Add a way to display unrelated to language support language servers' logs (#2991)

Copilot is being used in every buffer, but we do not see its logs that
easily.
In the future, prettier wrapper will pretend to be an LSP server, it is
better to log its messages somewhere, so prepare an infrastructure for
that.

<img width="1727" alt="image"
src="https://github.com/zed-industries/zed/assets/2690773/d31a257c-9608-46fa-8be1-f0a2a2bdbdb7">

Copilot seem to have no rpc messages logged for some reason now,
prettier wrapper might be a better case to investigate this, so leaving
as is.

Release Notes:

- N/A

crates/project/src/project.rs

@@ -108,6 +108,8 @@ pub struct Project {
     active_entry: Option<ProjectEntryId>,
     buffer_ordered_messages_tx: mpsc::UnboundedSender<BufferOrderedMessage>,
     languages: Arc<LanguageRegistry>,
+    supplementary_language_servers:
+        HashMap<LanguageServerId, (LanguageServerName, Arc<LanguageServer>)>,
     language_servers: HashMap<LanguageServerId, LanguageServerState>,
     language_server_ids: HashMap<(WorktreeId, LanguageServerName), LanguageServerId>,
     language_server_statuses: BTreeMap<LanguageServerId, LanguageServerStatus>,
@@ -147,7 +149,8 @@ pub struct Project {
     _maintain_buffer_languages: Task<()>,
     _maintain_workspace_config: Task<()>,
     terminals: Terminals,
-    copilot_enabled: bool,
+    copilot_lsp_subscription: Option<gpui::Subscription>,
+    copilot_log_subscription: Option<lsp::Subscription>,
     current_lsp_settings: HashMap<Arc<str>, LspSettings>,
 }
 
@@ -618,6 +621,8 @@ impl Project {
             let (tx, rx) = mpsc::unbounded();
             cx.spawn_weak(|this, cx| Self::send_buffer_ordered_messages(this, rx, cx))
                 .detach();
+            let copilot_lsp_subscription =
+                Copilot::global(cx).map(|copilot| subscribe_for_copilot_events(&copilot, cx));
             Self {
                 worktrees: Default::default(),
                 buffer_ordered_messages_tx: tx,
@@ -647,6 +652,7 @@ impl Project {
                 fs,
                 next_entry_id: Default::default(),
                 next_diagnostic_group_id: Default::default(),
+                supplementary_language_servers: HashMap::default(),
                 language_servers: Default::default(),
                 language_server_ids: Default::default(),
                 language_server_statuses: Default::default(),
@@ -658,7 +664,8 @@ impl Project {
                 terminals: Terminals {
                     local_handles: Vec::new(),
                 },
-                copilot_enabled: Copilot::global(cx).is_some(),
+                copilot_lsp_subscription,
+                copilot_log_subscription: None,
                 current_lsp_settings: settings::get::<ProjectSettings>(cx).lsp.clone(),
             }
         })
@@ -694,6 +701,8 @@ impl Project {
             let (tx, rx) = mpsc::unbounded();
             cx.spawn_weak(|this, cx| Self::send_buffer_ordered_messages(this, rx, cx))
                 .detach();
+            let copilot_lsp_subscription =
+                Copilot::global(cx).map(|copilot| subscribe_for_copilot_events(&copilot, cx));
             let mut this = Self {
                 worktrees: Vec::new(),
                 buffer_ordered_messages_tx: tx,
@@ -723,6 +732,7 @@ impl Project {
                     remote_id,
                     replica_id,
                 }),
+                supplementary_language_servers: HashMap::default(),
                 language_servers: Default::default(),
                 language_server_ids: Default::default(),
                 language_server_statuses: response
@@ -751,7 +761,8 @@ impl Project {
                 terminals: Terminals {
                     local_handles: Vec::new(),
                 },
-                copilot_enabled: Copilot::global(cx).is_some(),
+                copilot_lsp_subscription,
+                copilot_log_subscription: None,
                 current_lsp_settings: settings::get::<ProjectSettings>(cx).lsp.clone(),
             };
             for worktree in worktrees {
@@ -882,12 +893,14 @@ impl Project {
             self.restart_language_servers(worktree, language, cx);
         }
 
