import {
	PythagorasIncomingMessageType, type PythagorasClient, type PythagorasIncomingMessage
} from "./pythagoras_client";
import { ScrollingTextBox } from "./scrolling_textbox";
import { dict, IDLE_LOGOS, QUESTION_LINK, QUESTION_QR } from "./settings";
import { AsyncRunner, el, sleep, wait_for_dom_refresh } from "./tools";

interface PresentationScreen {
	prepare(): Promise<void>;
	start(): Promise<void>;
	end(): Promise<void>;
	serve(trigger: PythagorasIncomingMessage): Promise<void>;
	dom: HTMLDivElement;
}

export class PresentationManager {
	private screen: PresentationScreen;
	private dom_root: HTMLDivElement;

	public constructor() {
		this.dom_root = el.div([]);

		this.screen = new BlankScreen();
	}

	private async update_dom_screen(): Promise<void> {
		await this.screen.prepare();
		this.dom_root.innerHTML = "";
		this.dom_root.appendChild(this.screen.dom);
		await wait_for_dom_refresh();
	}

	public async serve(ws_client: PythagorasClient): Promise<void> {
		while (true) {
			const received = await ws_client.recv();
			if (received.type == PythagorasIncomingMessageType.SetScreen) {
				await this.screen.end();
				this.set_screen(received.screen);
				await this.update_dom_screen();
				await this.screen.start();
				continue;
			}
			await this.screen.serve(received);
		}
	}

	private set_screen(screen: "idle" | "video" | "main"): void {
		switch (screen) {
			case "idle":
				this.screen = new IdleScreen();
				break;
			case "video":
				this.screen = new VideoScreen();
				break;
			case "main":
				this.screen = new MainScreen();
				break;
			default:
				throw new Error("unknown screen id");
		}
	}

	public get dom(): HTMLDivElement {
		return this.dom_root;
	}
}

class MainScreen implements PresentationScreen {
	private dom_root: HTMLDivElement;
	private subs_english: AsyncRunner<ScrollingTextBox>;
	private subs_czech: AsyncRunner<ScrollingTextBox>;
	private dom_question: HTMLDivElement;
	private dom_question_link: HTMLDivElement;
	private question_insert: HTMLParagraphElement;

	public constructor() {
		const subs_en = new ScrollingTextBox();
		const subs_cz = new ScrollingTextBox();
		this.subs_english = new AsyncRunner(subs_en);
		this.subs_czech = new AsyncRunner(subs_cz);
		this.question_insert = el.p("Otázka");
		this.dom_question_link = el.div([el.h1(QUESTION_LINK)], ["link"]);
		this.dom_question = el.div([this.dom_question_link, this.question_insert], ["question"]);
		this.dom_root = el.div([
			this.dom_question,
			el.div([
				el.div([subs_en.dom], ["lang"]),
				el.div([subs_cz.dom], ["lang"]),
			], ["subtitles"]),
			el.div([
				el.p("Jedná se o automaticky generovaný přepis. Omluvte, prosíme, případné chyby.", ["disclaimer"]),
			]),
		], ["main"]);
	}

	public async prepare(): Promise<void> {
		//this.dom_question_link.append(await el.img(QUESTION_QR, ["qr"]));
	}

	public async start(): Promise<void> {
		await wait_for_dom_refresh();
		this.dom_root.style.opacity = "1";
		await sleep(500);
	}

	public async end(): Promise<void> {
		this.dom_root.style.opacity = "0";
		await sleep(500);
	}

	private async show_question(text: string): Promise<void> {
		this.question_insert.innerText = text;
		this.question_insert.style.opacity = "1";
		await sleep(500);
	}

	private async hide_question(): Promise<void> {
		this.question_insert.style.opacity = "0";
		await sleep(500);
	}

	public async serve(trigger: PythagorasIncomingMessage): Promise<void> {
		switch (trigger.type) {
			case PythagorasIncomingMessageType.SubEnUpdateCur:
				this.subs_english.run((target: ScrollingTextBox) => {
					return target.update_current(trigger.text)
				});
				break;
			case PythagorasIncomingMessageType.SubEnSubmit:
				this.subs_english.run((target: ScrollingTextBox) => {
					return target.finish_current(trigger.text);
				});
				break;
			case PythagorasIncomingMessageType.SubCzSubmit:
				this.subs_czech.run((target: ScrollingTextBox) => {
					return target.add_line(trigger.text);
				});
				break;
			case PythagorasIncomingMessageType.SelectedMessage:
				if (trigger.message === null) { this.hide_question(); }
				else { this.show_question(trigger.message); }
				break;
		}
	}

