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1+//! The Crux `App`: model, events, effects, update logic and view.
2+//!
3+//! Streaming works like this: after a successful connect the shell opens the
4+//! `/event` SSE stream and forwards every decoded event as
5+//! [`Event::ServerEvent`]. The core parses those and mutates the chat
6+//! incrementally — creating the assistant message on `message.updated`, growing
7+//! its text on `message.part.updated`, and clearing the "generating" flag on
8+//! `session.idle`. User messages are shown optimistically the moment they're
9+//! sent, so the stream only ever *adds* assistant content.
10+
11+use base64::Engine;
12+use crux_core::{
13+ macros::effect,
14+ render::{render, RenderOperation},
15+ App, Command,
16+};
17+use crux_http::command::{Http, RequestBuilder};
18+use crux_http::protocol::HttpRequest;
19+use serde::{Deserialize, Serialize};
20+
21+use crate::protocol::{self, ServerEvent, WireMessageEnvelope, WirePart};
22+
23+/// Result of an HTTP effect handed back to the core.
24+pub type HttpResult = Result<crux_http::Response<String>, crux_http::HttpError>;
25+
26+// ─── Events ──────────────────────────────────────────────────────────────────
27+
28+pub enum Event {
29+ // Lifecycle / connect
30+ Start,
31+ ServerUrlChanged(String),
32+ UsernameChanged(String),
33+ PasswordChanged(String),
34+ Connect,
35+
36+ // Sessions
37+ LoadSessions,
38+ SelectSession(String),
39+ CreateSession,
40+ DeleteSession(String),
41+
42+ // Chat
43+ LoadMessages(String),
44+ DraftChanged(String),
45+ SendMessage(String),
46+ CancelGeneration,
47+
48+ // A raw event line from the shell's `/event` SSE subscription.
49+ ServerEvent(String),
50+
51+ // Navigation / misc
52+ NavigateToSessions,
53+ NavigateToConnect,
54+ DismissError,
55+
56+ // ── Internal: results of HTTP effects (never sent by the shell) ──────────
57+ HealthProbed(HttpResult),
58+ SessionsLoaded(HttpResult),
59+ SessionCreated(HttpResult),
60+ MessagesLoaded(String, HttpResult),
61+ PromptSent(HttpResult),
62+ SessionDeleted(HttpResult),
63+ Aborted(HttpResult),
64+}
65+
66+// ─── Effects ─────────────────────────────────────────────────────────────────
67+
68+#[effect]
69+#[derive(Debug)]
70+pub enum Effect {
71+ Render(RenderOperation),
72+ Http(HttpRequest),
73+}
74+
75+// ─── Model ───────────────────────────────────────────────────────────────────
76+
77+#[derive(Default)]
78+pub struct Model {
79+ server_url: String,
80+ username: String,
81+ password: String,
82+ /// The server answered 401 to an unauthenticated probe — show credentials.
83+ auth_required: bool,
84+ /// Credentials were accepted; attach the auth header to every request.
85+ authed: bool,
86+ connected: bool,
87+ loading: bool,
88+ error: Option<String>,
89+ screen: Screen,
90+
91+ sessions: Vec<SessionView>,
92+ current_session_id: Option<String>,
93+ current_session_title: String,
94+
95+ messages: Vec<MsgState>,
96+ draft: String,
97+ generating: bool,
98+
99+ /// Monotonic counter for optimistic (client-side) user-message ids.
100+ local_seq: u64,
101+}
102+
103+impl Model {
104+ fn message_mut(&mut self, id: &str) -> Option<&mut MsgState> {
105+ self.messages.iter_mut().find(|m| m.id == id)
106+ }
107+
108+ fn has_credentials(&self) -> bool {
109+ !self.username.is_empty() || !self.password.is_empty()
110+ }
111+
112+ fn is_current(&self, session_id: &str) -> bool {
113+ self.current_session_id.as_deref() == Some(session_id)
114+ }
115+}
116+
117+/// Internal per-message state. Parts are tracked by id so streaming updates can
118+/// upsert them; the [`MessageView`] handed to the shell is derived from these.
