aether-agent-cli 0.9.1

use super::fake_prompt_mcp::FakePromptMcp;
use super::server::{AcpServer, ServerRunError};
use super::session::actor::SessionActorInit;
use super::session::agent_key::AgentKey;
use super::session::agents::SessionAgents;
use super::session::config::SessionConfigState;
use super::session::error::SessionError;
use super::session::model::{Modes, ValidatedMode};
use super::session::runtime::{AgentRuntime, RuntimeFactory};
use super::state::{AcpState, AcpStateConfig};
use crate::error::CliError;
use crate::resolve::InitialSessionSelection;
use crate::settings_args::SettingsSourceArgs;
use crate::workspace::WorkspaceManager;
use crate::workspace::testing::StdCopyCloner;
use acp_utils::notifications::{AuthMethodsUpdatedParams, McpNotification};
use acp_utils::testing::{TestPeer, duplex_pair, initialize_request};
use aether_auth::OAuthCredentialStorage;
use aether_core::agent_spec::{AgentSpec, AgentSpecExposure};
use aether_core::core::{AgentBuilder, AgentHandle, Prompt};
use aether_core::events::{AgentEvent, Command, MessageEvent, TurnEvent, TurnOutcome};
use aether_core::mcp::{ServerFactory, mcp};
use aether_project::AgentCatalog;
use aether_sessions::SessionStore;
use aether_sessions::{SessionControlEvent, SessionEvent, SessionMeta, UserEvent, last_agent_from_events};
use agent_client_protocol::schema::v2::{InitializeResponse, SessionId, SessionUpdate, StateUpdate, StopReason};
use agent_client_protocol::{Agent, Client, ConnectionTo, on_receive_notification};
use futures::FutureExt;
use llm::testing::FakeLlmProvider;
use llm::{ChatMessage, Context, LlmResponse, SessionUsageEvent, StreamingModelProvider};
use llm::{MessageId, ProviderConnectionOverrides};
use mcp_utils::client::{InMemoryServerSpec, McpServer, McpTransport, ToolExposure};
use std::collections::HashMap;
use std::net::SocketAddr;
use std::path::PathBuf;
use std::sync::{Arc, Mutex};
use tokio::sync::{mpsc, oneshot, watch};
use tokio::task::{JoinHandle, JoinSet};
use tokio_util::sync::CancellationToken;

const PLANNER_REPLY: &str = "planner reply";
const CODER_REPLY: &str = "coder reply";

pub struct AcpTestHarness {
    pub client_cx: ConnectionTo<Agent>,
    pub peer: TestPeer,
    pub initialize_response: InitializeResponse,
    connection: Option<HarnessConnectionTasks>,
    pub auth_updates: mpsc::UnboundedReceiver<acp_utils::notifications::AuthMethodsUpdatedParams>,
    resume_agent: FakeAcpAgent,
    runtime_control: Arc<Mutex<FakeRuntimeControl>>,
    pub oauth_store: Arc<aether_auth::FakeOAuthCredentialStore>,
    agent_cx: ConnectionTo<Client>,
    state: Arc<AcpState>,
    session_store: Arc<SessionStore>,
    _tmp: tempfile::TempDir,
}

/// A real loopback listener backed by the harness's existing state and fake runtimes.
pub struct AcpWebSocketTestServer {
    pub address: SocketAddr,
    detached: watch::Receiver<u64>,
    shutdown: Option<oneshot::Sender<()>>,
    task: JoinHandle<Result<(), ServerRunError>>,
}

impl AcpWebSocketTestServer {
    pub fn url(&self) -> String {
        format!("ws://{}", self.address)
    }

    pub fn subscribe(&self) -> watch::Receiver<u64> {
        self.detached.clone()
    }

    /// Join networking cleanup without shutting down the harness-owned host.
    pub async fn shutdown(mut self) {
        let _ = self.shutdown.take().expect("server is running").send(());
        (&mut self.task).await.expect("listener task joins").expect("listener shuts down");
    }

    /// Drop the running server without executing the normal async shutdown path.
    pub async fn abort(mut self) {
        self.task.abort();
        assert!((&mut self.task).await.expect_err("listener task is aborted").is_cancelled());
    }
}

impl Drop for AcpWebSocketTestServer {
    fn drop(&mut self) {
        self.task.abort();
    }
}

pub struct FakeAgentSwitchingSession {
    session_id: SessionId,
    planner: FakeAcpAgent,
    coder: FakeAcpAgent,
}

