module Test.Main where

import Prelude
import Control.Monad.Eff (Eff)
import Control.Monad.Eff.AVar (AVAR)
import Control.Monad.Eff.Console (CONSOLE)
import Data.Maybe (Maybe(..))
import Test.Unit.Assert as Assert
import Test.Unit (TestSuite, suite, test)
import Test.Unit.Console (TESTOUTPUT)
import Test.Unit.Main (runTest)
import LargestSeriesProduct (largestProduct)

main :: forall eff
  . Eff ( avar :: AVAR
        , console :: CONSOLE
        , testOutput :: TESTOUTPUT
        | eff                     
        )
        Unit
main = runTest suites

suites :: forall e. TestSuite e
suites = do
  suite "LargestSeriesProduct.largestProduct" do
    
    test "finds the largest product if span equals length" $
      Assert.equal (Just 18)
                   (largestProduct "29" 2)
    
    test "can find the largest product of 2 with numbers in order" $
      Assert.equal (Just 72)
                   (largestProduct "0123456789" 2)
    
    test "can find the largest product of 2" $
      Assert.equal (Just 48)
                   (largestProduct "576802143" 2)
    
    test "can find the largest product of 3 with numbers in order" $
      Assert.equal (Just 504)
                   (largestProduct "0123456789" 3)
    
    test "can find the largest product of 3" $
      Assert.equal (Just 270)
                   (largestProduct "1027839564" 3)
    
    test "can find the largest product of 5 with numbers in order" $
      Assert.equal (Just 15120)
                   (largestProduct "0123456789" 5)
    
    test "can get the largest product of a big number" $
      Assert.equal (Just 23520)
                   (largestProduct "73167176531330624919225119674426574742355349194934" 6)
    
    test "reports zero if the only digits are zero" $
      Assert.equal (Just 0)
                   (largestProduct "0000" 2)
    
    test "reports zero if all spans include zero" $
      Assert.equal (Just 0)
                   (largestProduct "99099" 3)
    
    test "rejects span longer than string length" $
      Assert.equal Nothing
                   (largestProduct "123" 4)
    
    test "reports 1 for empty string and empty product (0 span)" $
      Assert.equal (Just 1)
                   (largestProduct "" 0)
    
    test "reports 1 for nonempty string and empty product (0 span)" $
      Assert.equal (Just 1)
                   (largestProduct "123" 0)
    
    test "rejects empty string and nonzero span" $
      Assert.equal Nothing
                   (largestProduct "" 1)
    
    test "rejects invalid character in digits" $
      Assert.equal Nothing
                   (largestProduct "1234a5" 2)
    
    test "rejects negative span" $
      Assert.equal Nothing
                   (largestProduct "12345" (-1))