package org.keycloak.protocol.oidc;

import org.jboss.logging.Logger;
import org.jboss.resteasy.annotations.cache.NoCache;
import org.jboss.resteasy.specimpl.MultivaluedMapImpl;
import org.jboss.resteasy.spi.BadRequestException;
import org.jboss.resteasy.spi.HttpRequest;
import org.jboss.resteasy.spi.HttpResponse;
import org.jboss.resteasy.spi.NotAcceptableException;
import org.jboss.resteasy.spi.NotFoundException;
import org.jboss.resteasy.spi.ResteasyProviderFactory;
import org.jboss.resteasy.spi.UnauthorizedException;
import org.keycloak.ClientConnection;
import org.keycloak.Config;
import org.keycloak.OAuth2Constants;
import org.keycloak.OAuthErrorException;
import org.keycloak.RSATokenVerifier;
import org.keycloak.constants.AdapterConstants;
import org.keycloak.events.Details;
import org.keycloak.events.Errors;
import org.keycloak.events.EventBuilder;
import org.keycloak.events.EventType;
import org.keycloak.login.LoginFormsProvider;
import org.keycloak.models.ApplicationModel;
import org.keycloak.models.ClientModel;
import org.keycloak.models.ClientSessionModel;
import org.keycloak.models.Constants;
import org.keycloak.models.IdentityProviderModel;
import org.keycloak.models.KeycloakSession;
import org.keycloak.models.OAuthClientModel;
import org.keycloak.models.RealmModel;
import org.keycloak.models.RequiredCredentialModel;
import org.keycloak.models.UserModel;
import org.keycloak.models.UserSessionModel;
import org.keycloak.models.UserSessionProvider;
import org.keycloak.models.utils.KeycloakModelUtils;
import org.keycloak.representations.AccessToken;
import org.keycloak.representations.AccessTokenResponse;
import org.keycloak.representations.RefreshToken;
import org.keycloak.services.ForbiddenException;
import org.keycloak.services.managers.AuthenticationManager;
import org.keycloak.services.managers.AuthenticationManager.AuthenticationStatus;
import org.keycloak.services.managers.ClientSessionCode;
import org.keycloak.services.managers.HttpAuthenticationManager;
import org.keycloak.services.resources.Cors;
import org.keycloak.services.resources.RealmsResource;
import org.keycloak.services.resources.flows.Flows;
import org.keycloak.services.resources.flows.Urls;
import org.keycloak.util.BasicAuthHelper;
import org.keycloak.util.StreamUtil;
import org.keycloak.util.UriUtils;

import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.HeaderParam;
import javax.ws.rs.OPTIONS;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.CacheControl;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.SecurityContext;
import javax.ws.rs.core.UriBuilder;
import javax.ws.rs.core.UriInfo;
import javax.ws.rs.ext.Providers;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import static org.keycloak.constants.AdapterConstants.K_IDP_HINT;

/**
 * Resource class for the oauth/openid connect token service
 *
 * @author <a href="mailto:bill@burkecentral.com">Bill Burke</a>
 * @version $Revision: 1 $
 */
public class OIDCLoginProtocolService {

    protected static final Logger logger = Logger.getLogger(OIDCLoginProtocolService.class);

    protected RealmModel realm;
    protected TokenManager tokenManager;
    private EventBuilder event;
    protected AuthenticationManager authManager;

    @Context
    protected Providers providers;
    @Context
    protected SecurityContext securityContext;
    @Context
    protected UriInfo uriInfo;
    @Context
    protected HttpHeaders headers;
    @Context
    protected HttpRequest request;
    @Context
    protected HttpResponse response;
    @Context
    protected KeycloakSession session;
    @Context
    protected ClientConnection clientConnection;

    /*
    @Context
    protected ResourceContext resourceContext;
    */

    public OIDCLoginProtocolService(RealmModel realm, EventBuilder event, AuthenticationManager authManager) {
        this.realm = realm;
        this.tokenManager = new TokenManager();
        this.event = event;
        this.authManager = authManager;
    }

    public static UriBuilder tokenServiceBaseUrl(UriInfo uriInfo) {
        UriBuilder baseUriBuilder = uriInfo.getBaseUriBuilder();
        return tokenServiceBaseUrl(baseUriBuilder);
    }

    public static UriBuilder tokenServiceBaseUrl(UriBuilder baseUriBuilder) {
        return baseUriBuilder.path(RealmsResource.class).path("{realm}/protocol/" + OIDCLoginProtocol.LOGIN_PROTOCOL);
    }

    public static UriBuilder accessCodeToTokenUrl(UriInfo uriInfo) {
        UriBuilder baseUriBuilder = uriInfo.getBaseUriBuilder();
        return accessCodeToTokenUrl(baseUriBuilder);

    }

    public static UriBuilder accessCodeToTokenUrl(UriBuilder baseUriBuilder) {
        UriBuilder uriBuilder = tokenServiceBaseUrl(baseUriBuilder);
        return uriBuilder.path(OIDCLoginProtocolService.class, "accessCodeToToken");
    }

    public static UriBuilder validateAccessTokenUrl(UriBuilder baseUriBuilder) {
        UriBuilder uriBuilder = tokenServiceBaseUrl(baseUriBuilder);
        return uriBuilder.path(OIDCLoginProtocolService.class, "validateAccessToken");
    }

    public static UriBuilder grantAccessTokenUrl(UriInfo uriInfo) {
        UriBuilder baseUriBuilder = uriInfo.getBaseUriBuilder();
        return grantAccessTokenUrl(baseUriBuilder);

    }

    public static UriBuilder grantAccessTokenUrl(UriBuilder baseUriBuilder) {
        UriBuilder uriBuilder = tokenServiceBaseUrl(baseUriBuilder);
        return uriBuilder.path(OIDCLoginProtocolService.class, "grantAccessToken");
    }

    public static UriBuilder loginPageUrl(UriInfo uriInfo) {
        UriBuilder baseUriBuilder = uriInfo.getBaseUriBuilder();
        return loginPageUrl(baseUriBuilder);
    }

    public static UriBuilder loginPageUrl(UriBuilder baseUriBuilder) {
        UriBuilder uriBuilder = tokenServiceBaseUrl(baseUriBuilder);
        return uriBuilder.path(OIDCLoginProtocolService.class, "loginPage");
    }

    public static UriBuilder logoutUrl(UriInfo uriInfo) {
        UriBuilder baseUriBuilder = uriInfo.getBaseUriBuilder();
        return logoutUrl(baseUriBuilder);
    }

    public static UriBuilder logoutUrl(UriBuilder baseUriBuilder) {
        UriBuilder uriBuilder = tokenServiceBaseUrl(baseUriBuilder);
        return uriBuilder.path(OIDCLoginProtocolService.class, "logout");
    }

    public static UriBuilder refreshUrl(UriBuilder baseUriBuilder) {
        UriBuilder uriBuilder = tokenServiceBaseUrl(baseUriBuilder);
        return uriBuilder.path(OIDCLoginProtocolService.class, "refreshAccessToken");
    }

