module Build.Source (build) where

import Data.Data
import Control.Monad.State
import qualified Data.Graph as Graph
import qualified Data.List as List
import qualified Data.Map as Map
import qualified Data.Set as Set
import System.Directory
import System.Exit
import System.FilePath as FP
import Text.PrettyPrint (Doc)

import SourceSyntax.Declaration
import SourceSyntax.Module
import qualified SourceSyntax.Expression as Expr
import qualified SourceSyntax.Type as Type
import qualified Parse.Parse as Parse
import qualified Metadata.Prelude as Prelude
import qualified Transform.Check as Check
import qualified Transform.SortDefinitions as SD
import qualified Type.Inference as TI
import qualified Type.Constrain.Declaration as TcDecl
import qualified Transform.Canonicalize as Canonical

build :: Bool -> Interfaces -> String -> Either [Doc] (MetadataModule () ())
build noPrelude interfaces source =
  do let add = if noPrelude then id else Prelude.add
         infixes = Map.fromList . map (\(assoc,lvl,op) -> (op,(lvl,assoc)))
                 . concatMap iFixities $ Map.elems interfaces

     modul@(Module _ _ _ decls') <- add `fmap` Parse.program infixes source

     -- check for structural errors
     Module names exs ims decls <-
         case Check.mistakes decls' of
           [] -> return modul
           ms -> Left ms

     let exports'
             | null exs =
                 let get = Set.toList . SD.boundVars in
                 concat [ get pattern | Definition (Expr.Def pattern _) <- decls ] ++
                 concat [ map fst ctors | Datatype _ _ ctors <- decls ] ++
                 [ name | TypeAlias name _ (Type.Record _ _) <- decls ]
             | otherwise = exs

     metaModule <- Canonical.metadataModule interfaces $ MetadataModule {
           names = names,
           path = FP.joinPath names,
           exports = exports',
           imports = ims,
           -- reorder AST into strongly connected components
           program = SD.sortDefs . Expr.dummyLet $ TcDecl.toExpr decls,
           types = Map.empty,
           datatypes = [ (name,vars,ctors) | Datatype name vars ctors <- decls ],
           fixities = [ (assoc,level,op) | Fixity assoc level op <- decls ],
           aliases = [ (name,tvs,tipe) | TypeAlias name tvs tipe <- decls ],
           foreignImports = [ (evt,v,name,typ) | ImportEvent evt v name typ <- decls ],
           foreignExports = [ (evt,name,typ) | ExportEvent evt name typ <- decls ]
          }

     types <- TI.infer interfaces metaModule

     return $ metaModule { types = types }