import { makeIDGen } from "./util";
import { $ } from "zx";

const producerIndexGen = makeIDGen(0);

export abstract class Producer {
	index: number;
	constructor(public path: string) {
		this.index = producerIndexGen.next().value;
	}

	async getNativeMltXml(fps: number): Promise<string> {
		const xml = (
			await $`melt ${
				this.path
			} -consumer xml ${`frame_rate_num=${fps}`} | htmlq producer`
		).stdout;
		return xml.replace("producer0", this.id);
	}

	async toXML(fps: number): Promise<string> {
		return await this.getNativeMltXml(fps);
	}

	get id() {
		return "producer" + this.index;
	}
}

export class ConcreteProducer extends Producer {
	video_only: VideoOnlyProducer;
	audio_only: AudioOnlyProducer;
	constructor(path: string) {
		super(path);
		this.video_only = new VideoOnlyProducer(path);
		this.audio_only = new AudioOnlyProducer(path);
	}

	async toXML(fps: number) {
		return (
			await Promise.all([
				super.toXML(fps),
				this.video_only.toXML(fps),
				this.audio_only.toXML(fps),
			])
		).join("\n");
	}
}

class VideoOnlyProducer extends Producer {
	async toXML(fps: number) {
		const xml = await super.toXML(fps);
		return xml.replace(
			"</producer>",
			` <property name="set.test_audio">0</property>
        <property name="set.test_image">1</property>
       </producer>`
		);
	}
}

class AudioOnlyProducer extends Producer {
	async toXML(fps: number) {
		const xml = await super.toXML(fps);
		return xml.replace(
			"</producer>",
			` <property name="set.test_audio">1</property>
        <property name="set.test_image">0</property>
       </producer>`
		);
	}
}

export class BlackTrack extends Producer {
	constructor() {
		super("");
	}

	async toXML() {
		return /* HTML */ `<producer
			id="black_track"
			in="00:00:00.000"
			out="00:16:43.344"
		>
			<property name="length">2147483647</property>
			<property name="eof">continue</property>
			<property name="resource">black</property>
			<property name="aspect_ratio">1</property>
			<property name="mlt_service">color</property>
			<property name="mlt_image_format">rgb24a</property>
			<property name="set.test_audio">0</property>
		</producer>`;
	}

	get id() {
		return "black_track";
	}
}