119+struct MsgState {
120+ id: String,
121+ role: String,
122+ time: u64,
123+ status: MessageStatus,
124+ streaming: bool,
125+ text_parts: Vec<(String, String)>,
126+ reasoning_parts: Vec<(String, String)>,
127+ tool_parts: Vec<(String, ToolView)>,
128+}
129+
130+impl MsgState {
131+ fn new(id: String, role: String, time: u64) -> Self {
132+ Self {
133+ id,
134+ role,
135+ time,
136+ status: MessageStatus::Sent,
137+ streaming: false,
138+ text_parts: Vec::new(),
139+ reasoning_parts: Vec::new(),
140+ tool_parts: Vec::new(),
141+ }
142+ }
143+
144+ fn upsert_part(parts: &mut Vec<(String, String)>, id: &str, text: String) {
145+ if let Some(slot) = parts.iter_mut().find(|(pid, _)| pid == id) {
146+ slot.1 = text;
147+ } else {
148+ parts.push((id.to_string(), text));
149+ }
150+ }
151+
152+ fn upsert_tool(&mut self, id: &str, view: ToolView) {
153+ if let Some(slot) = self.tool_parts.iter_mut().find(|(pid, _)| pid == id) {
154+ slot.1 = view;
155+ } else {
156+ self.tool_parts.push((id.to_string(), view));
157+ }
158+ }
159+
160+ fn remove_part(&mut self, part_id: &str) {
161+ self.text_parts.retain(|(pid, _)| pid != part_id);
162+ self.reasoning_parts.retain(|(pid, _)| pid != part_id);
163+ self.tool_parts.retain(|(pid, _)| pid != part_id);
164+ }
165+
166+ fn to_view(&self) -> MessageView {
167+ let join = |parts: &[(String, String)]| {
168+ parts.iter().map(|(_, t)| t.as_str()).collect::<String>()
169+ };
170+ let reasoning = join(&self.reasoning_parts);
171+ MessageView {
172+ id: self.id.clone(),
173+ role: self.role.clone(),
174+ text: join(&self.text_parts),
175+ reasoning: (!reasoning.is_empty()).then_some(reasoning),
176+ tools: self.tool_parts.iter().map(|(_, t)| t.clone()).collect(),
177+ time: self.time,
178+ status: self.status.clone(),
179+ streaming: self.streaming,
180+ }
181+ }
182+}
183+
184+// ─── View model ──────────────────────────────────────────────────────────────
185+
186+#[derive(Serialize, Deserialize, Clone, Debug, Default, PartialEq, Eq)]
187+pub enum Screen {
188+ #[default]
189+ Connect,
190+ Sessions,
191+ Chat,
192+}
193+
194+#[derive(Serialize, Deserialize, Clone, Debug, Default)]
195+pub struct SessionView {
196+ pub id: String,
197+ pub title: String,
198+}
199+
200+#[derive(Serialize, Deserialize, Clone, Debug, Default, PartialEq, Eq)]
201+pub enum MessageStatus {
202+ #[default]
203+ Sent,
204+ Pending,
205+ Failed,
206+}
207+
208+#[derive(Serialize, Deserialize, Clone, Debug, Default)]
209+pub struct ToolView {
210+ pub name: String,
211+ pub status: String,
212+ pub title: Option<String>,
213+}
214+
215+#[derive(Serialize, Deserialize, Clone, Debug, Default)]
216+pub struct MessageView {
217+ pub id: String,
218+ pub role: String,
219+ pub text: String,
220+ pub reasoning: Option<String>,
221+ pub tools: Vec<ToolView>,
222+ pub time: u64,
223+ pub status: MessageStatus,
224+ pub streaming: bool,
225+}
226+
227+#[derive(Serialize, Deserialize, Clone, Debug, Default)]
228+pub struct ViewModel {
229+ pub screen: Screen,
230+ pub server_url: String,
231+ pub username: String,
232+ pub password: String,
233+ pub auth_required: bool,
234+ pub connected: bool,
235+ pub loading: bool,
236+ pub error: Option<String>,
237+ pub sessions: Vec<SessionView>,
238+ pub current_session_id: Option<String>,
239+ pub current_session_title: String,
240+ pub messages: Vec<MessageView>,
241+ pub draft: String,
242+ pub generating: bool,
243+}
244+
245+// ─── App ─────────────────────────────────────────────────────────────────────
246+
247+#[derive(Default)]
248+pub struct OpencodeApp;
249+
250+impl OpencodeApp {
251+ fn get(&self, model: &Model, path: &str) -> RequestBuilder<Effect, Event, String> {
252+ let url = format!("{}{path}", model.server_url);
253+ self.with_auth(Http::get(&url).expect_string(), model)
254+ }
255+
256+ fn post_json(&self, model: &Model, path: &str, body: &serde_json::Value) -> RequestBuilder<Effect, Event, String> {
257+ let url = format!("{}{path}", model.server_url);
258+ let bytes = serde_json::to_vec(body).unwrap_or_default();
259+ let req = Http::post(&url)
260+ .expect_string()
261+ .header("Content-Type", "application/json")
262+ .body_bytes(bytes);
263+ self.with_auth(req, model)
264+ }
265+
266+ fn delete(&self, model: &Model, path: &str) -> RequestBuilder<Effect, Event, String> {
267+ let url = format!("{}{path}", model.server_url);
268+ self.with_auth(Http::delete(&url).expect_string(), model)
269+ }
270+
271+ /// Attach an RFC 7617 Basic-Auth header when the model carries credentials.