	public get dom(): HTMLDivElement {
		return this.dom_root;
	}
}

class VideoScreen implements PresentationScreen {
	private dom_root: HTMLDivElement;
	private dom_video: HTMLVideoElement;

	private src: string | null;
	private subtitles: string | null;

	public constructor() {
		this.src = null;
		this.subtitles = null;
		this.dom_video = document.createElement("video");
		this.dom_root = el.div([this.dom_video], ["video"]);
	}

	public async prepare(): Promise<void> {
		this.dom_root.innerHTML = "";
		if (this.src !== null) {
			this.dom_video = await el.video(
				this.src, this.subtitles === null ? "" : this.subtitles
			);
			this.dom_video.volume = 0;
			this.dom_root.appendChild(this.dom_video);
		}
	}

	public async start(): Promise<void> {
		this.dom_video.style.opacity = "1";
		for (let i = 0; i <= 100; ++i) {
			this.dom_video.volume = i / 100;
			await sleep(10);
		}
	}

	public async end(): Promise<void> {
		this.dom_video.style.opacity = "0";
		for (let i = 100; i >= 0; --i) {
			this.dom_video.volume = i / 100;
			await sleep(10);
		}
	}

	public async serve(trigger: PythagorasIncomingMessage): Promise<void> {
		switch (trigger.type) {
			case PythagorasIncomingMessageType.PlayVideo:
				await this.play_video(
					trigger.filename, trigger.subtitles, trigger.seconds_from_start
				);
				break;
			case PythagorasIncomingMessageType.SeekVideo:
				this.seek_video(trigger.timestamp);
				break;
		}
	}

	private async play_video(
		video_url: string, subtitles_url: string | null, seconds_from_start: number
	): Promise<void> {
		this.dom_video = await el.video(video_url, subtitles_url);
		this.dom_video.currentTime = seconds_from_start;
		this.dom_root.innerHTML = "";
		this.dom_root.appendChild(this.dom_video);
		await wait_for_dom_refresh();
		await this.start();
	}

	private seek_video(seconds_from_start: number): void {
		this.dom_video.currentTime = seconds_from_start;
	}

	public get dom(): HTMLDivElement {
		return this.dom_root;
	}
}

class IdleScreen implements PresentationScreen {
	private dom_root: HTMLDivElement;
	private dom_title: HTMLHeadingElement;
	private dom_subtitle: HTMLHeadingElement;
	private dom_logos: HTMLDivElement[];

	public constructor() {
		this.dom_title = el.h1(dict.IDLE_TITLE)
		this.dom_subtitle = el.h2(dict.IDLE_STARTING);
		this.dom_logos = [];
		this.dom_root = el.div([this.dom_title, this.dom_subtitle], ["idle"]);
	}

	public async prepare(): Promise<void> {
		for (const logo of IDLE_LOGOS) {
			this.dom_logos.push(el.div([await el.img(logo)], ["logo"]));
		}
		const logos = el.div([...this.dom_logos], ["logos"]);
		this.dom_root.appendChild(logos);
	}

	public async start(): Promise<void> {
		await wait_for_dom_refresh();
		this.dom_title.style.transform = "translateY(0)";
		this.dom_title.style.opacity = "1";
		await sleep(250);
		this.dom_subtitle.style.opacity = "1";
		await sleep(250);
		for (const logo of this.dom_logos) {
			logo.style.transform = "translateY(0)";
			logo.style.opacity = "1";
			await sleep(250);
		}
		await sleep(250);
	}

	public async end(): Promise<void> {
		for (const logo of this.dom_logos) {
			logo.style.transform = "translateY(100%)";
			logo.style.opacity = "0";
			await sleep(250);
		}
		this.dom_subtitle.style.opacity = "0";
		await sleep(250);
		this.dom_title.style.transform = "translateY(-100%)";
		this.dom_title.style.opacity = "0";
		await sleep(500);
	}

	public async serve(trigger: PythagorasIncomingMessage): Promise<void> {}

	public get dom(): HTMLDivElement {
		return this.dom_root;
	}
}

class BlankScreen implements PresentationScreen {
	private dom_root: HTMLDivElement;

	public constructor() {
		this.dom_root = el.div([]);
	}

	public async prepare() {}
	public async start() {}
	public async end() {}
	public async serve(_: PythagorasIncomingMessage) {}

	public get dom(): HTMLDivElement {
		return this.dom_root;
	}
}