open OUnit ;;
open Num ;;

let testData = [
  ( Int 0 , Int 1 ) ;
  ( Int 1 , Int 1 ) ;
  ( Int 2 , Int 2 ) ;
  ( Int 3 , Int 6 ) ;
  ( Int 4 , Int 24 ) ;
  ( Int 5 , Int 120 ) ;
  ( Int 6 , Int 720 ) ;
  ( Int 7 , Int 5040 ) ;
  ( Int 8 , Int 40320 ) ;
  ( Int 9 , Int 362880 ) ;
  ( Int 10 , Int 3628800 ) ;
  ( Int 11 , Int 39916800 ) ;
  ( Int 12 , Int 479001600 ) ;
  ( Int 13 , num_of_string "6227020800" ) ;
  ( Int 14 , num_of_string "87178291200" ) ;
  ( Int 20 , num_of_string "2432902008176640000" ) ;
  ( Int 30 , num_of_string "265252859812191058636308480000000" ) ;
  ( Int 40 , num_of_string "815915283247897734345611269596115894272000000000" )
]
;;

let rec createRecursiveTestList data result = match data with
  [ ] -> List.rev result
| _ -> let ( i , r ) = List.hd ( data ) in
  createRecursiveTestList ( List.tl data )  ( ( "recursive test " ^ ( string_of_num i ) >:: ( fun _ -> assert_equal r ( Factorial.recursive i ) ) ) :: result )
;;

let rec createTailRecursiveTestList data result = match data with
  [ ] -> List.rev result
| _ -> let ( i , r ) = List.hd ( data ) in
  createTailRecursiveTestList ( List.tl data )  ( ( "tailRecursive test " ^ ( string_of_num i ) >:: ( fun _ -> assert_equal r ( Factorial.tailRecursive i ) ) ) :: result )
;;

let negativeData = [ -20 ; -10 ; -4 ; -2 ; -1 ]

let rec createRecursiveNegativeList data result = match data with
  [ ] -> result
| _ -> let i = List.hd data in
  createRecursiveNegativeList  ( List.tl data ) ( ( "recursive negative test  " ^ ( string_of_int i ) >:: ( fun _ -> assert_raises "negative" NegativeValue Factorial.recursive i ) ) :: result )
;;

let testFactorialZero _ =
  assert_equal ( Int 1 ) ( Factorial.tailRecursive ( Int 0 ) )
;;

let testFactorialOne _ =
  assert_equal ( Int 1 ) ( Factorial.tailRecursive ( Int 1 ) )
;;

let testFactorialTwo _ =
  assert_equal ( Int 2 ) ( Factorial.tailRecursive ( Int 2 ) )
;;


let suite = "Factorial Test" >::: createRecursiveTestList testData [ ] @ createTailRecursiveTestList testData [ ] @ [
                                 "testFactorialZero" >:: testFactorialZero  ;
                                 "testFactorialOne" >:: testFactorialOne ;
                                 "testFactorialTwo" >:: testFactorialTwo
                               ]

let _ =
  run_test_tt_main suite
;;