import { assertEquals } from "@std/assert";
import { chordsOf } from "./chords.ts";

const note = (start: number, dur: number, pitch: number) => ({ start, dur, pitch, vel: 1 });
const layout = (notes: ReturnType<typeof note>[]) =>
  chordsOf(notes).map(c => [c.start, c.start + c.dur, c.notes]);

Deno.test("block chords come out one chord each, leaving silences empty", () => {
  assertEquals(
    layout([
      note(0, 2, 64),
      note(0, 2, 60),
      note(0, 2, 67),
      note(3, 1, 65),
      note(3, 1, 69),
      note(3, 1, 60),
    ]),
    [
      [0, 2, [60, 64, 67]],
      [3, 4, [60, 65, 69]],
    ],
  );
});

Deno.test("a new chord starts wherever a note comes in or drops out", () => {
  assertEquals(layout([note(0, 4, 48), note(0, 2, 64), note(1, 1, 67), note(2, 2, 65)]), [
    [0, 1, [48, 64]],
    [1, 2, [48, 64, 67]],
    [2, 4, [48, 65]],
  ]);
});

Deno.test("the same notes struck again straight after carry on as one chord", () => {
  assertEquals(layout([note(0, 1, 60), note(0, 1, 64), note(1, 1, 64), note(1, 1, 60)]), [
    [0, 2, [60, 64]],
  ]);
});

Deno.test("a pitch doubled across overlapping notes is one chord tone", () => {
  assertEquals(layout([note(0, 2, 60), note(1, 2, 60), note(1, 1, 67)]), [
    [0, 1, [60]],
    [1, 2, [60, 67]],
    [2, 3, [60]],
  ]);
});