/*
 * Copyright 2016 Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags.
 *
 * 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
 *
 * http://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 org.keycloak.services.resources.admin;

import org.jboss.logging.Logger;
import org.jboss.resteasy.spi.HttpRequest;
import org.jboss.resteasy.spi.HttpResponse;
import org.jboss.resteasy.spi.NoLogWebApplicationException;
import org.jboss.resteasy.spi.NotFoundException;
import org.jboss.resteasy.spi.ResteasyProviderFactory;
import org.jboss.resteasy.spi.UnauthorizedException;
import org.keycloak.common.ClientConnection;
import org.keycloak.jose.jws.JWSInput;
import org.keycloak.jose.jws.JWSInputException;
import org.keycloak.models.AdminRoles;
import org.keycloak.models.ClientModel;
import org.keycloak.models.KeycloakSession;
import org.keycloak.models.RealmModel;
import org.keycloak.protocol.oidc.TokenManager;
import org.keycloak.representations.AccessToken;
import org.keycloak.services.ForbiddenException;
import org.keycloak.services.managers.AppAuthManager;
import org.keycloak.services.managers.AuthenticationManager;
import org.keycloak.services.managers.RealmManager;
import org.keycloak.services.resources.Cors;
import org.keycloak.services.resources.admin.info.ServerInfoAdminResource;
import org.keycloak.theme.Theme;
import org.keycloak.theme.ThemeProvider;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.UriBuilder;
import javax.ws.rs.core.UriInfo;
import java.io.IOException;
import java.util.Locale;
import java.util.Properties;

/**
 * Root resource for admin console and admin REST API
 *
 * @author <a href="mailto:bill@burkecentral.com">Bill Burke</a>
 * @version $Revision: 1 $
 */
@Path("/admin")
public class AdminRoot {
    protected static final Logger logger = Logger.getLogger(AdminRoot.class);

    @Context
    protected UriInfo uriInfo;

    @Context
    protected ClientConnection clientConnection;

    @Context
    protected HttpRequest request;

    @Context
    protected HttpResponse response;

    protected AppAuthManager authManager;
    protected TokenManager tokenManager;

    @Context
    protected KeycloakSession session;

    public AdminRoot() {
        this.tokenManager = new TokenManager();
        this.authManager = new AppAuthManager();
    }

    public static UriBuilder adminBaseUrl(UriInfo uriInfo) {
        return adminBaseUrl(uriInfo.getBaseUriBuilder());
    }

    public static UriBuilder adminBaseUrl(UriBuilder base) {
        return base.path(AdminRoot.class);
    }

    /**
     * Convenience path to master realm admin console
     *
     * @exclude
     * @return
     */
    @GET
    public Response masterRealmAdminConsoleRedirect() {
        RealmModel master = new RealmManager(session).getKeycloakAdminstrationRealm();
        return Response.status(302).location(
                uriInfo.getBaseUriBuilder().path(AdminRoot.class).path(AdminRoot.class, "getAdminConsole").path("/").build(master.getName())
        ).build();
    }

    /**
     * Convenience path to master realm admin console
     *
     * @exclude
     * @return
     */
    @Path("index.{html:html}") // expression is actually "index.html" but this is a hack to get around jax-doclet bug
    @GET
    public Response masterRealmAdminConsoleRedirectHtml() {
        return masterRealmAdminConsoleRedirect();
    }

    protected RealmModel locateRealm(String name, RealmManager realmManager) {
        RealmModel realm = realmManager.getRealmByName(name);
        if (realm == null) {
            throw new NotFoundException("Realm not found.  Did you type in a bad URL?");
        }
        session.getContext().setRealm(realm);
        return realm;
    }


    public static UriBuilder adminConsoleUrl(UriInfo uriInfo) {
        return adminConsoleUrl(uriInfo.getBaseUriBuilder());
    }

    public static UriBuilder adminConsoleUrl(UriBuilder base) {
        return adminBaseUrl(base).path(AdminRoot.class, "getAdminConsole");
    }

    /**
     * path to realm admin console ui
     *
     * @exclude
     * @param name Realm name (not id!)
     * @return
     */
    @Path("{realm}/console")
    public AdminConsole getAdminConsole(final @PathParam("realm") String name) {
        RealmManager realmManager = new RealmManager(session);
        RealmModel realm = locateRealm(name, realmManager);
        AdminConsole service = new AdminConsole(realm);
        ResteasyProviderFactory.getInstance().injectProperties(service);
        return service;
    }


    protected AdminAuth authenticateRealmAdminRequest(HttpHeaders headers) {
        String tokenString = authManager.extractAuthorizationHeaderToken(headers);
        if (tokenString == null) throw new UnauthorizedException("Bearer");
        AccessToken token;
        try {
            JWSInput input = new JWSInput(tokenString);
            token = input.readJsonContent(AccessToken.class);
        } catch (JWSInputException e) {
            throw new UnauthorizedException("Bearer token format error");
        }
        String realmName = token.getIssuer().substring(token.getIssuer().lastIndexOf('/') + 1);
        RealmManager realmManager = new RealmManager(session);
        RealmModel realm = realmManager.getRealmByName(realmName);
        if (realm == null) {
            throw new UnauthorizedException("Unknown realm in token");
        }
        session.getContext().setRealm(realm);
        AuthenticationManager.AuthResult authResult = authManager.authenticateBearerToken(session, realm, uriInfo, clientConnection, headers);
        if (authResult == null) {
            logger.debug("Token not valid");
            throw new UnauthorizedException("Bearer");
        }

