module SemanticGitDiffSpec where

import Arguments
import Data.Aeson
import Control.Exception
import qualified Data.ByteString.Lazy as DL
import JSONTestCase
import Test.Hspec (Spec, describe, it, SpecWith, runIO, parallel)
import Prelude
import Prologue
import Renderer
import SemanticDiff
import System.FilePath.Glob
import Data.Maybe (fromJust)
import Test.Hspec.Expectations.Pretty

catchException :: IO [Text] -> IO [Text]
catchException = handle errorHandler
  where errorHandler :: (SomeException -> IO [Text])
        errorHandler exception = return [toS . encode $ ["Crashed: " <> Prologue.show exception :: Text]]

assertDiffSummary :: JSONTestCase -> Format -> (Either String ExpectedResult -> Either String ExpectedResult -> Expectation) -> Expectation
assertDiffSummary JSONTestCase {..} format matcher = do
  diffs <- fetchDiffs $ args gitDir sha1 sha2 filePaths format
  result <- catchException . pure . pure . concatOutputs $ diffs
  let actual = eitherDecode . DL.fromStrict . encodeUtf8 . fromJust . listToMaybe $ result
  matcher actual (Right expectedResult)

runTestsIn :: [FilePath] -> Format -> (Either String ExpectedResult -> Either String ExpectedResult -> Expectation) -> SpecWith ()
runTestsIn filePaths format matcher = do
  contents <- runIO $ traverse DL.readFile filePaths
  let filePathContents = zip filePaths contents
  let jsonContents = (\(filePath, content) -> (filePath, eitherDecode content)) <$> filePathContents :: [(FilePath, Either String [JSONTestCase])]
  traverse_ handleJSONTestCase jsonContents
  where handleJSONTestCase :: (FilePath, Either String [JSONTestCase]) -> SpecWith ()
        handleJSONTestCase (filePath, eitherJSONTestCase) =
          case eitherJSONTestCase of
            Left err ->  it ("An error occurred " <> err <> " (" <> filePath <> ")") $ True `shouldBe` False
            Right testCases -> traverse_ (\testCase -> it (testCaseDescription testCase) $ assertDiffSummary testCase format matcher) testCases

spec :: Spec
spec = parallel $ do
  diffSummaryFiles <- runIO $ testCaseFiles "test/corpus/diff-summaries"
  diffSummaryToDoFiles <- runIO $ testCaseFiles "test/corpus/diff-summaries-todo"
  diffSummaryCrasherFiles <- runIO $ testCaseFiles "test/corpus/diff-summary-crashers"

  describe "diff summaries" $ runTestsIn diffSummaryFiles Summary shouldBe
  describe "diff summaries todo" $ runTestsIn diffSummaryToDoFiles Summary shouldNotBe
  describe "diff summaries crashers todo" $ runTestsIn diffSummaryCrasherFiles Summary shouldBe
  jsonFormatFiles <- runIO $ testCaseFiles "test/corpus/json"
  describe "JSON format" $ runTestsIn jsonFormatFiles JSON shouldBe

  where testCaseFiles :: String -> IO [FilePath]
        testCaseFiles = globDir1 (compile "*/*.json")