    /**
     *
     *
     * @param client_id
     * @param origin
     * @return
     */
    @Path("login-status-iframe.html")
    @GET
    @Produces(MediaType.TEXT_HTML)
    public Response getLoginStatusIframe(@QueryParam("client_id") String client_id,
                                         @QueryParam("origin") String origin) {
        if (!UriUtils.isOrigin(origin)) {
            throw new BadRequestException("Invalid origin");
        }

        ClientModel client = realm.findClient(client_id);
        if (client == null) {
            throw new NotFoundException("could not find client");
        }

        InputStream is = getClass().getClassLoader().getResourceAsStream("login-status-iframe.html");
        if (is == null) throw new NotFoundException("Could not find login-status-iframe.html ");

        boolean valid = false;
        for (String o : client.getWebOrigins()) {
            if (o.equals("*") || o.equals(origin)) {
                valid = true;
                break;
            }
        }

        for (String r : OIDCLoginProtocolService.resolveValidRedirects(uriInfo, client.getRedirectUris())) {
            int i = r.indexOf('/', 8);
            if (i != -1) {
                r = r.substring(0, i);
            }

            if (r.equals(origin)) {
                valid = true;
                break;
            }
        }

        if (!valid) {
            throw new BadRequestException("Invalid origin");
        }

        try {
            String file = StreamUtil.readString(is);
            file = file.replace("ORIGIN", origin);

            CacheControl cacheControl = new CacheControl();
            cacheControl.setNoTransform(false);
            cacheControl.setMaxAge(Config.scope("theme").getInt("staticMaxAge", -1));

            return Response.ok(file).cacheControl(cacheControl).build();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }


    /**
     * Direct grant REST invocation.  One stop call to obtain an access token.
     *
     * If the client is a confidential client
     * you must include the client-id (application name or oauth client name) and secret in an Basic Auth Authorization header.
     *
     * If the client is a public client, then you must include a "client_id" form parameter with the app's or oauth client's name.
     *
     * The realm must be configured to allow these types of auth requests.  (Direct Grant API in admin console Settings page)
     *
     *
     * @See  <a href="http://tools.ietf.org/html/rfc6749#section-4.3">http://tools.ietf.org/html/rfc6749#section-4.3</a>
     *
     * @param authorizationHeader
     * @param form
     * @return @see org.keycloak.representations.AccessTokenResponse
     */
    @Path("grants/access")
    @POST
    @Consumes(MediaType.APPLICATION_FORM_URLENCODED)
    @Produces(MediaType.APPLICATION_JSON)
    public Response grantAccessToken(final @HeaderParam(HttpHeaders.AUTHORIZATION) String authorizationHeader,
                                     final MultivaluedMap<String, String> form) {
        if (!checkSsl()) {
            return createError("https_required", "HTTPS required", Response.Status.FORBIDDEN);
        }

        if (!realm.isPasswordCredentialGrantAllowed()) {
            return createError("not_enabled", "Direct Grant REST API not enabled", Response.Status.FORBIDDEN);
        }

        event.event(EventType.LOGIN).detail(Details.AUTH_METHOD, "oauth_credentials").detail(Details.RESPONSE_TYPE, "token");

        String username = form.getFirst(AuthenticationManager.FORM_USERNAME);
        if (username == null) {
            event.error(Errors.USERNAME_MISSING);
            throw new UnauthorizedException("No username");
        }
        event.detail(Details.USERNAME, username);

        UserModel user = KeycloakModelUtils.findUserByNameOrEmail(session, realm, username);
        if (user != null) event.user(user);

        ClientModel client = authorizeClient(authorizationHeader, form, event);

        if (!realm.isEnabled()) {
            event.error(Errors.REALM_DISABLED);
            return createError("realm_disabled", "Realm is disabled", Response.Status.UNAUTHORIZED);
        }

        AuthenticationStatus authenticationStatus = authManager.authenticateForm(session, clientConnection, realm, form);
        Map<String, String> err;

        switch (authenticationStatus) {
            case SUCCESS:
                break;
            case ACCOUNT_TEMPORARILY_DISABLED:
            case ACTIONS_REQUIRED:
                err = new HashMap<String, String>();
                err.put(OAuth2Constants.ERROR, "invalid_grant");
                err.put(OAuth2Constants.ERROR_DESCRIPTION, "AccountProvider temporarily disabled");
                event.error(Errors.USER_TEMPORARILY_DISABLED);
                return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(err)
                        .build();
            case ACCOUNT_DISABLED:
                err = new HashMap<String, String>();
                err.put(OAuth2Constants.ERROR, "invalid_grant");
                err.put(OAuth2Constants.ERROR_DESCRIPTION, "AccountProvider disabled");
                event.error(Errors.USER_DISABLED);
                return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(err)
                        .build();
            default:
                err = new HashMap<String, String>();
                err.put(OAuth2Constants.ERROR, "invalid_grant");
                err.put(OAuth2Constants.ERROR_DESCRIPTION, "Invalid user credentials");
                event.error(Errors.INVALID_USER_CREDENTIALS);
                return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(err)
                        .build();
        }

        String scope = form.getFirst(OAuth2Constants.SCOPE);

        UserSessionProvider sessions = session.sessions();

        UserSessionModel userSession = sessions.createUserSession(realm, user, username, clientConnection.getRemoteAddr(), "oauth_credentials", false);
        event.session(userSession);

        ClientSessionModel clientSession = sessions.createClientSession(realm, client);
        clientSession.setAuthMethod(OIDCLoginProtocol.LOGIN_PROTOCOL);

        TokenManager.attachClientSession(userSession, clientSession);

