{levenshtein: {permutations}} = require '../../src/util/permutations'

module.exports =
  'There should be no permutations on an empty list': (test) ->
    test.deepEqual(permutations([]), [])
    test.done()
  'The only permutation on a singleton list should be the same list': (test) ->
    test.deepEqual(permutations([1]), [[1]])
    test.done()
  'There should be 2-factorial, distinct permutations on a pair': (test) ->
    test.deepEqual(permutations([1,2]),[
      [1,2]
      [2,1]
    ])
    test.done()
  'There should be 3-factorial, distinct permutations on a triple': (test) ->
    test.deepEqual(permutations([1..3]), [
      [1, 2, 3]
      [1, 3, 2]
      [2, 1, 3]
      [2, 3, 1]
      [3, 2, 1]
      [3, 1, 2]
    ])
    test.done()
  'There should be 4-factorial, distinct permutations on a quadruple': (test) ->
    test.deepEqual(permutations([1..4]), [
      [1, 2, 3, 4]
      [1, 2, 4, 3]
      [1, 3, 2, 4]
      [1, 3, 4, 2]
      [1, 4, 3, 2]
      [1, 4, 2, 3]
      [2, 1, 3, 4]
      [2, 1, 4, 3]
      [2, 3, 1, 4]
      [2, 3, 4, 1]
      [2, 4, 3, 1]
      [2, 4, 1, 3]
      [3, 2, 1, 4]
      [3, 2, 4, 1]
      [3, 1, 2, 4]
      [3, 1, 4, 2]
      [3, 4, 1, 2]
      [3, 4, 2, 1]
      [4, 2, 3, 1]
      [4, 2, 1, 3]
      [4, 3, 2, 1]
      [4, 3, 1, 2]
      [4, 1, 3, 2]
      [4, 1, 2, 3]
    ])
    test.done()
  'There should be 5-factorial, distinct permutations on a 5-tuple': (test) ->
    test.deepEqual(permutations([1..5]), [
      [1, 2, 3, 4, 5]
      [1, 2, 3, 5, 4]
      [1, 2, 4, 3, 5]
      [1, 2, 4, 5, 3]
      [1, 2, 5, 4, 3]
      [1, 2, 5, 3, 4]
      [1, 3, 2, 4, 5]
      [1, 3, 2, 5, 4]
      [1, 3, 4, 2, 5]
      [1, 3, 4, 5, 2]
      [1, 3, 5, 4, 2]
      [1, 3, 5, 2, 4]
      [1, 4, 3, 2, 5]
      [1, 4, 3, 5, 2]
      [1, 4, 2, 3, 5]
      [1, 4, 2, 5, 3]
      [1, 4, 5, 2, 3]
      [1, 4, 5, 3, 2]
      [1, 5, 3, 4, 2]
      [1, 5, 3, 2, 4]
      [1, 5, 4, 3, 2]
      [1, 5, 4, 2, 3]
      [1, 5, 2, 4, 3]
      [1, 5, 2, 3, 4]
      [2, 1, 3, 4, 5]
      [2, 1, 3, 5, 4]
      [2, 1, 4, 3, 5]
      [2, 1, 4, 5, 3]
      [2, 1, 5, 4, 3]
      [2, 1, 5, 3, 4]
      [2, 3, 1, 4, 5]
      [2, 3, 1, 5, 4]
      [2, 3, 4, 1, 5]
      [2, 3, 4, 5, 1]
      [2, 3, 5, 4, 1]
      [2, 3, 5, 1, 4]
      [2, 4, 3, 1, 5]
      [2, 4, 3, 5, 1]
      [2, 4, 1, 3, 5]
      [2, 4, 1, 5, 3]
      [2, 4, 5, 1, 3]
      [2, 4, 5, 3, 1]
      [2, 5, 3, 4, 1]
      [2, 5, 3, 1, 4]
      [2, 5, 4, 3, 1]
      [2, 5, 4, 1, 3]
      [2, 5, 1, 4, 3]
      [2, 5, 1, 3, 4]
      [3, 2, 1, 4, 5]
      [3, 2, 1, 5, 4]
      [3, 2, 4, 1, 5]
      [3, 2, 4, 5, 1]
      [3, 2, 5, 4, 1]
      [3, 2, 5, 1, 4]
      [3, 1, 2, 4, 5]
      [3, 1, 2, 5, 4]
      [3, 1, 4, 2, 5]
      [3, 1, 4, 5, 2]
      [3, 1, 5, 4, 2]
      [3, 1, 5, 2, 4]
      [3, 4, 1, 2, 5]
      [3, 4, 1, 5, 2]
      [3, 4, 2, 1, 5]
      [3, 4, 2, 5, 1]
      [3, 4, 5, 2, 1]
      [3, 4, 5, 1, 2]
      [3, 5, 1, 4, 2]
      [3, 5, 1, 2, 4]
      [3, 5, 4, 1, 2]
      [3, 5, 4, 2, 1]
      [3, 5, 2, 4, 1]
      [3, 5, 2, 1, 4]
      [4, 2, 3, 1, 5]
      [4, 2, 3, 5, 1]
      [4, 2, 1, 3, 5]
      [4, 2, 1, 5, 3]
      [4, 2, 5, 1, 3]
      [4, 2, 5, 3, 1]
      [4, 3, 2, 1, 5]
      [4, 3, 2, 5, 1]
      [4, 3, 1, 2, 5]
      [4, 3, 1, 5, 2]
      [4, 3, 5, 1, 2]
      [4, 3, 5, 2, 1]
      [4, 1, 3, 2, 5]
      [4, 1, 3, 5, 2]
      [4, 1, 2, 3, 5]
      [4, 1, 2, 5, 3]
      [4, 1, 5, 2, 3]
      [4, 1, 5, 3, 2]
      [4, 5, 3, 1, 2]
      [4, 5, 3, 2, 1]
      [4, 5, 1, 3, 2]
      [4, 5, 1, 2, 3]
      [4, 5, 2, 1, 3]
      [4, 5, 2, 3, 1]
      [5, 2, 3, 4, 1]
      [5, 2, 3, 1, 4]
      [5, 2, 4, 3, 1]
      [5, 2, 4, 1, 3]
      [5, 2, 1, 4, 3]
      [5, 2, 1, 3, 4]
      [5, 3, 2, 4, 1]
      [5, 3, 2, 1, 4]
      [5, 3, 4, 2, 1]
      [5, 3, 4, 1, 2]
      [5, 3, 1, 4, 2]
      [5, 3, 1, 2, 4]
      [5, 4, 3, 2, 1]
      [5, 4, 3, 1, 2]
      [5, 4, 2, 3, 1]
      [5, 4, 2, 1, 3]
      [5, 4, 1, 2, 3]
      [5, 4, 1, 3, 2]
      [5, 1, 3, 4, 2]
      [5, 1, 3, 2, 4]
      [5, 1, 4, 3, 2]
      [5, 1, 4, 2, 3]
      [5, 1, 2, 4, 3]
      [5, 1, 2, 3, 4]
    ])
    test.done()