#[derive(Clone)]
pub struct FakeAcpAgent {
    name: String,
    captured_contexts: Arc<Mutex<Vec<Context>>>,
}

pub struct PendingRuntime {
    started: oneshot::Receiver<()>,
    release: oneshot::Sender<bool>,
}

impl PendingRuntime {
    pub async fn wait_until_started(&mut self) {
        (&mut self.started).await.expect("runtime startup reached");
    }

    pub fn finish(self, succeed: bool) {
        self.release.send(succeed).expect("runtime startup is waiting");
    }
}

impl AcpTestHarness {
    pub fn pause_next_runtime(&self) -> PendingRuntime {
        let (started, observed) = oneshot::channel();
        let (release, proceed) = oneshot::channel();
        self.runtime_control.lock().unwrap().pending = Some((started, proceed));
        PendingRuntime { started: observed, release }
    }

    pub fn pause_prompt_expansion(&self) -> (Arc<tokio::sync::Notify>, Arc<tokio::sync::Notify>) {
        let gate = (Arc::new(tokio::sync::Notify::new()), Arc::new(tokio::sync::Notify::new()));
        self.runtime_control.lock().unwrap().prompt_gate = Some(gate.clone());
        gate
    }

    pub fn elicit_during_prompt_expansion(&self) -> mpsc::UnboundedReceiver<rmcp::model::ElicitResult> {
        let (sender, receiver) = mpsc::unbounded_channel();
        self.runtime_control.lock().unwrap().elicitation_results = Some(sender);
        receiver
    }

    pub fn live_runtime_count(&self) -> usize {
        self.runtime_control.lock().unwrap().agents.iter().filter(|sender| !sender.is_closed()).count()
    }

    pub async fn disconnect(&mut self) {
        if let Some(connection) = self.connection.take() {
            connection.shutdown().await;
        }
    }

    /// Connect a fresh initialized client to the same host and session store.
    pub async fn reconnect(&mut self) {
        assert!(self.connection.is_none(), "disconnect the current client before reconnecting");
        assert!(!self.state.stop_token().is_cancelled(), "host is running");
        let connection = connect_client(self.state.clone()).await;
        self.client_cx = connection.client_cx;
        self.agent_cx = connection.agent_cx;
        self.peer = connection.peer;
        self.initialize_response = connection.initialize_response;
        self.auth_updates = connection.auth_updates;
        self.connection = Some(connection.tasks);
    }

    /// Move this persistent host from its in-memory connection to a real port-zero listener.
    pub async fn serve_websocket(&mut self) -> AcpWebSocketTestServer {
        self.disconnect().await;
        self.listen_websocket().await
    }

    /// Listen without disconnecting any existing client.
    pub async fn listen_websocket(&self) -> AcpWebSocketTestServer {
        assert!(!self.state.stop_token().is_cancelled(), "host is running");
        let server =
            AcpServer::bind("127.0.0.1:0".parse().unwrap(), self.state.clone()).await.expect("bind test server");
        let address = server.local_addr().expect("listener address");
        let detached = self.state.client_slot().subscribe();
        let (shutdown, stopped) = oneshot::channel();
        let task = tokio::spawn(server.run_until(async move {
            let _ = stopped.await;
            Ok(())
        }));
        AcpWebSocketTestServer { address, detached, shutdown: Some(shutdown), task }
    }

    /// Stop the connection and all host-owned session runtimes.
    pub async fn shutdown(&mut self) {
        self.disconnect().await;
        self.state.shutdown_all().await;
    }

    pub fn stored_events(&self, session_id: &SessionId) -> Vec<SessionEvent> {
        self.session_store.load(session_id.0.as_ref()).expect("stored session loads").1
    }

    pub async fn start() -> Self {
        let tmp = tempfile::tempdir().expect("tempdir for session store");
        let session_store = Arc::new(SessionStore::from_path(tmp.path().to_path_buf()));
        let workspace_manager = Arc::new(WorkspaceManager::from_registry_path_with_cloner(
            tmp.path().join("workspaces.json"),
            Arc::new(StdCopyCloner),
        ));
        let (resume_def, resume_agent) = fake_agent("Resume", "resume-mcp", "resume", "resumed reply");
        let mut resume_agents = HashMap::new();
        resume_agents.insert(resume_def.spec.name.clone(), resume_def);
        let runtime_control = Arc::new(Mutex::new(FakeRuntimeControl::default()));
        let runtime_factory = Arc::new(FakeRuntimeFactory {
            cwd: PathBuf::from("/tmp"),
            agents: resume_agents,
            control: runtime_control.clone(),
        });
        let oauth_store = Arc::new(aether_auth::FakeOAuthCredentialStore::new());
        let state = Arc::new(AcpState::with_login(
            AcpStateConfig {
                session_store: session_store.clone(),
                workspace_manager,
                oauth_credential_store: oauth_store.clone(),
                initial_selection: InitialSessionSelection::default(),
                settings_source: SettingsSourceArgs::default(),
                provider_connections: ProviderConnectionOverrides::default(),
                telemetry: None,
                runtime_factory: Some(runtime_factory),
                cwd: PathBuf::from("/tmp"),
            },
            Arc::new(FakeProviderLogin),
        ));

