package org.gcube.portal.threadlocalexec;

import static org.gcube.common.authorization.client.Constants.authorizationService;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.apache.catalina.connector.Request;
import org.apache.catalina.connector.Response;
import org.apache.catalina.valves.ValveBase;
import org.gcube.common.authorization.client.exceptions.ObjectNotFound;
import org.gcube.common.authorization.library.provider.AuthorizationProvider;
import org.gcube.common.authorization.library.provider.SecurityTokenProvider;
import org.gcube.common.authorization.library.provider.UmaJWTProvider;
import org.gcube.common.authorization.library.provider.UserInfo;
import org.gcube.common.portal.PortalContext;
import org.gcube.common.scope.api.ScopeProvider;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.liferay.portal.model.User;
import com.liferay.portal.service.UserLocalServiceUtil;
import com.nubisware.oidc.lr62.JWTTokenUtil;
import com.nubisware.oidc.lr62.LiferayOpenIdConnectConfiguration;
import com.nubisware.oidc.lr62.OIDCTokenProxy;
import com.nubisware.oidc.rest.JWTToken;
import com.nubisware.oidc.rest.OpenIdConnectConfiguration;
import com.nubisware.oidc.rest.OpenIdConnectRESTHelper;

/**
 * 
 * @author Massimiliano Assante, CNR ISTI
 * @author Lucio Lelii, CNR ISTI
 * @author Mauro Mugnaini, Nubisware S.r.l.
 *
 */
public class SmartGearsPortalValve extends ValveBase {

    private static final Logger _log = LoggerFactory.getLogger(SmartGearsPortalValve.class);
    private final static String DEFAULT_ROLE = "OrganizationMember";
    private final static String LIFERAY_POLLER_CONTEXT = "poller/receive";

    @Override
    public void invoke(Request req, Response resp) throws IOException, ServletException {
        SecurityTokenProvider.instance.reset();
        ScopeProvider.instance.reset();
        AuthorizationProvider.instance.reset();
        UmaJWTProvider.instance.reset();
        //_log.trace("SmartGearsPortalValve SecurityTokenProvider and AuthorizationProvider reset OK");
        if (req instanceof HttpServletRequest) {
            HttpServletRequest request = (HttpServletRequest) req;
            if (!req.getRequestURL().toString().endsWith(LIFERAY_POLLER_CONTEXT)) { //avoid calling gCube auth service for liferay internal poller
                PortalContext context = PortalContext.getConfiguration();
                String scope = context.getCurrentScope(request);
                String username = getCurrentUsername(request);
                if (scope != null && username != null && validateContext(scope)) {
                    String userToken = null;
                    try {
                        ScopeProvider.instance.set(scope);
                        userToken = authorizationService().resolveTokenByUserAndContext(username, scope);
                        SecurityTokenProvider.instance.set(userToken);
                    } catch (ObjectNotFound ex) {
                        userToken = generateAuthorizationToken(username, scope);
                        SecurityTokenProvider.instance.set(userToken);
                        _log.debug("generateAuthorizationToken OK for " + username + " in scope " + scope);
                    } catch (Exception e) {
                        _log.error("Something went wrong in generating token for " + username + " in scope " + scope);
                        e.printStackTrace();
                    }
                    checkUMATicket(request, scope);

                    //_log.trace("Security token set OK for " + username + " in scope " + scope);
                }
            }
        }
        getNext().invoke(req, resp);
    }

