module QCInterval (qcIntervalTests) where 

import Test.QuickCheck.Batch
import Test.QuickCheck

import Music.Diatonic
import QCNote


instance Arbitrary Interval where
  arbitrary = do
    i <- elements [Unison, Min2nd, Maj2nd, Min3rd, Maj3rd, Perf4th, Perf5th, Min6th, Maj6th, Min7th, Maj7th, min9th, maj9th, perf11th, min13th, maj13th]
    a <- elements [diminish.diminish, diminish, id, augment, augment.augment]
    return (a i)
  coarbitrary = error "Not implemented"


prop_interval_up_down i = (augment . diminish $ i) == i
prop_interval_down_up i = (diminish . augment $ i) == i
prop_interval_up_semis i = (semitones . augment $ i) == ((semitones i) + 1)
prop_interval_down_semis i = (semitones . diminish $ i) == ((semitones i) - 1)
prop_interval_up_steps i = (steps . augment $ i) == steps i
prop_interval_down_steps i = (steps . diminish $ i) == steps i
prop_interval_above_below i n = (i `below` (i `above` n)) == n
prop_interval_distance_above n1 n2 = (n1 `distance` n2) `above` n1 == n2
prop_interval_distance_below n1 n2 = (n1 `distance` n2) `below` n2 == n1


options = TestOptions { no_of_tests = 100, length_of_tests = 0, debug_tests = False }

qcIntervalTests = do
    runTests "Music.Diatonic.Interval" options
        [ run prop_interval_up_down
        , run prop_interval_down_up
        , run prop_interval_up_semis
        , run prop_interval_down_semis
        , run prop_interval_up_steps
        , run prop_interval_down_steps
        , run prop_interval_above_below
        , run prop_interval_distance_above
        , run prop_interval_distance_below
        ]