/*
 * Copyright 2002-2020 the original author or authors.
 *
 * Licensed 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
 *
 *      https://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.
 */

package example;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.zip.Deflater;
import java.util.zip.DeflaterOutputStream;
import java.util.zip.Inflater;
import java.util.zip.InflaterOutputStream;

import org.apache.commons.codec.binary.Base64;

import org.springframework.security.saml2.Saml2Exception;

/**
 * @since 5.3
 */
final class Saml2Utils {

	private static Base64 BASE64 = new Base64(0, new byte[] { '\n' });

	private Saml2Utils() {
	}

	static String samlEncode(byte[] b) {
		return BASE64.encodeAsString(b);
	}

	static byte[] samlDecode(String s) {
		return BASE64.decode(s);
	}

	static byte[] samlDeflate(String s) {
		try {
			ByteArrayOutputStream b = new ByteArrayOutputStream();
			DeflaterOutputStream deflater = new DeflaterOutputStream(b, new Deflater(Deflater.DEFLATED, true));
			deflater.write(s.getBytes(StandardCharsets.UTF_8));
			deflater.finish();
			return b.toByteArray();
		}
		catch (IOException ex) {
			throw new Saml2Exception("Unable to deflate string", ex);
		}
	}

	static String samlInflate(byte[] b) {
		try {
			ByteArrayOutputStream out = new ByteArrayOutputStream();
			InflaterOutputStream iout = new InflaterOutputStream(out, new Inflater(true));
			iout.write(b);
			iout.finish();
			return new String(out.toByteArray(), StandardCharsets.UTF_8);
		}
		catch (IOException ex) {
			throw new Saml2Exception("Unable to inflate string", ex);
		}
	}

}
