.w3c.css.values;

import org.w3c.css.util.ApplContext;
import org.w3c.css.util.CssVersion;
import org.w3c.css.util.InvalidParamException;

import java.math.BigDecimal;

/**
 * @since CSS3
 */
public class CssVolume extends CssCheckableValue {

    public static final int type = CssTypes.CSS_VOLUME;

    public final int getType() {
        return type;
    }


    private BigDecimal value;
    protected String unit;

    /**
     * Create a new CssVolume
     */
    public CssVolume() {
        value = BigDecimal.ZERO;
    }

    /**
     * Set the value of this length.
     *
     * @param s the string representation of the length.
     * @throws org.w3c.css.util.InvalidParamException The unit is incorrect
     */
    public void set(String s, ApplContext ac) throws InvalidParamException {
        String low_s = s.toLowerCase();
        int length = low_s.length();
        int unitIdx = length - 1;
        char c = low_s.charAt(unitIdx);
        while (unitIdx > 0 && c <= 'z' && c >= 'a') {
            c = low_s.charAt(--unitIdx);
        }
        if (unitIdx == length - 1) {
            throw new InvalidParamException("unit", s, ac);
        }
        // we go back to the beginning of the unit
        unitIdx++;
        String unit_str = low_s.substring(unitIdx, length);
        // let's test the unit

        // TODO check the  if (!BigDecimal.ZERO.equals(value))) test
        // that was here earlier
        // seems legit to always test the unit no matter the value
        switch (ac.getCssVersion()) {
            case CSS3:
                CssUnitsCSS3.parseVolumeUnit(unit_str, this, ac);
                break;
            default:
                throw new InvalidParamException("unit", s, ac);
        }
        try {
            String num_s = low_s.substring(0, unitIdx);
            if (ac.getCssVersion().compareTo(CssVersion.CSS3) < 0) {
                // check for scientific notation in CSS < 3
                if (num_s.indexOf('e') >= 0 || num_s.indexOf('E') >= 0) {
                    throw new InvalidParamException("invalid-number", num_s, ac);
                }
            }
            value = new BigDecimal(num_s);
        } catch (NumberFormatException nex) {
            throw new InvalidParamException("invalid-number",
                    low_s.substring(0, unitIdx), ac);
        }
    }


    /**
     * set the native value
     *
     * @param v the BigDecimal
     */
    public void setValue(BigDecimal v) {
        value = v;
    }

    // return self
    public CssVolume getVolume() throws InvalidParamException {
        return this;
    }

    /**
     * Returns the current value
     */
    public Object get() {
        // TODO this is old ugly crap, needed for not breaking everything
        // remove as soon as reference to get is removed...
        return value.floatValue();
    }

    /**
     * return the float value
     */
    public float floatValue() {
        return value.floatValue();
    }

    /**
     * Returns true is the value is positive of null
     *
     * @return a boolean
     */
    public boolean isPositive() {
        return (value.signum() >= 0);
    }

    /**
     * Returns true is the value is positive of null
     *
     * @return a boolean
     */
    public boolean isStrictlyPositive() {
        return (value.signum() == 1);
    }

    /**
     * Returns true is the value is zero
     *
     * @return a boolean
     */
    public boolean isZero() {
        return (BigDecimal.ZERO.compareTo(value) == 0);
    }

    /**
     * Returns the current value
     */
    public String getUnit() {
        return unit;
    }

    /**
     * Returns a string representation of the object.
     */
    public String toString() {
        return value.toPlainString() + unit;
    }

    /**
     * Compares two values for equality.
     *
     * @param value The other value.
     */
    public boolean equals(Object value) {
        return (value instanceof CssVolume &&
                this.value.equals(((CssVolume) value).value) &&
                unit.equals(((CssVolume) value).unit));
    }

    /**
     * check if the value is equal to zero
     *
     * @param ac         the validation context
     * @param callername the String value of the object it is defined in
     * @throws InvalidParamException
     */
    public void checkEqualsZero(ApplContext ac, String callername)
            throws InvalidParamException {
        checkEqualsZero(ac, new String[]{"volume", toString(), callername});
    }

    /**
     * warn if the value is not zero
     *
     * @param ac         the validation context
     * @param callername the String value of the object it is defined in
     */
    public boolean warnEqualsZero(ApplContext ac, String callername) {
        return warnEqualsZero(ac, new String[]{"volume", callername});
    }
}