Allow chats to choose a locale

src/db.rs

@@ -12,6 +12,7 @@ pub struct DbChat {
 	next_appointment_end: Option<i64>,
 	last_reminder: Option<i64>,
 	pinned_message: Option<i32>,
+	locale: Option<String>,
 }
 
 pub struct ChatInfo<Tz: TimeZone> {
@@ -20,6 +21,7 @@ pub struct ChatInfo<Tz: TimeZone> {
 	pub next_appointment: Option<Appointment<Tz>>,
 	pub last_reminder: Option<DateTime<Tz>>,
 	pub pinned_message_id: Option<i32>,
+	pub locale: String,
 }
 
 impl From<DbChat> for ChatInfo<Utc> {
@@ -42,12 +44,15 @@ impl From<DbChat> for ChatInfo<Utc> {
 			.map(|timestamp| NaiveDateTime::from_timestamp(timestamp, 0))
 			.map(|date_time| DateTime::<Utc>::from_utc(date_time, Utc));
 
+		let locale = db_chat.locale.unwrap_or("de".into());
+
 		ChatInfo {
 			id: db_chat.telegram_id,
 			calendar: db_chat.calendar,
 			next_appointment: next_appointment,
 			last_reminder,
 			pinned_message_id: db_chat.pinned_message,
+			locale,
 		}
 	}
 }