import { VertFile } from "$lib/types";
import { Converter } from "./converter.svelte";
import { FFmpeg } from "@ffmpeg/ffmpeg";
import { browser } from "$app/environment";
import { error, log } from "$lib/logger";
import { addToast } from "$lib/store/ToastProvider";

export class FFmpegConverter extends Converter {
	private ffmpeg: FFmpeg = null!;
	public name = "ffmpeg";
	public ready = $state(false);

	public supportedFormats = [
		".mp3",
		".wav",
		".flac",
		".ogg",
		".aac",
		".m4a",
		".wma",
		".m4a",
		".amr",
		".ac3",
		".alac",
		".aiff",
	];

	public readonly reportsProgress = true;

	constructor() {
		super();
		log(["converters", this.name], `created converter`);
		if (!browser) return;
		try {
			this.ffmpeg = new FFmpeg();
			(async () => {
				const baseURL =
					"https://cdn.jsdelivr.net/npm/@ffmpeg/core@0.12.6/dist/esm";
				await this.ffmpeg.load({
					coreURL: `${baseURL}/ffmpeg-core.js`,
					wasmURL: `${baseURL}/ffmpeg-core.wasm`,
				});
				// this is just to cache the wasm and js for when we actually use it. we're not using this ffmpeg instance
				this.ready = true;
			})();
		} catch (err) {
			error(["converters", this.name], `error loading ffmpeg: ${err}`);
			addToast(
				"error",
				`Error loading ffmpeg, some features may not work.`,
			);
		}
	}

	public async convert(input: VertFile, to: string): Promise<VertFile> {
		if (!to.startsWith(".")) to = `.${to}`;
		const ffmpeg = new FFmpeg();
		ffmpeg.on("progress", (progress) => {
			input.progress = progress.progress * 100;
		});
		const baseURL =
			"https://cdn.jsdelivr.net/npm/@ffmpeg/core@0.12.6/dist/esm";
		await ffmpeg.load({
			coreURL: `${baseURL}/ffmpeg-core.js`,
			wasmURL: `${baseURL}/ffmpeg-core.wasm`,
		});
		const buf = new Uint8Array(await input.file.arrayBuffer());
		await ffmpeg.writeFile("input", buf);
		log(
			["converters", this.name],
			`wrote ${input.name} to ffmpeg virtual fs`,
		);
		await ffmpeg.exec(["-i", "input", "output" + to]);
		log(["converters", this.name], `executed ffmpeg command`);
		const output = (await ffmpeg.readFile(
			"output" + to,
		)) as unknown as Uint8Array;
		log(
			["converters", this.name],
			`read ${input.name.split(".").slice(0, -1).join(".") + to} from ffmpeg virtual fs`,
		);
		window.plausible("convert", {
			props: {
				type: "audio",
			}
		});
		ffmpeg.terminate();
		return new VertFile(new File([output], input.name), to);
	}
}