Split login case bodies into handlers.

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

src/api/client/session/appservice.rs

@@ -0,0 +1,48 @@
+use ruma::{
+	OwnedUserId, UserId,
+	api::client::{
+		session::login::v3::{ApplicationService, Request},
+		uiaa,
+	},
+};
+use tuwunel_core::{Err, Result, err};
+use tuwunel_service::Services;
+
+use crate::Ruma;
+
+pub(super) async fn handle_login(
+	services: &Services,
+	body: &Ruma<Request>,
+	info: &ApplicationService,
+) -> Result<OwnedUserId> {
+	#[allow(deprecated)]
+	let ApplicationService { identifier, user } = info;
+
+	let Some(ref info) = body.appservice_info else {
+		return Err!(Request(MissingToken("Missing appservice token.")));
+	};
+
+	let user_id = if let Some(uiaa::UserIdentifier::UserIdOrLocalpart(user_id)) = identifier {
+		UserId::parse_with_server_name(user_id, &services.config.server_name)
+	} else if let Some(user) = user {
+		UserId::parse_with_server_name(user, &services.config.server_name)
+	} else {
+		return Err!(Request(Unknown(debug_warn!(
+			?body.login_info,
+			"Valid identifier or username was not provided (invalid or unsupported login type?)"
+		))));
+	}
+	.map_err(|e| err!(Request(InvalidUsername(warn!("Username is invalid: {e}")))))?;
+
+	if !services.globals.user_is_local(&user_id) {
+		return Err!(Request(Unknown("User ID does not belong to this homeserver")));
+	}
+
+	let emergency_mode_enabled = services.config.emergency_password.is_some();
+
+	if !info.is_user_match(&user_id) && !emergency_mode_enabled {
+		return Err!(Request(Exclusive("Username is not in an appservice namespace.")));
+	}
+
+	Ok(user_id)
+}