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 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
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 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
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package gov.samhsa.acs.brms.guvnor;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

import javax.ws.rs.core.MediaType;

import org.apache.commons.codec.binary.Base64;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * The Class GuvnorServiceImpl.
 */
public class GuvnorServiceImpl implements GuvnorService {

	/** The logger. */
	private final Logger logger = LoggerFactory.getLogger(this.getClass());

	/** The endpoint address. */
	private final String endpointAddress;

	/** The guvnor service username. */
	private final String guvnorServiceUsername;

	/** The guvnor service password. */
	private final String guvnorServicePassword;

	/**
	 * Instantiates a new clinically adaptive rules implementation.
	 *
	 * @param endpointAddress
	 *            the endpoint address
	 * @param guvnorServiceUsername
	 *            the guvnor service username
	 * @param guvnorServicePassword
	 *            the guvnor service password
	 */
	public GuvnorServiceImpl(String endpointAddress,
			String guvnorServiceUsername, String guvnorServicePassword) {
		this.endpointAddress = endpointAddress;
		this.guvnorServiceUsername = guvnorServiceUsername;
		this.guvnorServicePassword = guvnorServicePassword;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * gov.samhsa.consent2share.accesscontrolservices.brms.RuleExecutionService
	 * #getVersionedRulesFromPackage()
	 */
	@Override
	public String getVersionedRulesFromPackage() throws IOException {
		String source = null;

		final HttpURLConnection connection = openConnection(this.endpointAddress);

		connection.setRequestMethod("GET");
		connection.setRequestProperty("Accept", MediaType.TEXT_PLAIN);
		final StringBuilder passwordStringBuilder = new StringBuilder();
		passwordStringBuilder.append(guvnorServiceUsername);
		passwordStringBuilder.append(":");
		passwordStringBuilder.append(guvnorServicePassword);
		final String passwordString = passwordStringBuilder.toString();
		final StringBuilder propertyStringBuilder = new StringBuilder();
		propertyStringBuilder.append("Basic ");
		propertyStringBuilder.append(new Base64().encodeToString(passwordString
				.getBytes()));
		connection.setRequestProperty("Authorization",
				propertyStringBuilder.toString());
		connection.connect();

		source = readAsString(connection.getInputStream());
		logger.debug("DRL source: " + source);

		return source;
	}

	/**
	 * Open connection.
	 *
	 * @param endpointAddress
	 *            the endpoint address
	 * @return the http url connection
	 * @throws IOException
	 *             Signals that an I/O exception has occurred.
	 */
	HttpURLConnection openConnection(String endpointAddress) throws IOException {
		final URL url = new URL(endpointAddress);
		final HttpURLConnection connection = (HttpURLConnection) url
				.openConnection();
		return connection;
	}

	/**
	 * Read as string.
	 *
	 * @param inputStream
	 *            the input stream
	 * @return the string
	 * @throws IOException
	 *             Signals that an I/O exception has occurred.
	 */
	private String readAsString(InputStream inputStream) throws IOException {
		final StringBuffer ret = new StringBuffer();
		final BufferedReader reader = new BufferedReader(new InputStreamReader(
				inputStream));
		String line;
		while ((line = reader.readLine()) != null) {
			final StringBuilder builder = new StringBuilder();
			builder.append(line);
			builder.append("\n");
			ret.append(builder.toString());
		}
		return ret.toString();
	}

}