272+ fn with_auth<E>(&self, req: RequestBuilder<Effect, Event, E>, model: &Model) -> RequestBuilder<Effect, Event, E>
273+ where
274+ E: 'static,
275+ {
276+ if model.has_credentials() {
277+ let creds = format!("{}:{}", model.username, model.password);
278+ let encoded = base64::engine::general_purpose::STANDARD.encode(creds.as_bytes());
279+ req.header("Authorization", format!("Basic {encoded}"))
280+ } else {
281+ req
282+ }
283+ }
284+}
285+
286+impl App for OpencodeApp {
287+ type Event = Event;
288+ type Model = Model;
289+ type ViewModel = ViewModel;
290+ type Effect = Effect;
291+
292+ fn update(&self, event: Event, model: &mut Model) -> Command<Effect, Event> {
293+ match event {
294+ // ── Lifecycle / connect ─────────────────────────────────────────
295+ Event::Start => render(),
296+
297+ // Store the field verbatim while typing; normalizing here would fight
298+ // the user's edits (e.g. eat the "://" as they type it). The URL is
299+ // normalized once, on Connect.
300+ // Clear any prior error as soon as the user edits a field, so a stale
301+ // message (e.g. "Invalid credentials") doesn't linger while they correct it.
302+ Event::ServerUrlChanged(url) => {
303+ model.server_url = url;
304+ if model.error.is_some() {
305+ model.error = None;
306+ }
307+ render()
308+ }
309+ Event::UsernameChanged(u) => {
310+ model.username = u;
311+ if model.error.is_some() {
312+ model.error = None;
313+ }
314+ render()
315+ }
316+ Event::PasswordChanged(p) => {
317+ model.password = p;
318+ if model.error.is_some() {
319+ model.error = None;
320+ }
321+ render()
322+ }
323+
324+ Event::Connect => {
325+ model.server_url = normalize_url(&model.server_url);
326+ if model.server_url.is_empty() {
327+ model.error = Some("Enter a server URL".to_string());
328+ return render();
329+ }
330+ model.loading = true;
331+ model.error = None;
332+ model.auth_required = false;
333+ render().and(self.get(model, "/global/health").build().then_send(Event::HealthProbed))
334+ }
335+
336+ Event::HealthProbed(result) => self.on_health_probed(model, result),
337+
338+ // ── Sessions ────────────────────────────────────────────────────
339+ Event::LoadSessions => {
340+ model.loading = true;
341+ render().and(self.get(model, "/session").build().then_send(Event::SessionsLoaded))
342+ }
343+
344+ Event::SessionsLoaded(result) => {
345+ model.loading = false;
346+ match ok_body(result) {
347+ Ok(body) => {
348+ model.sessions = protocol::parse_sessions(&body)
349+ .into_iter()
350+ .map(|s| SessionView {
351+ id: s.id,
352+ title: display_title(&s.title),
353+ })
354+ .collect();
355+ // Impose a stable alphabetical order so the list doesn't shuffle
356+ // with whatever order the server happens to return sessions in.
357+ model.sessions.sort_by_key(|s| s.title.to_lowercase());
358+ }
359+ Err(e) => model.error = Some(e),
360+ }
361+ render()
362+ }
363+
364+ Event::SelectSession(id) => {
365+ model.current_session_title = model
366+ .sessions
367+ .iter()
368+ .find(|s| s.id == id)
369+ .map(|s| s.title.clone())
370+ .unwrap_or_default();
371+ model.current_session_id = Some(id.clone());
372+ model.messages.clear();
373+ model.screen = Screen::Chat;
374+ model.loading = true;
375+ model.error = None;
376+ render().and(Command::event(Event::LoadMessages(id)))
377+ }
378+
379+ Event::CreateSession => {
380+ model.loading = true;
381+ render().and(
382+ self.post_json(model, "/session", &serde_json::json!({}))
383+ .build()
384+ .then_send(Event::SessionCreated),
385+ )
386+ }
387+
388+ Event::SessionCreated(result) => {
389+ model.loading = false;
390+ match ok_body(result) {
391+ Ok(body) => {
392+ if let Some(s) = protocol::parse_session(&body) {
393+ let view = SessionView {
394+ id: s.id.clone(),
395+ title: display_title(&s.title),
396+ };
397+ if !model.sessions.iter().any(|e| e.id == view.id) {
398+ model.sessions.insert(0, view);
399+ }
400+ return render().and(Command::event(Event::SelectSession(s.id)));
401+ }
402+ model.error = Some("Malformed session response".to_string());
403+ }
404+ Err(e) => model.error = Some(e),
405+ }
406+ render()
407+ }
408+
409+ Event::DeleteSession(id) => {
410+ model.sessions.retain(|s| s.id != id);
411+ let mut cmd = self.delete(model, &format!("/session/{id}")).build().then_send(Event::SessionDeleted);
412+ if model.is_current(&id) {
413+ model.current_session_id = None;
414+ model.messages.clear();
415+ model.screen = Screen::Sessions;
416+ }
417+ cmd = render().and(cmd);
418+ cmd
419+ }
420+
421+ Event::SessionDeleted(result) => {
422+ if let Err(e) = ok_body(result) {
423+ model.error = Some(e);
424+ }
425+ render()
426+ }
427+
428+ // ── Chat ────────────────────────────────────────────────────────
429+ Event::LoadMessages(id) => {
430+ render().and(
431+ self.get(model, &format!("/session/{id}/message"))
432+ .build()
433+ .then_send(move |result| Event::MessagesLoaded(id.clone(), result)),
434+ )
435+ }
436+
437+ Event::MessagesLoaded(session_id, result) => {
