    {-# LANGUAGE DeriveDataTypeable, FlexibleContexts, OverloadedStrings #-}
    module Facebook.Object.User
        ( User(..)
        , Gender(..)
        , getUser
        , searchUsers
        , getUserCheckins
        , Friend(..)
        , getUserFriends
        ) where

    import Control.Applicative
    import Control.Monad (mzero)
    import Control.Monad.Trans.Control (MonadBaseControl)
    import Data.Aeson ((.:), (.:?))
    import Data.Text (Text)
    import Data.Typeable (Typeable)

    import qualified Control.Monad.Trans.Resource as R
    import qualified Data.Aeson as A

    import Facebook.Types
    import Facebook.Monad
    import Facebook.Graph
    import Facebook.Pager
    import Facebook.Object.Checkin

    -- | A Facebook user profile (see
    -- <https://developers.facebook.com/docs/reference/api/user/>).
    --
    -- /NOTE:/ We still don't support all fields supported by
    -- Facebook. Please fill an issue if you need access to any other
    -- fields.
    data User =
        User { userId         :: UserId
             , userName       :: Maybe Text
             , userFirstName  :: Maybe Text
             , userMiddleName :: Maybe Text
             , userLastName   :: Maybe Text
             , userGender     :: Maybe Gender
             , userLocale     :: Maybe Text
             , userUsername   :: Maybe Text
             , userVerified   :: Maybe Bool
             , userEmail      :: Maybe Text
             , userLocation   :: Maybe Place
             }
        deriving (Eq, Ord, Show, Read, Typeable)

    instance A.FromJSON User where
        parseJSON (A.Object v) =
          User <$> v .:  "id"
               <*> v .:? "name"
               <*> v .:? "first_name"
               <*> v .:? "middle_name"
               <*> v .:? "last_name"
               <*> v .:? "gender"
               <*> v .:? "locale"
               <*> v .:? "username"
               <*> v .:? "verified"
               <*> v .:? "email"
               <*> v .:? "location"
        parseJSON _ = mzero

    -- | An user's gender.
    data Gender = Male | Female deriving (Eq, Ord, Show, Read, Enum, Typeable)

    instance A.FromJSON Gender where
        parseJSON (A.String "male")   = return Male
        parseJSON (A.String "female") = return Female
        parseJSON _                   = mzero

    instance A.ToJSON Gender where
        toJSON = A.toJSON . toText
            where
              toText :: Gender -> Text
              toText Male   = "male"
              toText Female = "female"

    -- | Get an user using his user ID.  The user access token is
    -- optional, but when provided more information can be returned
    -- back by Facebook.  The user ID may be @\"me\"@, in which
    -- case you must provide an user access token and information
    -- about the token's owner is given.
    getUser :: (R.MonadResource m, MonadBaseControl IO m) =>
               UserId         -- ^ User ID or @\"me\"@.
            -> [Argument]     -- ^ Arguments to be passed to Facebook.
            -> Maybe UserAccessToken -- ^ Optional user access token.
            -> FacebookT anyAuth m User
    getUser id_ query mtoken = getObject ("/" <> idCode id_) query mtoken

    -- | Search users by keyword.
    searchUsers :: (R.MonadResource m, MonadBaseControl IO m)
                => Text
                -> [Argument]
                -> Maybe UserAccessToken
                -> FacebookT anyAuth m (Pager User)
    searchUsers = searchObjects "user"

    -- | Get a list of check-ins made by a given user.
    getUserCheckins ::
         (R.MonadResource m, MonadBaseControl IO m) =>
         UserId          -- ^ User ID or @\"me\"@.
      -> [Argument]      -- ^ Arguments to be passed to Facebook.
      -> UserAccessToken -- ^ User access token.
      -> FacebookT anyAuth m (Pager Checkin)
    getUserCheckins id_ query token =
      getObject ("/" <> idCode id_ <> "/checkins") query (Just token)

    -- | A friend connection of a 'User'.
    data Friend =
        Friend { friendId   :: UserId
               , friendName :: Text
               }
        deriving (Eq, Ord, Show, Read, Typeable)

    instance A.FromJSON Friend where
        parseJSON (A.Object v) =
          Friend <$> v .: "id"
                 <*> v .: "name"
        parseJSON _ = mzero

    -- | Get the list of friends of the given user.
    getUserFriends ::
         (R.MonadResource m, MonadBaseControl IO m) =>
         UserId          -- ^ User ID or @\"me\"@.
      -> [Argument]      -- ^ Arguments to be passed to Facebook.
      -> UserAccessToken -- ^ User access token.
      -> FacebookT anyAuth m (Pager Friend)
    getUserFriends id_ query token =
      getObject ("/" <> idCode id_ <> "/friends") query (Just token)