src/Twitter/Http.hs

   1 module Twitter.Http (
   2   get_user_new_statuses,
   3   get_user_timeline,
   4   http_get )
   5 where
   6
   7 import qualified Data.ByteString.Lazy as B ( ByteString )
   8 import qualified Data.ByteString.Char8 as BC ( pack )
   9 import Network.HTTP.Client (
  10   httpLbs,
  11   newManager,
  12   parseUrl,
  13   responseBody )
  14 import Network.HTTP.Client.TLS ( tlsManagerSettings )
  15 import Web.Authenticate.OAuth (
  16   OAuth(..),
  17   Credential,
  18   newCredential,
  19   newOAuth,
  20   signOAuth )
  21
  22 import Configuration ( Cfg(..) )
  23
  24
  25 -- | The API URL of username's timeline.
  26 --
  27 -- See,
  28 --
  29 --   <https://dev.twitter.com/docs/api/1.1/get/statuses/user_timeline>
  30 --
  31 user_timeline_url :: String -> String
  32 user_timeline_url username =
  33   concat [ "https://api.twitter.com/",
  34            "1.1/",
  35            "statuses/",
  36            "user_timeline.json?",
  37            "screen_name=",
  38            username,
  39            "&include_rts=true&",
  40            "count=10" ]
  41
  42
  43 -- | Given username's last status id, constructs the API URL for
  44 --   username's new statuses. Essentially, 'user_timeline_url' with a
  45 --   \"since_id\" parameter tacked on.
  46 --
  47 user_new_statuses_url :: String -> Integer -> String
  48 user_new_statuses_url username last_status_id =
  49   url ++ "&since_id=" ++ since_id
  50   where
  51     url = user_timeline_url username
  52     since_id = show last_status_id
  53
  54
  55 -- | Return's username's timeline.
  56 --
  57 get_user_timeline :: Cfg -> String -> IO B.ByteString
  58 get_user_timeline cfg username = do
  59   let uri = user_timeline_url username
  60   http_get cfg uri
  61
  62
  63 -- | Returns the JSON representing all of username's statuses that are
  64 --   newer than @last_status_id@.
  65 --
  66 get_user_new_statuses :: Cfg -> String -> Integer -> IO B.ByteString
  67 get_user_new_statuses cfg username last_status_id = do
  68   let uri = user_new_statuses_url username last_status_id
  69   http_get cfg uri
  70
  71
  72 -- | Retrieve a URL, or crash. The request is signed using all of the
  73 --   OAuth junk contained in the configuration.
  74 --
  75 http_get :: Cfg -> String -> IO B.ByteString
  76 http_get cfg url = do
  77   manager <- newManager tlsManagerSettings
  78   request <- parseUrl url
  79   signed_request <- signOAuth oauth credential request
  80   response <- httpLbs signed_request manager
  81   return $ responseBody response
  82
  83   where
  84     consumer_key' = BC.pack (consumer_key cfg)
  85     consumer_secret' = BC.pack (consumer_secret cfg)
  86     access_token' = BC.pack (access_token cfg)
  87     access_secret' = BC.pack (access_secret cfg)
  88
  89     oauth :: OAuth
  90     oauth = newOAuth {
  91               oauthConsumerKey = consumer_key',
  92               oauthConsumerSecret = consumer_secret' }
  93
  94     credential :: Credential
  95     credential = newCredential access_token' access_secret'