438+ if !model.is_current(&session_id) {
439+ return render();
440+ }
441+ model.loading = false;
442+ match ok_body(result) {
443+ Ok(body) => {
444+ model.messages = protocol::parse_messages(&body).iter().map(message_from_wire).collect();
445+ model.generating = model.messages.iter().any(|m| m.streaming);
446+ }
447+ Err(e) => model.error = Some(e),
448+ }
449+ render()
450+ }
451+
452+ Event::DraftChanged(text) => {
453+ model.draft = text;
454+ render()
455+ }
456+
457+ Event::SendMessage(text) => {
458+ let text = text.trim().to_string();
459+ let Some(session_id) = model.current_session_id.clone() else {
460+ return render();
461+ };
462+ if text.is_empty() {
463+ return render();
464+ }
465+ model.local_seq += 1;
466+ let mut user = MsgState::new(format!("local-{}", model.local_seq), "user".to_string(), 0);
467+ user.status = MessageStatus::Pending;
468+ MsgState::upsert_part(&mut user.text_parts, "local", text.clone());
469+ model.messages.push(user);
470+ model.draft.clear();
471+ model.generating = true;
472+ model.error = None;
473+
474+ let body = serde_json::json!({ "parts": [{ "type": "text", "text": text }] });
475+ render().and(
476+ self.post_json(model, &format!("/session/{session_id}/prompt_async"), &body)
477+ .build()
478+ .then_send(Event::PromptSent),
479+ )
480+ }
481+
482+ Event::PromptSent(result) => {
483+ match ok_body(result) {
484+ Ok(_) => set_last_pending(model, MessageStatus::Sent),
485+ Err(e) => {
486+ set_last_pending(model, MessageStatus::Failed);
487+ model.generating = false;
488+ model.error = Some(e);
489+ }
490+ }
491+ render()
492+ }
493+
494+ Event::CancelGeneration => {
495+ model.generating = false;
496+ match model.current_session_id.clone() {
497+ Some(id) => render().and(
498+ self.post_json(model, &format!("/session/{id}/abort"), &serde_json::json!({}))
499+ .build()
500+ .then_send(Event::Aborted),
501+ ),
502+ None => render(),
503+ }
504+ }
505+
506+ Event::Aborted(_) => render(),
507+
508+ // ── SSE ─────────────────────────────────────────────────────────
509+ Event::ServerEvent(json) => {
510+ if let Some(event) = protocol::parse_event(&json) {
511+ apply_server_event(model, event);
512+ }
513+ render()
514+ }
515+
516+ // ── Navigation / misc ───────────────────────────────────────────
517+ Event::NavigateToSessions => {
518+ model.screen = Screen::Sessions;
519+ model.current_session_id = None;
520+ model.messages.clear();
521+ model.generating = false;
522+ render().and(self.get(model, "/session").build().then_send(Event::SessionsLoaded))
523+ }
524+
525+ Event::NavigateToConnect => {
526+ model.screen = Screen::Connect;
527+ model.connected = false;
528+ model.sessions.clear();
529+ model.messages.clear();
530+ model.current_session_id = None;
531+ render()
532+ }
533+
534+ Event::DismissError => {
535+ model.error = None;
536+ render()
537+ }
538+ }
539+ }
540+
541+ fn view(&self, model: &Model) -> ViewModel {
542+ ViewModel {
543+ screen: model.screen.clone(),
544+ server_url: model.server_url.clone(),
545+ username: model.username.clone(),
546+ password: model.password.clone(),
547+ auth_required: model.auth_required,
548+ connected: model.connected,
549+ loading: model.loading,
550+ error: model.error.clone(),
551+ sessions: model.sessions.clone(),
552+ current_session_id: model.current_session_id.clone(),
553+ current_session_title: model.current_session_title.clone(),
554+ messages: model.messages.iter().map(MsgState::to_view).collect(),
555+ draft: model.draft.clone(),
556+ generating: model.generating,
557+ }
558+ }
559+}
560+
561+impl OpencodeApp {
562+ fn on_health_probed(&self, model: &mut Model, result: HttpResult) -> Command<Effect, Event> {
563+ let has_creds = model.has_credentials();
564+ match result {
565+ Ok(response) => {
566+ let status = response.status().as_u16();
567+ if status == 401 {
568+ model.loading = false;
569+ if has_creds {
570+ model.error = Some("Invalid credentials".to_string());
571+ } else {
572+ model.auth_required = true;
573+ }
574+ return render();
575+ }
576+ if (200..300).contains(&status) {
577+ if has_creds {
578+ model.authed = true;
579+ }
580+ model.connected = true;
581+ model.auth_required = false;
582+ model.error = None;
583+ model.screen = Screen::Sessions;
584+ model.loading = true;
585+ return render().and(self.get(model, "/session").build().then_send(Event::SessionsLoaded));
586+ }
587+ model.loading = false;
588+ model.error = Some(format!("Server returned status {status}"));
589+ render()
590+ }
591+ Err(e) => {
592+ model.loading = false;
593+ model.error = Some(format!("Connection failed: {e}"));
594+ render()
595+ }
596+ }
597+ }
598+}
599+
600+// ─── SSE application ─────────────────────────────────────────────────────────
601+
602+fn apply_server_event(model: &mut Model, event: ServerEvent) {
603+ match event {
604+ // Only assistant messages are created from the stream — the user's own
605+ // message is already shown optimistically, so ignoring the server's copy
606+ // avoids a duplicate bubble.
