module PascalUnitSyntaxTree where

import Data.Maybe

import Data.Char

data PascalUnit =

    Program Identifier Implementation Phrase

    | Unit Identifier Interface Implementation (Maybe Initialize) (Maybe Finalize)

    | System [TypeVarDeclaration]

    deriving Show

data Interface = Interface Uses TypesAndVars

    deriving Show

data Implementation = Implementation Uses TypesAndVars

    deriving Show

data Identifier = Identifier String BaseType

    deriving Show

data TypesAndVars = TypesAndVars [TypeVarDeclaration]

    deriving Show

data TypeVarDeclaration = TypeDeclaration Identifier TypeDecl

    | VarDeclaration Bool ([Identifier], TypeDecl) (Maybe InitExpression)

    | FunctionDeclaration Identifier TypeDecl [TypeVarDeclaration] (Maybe (TypesAndVars, Phrase))

    | OperatorDeclaration String Identifier TypeDecl [TypeVarDeclaration] (Maybe (TypesAndVars, Phrase))

    deriving Show

data TypeDecl = SimpleType Identifier

    | RangeType Range

    | Sequence [Identifier]

    | ArrayDecl (Maybe Range) TypeDecl

    | RecordType [TypeVarDeclaration] (Maybe [[TypeVarDeclaration]])

    | PointerTo TypeDecl

    | String Integer

    | Set TypeDecl

    | FunctionType TypeDecl [TypeVarDeclaration]

    | DeriveType InitExpression 

    | UnknownType

    deriving Show

data Range = Range Identifier

           | RangeFromTo InitExpression InitExpression

    deriving Show

data Initialize = Initialize String

    deriving Show

data Finalize = Finalize String

    deriving Show

data Uses = Uses [Identifier]

    deriving Show

data Phrase = ProcCall Reference [Expression]

        | IfThenElse Expression Phrase (Maybe Phrase)

        | WhileCycle Expression Phrase

        | RepeatCycle Expression [Phrase]

        | ForCycle Identifier Expression Expression Phrase

        | WithBlock Reference Phrase

        | Phrases [Phrase]

        | SwitchCase Expression [([InitExpression], Phrase)] (Maybe [Phrase])

        | Assignment Reference Expression

        | NOP

    deriving Show

data Expression = Expression String

    | BuiltInFunCall [Expression] Reference

    | PrefixOp String Expression

    | PostfixOp String Expression

    | BinOp String Expression Expression

    | StringLiteral String

    | CharCode String

    | HexCharCode String

    | NumberLiteral String

    | FloatLiteral String

    | HexNumber String

    | Reference Reference

    | SetExpression [Identifier]

    | Null

    deriving Show

data Reference = ArrayElement [Expression] Reference

    | FunCall [Expression] Reference

    | TypeCast Identifier Expression

    | SimpleReference Identifier

    | Dereference Reference

    | RecordField Reference Reference

    | Address Reference

    | RefExpression Expression

    deriving Show

data InitExpression = InitBinOp String InitExpression InitExpression

    | InitPrefixOp String InitExpression

    | InitReference Identifier

    | InitArray [InitExpression]

    | InitRecord [(Identifier, InitExpression)]

    | InitFloat String

    | InitNumber String

    | InitHexNumber String

    | InitString String

    | InitChar String

    | BuiltInFunction String [InitExpression]

    | InitSet [InitExpression]

    | InitAddress InitExpression

    | InitNull

    | InitRange Range

    | InitTypeCast Identifier InitExpression

    deriving Show

data BaseType = BTUnknown

    | BTChar

    | BTString

    | BTInt

    | BTRecord [(String, BaseType)]

    | BTArray BaseType BaseType

    | BTFunction

    | BTPointerTo BaseType

    | BTSet

    | BTEnum [String]

    | BTVoid

    deriving Show

{--

type2BaseType :: TypeDecl -> BaseType

type2BaseType st@(SimpleType (Identifier s _)) = f (map toLower s)

    where

    f "longint" = BTInt

    f "integer" = BTInt

    f "word" = BTInt

    f "pointer" = BTPointerTo BTVoid

    f _ = error $ show st

type2BaseType (Sequence ids) = BTEnum $ map (\(Identifier i _) -> i) ids

type2BaseType (RecordType tv mtvs) = BTRecord $ concatMap f (concat $ tv : fromMaybe [] mtvs)

    where

    f (VarDeclaration _ (ids, td) _) = map (\(Identifier i _) -> (i, type2BaseType td)) ids

type2BaseType (PointerTo t) = BTPointerTo $ type2BaseType t

type2BaseType a = error $ show a

--}