import { describe, expect, test } from "bun:test";
import {
	dBToLinear,
	getTrackVolume,
	resolveEffectiveAudioGain,
} from "@/timeline/audio-state";
import type { AudioElement, AudioTrack } from "@/timeline";
import { ZERO_MEDIA_TIME } from "@/wasm";

function audioElement(params?: AudioElement["params"]): AudioElement {
	return {
		id: "audio-1",
		name: "Audio",
		type: "audio",
		sourceType: "upload",
		mediaId: "media-1",
		duration: ZERO_MEDIA_TIME,
		startTime: ZERO_MEDIA_TIME,
		trimStart: ZERO_MEDIA_TIME,
		trimEnd: ZERO_MEDIA_TIME,
		params: params ?? { volume: 0, muted: false },
	};
}

describe("audio state", () => {
	test("track volume offsets element gain in decibels", () => {
		const gain = resolveEffectiveAudioGain({
			element: audioElement({ volume: -6, muted: false }),
			trackVolume: -6,
			localTime: 0,
		});

		expect(gain).toBeCloseTo(dBToLinear(-12), 6);
	});
	test("track volume and mute resolve to playback gain", () => {
		const element = audioElement({ volume: 0, muted: false });

		expect(
			resolveEffectiveAudioGain({ element, trackVolume: 0, localTime: 0 }),
		).toBe(1);
		expect(
			resolveEffectiveAudioGain({ element, trackVolume: -6, localTime: 0 }),
		).toBeCloseTo(dBToLinear(-6), 6);
		expect(
			resolveEffectiveAudioGain({
				element,
				trackMuted: true,
				trackVolume: 0,
				localTime: 0,
			}),
		).toBe(0);
	});

	test("missing track volume defaults to unity", () => {
		const track: AudioTrack = {
			id: "track-1",
			name: "Audio track",
			type: "audio",
			elements: [],
			muted: false,
		};

		expect(getTrackVolume({ track })).toBe(0);
	});
});