        AccessTokenResponse res = tokenManager.responseBuilder(realm, client, event, session, userSession, clientSession)
                .generateAccessToken(session, scope, client, user, userSession, clientSession)
                .generateRefreshToken()
                .generateIDToken()
                .build();

        event.success();

        return Response.ok(res, MediaType.APPLICATION_JSON_TYPE).build();
    }

    /**
     * Validate encoded access token.
     *
     * @param tokenString
     * @return Unmarshalled token
     */
    @Path("validate")
    @GET
    @NoCache
    @Produces(MediaType.APPLICATION_JSON)
    public Response validateAccessToken(@QueryParam("access_token") String tokenString) {
        if (!checkSsl()) {
            return createError("https_required", "HTTPS required", Response.Status.FORBIDDEN);
        }
        event.event(EventType.VALIDATE_ACCESS_TOKEN);
        AccessToken token = null;
        try {
            token = RSATokenVerifier.verifyToken(tokenString, realm.getPublicKey(), realm.getName());
        } catch (Exception e) {
            Map<String, String> err = new HashMap<String, String>();
            err.put(OAuth2Constants.ERROR, OAuthErrorException.INVALID_GRANT);
            err.put(OAuth2Constants.ERROR_DESCRIPTION, "Token invalid");
            event.error(Errors.INVALID_TOKEN);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(err)
                    .build();
        }
        event.user(token.getSubject()).session(token.getSessionState()).detail(Details.VALIDATE_ACCESS_TOKEN, token.getId());

        if (token.isExpired()
                || token.getIssuedAt() < realm.getNotBefore()
                ) {
            Map<String, String> err = new HashMap<String, String>();
            err.put(OAuth2Constants.ERROR, OAuthErrorException.INVALID_GRANT);
            err.put(OAuth2Constants.ERROR_DESCRIPTION, "Token expired");
            event.error(Errors.INVALID_TOKEN);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(err)
                    .build();
        }


        UserModel user = session.users().getUserById(token.getSubject(), realm);
        if (user == null) {
            Map<String, String> err = new HashMap<String, String>();
            err.put(OAuth2Constants.ERROR, OAuthErrorException.INVALID_GRANT);
            err.put(OAuth2Constants.ERROR_DESCRIPTION, "User does not exist");
            event.error(Errors.USER_NOT_FOUND);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(err)
                    .build();
        }

        if (!user.isEnabled()) {
            Map<String, String> err = new HashMap<String, String>();
            err.put(OAuth2Constants.ERROR, OAuthErrorException.INVALID_GRANT);
            err.put(OAuth2Constants.ERROR_DESCRIPTION, "User disabled");
            event.error(Errors.USER_DISABLED);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(err)
                    .build();
        }

        UserSessionModel userSession = session.sessions().getUserSession(realm, token.getSessionState());
        if (!AuthenticationManager.isSessionValid(realm, userSession)) {
            Map<String, String> err = new HashMap<String, String>();
            err.put(OAuth2Constants.ERROR, OAuthErrorException.INVALID_GRANT);
            err.put(OAuth2Constants.ERROR_DESCRIPTION, "Expired session");
            event.error(Errors.USER_SESSION_NOT_FOUND);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(err)
                    .build();
        }

        ClientModel client = realm.findClient(token.getIssuedFor());
        if (client == null) {
            Map<String, String> err = new HashMap<String, String>();
            err.put(OAuth2Constants.ERROR, OAuthErrorException.INVALID_CLIENT);
            err.put(OAuth2Constants.ERROR_DESCRIPTION, "Issued for client no longer exists");
            event.error(Errors.CLIENT_NOT_FOUND);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(err)
                    .build();

        }

        if (token.getIssuedAt() < client.getNotBefore()) {
            Map<String, String> err = new HashMap<String, String>();
            err.put(OAuth2Constants.ERROR, OAuthErrorException.INVALID_CLIENT);
            err.put(OAuth2Constants.ERROR_DESCRIPTION, "Issued for client no longer exists");
            event.error(Errors.INVALID_TOKEN);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(err)
                    .build();
        }

        try {
            tokenManager.verifyAccess(token, realm, client, user);
        } catch (OAuthErrorException e) {
            Map<String, String> err = new HashMap<String, String>();
            err.put(OAuth2Constants.ERROR, OAuthErrorException.INVALID_SCOPE);
            err.put(OAuth2Constants.ERROR_DESCRIPTION, "Role mappings have changed");
            event.error(Errors.INVALID_TOKEN);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(err)
                    .build();

        }

        event.success();

        return Response.ok(token, MediaType.APPLICATION_JSON_TYPE).build();
    }

    /**
     * CORS preflight path for refresh token requests
     *
     * @return
     */
    @Path("refresh")
    @OPTIONS
    @Produces(MediaType.APPLICATION_JSON)
    public Response refreshAccessTokenPreflight() {
        if (logger.isDebugEnabled()) {
            logger.debugv("cors request from: {0}", request.getHttpHeaders().getRequestHeaders().getFirst("Origin"));
        }
        return Cors.add(request, Response.ok()).auth().preflight().build();
    }

    /**
     * URL for making refresh token requests.
     *
     * @See <a href="http://tools.ietf.org/html/rfc6749#section-6">http://tools.ietf.org/html/rfc6749#section-6</a>
     *
     * If the client is a confidential client
     * you must include the client-id (application name or oauth client name) and secret in an Basic Auth Authorization header.
     *
     * If the client is a public client, then you must include a "client_id" form parameter with the app's or oauth client's name.
     *
     * @param authorizationHeader
     * @param form
     * @return
     */
    @Path("refresh")
    @POST
    @Consumes(MediaType.APPLICATION_FORM_URLENCODED)
    @Produces(MediaType.APPLICATION_JSON)
    public Response refreshAccessToken(final @HeaderParam(HttpHeaders.AUTHORIZATION) String authorizationHeader,
                                       final MultivaluedMap<String, String> form) {
        if (!checkSsl()) {
            return createError("https_required", "HTTPS required", Response.Status.FORBIDDEN);
        }

        event.event(EventType.REFRESH_TOKEN);

