From 814603350b702fe88c17dc8936543a488823bc2f Mon Sep 17 00:00:00 2001
From: Jeffrey Stedfast <jestedfa@microsoft.com>
Date: Fri, 2 Aug 2024 15:14:33 -0400
Subject: [PATCH] More OAuth2 example improvements

---
 Documentation/Examples/OAuth2ExchangeExample.cs | 17 ++++++++++++-----
 Documentation/Examples/OAuth2GMailExample.cs    |  6 +++---
 ExchangeOAuth2.md                               | 15 +++++----------
 3 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/Documentation/Examples/OAuth2ExchangeExample.cs b/Documentation/Examples/OAuth2ExchangeExample.cs
index 3661351fbc..8e3be0b6c4 100644
--- a/Documentation/Examples/OAuth2ExchangeExample.cs
+++ b/Documentation/Examples/OAuth2ExchangeExample.cs
@@ -43,17 +43,24 @@ static async Task AuthenticateAsync (ImapClient client)
                 //"https://outlook.office.com/SMTP.AccessAsUser.All", // Only needed for SMTP
             };
 
-            var authToken = await publicClientApplication.AcquireTokenInteractive (scopes).WithLoginHint (ExchangeAccount).ExecuteAsync (cancellationToken);
-            await publicClientApplication.AcquireTokenSilent (scopes, authToken.Account).ExecuteAsync (cancellationToken);
+            AuthenticationResult? result;
 
-            // Note: We use authToken.Account.Username here instead of ExchangeAccount because the user *may* have chosen a
+            try {
+                // First, check the cache for an auth token.
+                result = await publicClientApplication.AcquireTokenSilent (scopes, username).ExecuteAsync ();
+            } catch (MsalUiRequiredException) {
+                // If that fails, then try getting an auth token interactively.
+                result = await publicClientApplication.AcquireTokenInteractive (scopes).WithLoginHint (username).ExecuteAsync ();
+            }
+
+            // Note: We use result.Account.Username here instead of ExchangeAccount because the user *may* have chosen a
             // different Microsoft Exchange account when presented with the browser window during the authentication process.
             SaslMechanism oauth2;
 
             if (client.AuthenticationMechanisms.Contains ("OAUTHBEARER"))
-                oauth2 = new SaslMechanismOAuthBearer (authToken.Account.Username, authToken.AccessToken);
+                oauth2 = new SaslMechanismOAuthBearer (result.Account.Username, result.AccessToken);
             else
-                oauth2 = new SaslMechanismOAuth2 (authToken.Account.Username, authToken.AccessToken);
+                oauth2 = new SaslMechanismOAuth2 (result.Account.Username, result.AccessToken);
 
             await client.AuthenticateAsync (oauth2);
         }
diff --git a/Documentation/Examples/OAuth2GMailExample.cs b/Documentation/Examples/OAuth2GMailExample.cs
index a1da1f2ac1..95ad1dc03a 100644
--- a/Documentation/Examples/OAuth2GMailExample.cs
+++ b/Documentation/Examples/OAuth2GMailExample.cs
@@ -21,12 +21,12 @@ public static void Main (string[] args)
             using (var client = new ImapClient ()) {
                 client.Connect ("imap.gmail.com", 993, SecureSocketOptions.SslOnConnect);
                 if (client.AuthenticationMechanisms.Contains ("OAUTHBEARER") || client.AuthenticationMechanisms.Contains ("XOAUTH2"))
-                    OAuthAsync (client).GetAwaiter ().GetResult ();
+                    AuthenticateAsync (client).GetAwaiter ().GetResult ();
                 client.Disconnect (true);
             }
         }
 
-        static async Task OAuthAsync (ImapClient client)
+        static async Task AuthenticateAsync (ImapClient client)
         {
             var clientSecrets = new ClientSecrets {
                 ClientId = "XXX.apps.googleusercontent.com",
@@ -45,7 +45,7 @@ static async Task OAuthAsync (ImapClient client)
 
             var credential = await authCode.AuthorizeAsync (GMailAccount, CancellationToken.None);
 
-            if (credential.Token.IsExpired (SystemClock.Default))
+            if (credential.Token.IsStale)
                 await credential.RefreshTokenAsync (CancellationToken.None);
 
             // Note: We use credential.UserId here instead of GMailAccount because the user *may* have chosen a
diff --git a/ExchangeOAuth2.md b/ExchangeOAuth2.md
index c1bc538fc9..4318dd5c49 100644
--- a/ExchangeOAuth2.md
+++ b/ExchangeOAuth2.md
@@ -64,18 +64,13 @@ AuthenticationResult? result;
 
 try {
     // First, check the cache for an auth token.
-    result = await publicClientApplication
-        .AcquireTokenSilent (scopes, EmailAddress)
-        .ExecuteAsync ();
+    result = await publicClientApplication.AcquireTokenSilent (scopes, EmailAddress).ExecuteAsync ();
 } catch (MsalUiRequiredException) {
     // If that fails, then try getting an auth token interactively.
-    result = await publicClientApplication
-        .AcquireTokenInteractive (scopes)
-        .WithLoginHint (EmailAddress)
-        .ExecuteAsync ();
+    result = await publicClientApplication.AcquireTokenInteractive (scopes).WithLoginHint (EmailAddress).ExecuteAsync ();
 }
 
-// Note: We always use authToken.Account.Username instead of `Username` because the user may have selected an alternative account.
+// Note: We always use result.Account.Username instead of `Username` because the user may have selected an alternative account.
 var oauth2 = new SaslMechanismOAuth2 (result.Account.Username, result.AccessToken);
 
 using (var client = new ImapClient ()) {
@@ -86,11 +81,11 @@ using (var client = new ImapClient ()) {
 ```
 
 Note: Once you've acquired an auth token using the interactive method above, you can avoid prompting the user
-if you cache the `authToken.Account` information and then silently reacquire auth tokens in the future using
+if you cache the `result.Account` information and then silently reacquire auth tokens in the future using
 the following code:
 
 ```csharp
-var authToken = await publicClientApplication.AcquireTokenSilent(scopes, account).ExecuteAsync(cancellationToken);
+var result = await publicClientApplication.AcquireTokenSilent(scopes, account).ExecuteAsync(cancellationToken);
 ```
 
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