607+ ServerEvent::MessageUpdated { properties } => {
608+ let info = properties.info;
609+ if info.role != "assistant" || !model.is_current(&info.session_id) {
610+ return;
611+ }
612+ let streaming = info.time.completed.is_none() && info.error.is_none();
613+ if let Some(msg) = model.message_mut(&info.id) {
614+ msg.streaming = streaming;
615+ if msg.time == 0 {
616+ msg.time = info.time.created;
617+ }
618+ } else {
619+ let mut msg = MsgState::new(info.id.clone(), "assistant".to_string(), info.time.created);
620+ msg.streaming = streaming;
621+ model.messages.push(msg);
622+ }
623+ if let Some(err) = info.error {
624+ model.error = Some(err.message());
625+ model.generating = false;
626+ }
627+ }
628+
629+ // Apply only to a message we already track (an assistant message from the
630+ // event above). Parts for unknown ids are ignored — see module docs.
631+ ServerEvent::MessagePartUpdated { properties } => {
632+ let part = properties.part;
633+ let delta = properties.delta;
634+ let msg_id = part.message_id().to_string();
635+ let Some(msg) = model.message_mut(&msg_id) else {
636+ return;
637+ };
638+ match part {
639+ WirePart::Text { id, text, synthetic, .. } => {
640+ if synthetic {
641+ return;
642+ }
643+ let value = pick_text(text, &delta, &msg.text_parts, &id);
644+ MsgState::upsert_part(&mut msg.text_parts, &id, value);
645+ }
646+ WirePart::Reasoning { id, text, .. } => {
647+ let value = pick_text(text, &delta, &msg.reasoning_parts, &id);
648+ MsgState::upsert_part(&mut msg.reasoning_parts, &id, value);
649+ }
650+ WirePart::Tool { id, tool, state, .. } => {
651+ let sv = protocol::tool_state_view(&state);
652+ msg.upsert_tool(&id, ToolView { name: tool, status: sv.status, title: sv.title });
653+ }
654+ WirePart::Other => {}
655+ }
656+ }
657+
658+ ServerEvent::MessagePartRemoved { properties } => {
659+ if let Some(msg) = model.message_mut(&properties.message_id) {
660+ msg.remove_part(&properties.part_id);
661+ }
662+ }
663+
664+ ServerEvent::MessageRemoved { properties } => {
665+ model.messages.retain(|m| m.id != properties.message_id);
666+ }
667+
668+ ServerEvent::SessionIdle { properties } => {
669+ if model.is_current(&properties.session_id) {
670+ model.generating = false;
671+ for m in &mut model.messages {
672+ m.streaming = false;
673+ }
674+ }
675+ }
676+
677+ ServerEvent::SessionError { properties } => {
678+ let scoped = properties.session_id.as_deref().map_or(true, |s| model.is_current(s));
679+ if scoped {
680+ if let Some(err) = properties.error {
681+ model.error = Some(err.message());
682+ }
683+ model.generating = false;
684+ }
685+ }
686+
687+ ServerEvent::SessionCreated { properties } | ServerEvent::SessionUpdated { properties } => {
688+ let s = properties.info;
689+ let view = SessionView { id: s.id.clone(), title: display_title(&s.title) };
690+ if let Some(existing) = model.sessions.iter_mut().find(|e| e.id == view.id) {
691+ existing.title = view.title.clone();
692+ } else {
693+ model.sessions.insert(0, view);
694+ }
695+ if model.is_current(&s.id) {
696+ model.current_session_title = display_title(&s.title);
697+ }
698+ }
699+
700+ ServerEvent::SessionDeleted { properties } => {
701+ let id = properties.session_id.or(properties.info.map(|i| i.id));
702+ if let Some(id) = id {
703+ model.sessions.retain(|s| s.id != id);
704+ if model.is_current(&id) {
705+ model.current_session_id = None;
706+ model.messages.clear();
707+ model.screen = Screen::Sessions;
708+ }
709+ }
710+ }
711+
712+ ServerEvent::Other => {}
713+ }
714+}
715+
716+// ─── Helpers ─────────────────────────────────────────────────────────────────
717+
718+/// `part.text` is the full current text when present; otherwise fall back to
719+/// accumulating the incremental `delta` onto whatever we already have.
