//
// $Id$
// From Philippe Le Hegaret (Philippe.Le_Hegaret@sophia.inria.fr)
//
// (c) COPYRIGHT MIT, ERCIM and Keio, 1997-2010.
// 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.InvalidParamException;

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

/**
 * @spec http://www.w3.org/TR/2010/CR-css3-mediaqueries-20100727/#values
 * @since CSS3
 */
public class CssRatio extends CssValue {

    public static final int type = CssTypes.CSS_RATIO;

    public final int getType() {
        return type;
    }

    BigDecimal w = null, h = null;
    CssValue gw = null, gh = null;


    /**
     * Create a new CssRatio.
     */
    public CssRatio() {
    }

    public CssRatio(BigDecimal w, BigDecimal h) {
        this.w = w;
        this.h = h;
    }

    public CssRatio(BigDecimal w, CssValue gh) {
        this.w = w;
        if (gh.getRawType() == CssTypes.CSS_NUMBER) {
            try {
                this.h = gh.getNumber().getBigDecimalValue();
            } catch (Exception ex) {
                this.gh = gh;
            }
        } else {
            this.gh = gh;
        }
    }

    public CssRatio(CssValue gw, BigDecimal h) {
        if (gw.getRawType() == CssTypes.CSS_NUMBER) {
            try {
                this.w = gw.getNumber().getBigDecimalValue();
            } catch (Exception ex) {
                this.gw = gw;
            }
        } else {
            this.gw = gw;
        }
        this.h = h;
    }

    public CssRatio(CssValue gw, CssValue gh) {
        if (gw.getRawType() == CssTypes.CSS_NUMBER) {
            try {
                this.w = gw.getNumber().getBigDecimalValue();
            } catch (Exception ex) {
                this.gw = gw;
            }
        } else {
            this.gw = gw;
        }

        if (gh.getRawType() == CssTypes.CSS_NUMBER) {
            try {
                this.h = gh.getNumber().getBigDecimalValue();
            } catch (Exception ex) {
                this.gh = gh;
            }
        } else {
            this.gh = gh;
        }
    }

    /**
     * Set the value of this ratio.
     *
     * @param s  the string representation of the ratio.
     * @param ac For errors and warnings reports.
     * @throws org.w3c.css.util.InvalidParamException (incorrect format)
     */
    public void set(String s, ApplContext ac) throws InvalidParamException {
        String sw, sh;
        int slash = s.indexOf('/');

        if (slash == -1) {
            // invalid ratio
            throw new InvalidParamException("value",
                    s, ac);
        }
        // as we got spaces we need to trim the strings...
        sw = s.substring(0, slash).trim();
        sh = s.substring(slash + 1).trim();
        try {
            w = new BigDecimal(sw);
        } catch (NumberFormatException nex) {
            // not an int, not a float... bail out
            throw new InvalidParamException("value", s, ac);
        }
        // sanity check
        if (w.signum() != 1) {
            throw new InvalidParamException("strictly-positive", s, ac);
        }

        try {
            h = new BigDecimal(sh);
        } catch (NumberFormatException nex) {
            throw new InvalidParamException("value", s, ac);
        }
        // sanity check
        if (h.signum() != 1) {
            throw new InvalidParamException("strictly-positive", s, ac);
        }
    }

    /**
     * Returns the current value
     */
    public Object get() {
        return toString();
    }

    /**
     * Returns a string representation of the object.
     */
    public String toString() {
        StringBuilder sb = new StringBuilder();
        if (w != null) {
            sb.append(w.toPlainString());
        } else {
            sb.append(gw.toString()).append(' ');
        }
        sb.append('/');
        if (h != null) {
            sb.append(h.toPlainString());
        } else {
            sb.append(gh.toString());
        }
        return sb.toString();
    }

    /**
     * Compares two values for equality.
     *
     * @param value The other value.
     */
    public boolean equals(Object value) {
        try {
            CssRatio other = (CssRatio) value;
            // check that the ratio are the same
            BigDecimal ratio, other_ratio;
            ratio = w.divide(h, RoundingMode.CEILING);
            other_ratio = other.w.divide(other.h, RoundingMode.CEILING);
            return (ratio.compareTo(other_ratio) == 0);
        } catch (ClassCastException cce) {
            return false;
        } catch (Exception ex) {
            return false;
        }
    }
}