Cleanup/improve other async queries in some client handlers.

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

src/api/client/membership/kick.rs

@@ -0,0 +1,65 @@
+use axum::extract::State;
+use conduwuit::{Err, Result, matrix::pdu::PduBuilder};
+use ruma::{
+	api::client::membership::kick_user,
+	events::room::member::{MembershipState, RoomMemberEventContent},
+};
+
+use crate::Ruma;
+
+/// # `POST /_matrix/client/r0/rooms/{roomId}/kick`
+///
+/// Tries to send a kick event into the room.
+pub(crate) async fn kick_user_route(
+	State(services): State<crate::State>,
+	body: Ruma<kick_user::v3::Request>,
+) -> Result<kick_user::v3::Response> {
+	let sender_user = body.sender_user();
+	if services.users.is_suspended(sender_user).await? {
+		return Err!(Request(UserSuspended("You cannot perform this action while suspended.")));
+	}
+	let state_lock = services.rooms.state.mutex.lock(&body.room_id).await;
+
+	let Ok(event) = services
+		.rooms
+		.state_accessor
+		.get_member(&body.room_id, &body.user_id)
+		.await
+	else {
+		// copy synapse's behaviour of returning 200 without any change to the state
+		// instead of erroring on left users
+		return Ok(kick_user::v3::Response::new());
+	};
+
+	if !matches!(
+		event.membership,
+		MembershipState::Invite | MembershipState::Knock | MembershipState::Join,
+	) {
+		return Err!(Request(Forbidden(
+			"Cannot kick a user who is not apart of the room (current membership: {})",
+			event.membership
+		)));
+	}
+
+	services
+		.rooms
+		.timeline
+		.build_and_append_pdu(
+			PduBuilder::state(body.user_id.to_string(), &RoomMemberEventContent {
+				membership: MembershipState::Leave,
+				reason: body.reason.clone(),
+				is_direct: None,
+				join_authorized_via_users_server: None,
+				third_party_invite: None,
+				..event
+			}),
+			sender_user,
+			&body.room_id,
+			&state_lock,
+		)
+		.await?;
+
+	drop(state_lock);
+
+	Ok(kick_user::v3::Response::new())
+}