{-# LANGUAGE OverloadedStrings #-}

module Main where

import           Filesystem.Path.CurrentOS    (encodeString)
import qualified System.IO.Streams            as Streams
import           System.IO.Streams.Attoparsec (parseFromStream)
import           Turtle                       (Parser, argPath, options)

import           AWS.PubKeys                  (getPubKeys, instanceParser, writePubKeys)
import           AWS.Types                    (Ec2Instance (..))


main :: IO ()
main = options "Get SSH pubkeys from EC2" args >>= processPubKeys


args :: Parser (FilePath, FilePath)
args = (,)
    <$> (encodeString <$> argPath "instance_file" "File with information about EC2 hosts")
    <*> (encodeString <$> argPath "pubkey_file" "Path to JSON pubkey file to output")


-- TODO Implement a function to poll until all pubkeys are available
processPubKeys :: (FilePath, FilePath) -> IO ()
processPubKeys (instanceFile, pubKeyFile) = writePubKeys pubKeyFile =<< getPubKeys =<< readInstances instanceFile


readInstances :: FilePath -> IO [Ec2Instance]
readInstances = ($ parseFromStream instanceParser) . Streams.withFileAsInput