flashlang/src/background_frontend_commands.ts

import {
	Communicator,
	type commandFunction,
	type commandList,
} from "./communicator";
import browser from "webextension-polyfill";

interface BackgroundCommands extends commandList {
	setEnabled: setEnabled;
	getEnabled: getEnabled;
	translate: translate;
	addFlashcard: addFlashcard;
	removeFlashcard: removeFlashcard;
	getLanguages: getLanguages;
	getCurrentLanguages: getCurrentLanguages;
	setCurrentLanguages: setCurrentLanguages;
}

interface FrontendCommands extends commandList {
	setEnabled: setEnabled;
}

interface setEnabled extends commandFunction {
	args: boolean;
}

interface getEnabled extends commandFunction {
	return: boolean;
}

interface getLanguages extends commandFunction {
	return: Array<Language>;
}

interface translate extends commandFunction {
	args: string;
	return: Promise<Translation | Flashcard>;
}

interface getCurrentLanguages extends commandFunction {
	return: LanguagePair;
}

interface addFlashcard extends commandFunction {
	args: Translation | Flashcard;
	return: Flashcard;
}

interface removeFlashcard extends commandFunction {
	args: Flashcard;
}

interface setCurrentLanguages extends commandFunction {
	args: Partial<LanguagePair>;
}

export class BackgroundMessenger extends Communicator<
	BackgroundCommands,
	FrontendCommands
> {
	constructor() {
		super();
		browser.runtime.onMessage.addListener((m, s) => this.onMessage(m, s));
	}
	runCommand<K extends keyof BackgroundCommands>(
		command: K,
		args: BackgroundCommands[K]["args"],
		tabID: number
	) {
		const msg = this.getCommandMessage(command, args);
		return browser.tabs.sendMessage(tabID, msg);
	}
}

export class FrontendMessenger extends Communicator<
	FrontendCommands,
	BackgroundCommands
> {
	constructor() {
		super();
		browser.runtime.onMessage.addListener((m, s) => this.onMessage(m, s));
	}

	runCommand<K extends keyof BackgroundCommands>(
		command: K,
		args: BackgroundCommands[K]["args"]
	): Promise<BackgroundCommands[K]["return"]> {
		const message = this.getCommandMessage(command, args);
		return browser.runtime.sendMessage(message);
	}
}