package cpw.mods.fml.common.versioning;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/**
 * Describes a restriction in versioning.
 *
 * @author <a href="mailto:brett@apache.org">Brett Porter</a>
 */
public class Restriction
{
    private final ArtifactVersion lowerBound;

    private final boolean lowerBoundInclusive;

    private final ArtifactVersion upperBound;

    private final boolean upperBoundInclusive;

    public static final Restriction EVERYTHING = new Restriction( null, false, null, false );

    public Restriction( ArtifactVersion lowerBound, boolean lowerBoundInclusive, ArtifactVersion upperBound,
                        boolean upperBoundInclusive )
    {
        this.lowerBound = lowerBound;
        this.lowerBoundInclusive = lowerBoundInclusive;
        this.upperBound = upperBound;
        this.upperBoundInclusive = upperBoundInclusive;
    }

    public ArtifactVersion getLowerBound()
    {
        return lowerBound;
    }

    public boolean isLowerBoundInclusive()
    {
        return lowerBoundInclusive;
    }

    public ArtifactVersion getUpperBound()
    {
        return upperBound;
    }

    public boolean isUpperBoundInclusive()
    {
        return upperBoundInclusive;
    }

    public boolean containsVersion( ArtifactVersion version )
    {
        if ( lowerBound != null )
        {
            int comparison = lowerBound.compareTo( version );

            if ( ( comparison == 0 ) && !lowerBoundInclusive )
            {
                return false;
            }
            if ( comparison > 0 )
            {
                return false;
            }
        }
        if ( upperBound != null )
        {
            int comparison = upperBound.compareTo( version );

            if ( ( comparison == 0 ) && !upperBoundInclusive )
            {
                return false;
            }
            if ( comparison < 0 )
            {
                return false;
            }
        }

        return true;
    }

    @Override
    public int hashCode()
    {
        int result = 13;

        if ( lowerBound == null )
        {
            result += 1;
        }
        else
        {
            result += lowerBound.hashCode();
        }

        result *= lowerBoundInclusive ? 1 : 2;

        if ( upperBound == null )
        {
            result -= 3;
        }
        else
        {
            result -= upperBound.hashCode();
        }

        result *= upperBoundInclusive ? 2 : 3;

        return result;
    }

    @Override
    public boolean equals( Object other )
    {
        if ( this == other )
        {
            return true;
        }

        if ( !( other instanceof Restriction ) )
        {
            return false;
        }

        Restriction restriction = (Restriction) other;
        if ( lowerBound != null )
        {
            if ( !lowerBound.equals( restriction.lowerBound ) )
            {
                return false;
            }
        }
        else if ( restriction.lowerBound != null )
        {
            return false;
        }

        if ( lowerBoundInclusive != restriction.lowerBoundInclusive )
        {
            return false;
        }

        if ( upperBound != null )
        {
            if ( !upperBound.equals( restriction.upperBound ) )
            {
                return false;
            }
        }
        else if ( restriction.upperBound != null )
        {
            return false;
        }

        if ( upperBoundInclusive != restriction.upperBoundInclusive )
        {
            return false;
        }

        return true;
    }

    public String toString()
    {
        StringBuilder buf = new StringBuilder();

        buf.append( isLowerBoundInclusive() ? "[" : "(" );
        if ( getLowerBound() != null )
        {
            buf.append( getLowerBound().toString() );
        }
        buf.append( "," );
        if ( getUpperBound() != null )
        {
            buf.append( getUpperBound().toString() );
        }
        buf.append( isUpperBoundInclusive() ? "]" : ")" );

        return buf.toString();
    }
}