720+fn pick_text(text: String, delta: &Option<String>, existing: &[(String, String)], part_id: &str) -> String {
721+ if !text.is_empty() {
722+ return text;
723+ }
724+ let prior = existing.iter().find(|(pid, _)| pid == part_id).map(|(_, t)| t.clone()).unwrap_or_default();
725+ match delta {
726+ Some(d) => format!("{prior}{d}"),
727+ None => prior,
728+ }
729+}
730+
731+fn message_from_wire(env: &WireMessageEnvelope) -> MsgState {
732+ let info = &env.info;
733+ let mut msg = MsgState::new(info.id.clone(), info.role.clone(), info.time.created);
734+ msg.streaming = info.role == "assistant" && info.time.completed.is_none() && info.error.is_none();
735+ for part in &env.parts {
736+ match part {
737+ WirePart::Text { id, text, synthetic, .. } => {
738+ if !synthetic {
739+ MsgState::upsert_part(&mut msg.text_parts, id, text.clone());
740+ }
741+ }
742+ WirePart::Reasoning { id, text, .. } => {
743+ MsgState::upsert_part(&mut msg.reasoning_parts, id, text.clone());
744+ }
745+ WirePart::Tool { id, tool, state, .. } => {
746+ let sv = protocol::tool_state_view(state);
747+ msg.upsert_tool(id, ToolView { name: tool.clone(), status: sv.status, title: sv.title });
748+ }
749+ WirePart::Other => {}
750+ }
751+ }
752+ msg
753+}
754+
755+fn set_last_pending(model: &mut Model, status: MessageStatus) {
756+ if let Some(msg) = model.messages.iter_mut().rev().find(|m| m.status == MessageStatus::Pending) {
757+ msg.status = status;
758+ }
759+}
760+
761+/// Trim whitespace and any trailing `/` so paths concatenate cleanly, and
762+/// default to an `http://` scheme when the user didn't type one (e.g.
763+/// "192.168.1.10:4096") — otherwise the shell's URL parser rejects it.
764+fn normalize_url(url: &str) -> String {
765+ let trimmed = url.trim().trim_end_matches('/');
766+ if trimmed.is_empty() {
767+ String::new()
768+ } else if trimmed.contains("://") {
769+ trimmed.to_string()
770+ } else {
771+ format!("http://{trimmed}")
772+ }
773+}
774+
775+fn display_title(title: &str) -> String {
776+ let t = title.trim();
777+ if t.is_empty() {
778+ "Untitled".to_string()
779+ } else {
780+ t.to_string()
781+ }
782+}
783+
784+/// Reduce an [`HttpResult`] to `Ok(body)` for 2xx, or `Err(message)` otherwise.
785+fn ok_body(result: HttpResult) -> Result<String, String> {
786+ match result {
787+ Ok(mut response) => {
788+ let status = response.status().as_u16();
789+ if (200..300).contains(&status) {
790+ Ok(response.take_body().unwrap_or_default())
791+ } else {
792+ Err(format!("Server returned status {status}"))
793+ }
794+ }
795+ Err(e) => Err(format!("Request failed: {e}")),
796+ }
797+}
798+
799+// ─── Tests ───────────────────────────────────────────────────────────────────
800+
801+#[cfg(test)]
802+mod tests {
803+ use super::*;
804+
805+ fn app() -> OpencodeApp {
806+ OpencodeApp::default()
807+ }
808+
809+ /// Put the model into a connected Chat view for the given session.
810+ fn in_chat(session_id: &str) -> Model {
811+ let mut model = Model::default();
812+ model.server_url = "http://localhost:4096".to_string();
813+ model.connected = true;
814+ model.screen = Screen::Chat;
815+ model.current_session_id = Some(session_id.to_string());
816+ model
817+ }
818+
819+ fn feed(app: &OpencodeApp, model: &mut Model, json: serde_json::Value) {
820+ let _ = app.update(Event::ServerEvent(json.to_string()), model);
821+ }
822+
823+ #[test]
824+ fn server_url_is_kept_raw_while_typing() {
825+ let app = app();
826+ let mut model = Model::default();
827+ // Mid-scheme input must survive verbatim — normalizing per keystroke
828+ // would eat the "://" the user is typing and make the field unusable.
829+ let _ = app.update(Event::ServerUrlChanged("http:/".into()), &mut model);
830+ assert_eq!(app.view(&model).server_url, "http:/");
831+ }
832+
833+ #[test]
834+ fn connect_normalizes_scheme_less_url() {
835+ let app = app();
836+ let mut model = Model::default();
837+ // A scheme-less host (what a user often types) must gain http:// on
838+ // connect, or the shell's URL parser throws and the attempt crashes.