        ClientModel client = authorizeClient(authorizationHeader, form, event);
        String refreshToken = form.getFirst(OAuth2Constants.REFRESH_TOKEN);
        if (refreshToken == null) {
            Map<String, String> error = new HashMap<String, String>();
            error.put(OAuth2Constants.ERROR, OAuthErrorException.INVALID_REQUEST);
            error.put(OAuth2Constants.ERROR_DESCRIPTION, "No refresh token");
            event.error(Errors.INVALID_TOKEN);
            return Response.status(Response.Status.BAD_REQUEST).entity(error).type("application/json").build();
        }
        AccessTokenResponse res;
        try {
            res = tokenManager.refreshAccessToken(session, uriInfo, clientConnection, realm, client, refreshToken, event);
        } catch (OAuthErrorException e) {
            Map<String, String> error = new HashMap<String, String>();
            error.put(OAuth2Constants.ERROR, e.getError());
            if (e.getDescription() != null) error.put(OAuth2Constants.ERROR_DESCRIPTION, e.getDescription());
            event.error(Errors.INVALID_TOKEN);
            return Response.status(Response.Status.BAD_REQUEST).entity(error).type("application/json").build();
        }


        event.success();

        return Cors.add(request, Response.ok(res, MediaType.APPLICATION_JSON_TYPE)).auth().allowedOrigins(client).allowedMethods("POST").exposedHeaders(Cors.ACCESS_CONTROL_ALLOW_METHODS).build();
    }

    /**
     * CORS preflight path for access code to token
     *
     * @return
     */
    @Path("access/codes")
    @OPTIONS
    @Produces("application/json")
    public Response accessCodeToTokenPreflight() {
        if (logger.isDebugEnabled()) {
            logger.debugv("cors request from: {0}", request.getHttpHeaders().getRequestHeaders().getFirst("Origin"));
        }
        return Cors.add(request, Response.ok()).auth().preflight().build();
    }

    /**
     * URL invoked by adapter to turn an access code to access token
     *
     * @See <a href="http://tools.ietf.org/html/rfc6749#section-4.1">http://tools.ietf.org/html/rfc6749#section-4.1</a>
     *
     * @param authorizationHeader
     * @param formData
     * @return
     */
    @Path("access/codes")
    @POST
    @Produces("application/json")
    public Response accessCodeToToken(@HeaderParam(HttpHeaders.AUTHORIZATION) String authorizationHeader, final MultivaluedMap<String, String> formData) {
        if (!checkSsl()) {
            throw new ForbiddenException("HTTPS required");
        }

        event.event(EventType.CODE_TO_TOKEN);

        if (!realm.isEnabled()) {
            event.error(Errors.REALM_DISABLED);
            throw new UnauthorizedException("Realm not enabled");
        }

        String code = formData.getFirst(OAuth2Constants.CODE);
        if (code == null) {
            Map<String, String> error = new HashMap<String, String>();
            error.put(OAuth2Constants.ERROR, "invalid_request");
            error.put(OAuth2Constants.ERROR_DESCRIPTION, "code not specified");
            event.error(Errors.INVALID_CODE);
            throw new BadRequestException("Code not specified", Response.status(Response.Status.BAD_REQUEST).entity(error).type("application/json").build());
        }
        ClientSessionCode accessCode = ClientSessionCode.parse(code, session, realm);
        if (accessCode == null) {
            String[] parts = code.split("\\.");
            if (parts.length == 2) {
                try {
                    event.detail(Details.CODE_ID, new String(parts[1]));
                } catch (Throwable t) {
                }
            }
            Map<String, String> res = new HashMap<String, String>();
            res.put(OAuth2Constants.ERROR, "invalid_grant");
            res.put(OAuth2Constants.ERROR_DESCRIPTION, "Code not found");
            event.error(Errors.INVALID_CODE);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(res)
                    .build();
        }

        ClientSessionModel clientSession = accessCode.getClientSession();
        event.detail(Details.CODE_ID, clientSession.getId());
        if (!accessCode.isValid(ClientSessionModel.Action.CODE_TO_TOKEN)) {
            Map<String, String> res = new HashMap<String, String>();
            res.put(OAuth2Constants.ERROR, "invalid_grant");
            res.put(OAuth2Constants.ERROR_DESCRIPTION, "Code is expired");
            event.error(Errors.INVALID_CODE);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(res)
                    .build();
        }

        accessCode.setAction(null);
        UserSessionModel userSession = clientSession.getUserSession();
        event.user(userSession.getUser());
        event.session(userSession.getId());

        ClientModel client = authorizeClient(authorizationHeader, formData, event);

        String redirectUri = clientSession.getNote(OIDCLoginProtocol.REDIRECT_URI_PARAM);
        if (redirectUri != null && !redirectUri.equals(formData.getFirst(OAuth2Constants.REDIRECT_URI))) {
            Map<String, String> res = new HashMap<String, String>();
            res.put(OAuth2Constants.ERROR, "invalid_grant");
            res.put(OAuth2Constants.ERROR_DESCRIPTION, "Incorrect redirect_uri");
            event.error(Errors.INVALID_CODE);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(res)
                    .build();
        }

        if (!client.getClientId().equals(clientSession.getClient().getClientId())) {
            Map<String, String> res = new HashMap<String, String>();
            res.put(OAuth2Constants.ERROR, "invalid_grant");
            res.put(OAuth2Constants.ERROR_DESCRIPTION, "Auth error");
            event.error(Errors.INVALID_CODE);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(res)
                    .build();
        }

        UserModel user = session.users().getUserById(userSession.getUser().getId(), realm);
        if (user == null) {
            Map<String, String> res = new HashMap<String, String>();
            res.put(OAuth2Constants.ERROR, "invalid_grant");
            res.put(OAuth2Constants.ERROR_DESCRIPTION, "User not found");
            event.error(Errors.INVALID_CODE);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(res)
                    .build();
        }

        if (!user.isEnabled()) {
            Map<String, String> res = new HashMap<String, String>();
            res.put(OAuth2Constants.ERROR, "invalid_grant");
            res.put(OAuth2Constants.ERROR_DESCRIPTION, "User disabled");
            event.error(Errors.INVALID_CODE);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(res)
                    .build();
        }

        if (!AuthenticationManager.isSessionValid(realm, userSession)) {
            AuthenticationManager.logout(session, realm, userSession, uriInfo, clientConnection);
            Map<String, String> res = new HashMap<String, String>();
            res.put(OAuth2Constants.ERROR, "invalid_grant");
            res.put(OAuth2Constants.ERROR_DESCRIPTION, "Session not active");
            event.error(Errors.INVALID_CODE);
            return Response.status(Response.Status.BAD_REQUEST).type(MediaType.APPLICATION_JSON_TYPE).entity(res)
                    .build();
        }

