import { describe, expect, it } from 'vitest';
import { heldSongMarkers } from '../../src/core/music/markers';
import {
  MARKER_FLAG,
  MARKER_REACH,
  MARKER_STRIP,
  markerAt,
  markerNameX,
  markerSpans,
  SONG_TOP,
} from '../../src/editor/song/markerView';
import { RULER_HEIGHT } from '../../src/editor/music/timeView';

/** A tick a pixel, from x 100; every name 6 pixels a letter. */
const VIEW = { panX: 100, pxPerTick: 1 };
const measure = (name: string) => name.length * 6;

describe('the marker strip of the song tab (#338)', () => {
  it('lies between the ruler and the tracks', () => {
    expect(SONG_TOP).toBe(RULER_HEIGHT + MARKER_STRIP);
  });

  it('draws a marker at its tick, as wide as its flag and name, but not into the next one', () => {
    const markers = heldSongMarkers([
      { id: 'a', name: 'Intro', tick: 0 },
      { id: 'b', name: 'A long name', tick: 40 },
      { id: 'c', name: '', tick: 300 },
    ]);
    const spans = markerSpans(VIEW, markers, measure);
    expect(spans.map((s) => s.x)).toEqual([100, 140, 400]);
    // Room to the next one is 40 pixels, less 2: the name of "Intro" (30) and the flag fit just so.
    expect(spans[0]!.w).toBe(38);
    expect(spans[1]!.w).toBe(MARKER_FLAG + 3 + measure('A long name'));
    expect(spans[2]!.w).toBe(MARKER_FLAG + 3 + measure('Marker 3'));
    expect(markerNameX(spans[0]!)).toBe(100 + MARKER_FLAG + 3);
  });

  it('keeps the flag of a marker with another one close behind it', () => {
    const markers = heldSongMarkers([
      { id: 'a', name: 'Close', tick: 0 },
      { id: 'b', name: 'By', tick: 2 },
    ]);
    expect(markerSpans(VIEW, markers, measure)[0]!.w).toBe(MARKER_FLAG);
  });

  it('takes the marker near its line or on its flag and name, the later one where they overlap', () => {
    const markers = heldSongMarkers([
      { id: 'a', name: 'Intro', tick: 0 },
      { id: 'b', name: 'B', tick: 6 },
    ]);
    const spans = markerSpans(VIEW, markers, measure);
    expect(markerAt(spans, 100 - MARKER_REACH)).toBe('a');
    expect(markerAt(spans, 100 - MARKER_REACH - 1)).toBeNull();
    expect(markerAt(spans, 103)).toBe('b');
    expect(markerAt(spans, 106 + MARKER_FLAG + 3 + 6)).toBe('b');
    expect(markerAt(spans, 106 + MARKER_FLAG + 3 + 7)).toBeNull();
    expect(markerAt([], 100)).toBeNull();
  });
});