{-# LANGUAGE NamedFieldPuns    #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE Strict            #-}
module Tokstyle.Linter.DeclaredOnce (descr) where

import           Control.Monad.State.Strict  (State)
import qualified Control.Monad.State.Strict  as State
import           Data.Fix                    (Fix (..))
import           Data.Map                    (Map)
import qualified Data.Map                    as Map
import           Data.Text                   (Text)
import qualified Data.Text                   as Text
import           Language.Cimple             (Lexeme (..), LexemeClass (..),
                                              Node, NodeF (..))
import           Language.Cimple.Diagnostics (HasDiagnostics (..), warn)
import           Language.Cimple.TraverseAst (AstActions, astActions, doNode,
                                              traverseAst)


data Linter = Linter
    { Linter -> [Text]
diags :: [Text]
    , Linter -> Map Text (FilePath, Lexeme Text)
decls :: Map Text (FilePath, Lexeme Text)
    }

empty :: Linter
empty :: Linter
empty = [Text] -> Map Text (FilePath, Lexeme Text) -> Linter
Linter [] Map Text (FilePath, Lexeme Text)
forall k a. Map k a
Map.empty

instance HasDiagnostics Linter where
    addDiagnostic :: Text -> Linter -> Linter
addDiagnostic Text
diag l :: Linter
l@Linter{[Text]
diags :: [Text]
diags :: Linter -> [Text]
diags} = Linter
l{diags :: [Text]
diags = Text -> [Text] -> [Text]
forall a. HasDiagnostics a => Text -> a -> a
addDiagnostic Text
diag [Text]
diags}


linter :: AstActions (State Linter) Text
linter :: AstActions (State Linter) Text
linter = AstActions (State Linter) Text
forall (f :: * -> *) text. Applicative f => AstActions f text
astActions
    { doNode :: FilePath
-> Node (Lexeme Text) -> State Linter () -> State Linter ()
doNode = \FilePath
file Node (Lexeme Text)
node State Linter ()
act ->
        case Node (Lexeme Text) -> NodeF (Lexeme Text) (Node (Lexeme Text))
forall (f :: * -> *). Fix f -> f (Fix f)
unFix Node (Lexeme Text)
node of
            FunctionDecl Scope
_ (Fix (FunctionPrototype Node (Lexeme Text)
_ fn :: Lexeme Text
fn@(L AlexPosn
_ LexemeClass
IdVar Text
fname) [Node (Lexeme Text)]
_)) -> do
                l :: Linter
l@Linter{Map Text (FilePath, Lexeme Text)
decls :: Map Text (FilePath, Lexeme Text)
decls :: Linter -> Map Text (FilePath, Lexeme Text)
decls} <- State Linter Linter
forall s (m :: * -> *). MonadState s m => m s
State.get
                case Text
-> Map Text (FilePath, Lexeme Text)
-> Maybe (FilePath, Lexeme Text)
forall k a. Ord k => k -> Map k a -> Maybe a
Map.lookup Text
fname Map Text (FilePath, Lexeme Text)
decls of
                    Maybe (FilePath, Lexeme Text)
Nothing -> Linter -> State Linter ()
forall s (m :: * -> *). MonadState s m => s -> m ()
State.put Linter
l{decls :: Map Text (FilePath, Lexeme Text)
decls = Text
-> (FilePath, Lexeme Text)
-> Map Text (FilePath, Lexeme Text)
-> Map Text (FilePath, Lexeme Text)
forall k a. Ord k => k -> a -> Map k a -> Map k a
Map.insert Text
fname (FilePath
file, Lexeme Text
fn) Map Text (FilePath, Lexeme Text)
decls }
                    Just (FilePath
file', Lexeme Text
fn') -> do
                        FilePath -> Lexeme Text -> Text -> State Linter ()
forall at diags.
(HasLocation at, HasDiagnostics diags) =>
FilePath -> at -> Text -> DiagnosticsT diags ()
warn FilePath
file' Lexeme Text
fn' (Text -> State Linter ()) -> Text -> State Linter ()
forall a b. (a -> b) -> a -> b
$ Text
"duplicate declaration of function `" Text -> Text -> Text
forall a. Semigroup a => a -> a -> a
<> Text
fname Text -> Text -> Text
forall a. Semigroup a => a -> a -> a
<> Text
"`"
                        FilePath -> Lexeme Text -> Text -> State Linter ()
forall at diags.
(HasLocation at, HasDiagnostics diags) =>
FilePath -> at -> Text -> DiagnosticsT diags ()
warn FilePath
file Lexeme Text
fn (Text -> State Linter ()) -> Text -> State Linter ()
forall a b. (a -> b) -> a -> b
$ Text
"function `" Text -> Text -> Text
forall a. Semigroup a => a -> a -> a
<> Text
fname Text -> Text -> Text
forall a. Semigroup a => a -> a -> a
<> Text
"` also declared here"

            FunctionDefn{} -> () -> State Linter ()
forall (f :: * -> *) a. Applicative f => a -> f a
pure ()
            NodeF (Lexeme Text) (Node (Lexeme Text))
_ -> State Linter ()
act
    }

analyse :: [(FilePath, [Node (Lexeme Text)])] -> [Text]
analyse :: [(FilePath, [Node (Lexeme Text)])] -> [Text]
analyse [(FilePath, [Node (Lexeme Text)])]
tus = [Text] -> [Text]
forall a. [a] -> [a]
reverse ([Text] -> [Text]) -> (Linter -> [Text]) -> Linter -> [Text]
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Linter -> [Text]
diags (Linter -> [Text]) -> Linter -> [Text]
forall a b. (a -> b) -> a -> b
$ State Linter () -> Linter -> Linter
forall s a. State s a -> s -> s
State.execState (AstActions (State Linter) Text
-> [(FilePath, [Node (Lexeme Text)])] -> State Linter ()
forall text a (f :: * -> *).
(TraverseAst text a, Applicative f) =>
AstActions f text -> a -> f ()
traverseAst AstActions (State Linter) Text
linter [(FilePath, [Node (Lexeme Text)])]
tus) Linter
empty

descr :: ([(FilePath, [Node (Lexeme Text)])] -> [Text], (Text, Text))
descr :: ([(FilePath, [Node (Lexeme Text)])] -> [Text], (Text, Text))
descr = ([(FilePath, [Node (Lexeme Text)])] -> [Text]
analyse, (Text
"declared-once", [Text] -> Text
Text.unlines
    [ Text
"Checks that any function is declared exactly once."
    , Text
""
    , Text
"**Reason:** functions should never be declared in multiple files, and within the"
    , Text
"same file, declaring it twice is unnecessary and confusing."
    ]))