        String adapterSessionId = formData.getFirst(AdapterConstants.APPLICATION_SESSION_STATE);
        if (adapterSessionId != null) {
            String adapterSessionHost = formData.getFirst(AdapterConstants.APPLICATION_SESSION_HOST);
            logger.debugf("Adapter Session '%s' saved in ClientSession for client '%s'. Host is '%s'", adapterSessionId, client.getClientId(), adapterSessionHost);

            event.detail(AdapterConstants.APPLICATION_SESSION_STATE, adapterSessionId);
            clientSession.setNote(AdapterConstants.APPLICATION_SESSION_STATE, adapterSessionId);
            event.detail(AdapterConstants.APPLICATION_SESSION_HOST, adapterSessionHost);
            clientSession.setNote(AdapterConstants.APPLICATION_SESSION_HOST, adapterSessionHost);
        }

        AccessToken token = tokenManager.createClientAccessToken(session, accessCode.getRequestedRoles(), realm, client, user, userSession, clientSession);

        try {
            tokenManager.verifyAccess(token, realm, client, user);
        } catch (OAuthErrorException e) {
            Map<String, String> error = new HashMap<String, String>();
            error.put(OAuth2Constants.ERROR, e.getError());
            if (e.getDescription() != null) error.put(OAuth2Constants.ERROR_DESCRIPTION, e.getDescription());
            event.error(Errors.INVALID_CODE);
            return Response.status(Response.Status.BAD_REQUEST).entity(error).type("application/json").build();
        }

        AccessTokenResponse res = tokenManager.responseBuilder(realm, client, event, session, userSession, clientSession)
                .accessToken(token)
                .generateIDToken()
                .generateRefreshToken().build();

        event.success();

        return Cors.add(request, Response.ok(res)).auth().allowedOrigins(client).allowedMethods("POST").exposedHeaders(Cors.ACCESS_CONTROL_ALLOW_METHODS).build();
    }

    @Path("userinfo")
    public Object issueUserInfo() {
        UserInfoService userInfoEndpoint = new UserInfoService(this);

        ResteasyProviderFactory.getInstance().injectProperties(userInfoEndpoint);

        return userInfoEndpoint;
    }

    protected ClientModel authorizeClient(String authorizationHeader, MultivaluedMap<String, String> formData, EventBuilder event) {
        ClientModel client = authorizeClientBase(authorizationHeader, formData, event, realm);

        if ( (client instanceof ApplicationModel) && ((ApplicationModel)client).isBearerOnly()) {
            Map<String, String> error = new HashMap<String, String>();
            error.put(OAuth2Constants.ERROR, "invalid_client");
            error.put(OAuth2Constants.ERROR_DESCRIPTION, "Bearer-only not allowed");
            event.error(Errors.INVALID_CLIENT);
            throw new BadRequestException("Bearer-only not allowed", Response.status(Response.Status.BAD_REQUEST).entity(error).type("application/json").build());
        }

        return client;
    }

    // Just authorize client without further checking about client type
    public static ClientModel authorizeClientBase(String authorizationHeader, MultivaluedMap<String, String> formData, EventBuilder event, RealmModel realm) {
        String client_id;
        String clientSecret;
        if (authorizationHeader != null) {
            String[] usernameSecret = BasicAuthHelper.parseHeader(authorizationHeader);
            if (usernameSecret == null) {
                throw new UnauthorizedException("Bad Authorization header", Response.status(401).header(HttpHeaders.WWW_AUTHENTICATE, "Basic realm=\"" + realm.getName() + "\"").build());
            }
            client_id = usernameSecret[0];
            clientSecret = usernameSecret[1];
        } else {
            client_id = formData.getFirst(OAuth2Constants.CLIENT_ID);
            clientSecret = formData.getFirst("client_secret");
        }

        if (client_id == null) {
            Map<String, String> error = new HashMap<String, String>();
            error.put(OAuth2Constants.ERROR, "invalid_client");
            error.put(OAuth2Constants.ERROR_DESCRIPTION, "Could not find client");
            throw new BadRequestException("Could not find client", Response.status(Response.Status.BAD_REQUEST).entity(error).type("application/json").build());
        }

        event.client(client_id);

        ClientModel client = realm.findClient(client_id);
        if (client == null) {
            Map<String, String> error = new HashMap<String, String>();
            error.put(OAuth2Constants.ERROR, "invalid_client");
            error.put(OAuth2Constants.ERROR_DESCRIPTION, "Could not find client");
            event.error(Errors.CLIENT_NOT_FOUND);
            throw new BadRequestException("Could not find client", Response.status(Response.Status.BAD_REQUEST).entity(error).type("application/json").build());
        }

        if (!client.isEnabled()) {
            Map<String, String> error = new HashMap<String, String>();
            error.put(OAuth2Constants.ERROR, "invalid_client");
            error.put(OAuth2Constants.ERROR_DESCRIPTION, "Client is not enabled");
            event.error(Errors.CLIENT_DISABLED);
            throw new BadRequestException("Client is not enabled", Response.status(Response.Status.BAD_REQUEST).entity(error).type("application/json").build());
        }

        if (!client.isPublicClient()) {
            if (clientSecret == null || !client.validateSecret(clientSecret)) {
                Map<String, String> error = new HashMap<String, String>();
                error.put(OAuth2Constants.ERROR, "unauthorized_client");
                event.error(Errors.INVALID_CLIENT_CREDENTIALS);
                throw new BadRequestException("Unauthorized Client", Response.status(Response.Status.BAD_REQUEST).entity(error).type("application/json").build());
            }
        }

        return client;
    }

    /**
     * checks input and initializes variables based on a front page action like the login page or registration page
     *
     */
    private class FrontPageInitializer {
        protected String clientId;
        protected String redirect;
        protected String state;
        protected String scopeParam;
        protected String responseType;
        protected String loginHint;
        protected String prompt;
        protected ClientSessionModel clientSession;

        public Response processInput() {
            event.client(clientId).detail(Details.REDIRECT_URI, redirect).detail(Details.RESPONSE_TYPE, "code");
            if (!checkSsl()) {
                event.error(Errors.SSL_REQUIRED);
                return Flows.forwardToSecurityFailurePage(session, realm, uriInfo, "HTTPS required");
            }
            if (!realm.isEnabled()) {
                event.error(Errors.REALM_DISABLED);
                return Flows.forwardToSecurityFailurePage(session, realm, uriInfo, "Realm not enabled");
            }

