{-# LANGUAGE OverloadedStrings #-}
module Sender
  (generateMail
  ,send
  ) where
  
import Network.Mail.Mime
import Network.Mail.SMTP
import qualified Data.Text as ST
import qualified Data.Text.Lazy as LT
import Monad
import Data.Time.LocalTime (getZonedTime)
import Data.Time.Format (formatTime, defaultTimeLocale)

rfc5322Format :: String
rfc5322Format = "%a, %d %b %0Y %T %z"

generateMail :: (MonadIO m) => ST.Text -> ST.Text -> ST.Text -> LT.Text -> m Mail
generateMail to from subj body = do
  time <- liftIO getZonedTime
  let timeString = ST.pack $ formatTime defaultTimeLocale rfc5322Format time
      mailWithoutDate = simpleMail' (Address Nothing to) (Address Nothing from) subj body
      mailWithDate = mailWithoutDate {mailHeaders = ("Date",timeString) : mailHeaders mailWithoutDate}
  return mailWithDate

--     domain -> Username -> password -> To  -> From   -> Subject -> Body
send :: (MonadIO m) => String -> String -> String -> ST.Text -> ST.Text -> ST.Text -> LT.Text -> m ()
send domain user pass to from subj body = do
  mail <- liftIO $ generateMail to from subj body
  liftIO $ sendMailWithLoginTLS domain user pass mail