module PointTest exposing (specs)

import Point exposing (Point, Pos, downsample)
import Test exposing (..)
import Expect exposing (Expectation)

newPoint i = Point
             (1731437067 + (toFloat i)*1.2)
             (Pos 52 1 (Just 10))
             (Just (round(sin((toFloat i)/10)*10))) (Just i) Nothing


points n = List.map newPoint (List.range 0 n)

maybe default val =
    case val of
        Just v -> v
        Nothing -> default

specs: Test
specs =
    describe "downsample"
        [ test "it returns no more points than requested" <|
              \_ ->
              let orig = (points 10)
                  sampled = Point.downsample 5 orig
              in Expect.equal 5 (List.length sampled)
        , test "it drops points which are too close together" <|
              \_ ->
              let orig = List.map newPoint [ 0, 1, 2, 3, 4, 10, 500, 1000 ]
                  sampled = Point.downsample 10 orig
                  idx p = maybe 0 p.power
              in Expect.equalLists [0, 500, 1000] (List.map idx sampled)

        ]