{-# LANGUAGE OverloadedRecordDot #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE NoFieldSelectors #-}

module Dojang.Syntax.Manifest.Writer
  ( writeManifest
  , writeManifestFile
  ) where

import Data.Bifunctor (Bifunctor (bimap, second))
import Data.List (partition)
import Data.List.NonEmpty (NonEmpty ((:|)), length, toList)
import Data.Maybe (catMaybes, fromMaybe, listToMaybe)
import GHC.IsList (IsList (fromList))
import System.IO.Unsafe (unsafePerformIO)
import Prelude hiding (all, any, writeFile)

import Data.CaseInsensitive (CI (original))
import Data.HashMap.Strict (toList)
import Data.Map.Strict (toList)
import Data.Text (Text, unpack)
import Data.Text.Encoding (encodeUtf8)
import System.OsPath (OsPath, decodeFS)
import TextShow (FromStringShow (FromStringShow), TextShow (showt))
import Toml.Pretty (prettyTomlOrdered)
import Toml.ToValue (ToTable (toTable))
import Toml.Value (Table)

import Dojang.MonadFileSystem
  ( FileType (Directory)
  , MonadFileSystem (writeFile)
  )
import Dojang.Syntax.EnvironmentPredicate.Writer (writeEnvironmentPredicate)
import Dojang.Syntax.Manifest.Internal
  ( EnvironmentPredicate' (..)
  , FileRoute'
  , FileRouteMap'
  , FlatOrNonEmptyStrings (..)
  , IgnoreMap'
  , Manifest' (Manifest')
  , MonikerMap'
  , always
  )
import Dojang.Types.EnvironmentPredicate
  ( EnvironmentPredicate (..)
  , normalizePredicate
  )
import Dojang.Types.FilePathExpression (toPathText)
import Dojang.Types.FileRoute (FileRoute (..))
import Dojang.Types.FileRouteMap (FileRouteMap)
import Dojang.Types.Manifest (Manifest (..))
import Dojang.Types.MonikerMap (MonikerMap)
import Dojang.Types.MonikerName (MonikerName)


schema :: Text
schema = "https://schema.dojang.dev/2023-11/manifest.schema.json"


-- | Encodes a 'Manifest' into a TOML document.
writeManifest :: Manifest -> Text
writeManifest manifest =
  "#:schema "
    <> schema
    <> "\n\n"
    <> (showt $ FromStringShow $ prettyTomlOrdered order tbl)
 where
  manifest' :: Manifest'
  manifest' = mapManifest' manifest
  tbl :: Table
  tbl = toTable manifest'
  order :: [String] -> String -> Either Int String
  order [] field = case field of
    "dirs" -> Left 1
    "files" -> Left 2
    "ignores" -> Left 3
    "monikers" -> Left 4
    _ -> Right field
  order _ field = Right field


-- | Writes a 'Manifest' file to the given path.  Throw an 'IOError' if the
-- an occurs while writing the file.
writeManifestFile
  :: (MonadFileSystem m)
  => Manifest
  -- ^ The 'Manifest' to write.
  -> OsPath
  -- ^ The path to write the 'Manifest' to.
  -> m ()
writeManifestFile manifest filePath =
  writeFile filePath $ encodeUtf8 $ writeManifest manifest


mapManifest' :: Manifest -> Manifest'
mapManifest' manifest =
  Manifest' monikers' dirs files ignores
 where
  dirs :: FileRouteMap'
  files :: FileRouteMap'
  (dirs, files) = mapFiles manifest.fileRoutes manifest.monikers
  monikers' :: MonikerMap'
  monikers' = mapMonikers' manifest.monikers
  ignores :: IgnoreMap'
  ignores =
    fromList
      [ (decodePath path, pattern)
      | (path, pattern) <- Data.Map.Strict.toList manifest.ignorePatterns
      ]


mapFiles :: FileRouteMap -> MonikerMap -> (FileRouteMap', FileRouteMap')
mapFiles fileRouteMap monikers =
  ( fromList (bimap decodePath (`mapFileRoute'` monikers) <$> dirs)
  , fromList (bimap decodePath (`mapFileRoute'` monikers) <$> files)
  )
 where
  dirs :: [(OsPath, FileRoute)]
  files :: [(OsPath, FileRoute)]
  (dirs, files) =
    partition
      ((== Directory) . fileType . snd)
      $ Data.Map.Strict.toList fileRouteMap


decodePath :: OsPath -> FilePath
decodePath = unsafePerformIO . decodeFS


mapFileRoute' :: FileRoute -> MonikerMap -> FileRoute'
mapFileRoute' fileRoute monikers =
  (fromList . catMaybes)
    [ case (normalizePredicate pred', maybe "" toPathText filePath) of
      (Moniker n, path) -> Just (n, path)
      (pred'', path) -> case lookBack monikers pred'' of
        Just n -> Just (n, path)
        Nothing -> Nothing
    | (pred', filePath) <- fileRoute.predicates
    ]


