{- |
module: Main
description: Testing the Unicode character library and API
license: MIT

maintainer: Joe Leslie-Hurd <joe@gilith.com>
stability: provisional
portability: portable
-}
module Main
  ( main )
where

import qualified Data.List as List
import qualified Data.Either as Either
import qualified Data.Word as Word
import qualified System.Directory as Directory

import Unicode
import qualified OpenTheory.Unicode as Unicode

demoLength :: Int
demoLength = 7621

testLength :: Int
testLength = 79

noInvalid :: [Either Word.Word8 Unicode.Unicode] -> Bool
noInvalid = all (Either.either (const False) (const True))

getTestFiles :: FilePath -> IO [FilePath]
getTestFiles d =
    do fs <- Directory.getDirectoryContents d
       let fs' = filter (List.isPrefixOf "test") fs
       return (map (\f -> d ++ "/" ++ f) fs')

readTestCharFile :: Maybe Int -> FilePath -> IO ()
readTestCharFile x f =
    do l <- decodeFile f
       let a = noInvalid l
       case x of
         Nothing ->
             if a
               then error $ "invalid file " ++ f ++ " was successfully decoded"
               else return ()
         Just n ->
             if not a
               then error $ "valid file " ++ f ++ " could not be decoded"
               else
                 if length l == n
                   then return ()
                   else
                     error $ "valid file " ++ f ++ " has bad line length: " ++
                             show (length l)

readValidCharFile :: Int -> FilePath -> IO ()
readValidCharFile n = readTestCharFile (Just n)

readInvalidCharFile :: FilePath -> IO ()
readInvalidCharFile = readTestCharFile Nothing

partitionTestCharFile :: IO ()
partitionTestCharFile =
    do skip <- Directory.doesFileExist "test/valid/test061.txt"
       if skip
         then return ()
         else
           do putStrLn "\nsplitting UTF-8 test file into valid and invalid lines"
              cs <- decodeFile "test/test.txt"
              mapM_ outputLine (filter testLine (readLines 1 cs))
  where
    isNewline :: Either Word.Word8 Unicode.Unicode -> Bool
    isNewline (Left _) = False
    isNewline (Right c) = let n = Unicode.unUnicode c in n == 10 || n == 13

    chopNewline :: [Either Word.Word8 Unicode.Unicode] ->
                   [Either Word.Word8 Unicode.Unicode]
    chopNewline [] = []
    chopNewline (_ : cs) = cs

    readLines :: Int -> [Either Word.Word8 Unicode.Unicode] ->
                 [(Int,[Either Word.Word8 Unicode.Unicode])]
    readLines _ [] = []
    readLines lineno inp =
        let (line,inp') = List.span (not . isNewline) inp in
        let inp'' = chopNewline inp' in
        (lineno,line) : readLines (lineno + 1) inp''

    testLine :: (Int,[Either Word.Word8 Unicode.Unicode]) -> Bool
    testLine (lineno,line) = not (lineno < 61 || null line)

    outputLine :: (Int,[Either Word.Word8 Unicode.Unicode]) -> IO ()
    outputLine (lineno,line) =
        let valid = noInvalid line in
        let n = show lineno in
        let f = "test/" ++ (if valid then "valid" else "invalid") ++
                "/test" ++ replicate (3 - length n) '0' ++ n ++ ".txt" in
        reencodeFile f line

main :: IO ()
main =
    do partitionTestCharFile
       readValidCharFile demoLength "test/demo.txt"
       validTestFiles <- getTestFiles "test/valid"
       invalidTestFiles <- getTestFiles "test/invalid"
       mapM_ (readValidCharFile testLength) validTestFiles
       mapM_ readInvalidCharFile invalidTestFiles
       putStrLn "  all tests pass"
       return ()