839+ let _ = app.update(Event::ServerUrlChanged("192.168.1.10:4096".into()), &mut model);
840+ assert_eq!(app.view(&model).server_url, "192.168.1.10:4096");
841+ let _ = app.update(Event::Connect, &mut model);
842+ assert_eq!(app.view(&model).server_url, "http://192.168.1.10:4096");
843+ }
844+
845+ #[test]
846+ fn connect_trims_and_keeps_explicit_scheme() {
847+ let app = app();
848+ let mut model = Model::default();
849+ let _ = app.update(Event::ServerUrlChanged(" https://host:4096/ ".into()), &mut model);
850+ let _ = app.update(Event::Connect, &mut model);
851+ assert_eq!(app.view(&model).server_url, "https://host:4096");
852+ }
853+
854+ #[test]
855+ fn connect_requires_a_url() {
856+ let app = app();
857+ let mut model = Model::default();
858+ let _ = app.update(Event::Connect, &mut model);
859+ assert_eq!(app.view(&model).error.as_deref(), Some("Enter a server URL"));
860+ }
861+
862+ #[test]
863+ fn sending_adds_optimistic_user_message_and_sets_generating() {
864+ let app = app();
865+ let mut model = in_chat("ses_1");
866+ let _ = app.update(Event::DraftChanged("hello there".into()), &mut model);
867+ let _ = app.update(Event::SendMessage("hello there".into()), &mut model);
868+
869+ let view = app.view(&model);
870+ assert!(view.generating);
871+ assert!(view.draft.is_empty());
872+ assert_eq!(view.messages.len(), 1);
873+ assert_eq!(view.messages[0].role, "user");
874+ assert_eq!(view.messages[0].text, "hello there");
875+ assert_eq!(view.messages[0].status, MessageStatus::Pending);
876+ }
877+
878+ #[test]
879+ fn empty_send_is_ignored() {
880+ let app = app();
881+ let mut model = in_chat("ses_1");
882+ let _ = app.update(Event::SendMessage(" ".into()), &mut model);
883+ assert!(app.view(&model).messages.is_empty());
884+ assert!(!app.view(&model).generating);
885+ }
886+
887+ #[test]
888+ fn assistant_reply_streams_in_from_sse() {
889+ let app = app();
890+ let mut model = in_chat("ses_1");
891+
892+ // Assistant message shell arrives first.
893+ feed(&app, &mut model, serde_json::json!({
894+ "type": "message.updated",
895+ "properties": { "info": {
896+ "id": "msg_a", "role": "assistant", "sessionID": "ses_1",
897+ "time": { "created": 100 }
898+ }}
899+ }));
900+ assert_eq!(app.view(&model).messages.len(), 1);
901+ assert!(app.view(&model).messages[0].streaming);
902+
903+ // Two text deltas for the same part accumulate into full text.
904+ feed(&app, &mut model, serde_json::json!({
905+ "type": "message.part.updated",
906+ "properties": { "part": {
907+ "id": "prt_1", "messageID": "msg_a", "sessionID": "ses_1",
908+ "type": "text", "text": "Hello"
909+ }}
910+ }));
911+ feed(&app, &mut model, serde_json::json!({
912+ "type": "message.part.updated",
913+ "properties": { "part": {
914+ "id": "prt_1", "messageID": "msg_a", "sessionID": "ses_1",
915+ "type": "text", "text": "Hello, world"
916+ }}
917+ }));
918+
919+ let view = app.view(&model);
920+ assert_eq!(view.messages[0].role, "assistant");
921+ assert_eq!(view.messages[0].text, "Hello, world");
922+ }
923+
924+ #[test]
925+ fn text_delta_accumulates_when_full_text_absent() {
926+ let app = app();
927+ let mut model = in_chat("ses_1");
928+ feed(&app, &mut model, serde_json::json!({
929+ "type": "message.updated",
930+ "properties": { "info": { "id": "msg_a", "role": "assistant", "sessionID": "ses_1", "time": {"created": 1}}}
931+ }));
932+ for delta in ["Wor", "ld"] {
933+ feed(&app, &mut model, serde_json::json!({
934+ "type": "message.part.updated",
935+ "properties": {
936+ "part": { "id": "p", "messageID": "msg_a", "sessionID": "ses_1", "type": "text", "text": "" },
937+ "delta": delta
938+ }
939+ }));
940+ }
941+ assert_eq!(app.view(&model).messages[0].text, "World");
942+ }
943+
944+ #[test]
945+ fn user_message_from_sse_is_not_duplicated() {
946+ let app = app();
947+ let mut model = in_chat("ses_1");
948+ let _ = app.update(Event::SendMessage("hi".into()), &mut model);
949+ // Server echoes the user message on the stream — must be ignored.
