module Buffet.Toolbox.TestTools
  ( assertIsContainedIn
  , assertJsonIsSubstructure
  , folderBasedTests
  ) where

import qualified Buffet.Toolbox.TextTools as TextTools
import qualified Control.Monad as Monad
import qualified Data.Aeson as Aeson
import qualified Data.ByteString as ByteString
import qualified Data.Function as Function
import qualified Data.HashMap.Strict as HashMap
import qualified Data.HashSet as Set
import qualified Data.List as List
import qualified Data.Text as T
import qualified Data.Text.Encoding as Encoding
import qualified Data.Vector as Vector
import Prelude
  ( FilePath
  , IO
  , String
  , ($)
  , (.)
  , (<)
  , (<>)
  , either
  , error
  , fmap
  , fst
  , id
  , length
  , pure
  , sequence_
  , show
  , snd
  , traverse
  )
import qualified System.Directory as Directory
import qualified System.FilePath as FilePath
import qualified Test.Tasty as Tasty
import qualified Test.Tasty.HUnit as HUnit

assertIsContainedIn :: FilePath -> FilePath -> HUnit.Assertion
assertIsContainedIn needlePath haystackPath = do
  needle <- ByteString.readFile needlePath
  haystack <- ByteString.readFile haystackPath
  HUnit.assertBool "" $ ByteString.isInfixOf needle haystack

assertJsonIsSubstructure :: T.Text -> T.Text -> HUnit.Assertion
assertJsonIsSubstructure = Function.on (assert []) getJson
  where
    assert path (Aeson.Object expected) (Aeson.Object actual) = do
      let missingKeys =
            List.sort . Set.toList $
            Function.on Set.difference HashMap.keysSet expected actual
      HUnit.assertEqual (message path) [] missingKeys
      let asserts =
            fmap snd . List.sortOn fst . HashMap.toList $
            HashMap.intersectionWithKey
              (\key -> assert $ path <> [key])
              expected
              actual
      sequence_ asserts
    assert path (Aeson.Array expected) (Aeson.Array actual) = do
      Function.on
        (HUnit.assertEqual $ message path)
        Vector.length
        expected
        actual
      sequence_ $
        Vector.izipWith
          (\index -> assert (path <> [T.pack $ show index]))
          expected
          actual
    assert path expected actual =
      HUnit.assertEqual (message path) expected actual
    message :: [T.Text] -> String
    message = T.unpack . TextTools.decodeUtf8 . Aeson.encode
    getJson :: T.Text -> Aeson.Value
    getJson = either error id . Aeson.eitherDecodeStrict . Encoding.encodeUtf8

folderBasedTests ::
     (Tasty.TestName -> FilePath -> Tasty.TestTree)
  -> FilePath
  -> IO Tasty.TestTree
folderBasedTests assert folder = do
  folderEntries <- Directory.listDirectory folder
  subfolders <-
    Monad.filterM
      (Directory.doesDirectoryExist . FilePath.combine folder)
      folderEntries
  let hasMoreThanJustFolders = length subfolders < length folderEntries
  if hasMoreThanJustFolders
    then pure $ assert name folder
    else do
      tests <- traverse assertSubfolder $ List.sort subfolders
      pure $ Tasty.testGroup name tests
  where
    name = FilePath.takeFileName $ FilePath.dropTrailingPathSeparator folder
    assertSubfolder = folderBasedTests assert . FilePath.combine folder