    private void checkUMATicket(HttpServletRequest request, String scope) {
        HttpSession session = request.getSession(false);
        if (session == null) {
            if (_log.isDebugEnabled()) {
                _log.debug("Session is null");
            }
            return;
        }
        if (_log.isTraceEnabled()) {
            _log.trace("Session details: id=" + session.getId() + ", instance=" + session);
        }
        String urlEncodedScope = null;
        try {
            urlEncodedScope = URLEncoder.encode(scope, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            _log.error("Cannot URL encode scope", e);
            return;
        }
        if (_log.isDebugEnabled()) {
            _log.debug("URL encoded scope is: " + urlEncodedScope);
            _log.debug("Getting UMA token from session");
        }
        JWTToken umaToken = JWTTokenUtil.getUMAFromSession(session);
        if (umaToken == null) {
            if (_log.isDebugEnabled()) {
                _log.debug("UMA token not found in session");
            }
            if (_log.isDebugEnabled()) {
                _log.debug("Getting current user");
            }
            User user = getCurrentUser(request);
            if (user == null) {
                _log.error("Current user not found, cannot continue");
                return;
            }
            if (_log.isDebugEnabled()) {
                _log.debug("Trying to get UMA token from cache proxy");
            }
            umaToken = OIDCTokenProxy.getInstance().getUMAToken(user, session);
            if (umaToken == null || !umaToken.getAud().contains(urlEncodedScope)) {
                if (umaToken == null) {
                    if (_log.isDebugEnabled()) {
                        _log.debug("UMA token is null. Getting new one...");
                    }
                } else {
                    _log.info("UMA token for another scope (" + umaToken.getAud() + "). Getting new one for scope: "
                            + urlEncodedScope);
                }
                if (_log.isDebugEnabled()) {
                    _log.debug("Getting OIDC token from session");
                }
                JWTToken authToken = JWTTokenUtil.getOIDCFromSession(session);
                if (authToken == null) {
                    if (_log.isDebugEnabled()) {
                        _log.debug("OIDC token not found in session. Trying to get it from cache proxy");
                    }
                    authToken = getOIDCTokeFromProxyAndSetInSession(user, request, session);
                    if (authToken == null) {
                        _log.error("OIDC token is null, cannot continue");
                        return;
                    } else {
                        if (_log.isDebugEnabled()) {
                            _log.debug("OIDC token found in cache proxy");
                        }
                    }
                }
                _log.info("Getting UMA token from OIDC endpoint for scope: " + urlEncodedScope);
                OpenIdConnectConfiguration configuration = LiferayOpenIdConnectConfiguration.getConfiguration(request);
                try {
                    // TODO: handle the token expired case and renew it with refresh token.
                    umaToken = OpenIdConnectRESTHelper.queryUMAToken(configuration.getTokenUrl(),
                            authToken.getAsBearer(),
                            urlEncodedScope, null);
                } catch (Exception e) {
                    _log.error("Getting UMA token from server", e);
                    return;
                }
                if (_log.isDebugEnabled()) {
                    _log.debug("Setting UMA token in cache proxy");
                }
                OIDCTokenProxy.getInstance().setRPTToken(user, session, umaToken);
                if (_log.isDebugEnabled()) {
                    _log.debug("Setting UMA token in session");
                }
                JWTTokenUtil.putUMAInSession(umaToken, session);
            }
        }
        if (_log.isDebugEnabled()) {
            _log.debug("Setting UMA token in UMA JWT provider");
        }
        UmaJWTProvider.instance.set(umaToken.getRaw());
    }

    private JWTToken getOIDCTokeFromProxyAndSetInSession(User user, HttpServletRequest request, HttpSession session) {
        JWTToken token = OIDCTokenProxy.getInstance().getOIDCToken(user, session);
        if (token == null) {
            _log.warn("OIDC token is null also in cache proxy!");
        } else {
            if (_log.isDebugEnabled()) {
                _log.debug("Setting OIDC token took from cache proxy in session");
            }
            JWTTokenUtil.putOIDCInSession(token, session);
        }
        return token;
    }

    /**
     * 
     * @param context
     * @return true if is the context is syntactically valid
     */
    private static boolean validateContext(String context) {
        String separator = "/";
        if (!context.matches("\\S+"))
            return false;
        String[] components = context.split(separator);
        if (components.length < 2 || components.length > 4)
            return false;
        return true;
    }

    /**
     * 
     * @param username
     * @param scope
     * @throws Exception
     */
    private static String generateAuthorizationToken(String username, String scope) {
        List<String> userRoles = new ArrayList<>();
        userRoles.add(DEFAULT_ROLE);
        String token;
        try {
            token = authorizationService().generateUserToken(new UserInfo(username, userRoles), scope);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
        return token;
    }

    /**
     * 
     * @param httpServletRequest the httpServletRequest object
     * @return the instance of the user 
     * @see GCubeUser
     */
    public static String getCurrentUsername(HttpServletRequest httpServletRequest) {
        User user = getCurrentUser(httpServletRequest);
        return user != null ? user.getScreenName() : null;
    }

    public static User getCurrentUser(HttpServletRequest httpServletRequest) {
        String userIdNo = httpServletRequest.getHeader(PortalContext.USER_ID_ATTR_NAME);
        if (userIdNo != null && userIdNo.compareTo("undefined") != 0) {
            long userId = -1;
            try {
                userId = Long.parseLong(userIdNo);
                return UserLocalServiceUtil.getUser(userId);
            } catch (NumberFormatException e) {
                _log.error("The userId is not a number -> " + userIdNo);
                return null;
            } catch (Exception e) {
                _log.error("The userId does not belong to any user -> " + userIdNo);
                return null;
            }
        }
        return null;
    }
}