/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2010, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.type.descriptor.java;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.sql.Blob;
import java.sql.SQLException;
import java.util.Arrays;

import org.hibernate.HibernateException;
import org.hibernate.type.descriptor.BinaryStream;
import org.hibernate.type.descriptor.WrapperOptions;

/**
 * Descriptor for {@code byte[]} handling.
 *
 * @author Steve Ebersole
 */
public class PrimitiveByteArrayTypeDescriptor extends AbstractTypeDescriptor<byte[]> {
	public static final PrimitiveByteArrayTypeDescriptor INSTANCE = new PrimitiveByteArrayTypeDescriptor();

	@SuppressWarnings({ "unchecked" })
	public PrimitiveByteArrayTypeDescriptor() {
		super( byte[].class, ArrayMutabilityPlan.INSTANCE );
	}

	@Override
	public boolean areEqual(byte[] one, byte[] another) {
		return one == another 
				|| ( one != null && another != null && Arrays.equals( one, another ) );
	}

	@Override
	public int extractHashCode(byte[] bytes) {
		int hashCode = 1;
		for ( byte aByte : bytes ) {
			hashCode = 31 * hashCode + aByte;
		}
		return hashCode;
	}

	public String toString(byte[] bytes) {
		final StringBuffer buf = new StringBuffer();
		for ( byte aByte : bytes ) {
			final String hexStr = Integer.toHexString( aByte - Byte.MIN_VALUE );
			if ( hexStr.length() == 1 ) {
				buf.append( '0' );
			}
			buf.append( hexStr );
		}
		return buf.toString();
	}

	public byte[] fromString(String string) {
		if ( string == null ) {
			return null;
		}
		if ( string.length() % 2 != 0 ) {
			throw new IllegalArgumentException( "The string is not a valid string representation of a binary content." );
		}
		byte[] bytes = new byte[string.length() / 2];
		for ( int i = 0; i < bytes.length; i++ ) {
			final String hexStr = string.substring( i * 2, (i + 1) * 2 );
			bytes[i] = (byte) (Integer.parseInt(hexStr, 16) + Byte.MIN_VALUE);
		}
		return bytes;
	}

	@SuppressWarnings({ "unchecked" })
	public <X> X unwrap(byte[] value, Class<X> type, WrapperOptions options) {
		if ( value == null ) {
			return null;
		}
		if ( byte[].class.isAssignableFrom( type ) ) {
			return (X) value;
		}
		if ( InputStream.class.isAssignableFrom( type ) ) {
			return (X) new ByteArrayInputStream( value );
		}
		if ( BinaryStream.class.isAssignableFrom( type ) ) {
			return (X) new BinaryStreamImpl( value );
		}
		if ( Blob.class.isAssignableFrom( type ) ) {
			return (X) options.getLobCreator().createBlob( value );
		}

		throw unknownUnwrap( type );
	}

	public <X> byte[] wrap(X value, WrapperOptions options) {
		if ( value == null ) {
			return null;
		}
		if ( byte[].class.isInstance( value ) ) {
			return (byte[]) value;
		}
		if ( InputStream.class.isInstance( value ) ) {
			return DataHelper.extractBytes( (InputStream) value );
		}
		if ( Blob.class.isInstance( value ) || DataHelper.isNClob( value.getClass() ) ) {
			try {
				return DataHelper.extractBytes( ( (Blob) value ).getBinaryStream() );
			}
			catch ( SQLException e ) {
				throw new HibernateException( "Unable to access lob stream", e );
			}
		}

		throw unknownWrap( value.getClass() );
	}
}