{-# OPTIONS_GHC -Wall #-}
module Elm.Compiler
    ( version
    , parseDependencies
    , compile, Context(..), Result(..)
    , Dealiaser, dummyDealiaser
    , Error, errorToString, errorToJson, printError
    , Warning, warningToString, warningToJson, printWarning
    )
    where

import qualified Data.Aeson as Json
import qualified Data.Map as Map

import qualified AST.Module as Module
import qualified AST.Module.Name as ModuleName
import qualified Compile
import qualified Docs.Check as Docs
import qualified Elm.Compiler.Version
import qualified Elm.Compiler.Module as PublicModule
import qualified Elm.Docs as Docs
import qualified Elm.Package as Package
import qualified Generate.JavaScript as JS
import qualified Parse.Module as Parse
import qualified Parse.Parse as Parse
import qualified Reporting.Annotation as A
import qualified Reporting.Error as Error
import qualified Reporting.Render.Type as RenderType
import qualified Reporting.Result as Result
import qualified Reporting.Warning as Warning


-- VERSION

version :: Package.Version
version =
  Elm.Compiler.Version.version


-- DEPENDENCIES

parseDependencies
    :: String
    -> Either [Error] (PublicModule.Name, [PublicModule.Name])
parseDependencies sourceCode =
  let
    (Result.Result _warnings rawResult) =
      Parse.parse sourceCode Parse.header
  in
    case rawResult of
      Result.Err msgs ->
          Left $ map (Error . A.map Error.Syntax) msgs

      Result.Ok (Module.Header name _docs _exports imports) ->
          Right
            ( PublicModule.Name name
            , map (PublicModule.Name . fst . A.drop) imports
            )


-- COMPILATION

{-| Compiles Elm source code to JavaScript. -}
compile
    :: Context
    -> String
    -> PublicModule.Interfaces
    -> (Dealiaser, [Warning], Either [Error] Result)

compile context source interfaces =
  let
    (Context packageName isRoot isExposed dependencies) =
      context

    (Result.Result (localizer, warnings) rawResult) =
      do  modul <- Compile.compile packageName isRoot dependencies interfaces source
          docs <- docsGen isExposed modul

          let interface = Module.toInterface packageName modul
          let javascript = JS.generate modul

          return (Result docs interface javascript)
  in
    ( maybe dummyDealiaser Dealiaser localizer
    , map Warning warnings
    , Result.destruct (Left . map Error) Right rawResult
    )


data Context = Context
    { _packageName :: Package.Name
    , _isRoot :: Bool
    , _isExposed :: Bool
    , _dependencies :: [PublicModule.CanonicalName]
    }


data Result = Result
    { _docs :: Maybe Docs.Documentation
    , _interface :: PublicModule.Interface
    , _js :: String
    }


docsGen
    :: Bool
    -> Module.Optimized
    -> Result.Result w Error.Error (Maybe Docs.Documentation)
docsGen isExposed modul =
  if not isExposed then
    Result.ok Nothing
  else
    let
      getChecked =
        Docs.check (Module.exports modul) (Module.docs modul)

      name =
        PublicModule.Name (ModuleName._module (Module.name modul))

      toDocs checked =
        Docs.fromCheckedDocs name checked
    in
      (Just . toDocs) `fmap` Result.mapError Error.Docs getChecked


-- DEALIASER

newtype Dealiaser =
    Dealiaser RenderType.Localizer


dummyDealiaser :: Dealiaser
dummyDealiaser =
    Dealiaser Map.empty


-- ERRORS

newtype Error =
    Error (A.Located Error.Error)


errorToString :: Dealiaser -> String -> String -> Error -> String
errorToString (Dealiaser localizer) location source (Error err) =
    Error.toString localizer location source err


printError :: Dealiaser -> String -> String -> Error -> IO ()
printError (Dealiaser localizer) location source (Error err) =
    Error.print localizer location source err


errorToJson :: Dealiaser -> String -> Error -> Json.Value
errorToJson (Dealiaser localizer) location (Error err) =
    Error.toJson localizer location err


-- WARNINGS

newtype Warning =
    Warning (A.Located Warning.Warning)


warningToString :: Dealiaser -> String -> String -> Warning -> String
warningToString (Dealiaser localizer) location source (Warning err) =
    Warning.toString localizer location source err


printWarning :: Dealiaser -> String -> String -> Warning -> IO ()
printWarning (Dealiaser localizer) location source (Warning err) =
    Warning.print localizer location source err


warningToJson :: Dealiaser -> String -> Warning -> Json.Value
warningToJson (Dealiaser localizer) location (Warning err) =
    Warning.toJson localizer location err