{-# LANGUAGE FlexibleContexts #-}

module Main where

import Diagrams.Prelude hiding (value, option, (<>), Result)

import Diagrams.Puzzles.CmdLine

import Text.Puzzles.Puzzle
import Data.Puzzles.Compose
import Data.Puzzles.PuzzleTypes (typeNames)
import Diagrams.Puzzles.Draw

import Options.Applicative
import Control.Monad
import Data.Maybe
import Data.List (intercalate, sort)

import System.FilePath
import System.Environment (getProgName)

import qualified Data.Yaml as Y

optListTypes :: Parser (a -> a)
optListTypes =
    infoOption
        (unlines' . sort . map snd $ typeNames)
        (long "list-types"
         <> help "List supported puzzle types")
  where
    unlines' = intercalate "\n"

data PuzzleOpts = PuzzleOpts
    { _format   :: String
    , _type     :: Maybe String
    , _puzzle   :: Bool
    , _solution :: Bool
    , _example  :: Bool
    , _input    :: FilePath
    }

puzzleOpts :: Parser PuzzleOpts
puzzleOpts = PuzzleOpts
    <$> strOption
            (long "format" <> short 'f'
             <> value (head formats)
             <> metavar "FMT"
             <> help ("Desired output format by file extension " ++ fmts))
    <*> (optional . strOption $
            (long "type" <> short 't'
             <> metavar "TYPE"
             <> help "Puzzle type, overriding type in input file"))
    <*> switch
            (long "puzzle" <> short 'p'
             <> help "Render puzzle (to base.ext)")
    <*> switch
            (long "solution" <> short 's'
             <> help "Render solution (to base-sol.ext)")
    <*> switch
            (long "example" <> short 'e'
             <> help "Render example (to base.ext)")
    <*> argument str
            (metavar "INPUT"
             <> help "Puzzle file in .pzl format")
  where
    fmts = "(" ++ intercalate ", " formats ++ ")"

cmtopoint :: Double -> Double
cmtopoint = (* 28.3464567)

outputSuffix :: OutputChoice -> String
outputSuffix DrawPuzzle = ""
outputSuffix DrawSolution = "-sol"
outputSuffix DrawExample = ""

toRenderOpts :: OutputChoice -> Double -> PuzzleOpts -> RenderOpts
toRenderOpts oc w opts = RenderOpts out w'
  where
    f = _format opts
    u = case f of "png" -> Pixels
                  _     -> Points
    w' = toOutputWidth u w
    base = takeBaseName (_input opts)
    out = addExtension (base ++ outputSuffix oc) f

renderPuzzle :: PuzzleOpts -> (OutputChoice -> Maybe (Diagram B R2)) ->
                (OutputChoice, Bool) -> IO ()
renderPuzzle opts r (oc, req) = do
    let x = r oc
    when (req && isNothing x) $
        exitErr ("failed to render (no solution?): " ++ show oc)
    when (isJust x) $ do
        let Just x' = x
            ropts = toRenderOpts oc (diagramWidth x') opts
        renderToFile ropts x'

defaultOpts :: Parser a -> IO a
defaultOpts optsParser = do
    prog <- getProgName
    let p = info (helper <*> optListTypes <*> optsParser)
                (fullDesc
                 <> progDesc "Command-line diagram generation."
                 <> header prog)
    execParser p

checkOutput :: PuzzleOpts -> IO [(OutputChoice, Bool)]
checkOutput opts
    | (p || s) && e  = exitErr "example output conflicts with puzzle/solution"
    | e              = return . map req $ [DrawExample]
    | p && s         = return . map req $ [DrawPuzzle, DrawSolution]
    | p              = return . map req $ [DrawPuzzle]
    | s              = return . map req $ [DrawSolution]
    | otherwise      = return [req DrawPuzzle, opt DrawSolution]
  where
    p = _puzzle opts
    s = _solution opts
    e = _example opts
    req x = (x, True)
    opt x = (x, False)

maybeSkipSolution :: [(OutputChoice, Bool)] -> Maybe Y.Value -> Maybe Y.Value
maybeSkipSolution _ Nothing    = Nothing
maybeSkipSolution ocs (Just v) =
    if any hasSol . map fst $ ocs
        then Just v
        else Nothing
  where
    hasSol DrawSolution = True
    hasSol DrawExample  = True
    hasSol DrawPuzzle   = False

main :: IO ()
main = do
    opts <- defaultOpts puzzleOpts
    ocs <- checkOutput opts
    checkFormat (_format opts)
    mp <- readPuzzle (_input opts)
    TP mt pv msv <- case mp of Left  e -> exitErr $
                                          "parse failure: " ++ show e
                               Right p -> return p
    let msv' = maybeSkipSolution ocs msv
    t <- checkType $ _type opts `mplus` mt
    let ps = Y.parseEither (handle drawPuzzleMaybeSol t) (pv, msv')
    case ps of Right ps' -> mapM_ (renderPuzzle opts (draw ps')) ocs
               Left    e -> exitErr $ "parse failure: " ++ e