From 0ddc766aea2da868b4d8db92f508ee4a8eb1d60f Mon Sep 17 00:00:00 2001
From: Paul-Henri Froidmont <git.contact-57n2p@froidmont.org>
Date: Tue, 10 Dec 2019 00:09:55 +0100
Subject: [PATCH] Add nice, documented CLI parameters

---
 app/Main.hs       | 32 ++++++++++++++++++++++++--------
 minesweeper.cabal |  3 ++-
 package.yaml      |  1 +
 3 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/app/Main.hs b/app/Main.hs
index c766220..6e34175 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -1,19 +1,35 @@
+{-# LANGUAGE DataKinds          #-}
+{-# LANGUAGE DeriveGeneric      #-}
+{-# LANGUAGE FlexibleInstances  #-}
+{-# LANGUAGE OverloadedStrings  #-}
+{-# LANGUAGE StandaloneDeriving #-}
+{-# LANGUAGE TypeOperators      #-}
+
 module Main where
 
 import           Lib
-import           System.Environment
+import           Options.Generic
 import           System.Random
 import           Text.Read
 
+data Parameters w =
+  Parameters
+    { width  :: w ::: Int <?> "Width of the board"
+    , length :: w ::: Int <?> "Length of the board"
+    , bombs  :: w ::: Int <?> "Number of bombs to be placed"
+    }
+  deriving (Generic)
+
+instance ParseRecord (Parameters Wrapped)
+
+deriving instance Show (Parameters Unwrapped)
+
 main :: IO ()
 main = do
-  args <- getArgs
-  let boardWidth = read (head args)
-      boardLength = read (args !! 1)
-      bombs = read (args !! 2)
+  (Parameters boardWidth boardLength bombsCount) <- unwrapRecord "Minesweeper"
   generator <- newStdGen
   gameStep . createBoard boardWidth boardLength $
-    generateRandomCoordinates (boardWidth - 1) (boardLength - 1) bombs generator
+    generateRandomCoordinates (boardWidth - 1) (boardLength - 1) bombsCount generator
 
 gameStep :: Board -> IO ()
 gameStep board = do
@@ -32,8 +48,8 @@ getCoordinates = do
   xString <- getLine
   yString <- getLine
   case (readMaybe xString, readMaybe yString) of
-    (Just x, Just y) -> return (x,y)
-    _ -> putStrLn "Invalid coordinates!" >> getCoordinates
+    (Just x, Just y) -> return (x, y)
+    _                -> putStrLn "Invalid coordinates!" >> getCoordinates
 
 gameLost :: Board -> IO ()
 gameLost board = do
diff --git a/minesweeper.cabal b/minesweeper.cabal
index 140acb1..24359a6 100644
--- a/minesweeper.cabal
+++ b/minesweeper.cabal
@@ -4,7 +4,7 @@ cabal-version: 1.12
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 512c036467601196724c0e9412fc6175989ea1a8c48bf158d2cf62aa1c0b4311
+-- hash: ae0d0337fef94e96da9aaca377817a7cbca70851243db8fe2a6c435fe06f0cfa
 
 name:           minesweeper
 version:        0.1.0.0
@@ -37,6 +37,7 @@ executable minesweeper
   build-depends:
       base
     , minesweeper
+    , optparse-generic
     , random
   default-language: Haskell2010
 
diff --git a/package.yaml b/package.yaml
index bf66d5f..75ff961 100644
--- a/package.yaml
+++ b/package.yaml
@@ -24,6 +24,7 @@ executables:
     dependencies:
       - minesweeper
       - random
+      - optparse-generic
 
 tests:
   minesweeper-test: