import { describe, expect, it } from "vitest";
import { computeWebcamOverlayLayout } from "./webcamOverlay";

describe("computeWebcamOverlayLayout", () => {
	it("anchors the overlay in the lower-right corner", () => {
		const layout = computeWebcamOverlayLayout({
			stageWidth: 1920,
			stageHeight: 1080,
			videoWidth: 1280,
			videoHeight: 720,
		});

		expect(layout).not.toBeNull();
		expect(layout!.x + layout!.width).toBeLessThanOrEqual(1920);
		expect(layout!.y + layout!.height).toBeLessThanOrEqual(1080);
		expect(layout!.x).toBeGreaterThan(1920 / 2);
		expect(layout!.y).toBeGreaterThan(1080 / 2);
	});

	it("keeps the overlay within the configured stage fraction while preserving aspect ratio", () => {
		const layout = computeWebcamOverlayLayout({
			stageWidth: 1280,
			stageHeight: 720,
			videoWidth: 1920,
			videoHeight: 1080,
		});

		expect(layout).not.toBeNull();
		expect(layout!.width).toBeLessThanOrEqual(Math.round(1280 * 0.18) + 1);
		expect(layout!.height).toBeLessThanOrEqual(Math.round(720 * 0.18) + 1);
		expect(layout!.width / layout!.height).toBeCloseTo(1920 / 1080, 2);
	});
});