refactor admin outputs to asyncwrite

Signed-off-by: Jason Volk <jason@zemos.net>

src/admin/command.rs

@@ -1,6 +1,12 @@
-use std::time::SystemTime;
+use std::{fmt, time::SystemTime};
 
+use conduwuit::Result;
 use conduwuit_service::Services;
+use futures::{
+	io::{AsyncWriteExt, BufWriter},
+	lock::Mutex,
+	Future, FutureExt,
+};
 use ruma::EventId;
 
 pub(crate) struct Command<'a> {
@@ -8,4 +14,26 @@ pub(crate) struct Command<'a> {
 	pub(crate) body: &'a [&'a str],
 	pub(crate) timer: SystemTime,
 	pub(crate) reply_id: Option<&'a EventId>,
+	pub(crate) output: Mutex<BufWriter<Vec<u8>>>,
+}
+
+impl Command<'_> {
+	pub(crate) fn write_fmt(
+		&self,
+		arguments: fmt::Arguments<'_>,
+	) -> impl Future<Output = Result> + Send + '_ {
+		let buf = format!("{arguments}");
+		self.output.lock().then(|mut output| async move {
+			output.write_all(buf.as_bytes()).await.map_err(Into::into)
+		})
+	}
+
+	pub(crate) fn write_str<'a>(
+		&'a self,
+		s: &'a str,
+	) -> impl Future<Output = Result> + Send + 'a {
+		self.output.lock().then(move |mut output| async move {
+			output.write_all(s.as_bytes()).await.map_err(Into::into)
+		})
+	}
 }