import {Client, ClientEvents, Constants} from "discord.js";
import Storage from "./storage";
import $ from "./lib";

interface EventOptions<K extends keyof ClientEvents> {
    readonly on?: (...args: ClientEvents[K]) => void;
    readonly once?: (...args: ClientEvents[K]) => void;
}

export default class Event<K extends keyof ClientEvents> {
    private readonly on?: (...args: ClientEvents[K]) => void;
    private readonly once?: (...args: ClientEvents[K]) => void;

    constructor(options: EventOptions<K>) {
        this.on = options.on;
        this.once = options.once;
    }

    // For this function, I'm going to assume that the event is used with the correct arguments and that the event tag is checked in "storage.ts".
    public attach(client: Client, event: K) {
        if (this.on) client.on(event, this.on);
        if (this.once) client.once(event, this.once);
    }
}

export async function loadEvents(client: Client) {
    for (const file of Storage.open("dist/events", (filename: string) => filename.endsWith(".js"))) {
        const header = file.substring(0, file.indexOf(".js"));
        const event = (await import(`../events/${header}`)).default;

        if ((Object.values(Constants.Events) as string[]).includes(header)) {
            event.attach(client, header);
            $.log(`Loading Event: ${header}`);
        } else
            $.warn(
                `"${header}" is not a valid event type! Did you misspell it? (Note: If you fixed the issue, delete "dist" because the compiler won't automatically delete any extra files.)`
            );
    }
}