-        if !self.copilot_enabled && Copilot::global(cx).is_some() {
-            self.copilot_enabled = true;
-            for buffer in self.opened_buffers.values() {
-                if let Some(buffer) = buffer.upgrade(cx) {
-                    self.register_buffer_with_copilot(&buffer, cx);
+        if self.copilot_lsp_subscription.is_none() {
+            if let Some(copilot) = Copilot::global(cx) {
+                for buffer in self.opened_buffers.values() {
+                    if let Some(buffer) = buffer.upgrade(cx) {
+                        self.register_buffer_with_copilot(&buffer, cx);
+                    }
                 }
+                self.copilot_lsp_subscription = Some(subscribe_for_copilot_events(&copilot, cx));
             }
         }
 
@@ -2789,18 +2802,6 @@ impl Project {
             None => return Ok(None),
         };
 
-        language_server
-            .on_notification::<lsp::notification::LogMessage, _>({
-                move |params, mut cx| {
-                    if let Some(this) = this.upgrade(&cx) {
-                        this.update(&mut cx, |_, cx| {
-                            cx.emit(Event::LanguageServerLog(server_id, params.message))
-                        });
-                    }
-                }
-            })
-            .detach();
-
         language_server
             .on_notification::<lsp::notification::PublishDiagnostics, _>({
                 let adapter = adapter.clone();
@@ -7954,9 +7955,23 @@ impl Project {
             })
     }
 
+    pub fn supplementary_language_servers(
+        &self,
+    ) -> impl '_
+           + Iterator<
+        Item = (
+            &LanguageServerId,
+            &(LanguageServerName, Arc<LanguageServer>),
+        ),
+    > {
+        self.supplementary_language_servers.iter()
+    }
+
     pub fn language_server_for_id(&self, id: LanguageServerId) -> Option<Arc<LanguageServer>> {
         if let LanguageServerState::Running { server, .. } = self.language_servers.get(&id)? {
             Some(server.clone())
+        } else if let Some((_, server)) = self.supplementary_language_servers.get(&id) {
+            Some(Arc::clone(server))
         } else {
             None
         }
@@ -8016,6 +8031,43 @@ impl Project {
     }
 }
 
+fn subscribe_for_copilot_events(
+    copilot: &ModelHandle<Copilot>,
+    cx: &mut ModelContext<'_, Project>,
+) -> gpui::Subscription {
+    cx.subscribe(
+        copilot,
+        |project, copilot, copilot_event, cx| match copilot_event {
+            copilot::Event::CopilotLanguageServerStarted => {
+                if let Some((name, copilot_server)) = copilot.read(cx).language_server() {
+                    let new_server_id = copilot_server.server_id();
+                    if let hash_map::Entry::Vacant(v) =
+                        project.supplementary_language_servers.entry(new_server_id)
+                    {
+                        let weak_project = cx.weak_handle();
+                        let copilot_log_subscription = copilot_server
+                            .on_notification::<copilot::request::LogMessage, _>(
+                                move |params, mut cx| {
+                                    if let Some(project) = weak_project.upgrade(&mut cx) {
+                                        project.update(&mut cx, |_, cx| {
+                                            cx.emit(Event::LanguageServerLog(
+                                                new_server_id,
+                                                params.message,
+                                            ));
+                                        })
+                                    }
+                                },
+                            );
+                        project.copilot_log_subscription = Some(copilot_log_subscription);
+                        v.insert((name.clone(), Arc::clone(copilot_server)));
+                        cx.emit(Event::LanguageServerAdded(new_server_id));
+                    }
+                }
+            }
+        },
+    )
+}
+
 fn glob_literal_prefix<'a>(glob: &'a str) -> &'a str {
     let mut literal_end = 0;
     for (i, part) in glob.split(path::MAIN_SEPARATOR).enumerate() {