{-# LANGUAGE OverloadedStrings #-}

module HEyefi.Soap
       ( handleSoapAction
       , soapAction
       , mkResponse )
       where

import           HEyefi.Config (getUploadKeyForMacaddress)
import           HEyefi.GetPhotoStatus (getPhotoStatusResponse)
import           HEyefi.Hex (unhex)
import           HEyefi.Log (logInfo, logDebug)
import           HEyefi.MarkLastPhotoInRoll (markLastPhotoInRollResponse)
import           HEyefi.StartSession (startSessionResponse)
import           HEyefi.Types (HEyefiM, HEyefiApplication, lastSNonce)


import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as BL

import           Control.Arrow ((>>>))
import           Control.Monad.IO.Class (liftIO)
import           Control.Monad.State.Lazy (get)
import           Data.ByteString.Lazy (fromStrict)
import           Data.ByteString.Lazy.UTF8 (toString)
import           Data.ByteString.UTF8 (fromString)
import qualified Data.CaseInsensitive as CI
import           Data.Hash.MD5 (md5s, Str (..))
import           Data.List (find)
import           Data.Maybe (fromJust)
import           Data.Time.Clock (getCurrentTime, UTCTime)
import           Data.Time.Format (formatTime, rfc822DateFormat, defaultTimeLocale)
import           Network.HTTP.Types (status200, unauthorized401)
import Network.HTTP.Types.Header (hContentType,
                                  hServer,
                                  hContentLength,
                                  hDate,
                                  Header,
                                  HeaderName)
import Network.Wai ( responseLBS
                   , Request
                   , Response
                   , requestHeaders )
import           Text.HandsomeSoup (css)
import Text.XML.HXT.Core ( runX
                         , readString
                         , getText
                         , (/>))


data SoapAction = StartSession
                | GetPhotoStatus
                | MarkLastPhotoInRoll
                deriving (Show, Eq)

headerIsSoapAction :: Header -> Bool
headerIsSoapAction ("SOAPAction",_) = True
headerIsSoapAction _ = False

soapAction :: Request -> Maybe SoapAction
soapAction req =
  case find headerIsSoapAction (requestHeaders req) of
   Just (_,"\"urn:StartSession\"") -> Just StartSession
   Just (_,"\"urn:GetPhotoStatus\"") -> Just GetPhotoStatus
   Just (_,"\"urn:MarkLastPhotoInRoll\"") -> Just MarkLastPhotoInRoll
   Just (_,sa) -> error ((show sa) ++ " is not a defined SoapAction yet")
   _ -> Nothing

mkResponse :: String -> HEyefiM Response
mkResponse responseBody = do
  t <- liftIO getCurrentTime
  return (responseLBS
          status200
          (defaultResponseHeaders t (length responseBody))
          (fromStrict (fromString responseBody)))

mkUnauthorizedResponse :: Response
mkUnauthorizedResponse = responseLBS unauthorized401 [] ""

defaultResponseHeaders :: UTCTime ->
                          Int ->
                          [(HeaderName, B.ByteString)]
defaultResponseHeaders time size =
  [ (hContentType, "text/xml; charset=\"utf-8\"")
  , (hDate, fromString (formatTime defaultTimeLocale rfc822DateFormat time))
  , (CI.mk "Pragma", "no-cache")
  , (hServer, "Eye-Fi Agent/2.0.4.0 (Windows XP SP2)")
  , (hContentLength, fromString (show size))]

handleSoapAction :: SoapAction -> BL.ByteString -> HEyefiApplication
handleSoapAction StartSession body _ f = do
  logInfo "Got StartSession request"
  let xmlDocument = readString [] (toString body)
  let getTagText = \ s -> liftIO (runX (xmlDocument >>> css s /> getText))
  macaddress <- getTagText "macaddress"
  cnonce <- getTagText "cnonce"
  transfermode <- getTagText "transfermode"
  transfermodetimestamp <- getTagText "transfermodetimestamp"
  logDebug (show macaddress)
  logDebug (show transfermodetimestamp)
  responseBody <- (startSessionResponse
                   (head macaddress)
                   (head cnonce)
                   (head transfermode)
                   (head transfermodetimestamp))
  logDebug (show responseBody)
  response <- mkResponse responseBody
  liftIO (f response)
handleSoapAction GetPhotoStatus body _ f = do
  logInfo "Got GetPhotoStatus request"
  credentialGood <- checkCredential body
  if credentialGood then do
    responseBody <- getPhotoStatusResponse
    response <- mkResponse responseBody
    liftIO (f response)
  else do
    liftIO (f mkUnauthorizedResponse)
handleSoapAction MarkLastPhotoInRoll _ _ f = do
  logInfo "Got MarkLastPhotoInRoll request"
  responseBody <- markLastPhotoInRollResponse
  response <- mkResponse responseBody
  liftIO (f response)


checkCredential :: BL.ByteString -> HEyefiM Bool
checkCredential body = do
  let xmlDocument = readString [] (toString body)
  let getTagText = \ s -> liftIO (runX (xmlDocument >>> css s /> getText))
  macaddress <- getTagText "macaddress"
  credential <- getTagText "credential"
  state <- get
  let snonce = lastSNonce state
  upload_key_0 <- getUploadKeyForMacaddress (head macaddress)
  case upload_key_0 of
   Nothing -> do
     logInfo ("No upload key found in configuration for macaddress: " ++ (head macaddress))
     return False
   Just upload_key_0' -> do
     let credentialString = (head macaddress) ++ upload_key_0' ++ snonce
     let binaryCredentialString = unhex credentialString
     let expectedCredential = md5s (Str (fromJust binaryCredentialString))
     if ((head credential) /= expectedCredential) then do
       logInfo ("Invalid credential in GetPhotoStatus request. Expected: "
                ++ expectedCredential ++ " Actual: " ++ (head credential))
       return False
     else
       return True