modular api handling part 1

README.md

@@ -7,6 +7,7 @@ to get the needed dependencies.
 
 ### Dependencies
 This project makes use of the following dependencies (specified in `profun.cabal`):
-* http-client
-* http-client-tls
-* http-conduit
+* http-client (for API requests)
+* http-client-tls (for API requests)
+* http-conduit (for API requests)
+* aeson (JSON parsing)

app/Main.hs

@@ -1,8 +1,34 @@
-{-# LANGUAGE OverloadedStrings #-} --needed for string arguments
+{-# LANGUAGE OverloadedStrings #-} --needed for ByteString arguments
 import Network.HTTP.Simple
+import System.Environment (lookupEnv)
 
 main :: IO ()
 main = do
-    apiResponse <- httpLBS "POST http://httpbin.org/get"
+    apiKey <- getWeatherKey
+    let todayRequest = apiRequestBuilder apiKey "today"
+    response <- httpJSON todayRequest :: IO (Response ())
+    putStrLn $ show todayRequest
+    putStrLn $ show $ getResponseStatusCode response
+    --apiResponse <- httpJSON "http://httpbin.org/get" :: IO (Response ()) -- specifying type as httpJSON return value is ambigious
 
-    putStrLn $ "Status code: " ++ show (getResponseStatusCode apiResponse)
+
+
+getWeatherKey :: IO String
+getWeatherKey = do
+    result <- lookupEnv "WEATHER_API_KEY"
+    case result of
+        Just a -> return a
+        Nothing -> error "API key not set in environmental variables!" -- exception thrown (but not handled) per project requirement
+
+apiRequestBuilder :: String -> String -> Request
+apiRequestBuilder apiKey day = 
+            setRequestHost "api.weatherapi.com"
+            $ setRequestPath path
+            $ setRequestMethod "GET"
+            $ setRequestQueryString [("q", Just "Poznan"), ("key", Just "apiKey")]
+            $ setRequestPort 443
+            $ setRequestSecure True
+            $ defaultRequest
+                where path
+                        | day == "today" = "/v1/current.json"
+                        | otherwise = "/d"

profun.cabal

@@ -67,7 +67,8 @@ executable profun
     build-depends:    base ^>=4.17.2.1,
                       http-client ^>=0.7.17,
                       http-client-tls ^>=0.3.6.3,
-                      http-conduit ^>=2.3.8.3
+                      http-conduit ^>=2.3.8.3,
+                      aeson ^>=2.2.2.0
 
     -- Directories containing source files.
     hs-source-dirs:   app