From f9c09d61b14d0ed096df0ae6a4a28f9a4d7617ba Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Manuel=20V=C3=B6gele?= <develop@manuel-voegele.de>
Date: Tue, 25 Oct 2022 21:11:08 +0200
Subject: [PATCH] Send a reminder when the event starts

---
 src/main.rs | 67 +++++++++++++++++++++++++++++++----------------------
 1 file changed, 39 insertions(+), 28 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 794021a..628bc5d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -9,7 +9,7 @@ use std::{env, fs::File, io::BufReader, sync::Arc, time::Duration};
 use anyhow::Result;
 use async_mutex::Mutex;
 use bot::fetch_and_announce_appointment;
-use chrono::{NaiveTime, Utc};
+use chrono::{DateTime, NaiveTime, TimeZone, Utc};
 use chrono_tz::Europe;
 use db::ChatInfo;
 use diesel::{Connection, RunQueryDsl, SqliteConnection};
@@ -93,6 +93,11 @@ async fn main() {
 	bot::spawn(bot, db).await;
 }
 
+struct Reminder<Tz: TimeZone> {
+	time: DateTime<Tz>,
+	text: String,
+}
+
 async fn check_task(bot: &Throttle<Bot>, reminder_time: NaiveTime, db: &Database) -> Result<()> {
 	let chats = db.lock().await.transaction(|db| {
 		use schema::chat::dsl::*;
@@ -112,40 +117,46 @@ async fn check_task(bot: &Throttle<Bot>, reminder_time: NaiveTime, db: &Database
 		};
 		let appointment = appointment.with_timezone(&Europe::Berlin);
 
-		if appointment.start < now {
-			continue;
-		}
 		if appointment.start.date_naive() != today {
 			continue;
 		}
 
-		let reminder_date_time = now.date().and_time(reminder_time).unwrap();
-
-		if now < reminder_date_time {
-			continue;
+		let mut reminder = None;
+		if now >= appointment.start {
+			reminder = Some(Reminder {
+				time: appointment.start,
+				text: "Jetzt geht's weiter".into(),
+			});
+		} else {
+			let reminder_date_time = now.date().and_time(reminder_time).unwrap();
+			if now >= reminder_date_time {
+				reminder = Some(Reminder {
+					time: reminder_date_time,
+					text: format!(
+						"Heute um {} Uhr geht's weiter",
+						appointment.start.format("%H:%M")
+					),
+				})
+			}
 		}
 
-		if chat_info.last_reminder.is_some()
-			&& chat_info.last_reminder.unwrap() >= reminder_date_time
-		{
-			continue;
+		if let Some(reminder) = reminder {
+			if chat_info.last_reminder.is_some()
+				&& chat_info.last_reminder.unwrap() >= reminder.time
+			{
+				continue;
+			}
+
+			bot.send_message(ChatId(chat_info.id), reminder.text)
+				.await?;
+
+			db.lock().await.transaction(|db| {
+				use schema::chat::dsl::*;
+				diesel::update(chat.filter(telegram_id.eq(chat_info.id)))
+					.set((last_reminder.eq(now.timestamp()),))
+					.execute(db)
+			})?;
 		}
-
-		bot.send_message(
-			ChatId(chat_info.id),
-			format!(
-				"Heute um {} Uhr geht's weiter",
-				appointment.start.format("%H:%M")
-			),
-		)
-		.await?;
-
-		db.lock().await.transaction(|db| {
-			use schema::chat::dsl::*;
-			diesel::update(chat.filter(telegram_id.eq(chat_info.id)))
-				.set((last_reminder.eq(now.timestamp()),))
-				.execute(db)
-		})?;
 	}
 
 	Ok(())