            clientSession = null;
            ClientModel client = realm.findClient(clientId);
            if (client == null) {
                event.error(Errors.CLIENT_NOT_FOUND);
                return Flows.forwardToSecurityFailurePage(session, realm, uriInfo, "Unknown login requester.");
            }

            if (!client.isEnabled()) {
                event.error(Errors.CLIENT_DISABLED);
                return Flows.forwardToSecurityFailurePage(session, realm, uriInfo, "Login requester not enabled.");
            }
            if ((client instanceof ApplicationModel) && ((ApplicationModel)client).isBearerOnly()) {
                event.error(Errors.NOT_ALLOWED);
                return Flows.forwardToSecurityFailurePage(session, realm, uriInfo, "Bearer-only applications are not allowed to initiate browser login");
            }
            if (client.isDirectGrantsOnly()) {
                event.error(Errors.NOT_ALLOWED);
                return Flows.forwardToSecurityFailurePage(session, realm, uriInfo, "direct-grants-only clients are not allowed to initiate browser login");
            }
            String redirectUriParam = redirect;
            redirect = verifyRedirectUri(uriInfo, redirect, realm, client);
            if (redirect == null) {
                event.error(Errors.INVALID_REDIRECT_URI);
                return Flows.forwardToSecurityFailurePage(session, realm, uriInfo, "Invalid redirect_uri.");
            }
            clientSession = session.sessions().createClientSession(realm, client);
            clientSession.setAuthMethod(OIDCLoginProtocol.LOGIN_PROTOCOL);
            clientSession.setRedirectUri(redirect);
            clientSession.setAction(ClientSessionModel.Action.AUTHENTICATE);
            clientSession.setNote(ClientSessionCode.ACTION_KEY, KeycloakModelUtils.generateCodeSecret());
            clientSession.setNote(OIDCLoginProtocol.STATE_PARAM, state);
            clientSession.setNote(OIDCLoginProtocol.REDIRECT_URI_PARAM, redirectUriParam);
            if (scopeParam != null) clientSession.setNote(OIDCLoginProtocol.SCOPE_PARAM, scopeParam);
            if (responseType != null) clientSession.setNote(OIDCLoginProtocol.RESPONSE_TYPE_PARAM, responseType);
            if (loginHint != null) clientSession.setNote(OIDCLoginProtocol.LOGIN_HINT_PARAM, loginHint);
            if (prompt != null) clientSession.setNote(OIDCLoginProtocol.PROMPT_PARAM, prompt);
            return null;
        }
    }

    /**
     * Login page.  Must be redirected to from the application or oauth client.
     *
     * @See <a href="http://tools.ietf.org/html/rfc6749#section-4.1">http://tools.ietf.org/html/rfc6749#section-4.1</a>
     *
     *
     * @param responseType
     * @param redirect
     * @param clientId
     * @param scopeParam
     * @param state
     * @param prompt
     * @return
     */
    @Path("login")
    @GET
    public Response loginPage(@QueryParam(OIDCLoginProtocol.RESPONSE_TYPE_PARAM) String responseType,
                              @QueryParam(OIDCLoginProtocol.REDIRECT_URI_PARAM) String redirect,
                              @QueryParam(OIDCLoginProtocol.CLIENT_ID_PARAM) String clientId,
                              @QueryParam(OIDCLoginProtocol.SCOPE_PARAM) String scopeParam,
                              @QueryParam(OIDCLoginProtocol.STATE_PARAM) String state,
                              @QueryParam(OIDCLoginProtocol.PROMPT_PARAM) String prompt,
                              @QueryParam(OIDCLoginProtocol.LOGIN_HINT_PARAM) String loginHint,
                              @QueryParam(K_IDP_HINT) String idpHint) {
        event.event(EventType.LOGIN);
        FrontPageInitializer pageInitializer = new FrontPageInitializer();
        pageInitializer.responseType = responseType;
        pageInitializer.redirect = redirect;
        pageInitializer.clientId = clientId;
        pageInitializer.scopeParam = scopeParam;
        pageInitializer.state = state;
        pageInitializer.prompt = prompt;
        pageInitializer.loginHint = loginHint;
        Response response = pageInitializer.processInput();
        if (response != null) return response;
        ClientSessionModel clientSession = pageInitializer.clientSession;
        String accessCode = new ClientSessionCode(realm, clientSession).getCode();

        if (idpHint != null && !"".equals(idpHint)) {
            IdentityProviderModel identityProviderModel = realm.getIdentityProviderById(idpHint);

            if (identityProviderModel == null) {
                return Flows.forms(session, realm, null, uriInfo)
                        .setError("Could not find an identity provider with the identifier [" + idpHint + "].")
                        .createErrorPage();
            }
            return redirectToIdentityProvider(idpHint, accessCode);
        }

        response = authManager.checkNonFormAuthentication(session, clientSession, realm, uriInfo, request, clientConnection, headers, event);
        if (response != null) return response;

        // SPNEGO/Kerberos authentication TODO: This should be somehow pluggable instead of hardcoded this way (Authentication interceptors?)
        HttpAuthenticationManager httpAuthManager = new HttpAuthenticationManager(session, clientSession, realm, uriInfo, request, clientConnection, event);
        HttpAuthenticationManager.HttpAuthOutput httpAuthOutput = httpAuthManager.spnegoAuthenticate();
        if (httpAuthOutput.getResponse() != null) return httpAuthOutput.getResponse();

        if (prompt != null && prompt.equals("none")) {
            OIDCLoginProtocol oauth = new OIDCLoginProtocol(session, realm, uriInfo);
            return oauth.cancelLogin(clientSession);
        }

        List<IdentityProviderModel> identityProviders = realm.getIdentityProviders();
        for (IdentityProviderModel identityProvider : identityProviders) {
            if (identityProvider.isAuthenticateByDefault()) {
                return redirectToIdentityProvider(identityProvider.getId(), accessCode);
            }
        }

        List<RequiredCredentialModel> requiredCredentials = realm.getRequiredCredentials();
        if (requiredCredentials.isEmpty()) {
            if (!identityProviders.isEmpty()) {
                if (identityProviders.size() == 1) {
                    return redirectToIdentityProvider(identityProviders.get(0).getId(), accessCode);
                }

                return Flows.forms(session, realm, null, uriInfo).setError("Realm [" + this.realm.getName() + "] supports multiple identity providers. Could not determine which identity provider should be used to authenticate with.").createErrorPage();
            }

            return Flows.forms(session, realm, null, uriInfo).setError("Realm [" + this.realm.getName() + "] does not support any credential type.").createErrorPage();
        }

