refactor split board update and notifications to their modules

src/lib/notification.ts

@@ -0,0 +1,84 @@
+import { assertExists } from "https://deno.land/std@0.223.0/assert/assert_exists.ts";
+
+import { Client, EmbedBuilder } from "npm:discord.js";
+
+import { _1d, _1min, wait } from "./utils.ts";
+import { fetch_feed_channel, format_devoir_title } from "./lib.ts";
+import { Storage } from "./storage.ts";
+
+export async function notification_loop(bot: Client, storage: Storage) {
+	while (true) {
+		// get all devoirs to notify
+		const devoirs_to_notify = new Set<string>();
+		const notification_threshold = 7 * _1d;
+		for await (const [devoir_id, devoir] of storage.devoirs.list()) {
+			const time_left = devoir.date - Date.now();
+			if (time_left < 0) continue; // TODO : delete devoir.
+			if (time_left > notification_threshold) continue;
+			devoirs_to_notify.add(devoir_id.id);
+		}
+
+		// delete all obsolete notifications
+		for await (const [notification_id, notification] of storage.notifications.list()) {
+			if (devoirs_to_notify.has(notification.devoir_id)) continue;
+			const feed = await storage.feeds.get({ id: notification.feed_id });
+			if (feed === null) continue;
+			const feed_channel = await fetch_feed_channel(bot, feed);
+			try {
+				const message = await feed_channel.messages.fetch(notification.message_id);
+				await message.delete();
+			} catch (_) { /* . */ }
+			await storage.notifications.delete(notification_id);
+			await storage.feeds.update({ id: notification.feed_id }, (f) => f.notification_ids.delete(notification_id.id));
+		}
+
+		// create missing messages.
+		for await (const [feed_id, feed] of storage.feeds.list()) {
+			const feed_channel = await fetch_feed_channel(bot, feed);
+			// find devoirs needing to create a notification for
+			const devoirs_to_notify_in_feed = new Set(devoirs_to_notify.values());
+			for (const existing_notification_id of feed.notification_ids.values()) {
+				const notification = await storage.notifications.get({ id: existing_notification_id });
+				assertExists(notification);
+				devoirs_to_notify_in_feed.delete(notification.devoir_id);
+			}
+			// create notifications
+			for (const devoir_id of devoirs_to_notify_in_feed.values()) {
+				const devoir = await storage.devoirs.get({ id: devoir_id });
+				if (devoir === null) continue;
+				const embed = new EmbedBuilder()
+					.setTitle(format_devoir_title(devoir))
+					.setDescription(devoir.description);
+				const message = await feed_channel.send({ embeds: [embed] });
+				const notification_id = await storage.notifications.add({
+					devoir_id: devoir_id,
+					message_id: message.id,
+					feed_id: feed_id.id,
+				});
+				storage.feeds.update(feed_id, (f) => f.notification_ids.add(notification_id.id));
+			}
+		}
+
+		// for each notification, update.
+		for await (const [_, notification] of storage.notifications.list()) {
+			const devoir = await storage.devoirs.get({ id: notification.devoir_id });
+			if (devoir === null) continue;
+			const feed = await storage.feeds.get({ id: notification.feed_id });
+			if (feed === null) continue;
+			const feed_channel = await fetch_feed_channel(bot, feed);
+			const message = await feed_channel.messages.fetch(notification.message_id);
+			const ms_left = devoir.date - Date.now();
+			const days_left = Math.floor(ms_left / _1d);
+			const embed = new EmbedBuilder()
+				.setTitle(format_devoir_title(devoir) + ` (${days_left} jours)`)
+				.setDescription(devoir.description)
+				.setColor(0x8888ff);
+			if (days_left <= 5) embed.setColor(0xffd726);
+			if (days_left <= 3) embed.setColor(0xff8b26);
+			if (days_left <= 1) embed.setColor(0xff2626);
+			await message.edit({ embeds: [embed], content: "" });
+		}
+
+		await wait(15 * _1min);
+	}
+}