import { Client, EmbedBuilder } from "npm:discord.js";

import { fetch_feed_channel, format_devoir_title } from "./lib.ts";
import { Devoir, Feed, Storage } from "./storage.ts";
import { Channel, collect, log_from } from "./utils.ts";

const log = log_from(import.meta);

export async function update_loop(bot: Client, storage: Storage, update_display: Channel) {
	log("Waiting for updates.");
	while (true) {
		await update_display.receive();
		log("Updating board.");
		const sorted_devoirs = await get_devoirs_sorted(storage);
		for await (const [_, feed] of storage.feeds.list()) await update_feed(bot, feed, sorted_devoirs);
	}
}

async function get_devoirs_sorted(storage: Storage) {
	const devoirs = await collect(storage.devoirs.list());
	const sorted_devoirs = devoirs
		.map(([_, d]) => d)
		.toSorted((a, b) => a.date > b.date ? 1 : -1);
	return sorted_devoirs;
}

async function update_feed(bot: Client<boolean>, feed: Feed, sorted_devoirs: Devoir[]) {
	const embed = new EmbedBuilder()
		.setTitle("`📚` Devoirs")
		.setFooter({ text: "Mise à jour " + Date.now() });
	for (const devoir of sorted_devoirs) {
		embed.addFields({
			name: format_devoir_title(devoir),
			value: devoir.description,
		});
	}
	const feed_channel = await fetch_feed_channel(bot, feed);
	const board_message = await feed_channel.messages.fetch(feed.board_message_id);
	board_message.edit({ embeds: [embed], content: "" });
}