Setup commit, play around with Req, Aeson and Scotty

src/Lisa/Squeak.hs

@@ -0,0 +1,90 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Lisa.Squeak where
+
+import Data.Aeson (FromJSON(parseJSON), ToJSON(toJSON), Value, (.:), (.:?), (.=), object, withObject)
+import Data.Text (Text)
+import Data.Time.Calendar (Day)
+import Network.HTTP.Req (POST(..), ReqBodyJson(..), Req, https, jsonResponse, responseBody, req)
+
+data GQLQuery = GQLQuery
+    { gqlQueryQuery :: Text
+    }
+    deriving (Show)
+
+instance ToJSON GQLQuery where
+    toJSON (GQLQuery q) = object ["query" .= q]
+
+data GQLReply a = GQLReply
+    { gqlReplyData :: Maybe a
+    , gqlReplyErrors :: Maybe [GQLError]
+    }
+    deriving (Show)
+
+instance FromJSON a => FromJSON (GQLReply a) where
+    parseJSON = withObject "GQLReply" $ \v -> GQLReply
+        <$> v .: "data"
+        <*> v .:? "errors"
+
+data GQLError = GQLError
+    { gqlErrorMessage :: Text
+    }
+    deriving (Show)
+
+instance FromJSON GQLError where
+    parseJSON = withObject "GQLError" $ \v -> GQLError
+        <$> v .: "message"
+
+data Documents = Documents { getDocuments :: [Document] }
+    deriving (Show)
+
+instance FromJSON Documents where
+    parseJSON = withObject "Documents" $ \v -> Documents
+        <$> ((v .: "documents") >>= (.: "results"))
+
+data Document = Document
+    { documentId            :: Text
+    , documentDate          :: Day
+    , documentSemester      :: Text
+    , documentPublicComment :: Maybe Text
+    , documentFaculty       :: Faculty
+    , documentLectures      :: [Lecture]
+    }
+    deriving (Show)
+
+instance FromJSON Document where
+    parseJSON = withObject "Document" $ \v -> Document
+        <$> v .: "id"
+        <*> v .: "date"
+        <*> v .: "semester"
+        <*> v .: "publicComment"
+        <*> v .: "faculty"
+        <*> v .: "lectures"
+
+data Faculty = Faculty
+    { facultyId          :: Text
+    , facultyDisplayName :: Text
+    }
+    deriving (Show)
+
+instance FromJSON Faculty where
+    parseJSON = withObject "Faculty" $ \v -> Faculty
+        <$> v .: "id"
+        <*> v .: "displayName"
+
+data Lecture = Lecture
+    { lectureId          :: Text
+    , lectureDisplayName :: Text
+    }
+    deriving (Show)
+
+instance FromJSON Lecture where
+    parseJSON = withObject "Lecture" $ \v -> Lecture
+        <$> v .: "id"
+        <*> v .: "displayName"
+
+serverUrl = https "api.squeak-test.fsmi.uni-karlsruhe.de"
+
+getLectures :: Req (GQLReply Documents)
+getLectures = responseBody <$> req POST serverUrl (ReqBodyJson $ GQLQuery q) jsonResponse mempty
+    where q = "{ documents(filters: []) { results { id date semester publicComment faculty { id displayName } lectures { id displayName } } } }"