{-# LANGUAGE DeriveAnyClass, DerivingStrategies, GeneralizedNewtypeDeriving, OverloadedStrings, TypeApplications, TypeOperators #-}

module Main (main) where

import qualified Analysis.Eval as Eval
import           Control.Effect
import           Control.Effect.Fail
import           Control.Effect.Reader
import           Control.Monad hiding (fail)
import           Control.Monad.Catch
import           Control.Monad.IO.Class
import qualified Data.Aeson as Aeson
import qualified Data.Aeson.Encode.Pretty as Aeson
import qualified Data.ByteString.Char8 as ByteString
import qualified Data.ByteString.Lazy.Char8 as ByteString.Lazy
import qualified Data.ByteString.Streaming.Char8 as ByteStream
import           Data.Core
import           Data.Core.Pretty
import           Data.File
import           Data.Foldable
import           Data.Function
import           Data.List (sort)
import           Data.Loc
import           Data.Maybe
import           Data.Name
import           Data.Term
import           Data.String (fromString)
import           GHC.Stack
import qualified Language.Python.Core as Py
import           Prelude hiding (fail)
import           Streaming
import qualified Streaming.Process
import           System.Directory
import           System.Exit
import qualified TreeSitter.Span as TS (Span)
import qualified TreeSitter.Python as TSP
import qualified TreeSitter.Python.AST as TSP
import qualified TreeSitter.Unmarshal as TS
import           Text.Show.Pretty (ppShow)
import qualified System.Path as Path
import qualified System.Path.Directory as Path
import           System.Path ((</>))

import qualified Test.Tasty as Tasty
import qualified Test.Tasty.HUnit as HUnit

import           Analysis.ScopeGraph
import qualified Directive
import           Instances ()


assertJQExpressionSucceeds :: Show a => Directive.Directive -> a -> Term (Ann :+: Core) Name -> HUnit.Assertion
assertJQExpressionSucceeds directive tree core = do
  bod <- case scopeGraph Eval.eval [File interactive core] of
    (heap, [File _ (Right result)]) -> pure $ Aeson.object
      [ "scope" Aeson..= heap
      , "heap"  Aeson..= result
      , "tree"  Aeson..= Aeson.toJSON1 core
      ]
    _other                       -> HUnit.assertFailure "Couldn't run scope dumping mechanism; this shouldn't happen"

  let ignore = ByteStream.effects . hoist ByteStream.effects
      sgJSON = ByteStream.fromLazy $ Aeson.encode bod
      jqPipeline = Streaming.Process.withStreamingProcess (Directive.toProcess directive) sgJSON ignore
      errorMsg = "jq(1) returned non-zero exit code"
      dirMsg    = "jq expression: " <> show directive
      jsonMsg   = "JSON value: " <> ByteString.Lazy.unpack (Aeson.encodePretty bod)
      astMsg    = "AST (pretty): " <> ppShow tree
      treeMsg   = "Core expr (pretty): " <> showCore (stripAnnotations core)
      treeMsg'  = "Core expr (Show): " <> ppShow (stripAnnotations core)


  catch @_ @Streaming.Process.ProcessExitedUnsuccessfully jqPipeline $ \err -> do
    HUnit.assertFailure (unlines [errorMsg, dirMsg, jsonMsg, astMsg, treeMsg, treeMsg', show err])

fixtureTestTreeForFile :: HasCallStack => Path.RelFile -> Tasty.TestTree
fixtureTestTreeForFile fp = HUnit.testCaseSteps (Path.toString fp) $ \step -> withFrozenCallStack $ do
  let fullPath = Path.relDir "semantic-python/test/fixtures" </> fp

  fileContents <- ByteString.readFile (Path.toString fullPath)
  directives <- case Directive.parseDirectives fileContents of
    Right dir -> pure dir
    Left err  -> HUnit.assertFailure ("Directive parsing error: " <> err)

  result <- TS.parseByteString TSP.tree_sitter_python fileContents
  let coreResult = Control.Effect.run
                   . runFail
                   . runReader (fromString @Py.SourcePath . Path.toString $ fp)
                   . Py.compile @(TSP.Module TS.Span) @_ @(Term (Ann :+: Core))
                   <$> result

  for_ directives $ \directive -> do
    step (Directive.describe directive)
    case (coreResult, directive) of
      (Right (Left _), Directive.Fails)      -> pure ()
      (Left err, _)                          -> HUnit.assertFailure ("Parsing failed: " <> err)
      (Right (Left err), _)                  -> HUnit.assertFailure ("Compilation failed: " <> err)
      (Right (Right _), Directive.Fails)     -> HUnit.assertFailure ("Expected translation to fail")
      (Right (Right item), Directive.JQ _)   -> assertJQExpressionSucceeds directive result item
      (Right (Right item), Directive.Tree t) -> let msg = "lhs = " <> showCore t <> "\n rhs " <> showCore item'
                                                    item' = stripAnnotations item
                                                in HUnit.assertEqual msg t item' where

milestoneFixtures :: IO Tasty.TestTree
milestoneFixtures = do
  files <- liftIO (Path.filesInDir (Path.relDir "semantic-python/test/fixtures"))
  let pythons = sort (filter (Path.hasExtension ".py") files)
  pure $ Tasty.testGroup "Translation" (fmap fixtureTestTreeForFile pythons)

main :: IO ()
main = do
  jq <- findExecutable "jq"
  when (isNothing jq) (die "Error: jq(1) not found in $PATH.")
  milestoneFixtures >>= Tasty.defaultMain