{-# LANGUAGE
    OverloadedStrings
  #-}

module Data.Trie.PredSpec where

import Data.Trie.Pred.Base
import Data.Trie.Pred.Base.Step
import Data.Trie.Class
import Data.Trie.HashMap (HashMapStep (..))
import Data.List.NonEmpty (NonEmpty (..))
import qualified Data.List.NonEmpty as NE

import qualified Data.HashMap.Lazy as HM
import Data.Attoparsec.Text (parseOnly, double)
import qualified Data.Text as T
import Control.Error (hush)
import Prelude hiding (lookup)
import Test.QuickCheck
import Test.Tasty
import Test.Tasty.QuickCheck as QC


instance Arbitrary a => Arbitrary (NonEmpty a) where
  arbitrary = (:|) <$> arbitrary <*> arbitrary

predSpec :: TestTree
predSpec = testGroup "Data.Trie.Pred"
  [ testGroup "literals"
    [ QC.testProperty "lookup after insert should exist" lookupInsertExists
    , QC.testProperty "lookup after delete should not exist" lookupDeleteNotExists
    ]
  , testGroup "predicates"
    [ QC.testProperty "any double is parsed by a double" lookupDouble
    ]
  ]


lookupInsertExists :: NonEmpty Int -> Int -> PredTrie Int Int -> Bool
lookupInsertExists ks v xs = Just v == lookup ks (insert ks v xs)

lookupDeleteNotExists :: NonEmpty Int -> PredTrie Int Int -> Bool
lookupDeleteNotExists ks xs = Nothing == lookup ks (delete ks xs)

lookupDouble :: Double -> Bool
lookupDouble d = Just 0 == lookup ((T.pack $ show d) :| []) doubleTable


doubleTable :: PredTrie T.Text Int
doubleTable = PredTrie (HashMapStep HM.empty) $
  PredSteps [PredStep "double" (hush . parseOnly double) (Just $ \d -> 0) emptyPT]