import { describe, expect, it } from 'vitest';
import {
	detectChange,
	estimateProgress,
	formatClock,
	nextDelay,
	sseEvent,
	toLive,
	type PlayerSample
} from './now-playing';

const track = (id: string) => ({
	spotifyId: id,
	name: `Song ${id}`,
	durationMs: 200_000,
	explicit: false,
	artists: [
		{ spotifyId: null, name: 'A' },
		{ spotifyId: null, name: 'B' }
	],
	album: {
		spotifyId: null,
		name: 'Album',
		imageUrl: 'https://i/640',
		imageUrlSmall: 'https://i/300',
		releaseDate: null
	}
});
const sample = (over: Partial<PlayerSample> = {}): PlayerSample => ({
	trackId: 1,
	track: track('x'),
	isPlaying: true,
	progressMs: 10_000,
	sampledAt: 1_000_000,
	...over
});

describe('now playing', () => {
	it('builds the public payload', () => {
		expect(toLive(sample())).toEqual({
			isPlaying: true,
			track: 'Song x',
			artists: 'A, B',
			album: 'Album',
			image: 'https://i/300',
			url: 'https://open.spotify.com/track/x',
			progressMs: 10_000,
			durationMs: 200_000,
			sampledAt: 1_000_000
		});
		expect(toLive(sample({ track: null, trackId: null }))).toMatchObject({
			isPlaying: false,
			track: null
		});
	});
	it('detects track changes, play/pause and seeks, not normal progress', () => {
		const a = sample();
		expect(detectChange(null, a).any).toBe(true);
		expect(detectChange(a, sample({ progressMs: 15_000, sampledAt: 1_005_000 })).any).toBe(false);
		expect(detectChange(a, sample({ progressMs: 90_000, sampledAt: 1_005_000 })).seek).toBe(true);
		expect(detectChange(a, sample({ isPlaying: false })).playing).toBe(true);
		expect(detectChange(a, sample({ track: track('y') })).track).toBe(true);
	});
	it('estimates progress between events and clamps to the duration', () => {
		const l = toLive(sample());
		expect(estimateProgress(l, 0, 5_000)).toBe(15_000);
		expect(estimateProgress(l, 0, 10_000_000)).toBe(200_000);
		expect(estimateProgress({ ...l, isPlaying: false }, 0, 5_000)).toBe(10_000);
		expect(formatClock(75_000)).toBe('1:15');
	});
	it('formats SSE events with the sample age, and backs off when idle', () => {
		const event = sseEvent(toLive(sample()), 1_002_000);
		expect(event.startsWith('event: now\ndata: ')).toBe(true);
		expect(event.endsWith('\n\n')).toBe(true);
		expect(JSON.parse(event.split('data: ')[1]).ageMs).toBe(2_000);
		expect(nextDelay(true, 9)).toBe(5_000);
		expect(nextDelay(false, 0)).toBe(10_000);
		expect(nextDelay(false, 50)).toBe(30_000);
	});
});