lookBack :: MonikerMap -> EnvironmentPredicate -> Maybe MonikerName
lookBack monikers predicate =
  listToMaybe
    [ n
    | (n, p) <- Data.HashMap.Strict.toList monikers
    , normalizePredicate p == normalizedPred
    ]
 where
  normalizedPred :: EnvironmentPredicate
  normalizedPred = normalizePredicate predicate


mapMonikers' :: MonikerMap -> MonikerMap'
mapMonikers' monikers =
  fromList
    $ second (mapEnvironmentPredicate' . normalizePredicate)
    <$> Data.HashMap.Strict.toList monikers


mapEnvironmentPredicate' :: EnvironmentPredicate -> EnvironmentPredicate'
mapEnvironmentPredicate' Always = always
mapEnvironmentPredicate' (Moniker n) = always{all = Just $ fromList [n]}
mapEnvironmentPredicate' (OperatingSystem os) =
  always{os = Just $ Flat $ unpack $ original os.identifier}
mapEnvironmentPredicate' (Architecture arch) =
  always{arch = Just $ Flat $ unpack $ original arch.identifier}
mapEnvironmentPredicate' (KernelName kernel) =
  always{kernel = Just $ Flat $ unpack $ original kernel}
mapEnvironmentPredicate' (KernelRelease kernelRelease) =
  always{kernelRelease = Just $ Flat $ unpack $ original kernelRelease}
mapEnvironmentPredicate' (And predicates') =
  fromMaybe
    always{when = Just $ writeEnvironmentPredicate $ And predicates'}
    (xor' $ mapEnvironmentPredicate' <$> predicates')
 where
  xor' :: NonEmpty EnvironmentPredicate' -> Maybe EnvironmentPredicate'
  xor' (predicate :| []) = Just predicate
  xor' (a :| predicates'') =
    let r : est = predicates''
    in case xor' (r :| est) of
        Nothing -> Nothing
        Just b -> do
          os' <- xorMaybe a.os b.os
          arch' <- xorMaybe a.arch b.arch
          kernel' <- xorMaybe a.kernel b.kernel
          kernelRelease' <- xorMaybe a.kernelRelease b.kernelRelease
          all' <- xorMaybe a.all b.all
          any' <- xorMaybe a.any b.any
          when' <- xorMaybe a.when b.when
          return
            EnvironmentPredicate'
              { os = os'
              , arch = arch'
              , kernel = kernel'
              , kernelRelease = kernelRelease'
              , all = all'
              , any = any'
              , when = when'
              }
  xorMaybe :: Maybe a -> Maybe a -> Maybe (Maybe a)
  xorMaybe (Just _) (Just _) = Nothing
  xorMaybe (Just a) Nothing = Just $ Just a
  xorMaybe Nothing (Just b) = Just $ Just b
  xorMaybe Nothing Nothing = Just Nothing
mapEnvironmentPredicate' (Or predicates')
  | Prelude.length oses == length' =
      always{os = Just $ NonEmpty $ toNonEmpty oses}
  | Prelude.length arches == length' =
      always{arch = Just $ NonEmpty $ toNonEmpty arches}
  | Prelude.length kernels == length' =
      always{kernel = Just $ NonEmpty $ toNonEmpty kernels}
  | Prelude.length kernelReleases == length' =
      always{kernelRelease = Just $ NonEmpty $ toNonEmpty kernelReleases}
  | Prelude.length monikers' == length' =
      always{any = Just $ toNonEmpty monikers'}
  | otherwise =
      always{when = Just $ writeEnvironmentPredicate $ Or predicates'}
 where
  length' :: Int
  length' = Data.List.NonEmpty.length predicates'
  oses :: [String]
  oses =
    [ unpack $ original os'.identifier
    | OperatingSystem os' <- Data.List.NonEmpty.toList predicates'
    ]
  arches :: [String]
  arches =
    [ unpack $ original arch'.identifier
    | Architecture arch' <- Data.List.NonEmpty.toList predicates'
    ]
  kernels :: [String]
  kernels =
    [ unpack $ original kernel'
    | KernelName kernel' <- Data.List.NonEmpty.toList predicates'
    ]
  kernelReleases :: [String]
  kernelReleases =
    [ unpack $ original kernelRelease'
    | KernelRelease kernelRelease' <- Data.List.NonEmpty.toList predicates'
    ]
  monikers' :: [MonikerName]
  monikers' = [n | Moniker n <- Data.List.NonEmpty.toList predicates']
  toNonEmpty :: [a] -> NonEmpty a
  toNonEmpty l = head l :| tail l
mapEnvironmentPredicate' pred' =
  always{when = Just $ writeEnvironmentPredicate pred'}