-- | XEP 0077: In-Band Registration
-- http://xmpp.org/extensions/xep-0077.html

{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE NoMonomorphismRestriction #-}
{-# LANGUAGE PatternGuards #-}
{-# LANGUAGE OverloadedStrings #-}

module Network.Xmpp.Xep.InbandRegistration where

import           Control.Applicative((<$>))
import           Control.Arrow(left)
import           Control.Exception
import           Control.Monad.Error
import           Control.Monad.State

import           Data.Either (partitionEithers)
import qualified Data.Text as Text
import           Data.XML.Pickle
import qualified Data.XML.Types as XML

import           Network.Xmpp.Connection
import           Network.Xmpp.Pickle
import           Network.Xmpp.Types
import           Network.Xmpp.Xep.ServiceDiscovery


-- In-Band Registration name space
ibrns :: Text.Text
ibrns = "jabber:iq:register"

ibrName x = (XML.Name x (Just ibrns) Nothing)

data IbrError = IbrNotSupported
              | IbrNoConnection
              | IbrIQError IQError

                deriving (Show)
instance Error IbrError


data Query = Query { instructions :: Maybe Text.Text
                   , registered   :: Bool
                   , remove       :: Bool
                   , fields       ::[(Field, Maybe Text.Text)]
                   } deriving Show

emptyQuery = Query Nothing False False []

-- supported :: XmppConMonad (Either IbrError Bool)
-- supported = runErrorT $ fromFeatures <+> fromDisco
--   where
--   fromFeatures = do
--       fs <- other <$> gets sFeatures
--       let fe = XML.Element
--                    "{http://jabber.org/features/iq-register}register"
--                    []
--                    []
--       return $ fe `elem` fs
--   fromDisco = do
--       hn' <- gets sHostname
--       hn <- case hn' of
--           Just h -> return (Jid Nothing h Nothing)
--           Nothing -> throwError IbrNoConnection
--       qi <- lift $ xmppQueryInfo Nothing Nothing
--       case qi of
--           Left e -> return False
--           Right qir -> return $ "jabber:iq:register" `elem` qiFeatures qir
--   f <+> g = do
--             r <- f
--             if r then return True else g


query :: IQRequestType -> Query -> TMVar Connection -> IO (Either IbrError Query)
query queryType x con = do
    answer <- pushIQ' "ibr" Nothing queryType Nothing (pickleElem xpQuery x) con
    case answer of
        Right IQResult{iqResultPayload = Just b} ->
            case unpickleElem xpQuery b of
                Right query -> return $ Right query
                Left e -> throw . StreamXMLError $
                            "RequestField: unpickle failed, got "
                            ++ Text.unpack (ppUnpickleError e)
                            ++ " saw " ++ ppElement b
        Right _ -> return $ Right emptyQuery -- TODO: That doesn't seem right
        Left e -> return . Left $ IbrIQError e

data RegisterError = IbrError IbrError
                   | MissingFields   [Field]
                   | AlreadyRegistered
                     deriving (Show)

instance Error RegisterError

mapError f = mapErrorT (liftM $ left f)

-- | Retrieve the necessary fields and fill them in to register an account with
-- the server
registerWith :: [(Field, Text.Text)]
             -> TMVar Connection
             -> IO  (Either RegisterError Query)
registerWith givenFields con = runErrorT $ do
    fs <- mapError IbrError . ErrorT $ requestFields con
    when (registered fs) . throwError $ AlreadyRegistered
    let res = flip map (fields fs) $ \(field,_) ->
            case lookup field givenFields of
                Just entry -> Right (field, Just entry)
                Nothing -> Left field
    fields <- case partitionEithers res of
        ([],fs) -> return fs
        (fs,_) -> throwError $ MissingFields fs
    result <- mapError IbrError . ErrorT $ query Set (emptyQuery {fields}) con
    return result

-- | Terminate your account on the server. You have to be logged in for this to
-- work. You connection will most likely be terminated after unregistering.
unregister :: TMVar Connection -> IO (Either IbrError Query)
unregister = query Set $ emptyQuery {remove = True}

requestFields con = runErrorT $ do
--     supp <- ErrorT supported
--    unless supp $ throwError $ IbrNotSupported
    qr <- ErrorT $ query Get emptyQuery con
    return $ qr

xpQuery :: PU [XML.Node] Query
xpQuery = xpWrap
            (\(is, r, u, fs) -> Query is r u fs)
            (\(Query is r u fs) -> (is, r, u, fs)) $
            xpElemNodes (ibrName "query") $
              xp4Tuple
                 (xpOption $
                    xpElemNodes (ibrName "instructions") (xpContent $ xpText))
                 (xpElemExists (ibrName "registered"))
                 (xpElemExists (ibrName "remove"))
                 (xpAllByNamespace ibrns  ( xpWrap
                                              (\(name,_,c) -> (name, c))
                                              (\(name,c) -> (name,(),c)) $
                         xpElemByNamespace ibrns xpPrim xpUnit
                           (xpOption $ xpContent xpText)
                        ))

data Field = Username
           | Nick
           | Password
           | Name
           | First
           | Last
           | Email
           | Address
           | City
           | State
           | Zip
           | Phone
           | Url
           | Date
           | Misc
           | Text
           | Key
           | OtherField Text.Text
             deriving Eq

instance Show Field where
    show  Username       = "username"
    show  Nick           = "nick"
    show  Password       = "password"
    show  Name           = "name"
    show  First          = "first"
    show  Last           = "last"
    show  Email          = "email"
    show  Address        = "address"
    show  City           = "city"
    show  State          = "state"
    show  Zip            = "zip"
    show  Phone          = "phone"
    show  Url            = "url"
    show  Date           = "date"
    show  Misc           = "misc"
    show  Text           = "text"
    show  Key            = "key"
    show  (OtherField x) = Text.unpack x

instance Read Field where
    readsPrec _ "username" = [(Username     , "")]
    readsPrec _ "nick"     = [(Nick         , "")]
    readsPrec _ "password" = [(Password     , "")]
    readsPrec _ "name"     = [(Name         , "")]
    readsPrec _ "first"    = [(First        , "")]
    readsPrec _ "last"     = [(Last         , "")]
    readsPrec _ "email"    = [(Email        , "")]
    readsPrec _ "address"  = [(Address      , "")]
    readsPrec _ "city"     = [(City         , "")]
    readsPrec _ "state"    = [(State        , "")]
    readsPrec _ "zip"      = [(Zip          , "")]
    readsPrec _ "phone"    = [(Phone        , "")]
    readsPrec _ "url"      = [(Url          , "")]
    readsPrec _ "date"     = [(Date         , "")]
    readsPrec _ "misc"     = [(Misc         , "")]
    readsPrec _ "text"     = [(Text         , "")]
    readsPrec _ "key"      = [(Key          , "")]
    readsPrec _ x          = [(OtherField $ Text.pack x , "")]



-- Registered
-- Instructions