        LoginFormsProvider forms = Flows.forms(session, realm, clientSession.getClient(), uriInfo)
                .setClientSessionCode(accessCode);

        // Attach state from SPNEGO authentication
        if (httpAuthOutput.getChallenge() != null) {
            httpAuthOutput.getChallenge().sendChallenge(forms);
        }

        String rememberMeUsername = AuthenticationManager.getRememberMeUsername(realm, headers);

        if (loginHint != null || rememberMeUsername != null) {
            MultivaluedMap<String, String> formData = new MultivaluedMapImpl<String, String>();

            if (loginHint != null) {
                formData.add(AuthenticationManager.FORM_USERNAME, loginHint);
            } else {
                formData.add(AuthenticationManager.FORM_USERNAME, rememberMeUsername);
                formData.add("rememberMe", "on");
            }

            forms.setFormData(formData);
        }

        return forms.createLogin();
    }

    /**
     * Registration page.  Must be redirected to from login page.
     *
     * @param responseType
     * @param redirect
     * @param clientId
     * @param scopeParam
     * @param state
     * @return
     */
    @Path("registrations")
    @GET
    public Response registerPage(@QueryParam(OIDCLoginProtocol.RESPONSE_TYPE_PARAM) String responseType,
                                 @QueryParam(OIDCLoginProtocol.REDIRECT_URI_PARAM) String redirect,
                                 @QueryParam(OIDCLoginProtocol.CLIENT_ID_PARAM) String clientId,
                                 @QueryParam(OIDCLoginProtocol.SCOPE_PARAM) String scopeParam,
                                 @QueryParam(OIDCLoginProtocol.STATE_PARAM) String state) {
        event.event(EventType.REGISTER);
        if (!realm.isRegistrationAllowed()) {
            event.error(Errors.REGISTRATION_DISABLED);
            return Flows.forwardToSecurityFailurePage(session, realm, uriInfo, "Registration not allowed");
        }

        FrontPageInitializer pageInitializer = new FrontPageInitializer();
        pageInitializer.responseType = responseType;
        pageInitializer.redirect = redirect;
        pageInitializer.clientId = clientId;
        pageInitializer.scopeParam = scopeParam;
        pageInitializer.state = state;
        Response response = pageInitializer.processInput();
        if (response != null) return response;
        ClientSessionModel clientSession = pageInitializer.clientSession;


        authManager.expireIdentityCookie(realm, uriInfo, clientConnection);

        return Flows.forms(session, realm, clientSession.getClient(), uriInfo)
                .setClientSessionCode(new ClientSessionCode(realm, clientSession).getCode())
                .createRegistration();
    }

    /**
     * Logout user session.  User must be logged in via a session cookie.
     *
     * @param redirectUri
     * @return
     */
    @Path("logout")
    @GET
    @NoCache
    public Response logout(final @QueryParam(OIDCLoginProtocol.REDIRECT_URI_PARAM) String redirectUri) {
        event.event(EventType.LOGOUT);
        if (redirectUri != null) {
            event.detail(Details.REDIRECT_URI, redirectUri);
        }
        // authenticate identity cookie, but ignore an access token timeout as we're logging out anyways.
        AuthenticationManager.AuthResult authResult = authManager.authenticateIdentityCookie(session, realm, uriInfo, clientConnection, headers, false);
        if (authResult != null) {
            logout(authResult.getSession());
        }

        if (redirectUri != null) {
            String validatedRedirect = verifyRealmRedirectUri(uriInfo, redirectUri, realm);
            if (validatedRedirect == null) {
                return Flows.forwardToSecurityFailurePage(session, realm, uriInfo, "Invalid redirect uri.");
            }
            return Response.status(302).location(UriBuilder.fromUri(validatedRedirect).build()).build();
        } else {
            return Response.ok().build();
        }
    }

    /**
     * Logout a session via a non-browser invocation.  Similar signature to refresh token except there is no grant_type.
     * You must pass in the refresh token and
     * authenticate the client if it is not public.
     *
     * If the client is a confidential client
     * you must include the client-id (application name or oauth client name) and secret in an Basic Auth Authorization header.
     *
     * If the client is a public client, then you must include a "client_id" form parameter with the app's or oauth client's name.
     *
     * returns 204 if successful, 400 if not with a json error response.
     *
     * @param authorizationHeader
     * @param form
     * @return
     */
    @Path("logout")
    @POST
    @Consumes(MediaType.APPLICATION_FORM_URLENCODED)
    public Response logoutToken(final @HeaderParam(HttpHeaders.AUTHORIZATION) String authorizationHeader,
                                       final MultivaluedMap<String, String> form) {
        if (!checkSsl()) {
            throw new NotAcceptableException("HTTPS required");
        }

        event.event(EventType.LOGOUT);

        ClientModel client = authorizeClient(authorizationHeader, form, event);
        String refreshToken = form.getFirst(OAuth2Constants.REFRESH_TOKEN);
        if (refreshToken == null) {
            Map<String, String> error = new HashMap<String, String>();
            error.put(OAuth2Constants.ERROR, OAuthErrorException.INVALID_REQUEST);
            error.put(OAuth2Constants.ERROR_DESCRIPTION, "No refresh token");
            event.error(Errors.INVALID_TOKEN);
            return Response.status(Response.Status.BAD_REQUEST).entity(error).type("application/json").build();
        }
        try {
            RefreshToken token = tokenManager.verifyRefreshToken(realm, refreshToken);
            UserSessionModel userSessionModel = session.sessions().getUserSession(realm, token.getSessionState());
            if (userSessionModel != null) {
                logout(userSessionModel);
            }
        } catch (OAuthErrorException e) {
            Map<String, String> error = new HashMap<String, String>();
            error.put(OAuth2Constants.ERROR, e.getError());
            if (e.getDescription() != null) error.put(OAuth2Constants.ERROR_DESCRIPTION, e.getDescription());
            event.error(Errors.INVALID_TOKEN);
            return Response.status(Response.Status.BAD_REQUEST).entity(error).type("application/json").build();
        }
       return Cors.add(request, Response.noContent()).auth().allowedOrigins(client).allowedMethods("POST").exposedHeaders(Cors.ACCESS_CONTROL_ALLOW_METHODS).build();
    }

    private void logout(UserSessionModel userSession) {
        authManager.logout(session, realm, userSession, uriInfo, clientConnection);
        event.user(userSession.getUser()).session(userSession).success();
    }

