import { describe, it, expect, beforeEach } from 'vitest';
import { get } from 'svelte/store';
// Import the store module directly: the feature barrel re-exports .svelte
// components, which the unit runner (no Svelte plugin) cannot transform.
import { timelineStore, positionAt } from '$features/timeline/store';

beforeEach(() => {
	timelineStore.pause();
	timelineStore.setRange(0, 0);
	timelineStore.setSpeed(1);
	timelineStore.setMarkers([]);
});

describe('timelineStore', () => {
	it('clamps seek to the current range', () => {
		timelineStore.setRange(0, 10_000);
		timelineStore.seek(99_999);
		expect(get(timelineStore).time).toBe(10_000);
		timelineStore.seek(-5);
		expect(get(timelineStore).time).toBe(0);
	});

	it('clamps the current time when the range shrinks', () => {
		timelineStore.setRange(0, 10_000);
		timelineStore.seek(9_000);
		timelineStore.setRange(0, 4_000);
		expect(get(timelineStore).time).toBe(4_000);
	});

	it('ignores play when there is no duration', () => {
		timelineStore.play();
		expect(get(timelineStore).playing).toBe(false);
	});

	it('plays and pauses when a duration exists', () => {
		timelineStore.setRange(0, 10_000);
		timelineStore.play();
		expect(get(timelineStore).playing).toBe(true);
		timelineStore.pause();
		expect(get(timelineStore).playing).toBe(false);
	});

	it('rewinds to min on reset', () => {
		timelineStore.setRange(0, 10_000);
		timelineStore.seek(7_000);
		timelineStore.reset();
		expect(get(timelineStore).time).toBe(0);
		expect(get(timelineStore).playing).toBe(false);
	});

	it('stores the playback speed', () => {
		timelineStore.setSpeed(5);
		expect(get(timelineStore).speed).toBe(5);
	});
});

describe('positionAt', () => {
	const path: [number, number, ...number[]][] = [
		[60, 100],
		[62, 102],
		[64, 104]
	];

	it('returns the first point at t=0 and the last at t=duration', () => {
		expect(positionAt(path, 0, 1000)).toEqual([60, 100]);
		expect(positionAt(path, 1000, 1000)).toEqual([64, 104]);
	});

	it('interpolates linearly between samples', () => {
		// Quarter of the way = halfway along the first segment.
		const p = positionAt(path, 250, 1000)!;
		expect(p[0]).toBeCloseTo(61, 6);
		expect(p[1]).toBeCloseTo(101, 6);
	});

	it('clamps outside the flight window and handles an empty path', () => {
		expect(positionAt(path, -100, 1000)).toEqual([60, 100]);
		expect(positionAt(path, 99_999, 1000)).toEqual([64, 104]);
		expect(positionAt([], 0, 1000)).toBeNull();
	});
});