/**
 * Copyright (C) 2015 Red Hat, Inc.
 *
 * 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 io.fabric8.openshift.client.internal;

import okhttp3.Credentials;
import okhttp3.Interceptor;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

import io.fabric8.kubernetes.client.KubernetesClientException;
import io.fabric8.kubernetes.client.utils.URLUtils;
import io.fabric8.kubernetes.client.utils.Utils;
import io.fabric8.openshift.client.OpenShiftConfig;

import java.io.IOException;
import java.net.URL;
import java.util.concurrent.atomic.AtomicReference;

public class OpenShiftOAuthInterceptor implements Interceptor {

    private static final String AUTHORIZATION = "Authorization";
    private static final String LOCATION = "Location";
    private static final String AUTHORIZE_PATH = "oauth/authorize?response_type=token&client_id=openshift-challenging-client";

    private static final String BEFORE_TOKEN = "access_token=";
    private static final String AFTER_TOKEN = "&expires";

    private final OkHttpClient client;
    private final OpenShiftConfig config;
    private final AtomicReference<String> oauthToken = new AtomicReference<>();

    public OpenShiftOAuthInterceptor(OkHttpClient client, OpenShiftConfig config) {
        this.client = client;
        this.config = config;
    }

    @Override
    public Response intercept(Chain chain) throws IOException {
        Request request = chain.request();

        //Build new request
        Request.Builder builder = request.newBuilder();

        String token = oauthToken.get();
        // avoid overwriting basic auth token with stale bearer token
        if (Utils.isNotNullOrEmpty(token) && Utils.isNullOrEmpty(request.header(AUTHORIZATION))) {
            setAuthHeader(builder, token);
        }

        request = builder.build();
        Response response = chain.proceed(request);

        //If response is Forbidden or Unauthorized, try to obtain a token via authorize() or via config.
        if (response.code() != 401 && response.code() != 403) {
          return response;
        } else if (Utils.isNotNullOrEmpty(config.getUsername()) && Utils.isNotNullOrEmpty(config.getPassword())) {
          synchronized (client) {
            // current token (if exists) is borked, don't resend
            oauthToken.set(null);
            token = authorize();
            if (token != null) {
              oauthToken.set(token);
            }
          }
        } else if (Utils.isNotNullOrEmpty(config.getOauthToken())) {
          token = config.getOauthToken();
          oauthToken.set(token);
        }


      //If token was obtain, then retry request using the obtained token.
      if (Utils.isNotNullOrEmpty(token)) {
        // Close the previous response to prevent leaked connections.
        response.body().close();

        setAuthHeader(builder, token);
        request = builder.build();
        return chain.proceed(request); //repeat request with new token
      } else {
        return response;
      }
    }

    private void setAuthHeader(Request.Builder builder, String token) {
        if (token != null) {
            builder.header(AUTHORIZATION, String.format("Bearer %s", token));
        }
    }

    private  String authorize() {
        try {
            OkHttpClient.Builder builder = client.newBuilder();
            builder.interceptors().remove(this);
            OkHttpClient clone = builder.build();

            String credential = Credentials.basic(config.getUsername(), new String(config.getPassword()));
            URL url = new URL(URLUtils.join(config.getMasterUrl(), AUTHORIZE_PATH));
            Response response = clone.newCall(new Request.Builder().get().url(url).header(AUTHORIZATION, credential).build()).execute();

            response.body().close();
            response = response.priorResponse() != null ? response.priorResponse() : response;
            response = response.networkResponse() != null ? response.networkResponse() : response;
            String token = response.header(LOCATION);
            if (token == null || token.isEmpty()) {
              throw new KubernetesClientException("Unexpected response (" + response.code() + " " + response.message() + "), to the authorization request. Missing header:[" + LOCATION + "]!");
            }
            token = token.substring(token.indexOf(BEFORE_TOKEN) + BEFORE_TOKEN.length());
            token = token.substring(0, token.indexOf(AFTER_TOKEN));
            return token;
        } catch (Exception e) {
            throw KubernetesClientException.launderThrowable(e);
        }
    }
}


@@ -2060,49 +2060,452 @@
 ();%0A
-%0A        String token = oauthToken.get();
+        String token = null;%0A%0A        if (Utils.isNotNullOrEmpty(oauthToken.get()) && Utils.isNullOrEmpty(request.header(AUTHORIZATION))) %7B%0A          token = oauthToken.get();%0A        %7D else if (Utils.isNotNullOrEmpty(config.getUsername()) && Utils.isNotNullOrEmpty(config.getPassword())) %7B%0A          token = authorize();%0A        %7D else if (Utils.isNotNullOrEmpty(config.getOauthToken())) %7B%0A           token = config.getOauthToken();%0A        %7D%0A
 %0A   

fix (#888): OpenShiftOAuthInterceptor now always tries to set a token.