rosa/Main.hs

{-# LANGUAGE RecordWildCards, OverloadedStrings #-}

import Network.Wreq        (get, responseBody)
import Data.Aeson          (decode, toJSON)
import Data.Maybe          (fromJust)
import Data.HashMap.Strict (delete)
import Control.Lens
import Control.Applicative
import System.Console.ArgParser
import System.Process
import qualified Data.ByteString.Lazy.Char8 as C
import Json


data ProgArgs = ProgArgs
  { name     :: String
  , url      :: String
  , dnschain :: Bool
  , block    :: Bool
  , raw      :: Bool
  } deriving (Show)


parser :: ParserSpec ProgArgs
parser = ProgArgs
  `parsedBy` reqPos   "name"     `Descr` "Namecoin name id"
  `andBy`    optFlag  "http://dns.dnschain.net/" "url"
                                 `Descr` "Use custom api url"
  `andBy`    boolFlag "dnschain" `Descr` "Use dnschain api"
  `andBy`    boolFlag "block"    `Descr` "Show blockchain data (require local connecton)"
  `andBy`    boolFlag "raw"      `Descr` "Print raw JSON data"


interface :: IO (CmdLnInterface ProgArgs)
interface =
  (`setAppDescr`  "Query the namecoin blockchain") <$> 
  (`setAppEpilog` "Stat rosa pristina nomine, nomina nuda tenemus.") <$>
  mkApp parser


main :: IO ()
main = interface >>= flip runApp exec


exec :: ProgArgs -> IO ()
exec ProgArgs{..} = do
  if dnschain
  then handleDnschain url name raw
  else handleLocal name block


handleLocal :: String -> Bool -> IO ()
handleLocal name block = do
  out <- readProcess "namecoind" ["name_show", name] ""
  case decode (C.pack out) of
    Just res -> do
      pprint $ reparse (res |: "value")
      if block then pprint extra else return ()
      where
        reparse = fromJust . decode . C.pack
        extra   = toJSON $ delete "value" res
    Nothing  -> putStrLn "Error parsing data"


handleDnschain :: String -> String -> Bool -> IO ()
handleDnschain url name raw = do
  req <- get (url ++ name)
  let body = req ^. responseBody
  if raw
  then print body
  else putStrLn $
    case decode body of
      Just res -> repr res
      Nothing  -> "Error parsing data"