950+ feed(&app, &mut model, serde_json::json!({
951+ "type": "message.updated",
952+ "properties": { "info": { "id": "msg_user", "role": "user", "sessionID": "ses_1", "time": {"created": 5}}}
953+ }));
954+ let users = app.view(&model).messages.iter().filter(|m| m.role == "user").count();
955+ assert_eq!(users, 1);
956+ }
957+
958+ #[test]
959+ fn session_idle_clears_generating() {
960+ let app = app();
961+ let mut model = in_chat("ses_1");
962+ let _ = app.update(Event::SendMessage("hi".into()), &mut model);
963+ assert!(app.view(&model).generating);
964+ feed(&app, &mut model, serde_json::json!({
965+ "type": "session.idle", "properties": { "sessionID": "ses_1" }
966+ }));
967+ assert!(!app.view(&model).generating);
968+ }
969+
970+ #[test]
971+ fn idle_for_other_session_is_ignored() {
972+ let app = app();
973+ let mut model = in_chat("ses_1");
974+ let _ = app.update(Event::SendMessage("hi".into()), &mut model);
975+ feed(&app, &mut model, serde_json::json!({
976+ "type": "session.idle", "properties": { "sessionID": "ses_other" }
977+ }));
978+ assert!(app.view(&model).generating);
979+ }
980+
981+ #[test]
982+ fn reasoning_and_tool_parts_are_surfaced() {
983+ let app = app();
984+ let mut model = in_chat("ses_1");
985+ feed(&app, &mut model, serde_json::json!({
986+ "type": "message.updated",
987+ "properties": { "info": { "id": "m", "role": "assistant", "sessionID": "ses_1", "time": {"created": 1}}}
988+ }));
989+ feed(&app, &mut model, serde_json::json!({
990+ "type": "message.part.updated",
991+ "properties": { "part": { "id": "r", "messageID": "m", "type": "reasoning", "text": "thinking..." }}
992+ }));
993+ feed(&app, &mut model, serde_json::json!({
994+ "type": "message.part.updated",
995+ "properties": { "part": {
996+ "id": "t", "messageID": "m", "type": "tool", "tool": "bash",
997+ "state": { "status": "completed", "title": "ls -la" }
998+ }}
999+ }));
1000+ let msg = &app.view(&model).messages[0];
1001+ assert_eq!(msg.reasoning.as_deref(), Some("thinking..."));
1002+ assert_eq!(msg.tools.len(), 1);
1003+ assert_eq!(msg.tools[0].name, "bash");
1004+ assert_eq!(msg.tools[0].status, "completed");
1005+ assert_eq!(msg.tools[0].title.as_deref(), Some("ls -la"));
1006+ }
1007+
1008+ #[test]
1009+ fn session_created_event_updates_list() {
1010+ let app = app();
1011+ let mut model = in_chat("ses_1");
1012+ feed(&app, &mut model, serde_json::json!({
1013+ "type": "session.created",
1014+ "properties": { "info": { "id": "ses_new", "title": "Fresh" }}
1015+ }));
1016+ assert!(app.view(&model).sessions.iter().any(|s| s.id == "ses_new" && s.title == "Fresh"));
1017+ }
1018+
1019+ #[test]
1020+ fn unknown_event_types_are_ignored() {
1021+ let app = app();
1022+ let mut model = in_chat("ses_1");
1023+ feed(&app, &mut model, serde_json::json!({
1024+ "type": "pty.created", "properties": { "whatever": true }
1025+ }));
1026+ feed(&app, &mut model, serde_json::json!({ "type": "totally.new.event" }));
1027+ // No panic, no state change.
1028+ assert!(app.view(&model).messages.is_empty());
1029+ }
1030+
1031+ #[test]
1032+ fn messages_loaded_parses_info_and_parts() {
1033+ let app = app();
1034+ let mut model = in_chat("ses_1");
1035+ let body = serde_json::json!([
1036+ { "info": { "id": "m1", "role": "user", "sessionID": "ses_1", "time": {"created": 1} },
1037+ "parts": [{ "id": "p1", "type": "text", "text": "Question?" }] },
1038+ { "info": { "id": "m2", "role": "assistant", "sessionID": "ses_1", "time": {"created": 2, "completed": 3} },
1039+ "parts": [{ "id": "p2", "type": "text", "text": "Answer." }] }
1040+ ]).to_string();
1041+ let result: HttpResult = Ok(crux_http::testing::ResponseBuilder::ok().body(body).build());
1042+ let _ = app.update(Event::MessagesLoaded("ses_1".into(), result), &mut model);
1043+
1044+ let view = app.view(&model);
1045+ assert_eq!(view.messages.len(), 2);
1046+ assert_eq!(view.messages[0].text, "Question?");
1047+ assert_eq!(view.messages[1].text, "Answer.");
1048+ assert!(!view.messages[1].streaming);
1049+ assert!(!view.generating);
1050+ }
1051+}