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 qualified Data.ByteString.Lazy.Char8 as C
import System.Console.ArgParser
import System.Process

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

handleLocal :: String -> Bool -> IO ()
handleLocal name block = do
    out <- readProcess "namecoind" ["name_show", name] ""
    case decode (C.pack out) of
        Just res -> do
            jprint $ reparse (res |: "value")
            if block then jprint 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"

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

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