        ClientModel client = realm.getClientByClientId(token.getIssuedFor());
        if (client == null) {
            throw new NotFoundException("Could not find client for authorization");

        }

        return new AdminAuth(realm, authResult.getToken(), authResult.getUser(), client);
    }

    public static UriBuilder realmsUrl(UriInfo uriInfo) {
        return realmsUrl(uriInfo.getBaseUriBuilder());
    }

    public static UriBuilder realmsUrl(UriBuilder base) {
        return adminBaseUrl(base).path(AdminRoot.class, "getRealmsAdmin");
    }


    /**
     * Base Path to realm admin REST interface
     *
     * @param headers
     * @return
     */
    @Path("realms")
    public RealmsAdminResource getRealmsAdmin(@Context final HttpHeaders headers) {
        handlePreflightRequest();

        AdminAuth auth = authenticateRealmAdminRequest(headers);
        if (auth != null) {
            logger.debug("authenticated admin access for: " + auth.getUser().getUsername());
        }

        Cors.add(request).allowedOrigins(auth.getToken()).allowedMethods("GET", "PUT", "POST", "DELETE").exposedHeaders("Location").auth().build(response);

        RealmsAdminResource adminResource = new RealmsAdminResource(auth, tokenManager);
        ResteasyProviderFactory.getInstance().injectProperties(adminResource);
        return adminResource;
    }

    /**
     * General information about the server
     *
     * @param headers
     * @return
     */
    @Path("serverinfo")
    public ServerInfoAdminResource getServerInfo(@Context final HttpHeaders headers) {
        handlePreflightRequest();

        AdminAuth auth = authenticateRealmAdminRequest(headers);
        if (!isAdmin(auth)) {
            throw new ForbiddenException();
        }

        if (auth != null) {
            logger.debug("authenticated admin access for: " + auth.getUser().getUsername());
        }

        Cors.add(request).allowedOrigins(auth.getToken()).allowedMethods("GET", "PUT", "POST", "DELETE").auth().build(response);

        ServerInfoAdminResource adminResource = new ServerInfoAdminResource();
        ResteasyProviderFactory.getInstance().injectProperties(adminResource);
        return adminResource;
    }

    protected boolean isAdmin(AdminAuth auth) {

        RealmManager realmManager = new RealmManager(session);
        if (auth.getRealm().equals(realmManager.getKeycloakAdminstrationRealm())) {
            if (auth.hasOneOfRealmRole(AdminRoles.ADMIN, AdminRoles.CREATE_REALM)) {
                return true;
            }
            for (RealmModel realm : session.realms().getRealms()) {
                ClientModel client = realm.getMasterAdminClient();
                if (auth.hasOneOfAppRole(client, AdminRoles.ALL_REALM_ROLES)) {
                    return true;
                }
            }
            return false;
        } else {
            ClientModel client = auth.getRealm().getClientByClientId(realmManager.getRealmAdminClientId(auth.getRealm()));
            return auth.hasOneOfAppRole(client, AdminRoles.ALL_REALM_ROLES);
        }
    }

    protected void handlePreflightRequest() {
        if (request.getHttpMethod().equalsIgnoreCase("OPTIONS")) {
            logger.debug("Cors admin pre-flight");
            Response response = Cors.add(request, Response.ok()).preflight().allowedMethods("GET", "PUT", "POST", "DELETE").auth().build();
            throw new NoLogWebApplicationException(response);
        }
    }

    public static Theme getTheme(KeycloakSession session, RealmModel realm) throws IOException {
        ThemeProvider themeProvider = session.getProvider(ThemeProvider.class, "extending");
        return themeProvider.getTheme(realm.getAdminTheme(), Theme.Type.ADMIN);
    }

    public static Properties getMessages(KeycloakSession session, RealmModel realm, String lang) {
        try {
            Theme theme = getTheme(session, realm);
            Locale locale = lang != null ? Locale.forLanguageTag(lang) : Locale.ENGLISH;
            return theme.getMessages(locale);
        } catch (IOException e) {
            logger.error("Failed to load messages from theme", e);
            return new Properties();
        }
    }

    public static Properties getMessages(KeycloakSession session, RealmModel realm, String bundle, String lang) {
        try {
            Theme theme = getTheme(session, realm);
            Locale locale = lang != null ? Locale.forLanguageTag(lang) : Locale.ENGLISH;
            return theme.getMessages(bundle, locale);
        } catch (IOException e) {
            logger.error("Failed to load messages from theme", e);
            return new Properties();
        }
    }

}
