require client base_url, rename from authority

The previous code used `server_name` as a fallback but in reality there
is no real relationship between `server_name` and the location clients
are supposed to make requests to.

Additionally, the `insecure` option is gone, because we now allow users
to control the entire URL, so they're free to choose the scheme.

src/api/well_known.rs

@@ -30,24 +30,10 @@ pub(crate) async fn server(
 
 /// Handler for `/.well-known/matrix/client`
 pub(crate) async fn client(_: Ar<client::Request>) -> Ra<client::Response> {
-    let authority = services()
-        .globals
-        .config
-        .server_discovery
-        .client
-        .authority
-        .clone()
-        .unwrap_or_else(|| services().globals.config.server_name.clone());
-
-    let scheme = if services().globals.config.server_discovery.client.insecure {
-        "http"
-    } else {
-        "https"
-    };
-
-    let base_url = format!("{scheme}://{authority}");
-
     // I wish ruma used an actual URL type instead of `String`
+    let base_url =
+        services().globals.config.server_discovery.client.base_url.to_string();
+
     Ra(client::Response {
         homeserver: client::HomeserverInfo::new(base_url.clone()),
         identity_server: None,

src/config.rs

@@ -6,6 +6,7 @@ use std::{
 };
 
 use once_cell::sync::Lazy;
+use reqwest::Url;
 use ruma::{OwnedServerName, RoomVersionId};
 use serde::Deserialize;
 
@@ -35,7 +36,6 @@ pub(crate) struct Config {
     /// This is the value that will appear e.g. in user IDs and room aliases.
     pub(crate) server_name: OwnedServerName,
 
-    #[serde(default)]
     pub(crate) server_discovery: ServerDiscovery,
     pub(crate) database: DatabaseConfig,
     #[serde(default)]
@@ -69,14 +69,13 @@ pub(crate) struct Config {
     pub(crate) emergency_password: Option<String>,
 }
 
-#[derive(Debug, Default, Deserialize)]
+#[derive(Debug, Deserialize)]
 pub(crate) struct ServerDiscovery {
     /// Server-server discovery configuration
     #[serde(default)]
     pub(crate) server: ServerServerDiscovery,
 
     /// Client-server discovery configuration
-    #[serde(default)]
     pub(crate) client: ClientServerDiscovery,
 }
 
@@ -88,14 +87,10 @@ pub(crate) struct ServerServerDiscovery {
 }
 
 /// Client-server discovery configuration
-#[derive(Debug, Default, Deserialize)]
+#[derive(Debug, Deserialize)]
 pub(crate) struct ClientServerDiscovery {
-    /// The alternative authority to make client-server API requests to
-    pub(crate) authority: Option<OwnedServerName>,
-
-    /// Controls whether HTTPS is used
-    #[serde(default)]
-    pub(crate) insecure: bool,
+    /// The base URL to make client-server API requests to
+    pub(crate) base_url: Url,
 
     #[serde(default, rename = "advertise_buggy_sliding_sync")]
     pub(crate) advertise_sliding_sync: bool,