Add ClassLink plugin

.env.example

@@ -14,6 +14,9 @@ BATTLE_NET_CLIENT_SECRET=x
 BITBUCKET_CLIENT_ID=x
 BITBUCKET_CLIENT_SECRET=x
 
+CLASSLINK_CLIENT_ID=x
+CLASSLINK_CLIENT_SECRET=x
+
 EVE_ONLINE_CLIENT_ID=x
 EVE_ONLINE_CLIENT_SECRET=x
 

example/Main.hs

@@ -38,6 +38,7 @@ import Yesod.Auth
 import Yesod.Auth.OAuth2.AzureAD
 import Yesod.Auth.OAuth2.BattleNet
 import Yesod.Auth.OAuth2.Bitbucket
+import Yesod.Auth.OAuth2.ClassLink
 import Yesod.Auth.OAuth2.EveOnline
 import Yesod.Auth.OAuth2.GitHub
 import Yesod.Auth.OAuth2.GitLab
@@ -137,6 +138,7 @@ mkFoundation = do
         [ loadPlugin oauth2AzureAD "AZURE_AD"
         , loadPlugin (oauth2BattleNet [whamlet|TODO|] "en") "BATTLE_NET"
         , loadPlugin oauth2Bitbucket "BITBUCKET"
+        , loadPlugin oauth2ClassLink "CLASSLINK"
         , loadPlugin (oauth2Eve Plain) "EVE_ONLINE"
         , loadPlugin oauth2GitHub "GITHUB"
         , loadPlugin oauth2GitLab "GITLAB"

src/Yesod/Auth/OAuth2/ClassLink.hs

@@ -0,0 +1,51 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Yesod.Auth.OAuth2.ClassLink
+    ( oauth2ClassLink
+    , oauth2ClassLinkScoped
+    )
+where
+
+import Yesod.Auth.OAuth2.Prelude
+
+import qualified Data.Text as T
+
+newtype User = User Int
+
+instance FromJSON User where
+    parseJSON = withObject "User" $ \o -> User <$> o .: "UserId"
+
+pluginName :: Text
+pluginName = "classlink"
+
+defaultScopes :: [Text]
+defaultScopes = ["profile", "oneroster"]
+
+oauth2ClassLink :: YesodAuth m => Text -> Text -> AuthPlugin m
+oauth2ClassLink = oauth2ClassLinkScoped defaultScopes
+
+oauth2ClassLinkScoped :: YesodAuth m => [Text] -> Text -> Text -> AuthPlugin m
+oauth2ClassLinkScoped scopes clientId clientSecret =
+    authOAuth2 pluginName oauth2 $ \manager token -> do
+        (User userId, userResponse) <- authGetProfile
+            pluginName
+            manager
+            token
+            "https://nodeapi.classlink.com/v2/my/info"
+
+        pure Creds
+            { credsPlugin = pluginName
+            , credsIdent = T.pack $ show userId
+            , credsExtra = setExtra token userResponse
+            }
+  where
+    oauth2 = OAuth2
+        { oauthClientId = clientId
+        , oauthClientSecret = Just clientSecret
+        , oauthOAuthorizeEndpoint =
+            "https://launchpad.classlink.com/oauth2/v2/auth"
+                `withQuery` [scopeParam "," scopes]
+        , oauthAccessTokenEndpoint =
+            "https://launchpad.classlink.com/oauth2/v2/token"
+        , oauthCallback = Nothing
+        }