gunnerkrigg_court.hs

#!/usr/bin/env stack
{-
stack script
--resolver lts-13.29 --install-ghc
  --package base
  --package shake
  --package hspec
  --package getopt-generics
-}

{-# LANGUAGE ViewPatterns #-}
{-# LANGUAGE ScopedTypeVariables #-}

import Development.Shake
import Test.Hspec
import Data.Foldable
import WithCli
import Data.Maybe
import System.Environment

main :: IO ()
main = do
  withArgs [] $ hspec spec
  withCli run

run :: Maybe Int -> Maybe Int -> IO ()
run (fromMaybe 1 -> from :: Int) (fromMaybe 2182 -> to :: Int) = do
  forM_ [from .. to] $ \ n -> do
    unit $ cmd "wget" (mkUrl n)

mkUrl :: Int -> String
mkUrl n =
  "https://www.gunnerkrigg.com/comics/" ++
  formattedN ++
  ".jpg"
  where
    formattedN =
      replicate (8 - length (show n)) '0' ++ show n

spec :: Spec
spec = do
  describe "mkUrl" $ do
    it "returns the correctly formatted url" $ do
      mkUrl 1 `shouldBe`
        "https://www.gunnerkrigg.com/comics/00000001.jpg"

    it "works for higher numbers" $ do
      mkUrl 10 `shouldBe`
        "https://www.gunnerkrigg.com/comics/00000010.jpg"