    @Path("oauth/oob")
    @GET
    public Response installedAppUrnCallback(final @QueryParam("code") String code, final @QueryParam("error") String error, final @QueryParam("error_description") String errorDescription) {
        LoginFormsProvider forms = Flows.forms(session, realm, null, uriInfo);
        if (code != null) {
            return forms.setClientSessionCode(code).createCode();
        } else {
            return forms.setError(error).createCode();
        }
    }

    public static boolean matchesRedirects(Set<String> validRedirects, String redirect) {
        for (String validRedirect : validRedirects) {
            if (validRedirect.endsWith("*")) {
                // strip off *
                int length = validRedirect.length() - 1;
                validRedirect = validRedirect.substring(0, length);
                if (redirect.startsWith(validRedirect)) return true;
                // strip off trailing '/'
                if (length - 1 > 0 && validRedirect.charAt(length - 1) == '/') length--;
                validRedirect = validRedirect.substring(0, length);
                if (validRedirect.equals(redirect)) return true;
            } else if (validRedirect.equals(redirect)) return true;
        }
        return false;
    }

    public static Set<String> getValidateRedirectUris(RealmModel realm) {
        Set<String> redirects = new HashSet<String>();
        for (ApplicationModel client : realm.getApplications()) {
            for (String redirect : client.getRedirectUris()) {
                redirects.add(redirect);
            }
        }
        for (OAuthClientModel client : realm.getOAuthClients()) {
            for (String redirect : client.getRedirectUris()) {
                redirects.add(redirect);
            }
        }
        return redirects;
    }

    public static String verifyRealmRedirectUri(UriInfo uriInfo, String redirectUri, RealmModel realm) {
        Set<String> validRedirects = getValidateRedirectUris(realm);
        return verifyRedirectUri(uriInfo, redirectUri, realm, validRedirects);
    }

    public static String verifyRedirectUri(UriInfo uriInfo, String redirectUri, RealmModel realm, ClientModel client) {
        Set<String> validRedirects = client.getRedirectUris();
        return verifyRedirectUri(uriInfo, redirectUri, realm, validRedirects);
    }

    public static String verifyRedirectUri(UriInfo uriInfo, String redirectUri, RealmModel realm, Set<String> validRedirects) {
        if (redirectUri == null) {
            if (validRedirects.size() != 1) return null;
            String validRedirect = validRedirects.iterator().next();
            int idx = validRedirect.indexOf("/*");
            if (idx > -1) {
                validRedirect = validRedirect.substring(0, idx);
            }
            redirectUri = validRedirect;
        } else if (validRedirects.isEmpty()) {
            logger.debug("No Redirect URIs supplied");
            redirectUri = null;
        } else {
            String r = redirectUri.indexOf('?') != -1 ? redirectUri.substring(0, redirectUri.indexOf('?')) : redirectUri;
            Set<String> resolveValidRedirects = resolveValidRedirects(uriInfo, validRedirects);

            boolean valid = matchesRedirects(resolveValidRedirects, r);

            if (!valid && r.startsWith(Constants.INSTALLED_APP_URL) && r.indexOf(':', Constants.INSTALLED_APP_URL.length()) >= 0) {
                int i = r.indexOf(':', Constants.INSTALLED_APP_URL.length());

                StringBuilder sb = new StringBuilder();
                sb.append(r.substring(0, i));

                i = r.indexOf('/', i);
                if (i >= 0) {
                    sb.append(r.substring(i));
                }

                r = sb.toString();

                valid = matchesRedirects(resolveValidRedirects, r);
            }
            if (valid && redirectUri.startsWith("/")) {
                redirectUri = relativeToAbsoluteURI(uriInfo, redirectUri);
            }
            redirectUri = valid ? redirectUri : null;
        }

        if (Constants.INSTALLED_APP_URN.equals(redirectUri)) {
            return Urls.realmInstalledAppUrnCallback(uriInfo.getBaseUri(), realm.getName()).toString();
        } else {
            return redirectUri;
        }
    }

    public static Set<String> resolveValidRedirects(UriInfo uriInfo, Set<String> validRedirects) {
        // If the valid redirect URI is relative (no scheme, host, port) then use the request's scheme, host, and port
        Set<String> resolveValidRedirects = new HashSet<String>();
        for (String validRedirect : validRedirects) {
            resolveValidRedirects.add(validRedirect); // add even relative urls.
            if (validRedirect.startsWith("/")) {
                validRedirect = relativeToAbsoluteURI(uriInfo, validRedirect);
                logger.debugv("replacing relative valid redirect with: {0}", validRedirect);
                resolveValidRedirects.add(validRedirect);
            }
        }
        return resolveValidRedirects;
    }

    public static String relativeToAbsoluteURI(UriInfo uriInfo, String relative) {
        URI baseUri = uriInfo.getBaseUri();
        String uri = baseUri.getScheme() + "://" + baseUri.getHost();
        if (baseUri.getPort() != -1) {
            uri += ":" + baseUri.getPort();
        }
        relative = uri + relative;
        return relative;
    }

    private boolean checkSsl() {
        if (uriInfo.getBaseUri().getScheme().equals("https")) {
            return true;
        } else {
            return !realm.getSslRequired().isRequired(clientConnection);
        }
    }

    private Response createError(String error, String errorDescription, Response.Status status) {
        Map<String, String> e = new HashMap<String, String>();
        e.put(OAuth2Constants.ERROR, error);
        if (errorDescription != null) {
            e.put(OAuth2Constants.ERROR_DESCRIPTION, errorDescription);
        }
        return Response.status(status).entity(e).type("application/json").build();
    }

    private Response redirectToIdentityProvider(String providerId, String accessCode) {
        logger.debug("Automatically redirect to identity provider: " + providerId);
        return Response.temporaryRedirect(
                Urls.identityProviderAuthnRequest(this.uriInfo.getBaseUri(), providerId, this.realm.getName(), accessCode))
                .build();
    }

    TokenManager getTokenManager() {
        return this.tokenManager;
    }

    RealmModel getRealm() {
        return this.realm;
    }
}
