CrossRef.hs

{-# LANGUAGE OverloadedStrings   #-}
{-# LANGUAGE ScopedTypeVariables #-}
module Main where

import           Data.Aeson
import qualified Data.ByteString.Lazy as BSL
import qualified Data.Text            as T


main :: IO ()
main = do
  contents <- BSL.readFile "works.nofilter.json"
  let (t :: Maybe Test) = decode contents
  -- let something = parse json contents
  print t
  putStrLn "Hello, Haskell! Let's see if this works!"

  -- print

data Test = Test { status  :: T.Text
                 , message :: Message
                 -- , nope    :: Maybe T.Text
                 } deriving (Show, Eq, Ord)
instance FromJSON Test where
    -- parseJSON (Object v) = parseField v "status"
    parseJSON (Object v) = Test <$> v .: "status" <*> v .: "message"
    parseJSON _          = error "we didn't do this yet!"

data Message = Message {
      total_result :: Integer
    , items        :: [SResult]
    } deriving (Show, Ord, Eq)
instance FromJSON Message where
    parseJSON (Object v) = Message <$> v .: "total-results" <*> v .: "items"
    parseJSON _          = error "no"

data SResult = SResult {
      doi     :: T.Text
    , title   :: [T.Text]
    , authors :: [Author]
    -- , pubDate :: [Int]
    } deriving (Show, Eq, Ord)
instance FromJSON SResult where
    parseJSON (Object v) = SResult
                           <$> v .: "DOI"
                           <*> v .: "title"
                           <*> v .: "author"
                           -- <*> v .: "published-print" -- .: "date-parts"
    parseJSON _          = error "bad SResult"

data Author = Author {
      given  :: T.Text
    -- , family :: T.Text
    } deriving (Show, Eq, Ord)
instance FromJSON Author where
    parseJSON (Object v) = Author
                           <$> v .: "given"
                           -- <*> v .: "family"
    parseJSON _          = error "bad author"