public WebProxyState PrepareWebProxy()

in src/XmlNotepad/proxy.cs [127:235]
81 lines of code
19 McCabe index (conditional complexity)

        public WebProxyState PrepareWebProxy(IWebProxy proxy, string webCallUrl, WebProxyState oldProxyState, bool okToPrompt)
        {
            WebProxyState newProxyState = WebProxyState.Abort;

            if (string.IsNullOrEmpty(webCallUrl))
            {
                Debug.Fail("PrepareWebProxy called with an empty WebCallUrl.");
                webCallUrl = "http://go.microsoft.com/fwlink/?LinkId=81947";
            }

            // Get the web proxy url for the the current web call.
            Uri webCallProxy = null;
            if (proxy != null)
            {
                webCallProxy = proxy.GetProxy(new Uri(webCallUrl));
            }

            if ((proxy != null) && (webCallProxy != null))
            {
                // get proxy url.
                string proxyUrl = webCallProxy.Host;
                if (string.IsNullOrEmpty(_currentProxyUrl))
                {
                    _currentProxyUrl = proxyUrl;
                }

                switch (oldProxyState)
                {
                    case WebProxyState.NoCredentials:
                        // Add the default credentials only if there aren't any credentials attached to
                        // the DefaultWebProxy. If the first calls attaches the correct credentials, the
                        // second call will just use them, instead of overwriting it with the default credentials.
                        // This avoids multiple web calls. Note that state is transitioned to DefaultCredentials
                        // instead of CachedCredentials. This ensures that web calls be tried with the
                        // cached credentials if the currently attached credentials don't result in successful web call.
                        if ((proxy.Credentials == null))
                        {
                            proxy.Credentials = CredentialCache.DefaultCredentials;
                        }
                        newProxyState = WebProxyState.DefaultCredentials;
                        break;

                    case WebProxyState.DefaultCredentials:
                        // Fetch cached credentials if they are null or if the proxy url has changed.
                        if ((_cachedCredentials == null) ||
                            !string.Equals(_currentProxyUrl, proxyUrl, StringComparison.OrdinalIgnoreCase))
                        {
                            _cachedCredentials = GetCachedCredentials(proxyUrl);
                        }

                        if (_cachedCredentials != null)
                        {
                            proxy.Credentials = _cachedCredentials;
                            newProxyState = WebProxyState.CachedCredentials;
                            break;
                        }

                        // Proceed to next step if cached credentials are not available.
                        goto case WebProxyState.CachedCredentials;

                    case WebProxyState.CachedCredentials:
                    case WebProxyState.PromptForCredentials:
                        if (okToPrompt)
                        {
                            if (DialogResult.OK == PromptForCredentials(proxyUrl))
                            {
                                proxy.Credentials = _cachedCredentials;
                                newProxyState = WebProxyState.PromptForCredentials;
                            }
                            else
                            {
                                newProxyState = WebProxyState.Abort;
                            }
                        }
                        else
                        {
                            newProxyState = WebProxyState.Abort;
                        }
                        break;

                    case WebProxyState.Abort:
                        throw new InvalidOperationException();

                    default:
                        throw new ArgumentException(string.Empty, "oldProxyState");
                }
            }
            else
            {
                // No proxy for the webCallUrl scenario.
                if (oldProxyState == WebProxyState.NoCredentials)
                {
                    // if it is the first call, change the state and let the web call proceed.
                    newProxyState = WebProxyState.DefaultCredentials;
                }
                else
                {
                    Debug.Fail("This method is called a second time when 407 occurs. A 407 shouldn't have occurred as there is no default proxy.");
                    // We dont have a good idea of the circumstances under which
                    // WebProxy might be null for a url. To be safe, for VS 2005 SP1,
                    // we will just return the abort state, instead of throwing
                    // an exception. Abort state will ensure that no further procesing
                    // occurs and we will not bring down the app.
                    // throw new InvalidOperationException();
                    newProxyState = WebProxyState.Abort;
                }
            }
            return newProxyState;
        }