<?xml version='1.0' encoding='utf-8'?>
<Context>
	<Realm className="fr.ms.raspberry.openremote.controller.catalina.realm.ControllerAuthRealm"/>
</Context>

<?xml version='1.0' encoding='utf-8'?>
<Context>
	<Realm className="fr.ms.raspberry.openremote.controller.catalina.realm.ControllerAuthRealm" urlRestBeehive=""http://localhost:8080/beehive/rest/super/"/>
</Context>

package fr.ms.raspberry.openremote.controller.catalina.realm;

import java.net.ConnectException;
import java.net.HttpURLConnection;
import java.net.URI;
import java.net.URL;
import java.net.URLConnection;
import java.security.MessageDigest;
import java.security.Principal;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.catalina.realm.GenericPrincipal;
import org.apache.catalina.realm.RealmBase;
import org.apache.catalina.util.Base64;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;

public class ControllerAuthRealm extends RealmBase
{

    private static Log log = LogFactory.getLog(ControllerAuthRealm.class);

    private static final String NAME = "ControllerAuthRealm";

    private static final String ROLE = "openremote";

    private final Map<String, Principal> principals = Collections
            .synchronizedMap(new HashMap<String, Principal>());

    private String urlRestBeehive = "http://localhost:8080/beehive/rest/";

    @Override
    protected String getName()
    {
        return NAME;
    }

    @Override
    protected String getPassword(String username)
    {
        username = username.trim();

        final GenericPrincipal principal = (GenericPrincipal) principals
                .get(username);

        if (principal != null)
        {
            return principal.getPassword();
        }
        else
        {
            return null;
        }
    }

    @Override
    protected Principal getPrincipal(String username)
    {
        username = username.trim();

        return principals.get(username);
    }

    @Override
    public Principal authenticate(String username, String credentials)
    {
        username = username.trim();
        credentials = credentials.trim();

        Principal principal = getPrincipal(username);

        if (principal == null)
        {
            synchronized (this) {
                if (principal == null)
                {
                    principal = checkUser(username, credentials);
                    if (principal != null)
                    {
                        log.info("Ajout d'un nouvel utilisateur : " + username);
                        principals.put(username, principal);
                    }
                }
            }
        }
        return principal;
    }

    public final static String HTTP_AUTHORIZATION_HEADER = "Authorization";

    public final static String HTTP_BASIC_AUTHORIZATION = "Basic ";

    private final static String BEEHIVE_REST_USER_DIR = "user";

    private final static String BEEHIVE_REST_OPENREMOTE_ZIP = "openremote.zip";

    private Principal checkUser(final String username, final String password)
    {
        log.info("username : " + username + " - password : " + password);
        if (username.length() == 0 || password.length() == 0)
        {
            return null;
        }

        try
        {
            final String httpURI = BEEHIVE_REST_USER_DIR + "/" + username + "/"
                    + BEEHIVE_REST_OPENREMOTE_ZIP;

            final URL beehiveBaseURL = new URL(urlRestBeehive);
            final URI beehiveUserURI = beehiveBaseURL.toURI().resolve(httpURI);

            log.info("url : " + beehiveUserURI);
            final URLConnection connection = beehiveUserURI.toURL()
                    .openConnection();

            if (!(connection instanceof HttpURLConnection))
            {
                throw new ConnectException("The ''" + BEEHIVE_REST_USER_DIR
                        + "'' property ''" + urlRestBeehive
                        + "'' must be a URL with http:// schema.");
            }

            final HttpURLConnection http = (HttpURLConnection) connection;

            http.setDoInput(true);
            http.setRequestMethod("GET");

            final String encodePassword = encode(username, password);
            final String authString = username + ":" + encodePassword;
            final byte[] authEncBytes = Base64.encode(authString.getBytes());

            final String basicAuthn = new String(authEncBytes);
            http.addRequestProperty(HTTP_AUTHORIZATION_HEADER,
                    HTTP_BASIC_AUTHORIZATION + basicAuthn);

            http.connect();

            final int response = http.getResponseCode();

            log.info("Http Code Beehive : " + response);

            switch (response)
            {
            case HttpURLConnection.HTTP_OK:
                final List<String> roles = new ArrayList<String>();
                roles.add(ROLE);
                final GenericPrincipal principal = new GenericPrincipal(
                        this, username, password, roles);
                return principal;
            }

            return null;
        } catch (final Exception e)
        {
            throw new RuntimeException(e);
        }
    }

    private static String encode(final String username, final String password)
    {
        final String concat = password + "{" + username + "}";
        final String md5Hex = MD5Hex(concat);
        return md5Hex;
    }

    public static String MD5Hex(final String s)
    {
        String result = null;
        try
        {
            final MessageDigest md5 = MessageDigest.getInstance("MD5");
            final byte[] digest = md5.digest(s.getBytes("UTF-8"));
            result = toHex(digest);
        } catch (final Exception e)
        {
            throw new RuntimeException(e);
        }
        return result;
    }

    public static String toHex(final byte[] a)
    {
        final StringBuilder sb = new StringBuilder(a.length * 2);
        for (final byte element : a)
        {
            sb.append(Character.forDigit((element & 0xf0) >> 4, 16));
            sb.append(Character.forDigit(element & 0x0f, 16));
        }
        return sb.toString();
    }

    public void setUrlRestBeehive(final String urlRestBeehive) {
        this.urlRestBeehive = urlRestBeehive;
    }
}