/*
 *                    BioJava development code
 *
 * This code may be freely distributed and modified under the
 * terms of the GNU Lesser General Public Licence.  This should
 * be distributed with the code.  If you do not have a copy,
 * see:
 *
 *      http://www.gnu.org/copyleft/lesser.html
 *
 * Copyright for this code is held jointly by the individual
 * authors.  These should be listed in @author doc comments.
 *
 * For more information on the BioJava project and its aims,
 * or to join the biojava-l mailing list, visit the home page
 * at:
 *
 *      http://www.biojava.org/
 *
 */

package org.biojava.bio.search;

import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;

/**
 * Class for implementing tests with BlastLikeSearchFilter
 * objects.  Several precanned tests are included.
 * @author David Huen
 */
public interface FilterTest
{
    /**
     * @return returns true if test is successful.
     */
    public boolean accept(Object value);

    /**
     * Tests that the value associated with the specified
     * key is equal to the value supplied here by whatever
     * criterion of equality appropriate to those objects.
     * A value of false is returned by accept() if a
     * ClassCastException is thrown on comparing the objects.
     */
    public static class Equals
        implements FilterTest
    {
        private Object value;

        public Equals(Object value) { this.value = value; }

        public boolean accept(Object value)
        {
            try {
                return this.value.equals(value);
            }
            catch (ClassCastException ce) {
                return false;
            }
        }
    }

    /**
     * Tests that the value associated with the specified
     * key is matched in its entirety by the supplied regex.
     * A value of false is returned by accept() if a
     * ClassCastException is thrown on comparing the objects.
     */
    public static class MatchRegex
    {
        private Pattern pattern;

        public MatchRegex(String regex)
            throws PatternSyntaxException
        {
            pattern = Pattern.compile(regex);
        }

        public boolean accept(Object value)
        {
            try {
                return pattern.matcher((String) value).matches();
            }
            catch (ClassCastException ce) {
                return false;
            }
        }
    }

    /**
     * Tests that the value associated with the specified
     * key contains a part matched by the supplied regex.
     * A value of false is returned by accept() if a
     * ClassCastException is thrown on comparing the objects.
     */
    public static class FindRegex
    {
        private Pattern pattern;

        public FindRegex(String regex)
            throws PatternSyntaxException
        {
            pattern = Pattern.compile(regex);
        }

        public boolean accept(Object value)
        {
            try {
                return pattern.matcher((String) value).find();
            }
            catch (ClassCastException ce) {
                return false;
            }
        }
    }

    /**
     * Tests that the value associated with the specified
     * key is less than the specified threshold.  The test
     * assumes that value is a String representing a real
     * number.  If not, the test will return null.
     */
    public static class LessThan
        implements FilterTest
    {
        private double threshold;

        public LessThan(double threshold) { this. threshold = threshold; }

        public boolean accept(Object value)
        {
            return (value instanceof String) && (Double.parseDouble((String) value) < threshold);
        }
    }

    /**
     * Tests that the value associated with the specified
     * key is greater than the specified threshold.  The test
     * assumes that value is a String representing a real
     * number.  If not, the test will return null.
     */
    public static class GreaterThan
        implements FilterTest
    {
        private double threshold;

        public GreaterThan(double threshold) { this. threshold = threshold; }

        public boolean accept(Object value)
        {
            return (value instanceof String) && (Double.parseDouble((String) value) > threshold);
        }
    }
}