        let connection = connect_client(state.clone()).await;
        Self {
            client_cx: connection.client_cx,
            peer: connection.peer,
            initialize_response: connection.initialize_response,
            connection: Some(connection.tasks),
            auth_updates: connection.auth_updates,
            resume_agent,
            runtime_control,
            oauth_store,
            agent_cx: connection.agent_cx,
            state,
            session_store,
            _tmp: tmp,
        }
    }

    pub fn resume_agent(&self) -> &FakeAcpAgent {
        &self.resume_agent
    }

    pub async fn insert_agent_switching_session(&self) -> FakeAgentSwitchingSession {
        self.insert_switching_session(
            SessionId::new("agent-switching-session"),
            Vec::new(),
            Some("Planner".to_string()),
            false,
        )
        .await
    }

    pub async fn insert_agent_switching_session_with_serverless_coder(&self) -> FakeAgentSwitchingSession {
        self.insert_switching_session(
            SessionId::new("agent-switching-serverless-session"),
            Vec::new(),
            Some("Planner".to_string()),
            true,
        )
        .await
    }

    pub async fn insert_loaded_agent_switching_session(&self, session_id: &str) -> FakeAgentSwitchingSession {
        let events = self.session_store.load(session_id).map(|(_, events)| events).unwrap_or_default();
        let selected_mode = last_agent_from_events(Some("Planner".to_string()), &events);
        self.insert_switching_session(SessionId::new(session_id), events, selected_mode, false).await
    }

    pub async fn expect_idle(&mut self, session_id: &SessionId, expected: StopReason) {
        loop {
            let notification = self.peer.next_session_notification().await;
            if notification.session_id == *session_id
                && let SessionUpdate::StateUpdate(StateUpdate::Idle(idle)) = notification.update
            {
                assert_eq!(idle.stop_reason, Some(expected));
                return;
            }
        }
    }

    pub async fn expect_mcp_server_status(&mut self, expected: &[&str]) {
        assert_server_status(self.peer.next_mcp_notification().await, expected);
    }

    pub async fn expect_mcp_server_status_exact(&mut self, expected: &[&str]) {
        assert_server_status_exact(self.peer.next_mcp_notification().await, expected);
    }

    pub async fn expect_available_commands(&mut self, expected: &[&str], unexpected: &[&str]) {
        loop {
            let update = self.peer.next_session_notification().await.update;
            if matches!(update, SessionUpdate::AvailableCommandsUpdate(_)) {
                assert_available_commands(update, expected, unexpected);
                return;
            }
        }
    }

    pub fn append_agent_switch(&self, session_id: &str, from: Option<&str>, to: Option<&str>) {
        self.append_stored_event(
            session_id,
            &SessionEvent::Control(SessionControlEvent::AgentSwitched {
                from: from.map(str::to_string),
                to: to.map(str::to_string),
            }),
        );
    }

    /// Register a stub session built from a hand-spawned
    /// `(agent_tx, agent_rx, agent_handle)` triple — typically from
    /// `aether_core::core::agent(fake_llm).spawn().await`. Pairs the agent with a
    /// real but empty in-memory MCP (no servers). The session is routable via
    /// `state.route_prompt(id)` / `state.cancel(id)`.
    pub async fn insert_stub_session(
        &self,
        agent_tx: mpsc::Sender<Command>,
        agent_rx: mpsc::Receiver<AgentEvent>,
        agent_handle: AgentHandle,
        id: SessionId,
        model: &str,
    ) {
        let model_spec: llm::catalog::LlmModel = "anthropic:claude-sonnet-4-5".parse().expect("test model parses");
        let mut specs = SessionAgents::new(AgentCatalog::empty(PathBuf::from("/tmp")));
        specs.set_default(AgentSpec::bare(&model_spec, None, Vec::new()));
        self.runtime_control.lock().unwrap().agents.push(agent_tx.clone());
        let factory = Arc::new(StubRuntimeFactory {
            cwd: PathBuf::from("/tmp"),
            agent_parts: Mutex::new(Some(StubAgentParts { tx: agent_tx, rx: agent_rx, handle: agent_handle })),
        });

        self.state
            .register_session(SessionActorInit {
                cwd: PathBuf::from("/tmp"),
                mcp_servers: Vec::new(),
                session_id: id.clone(),
                connection: self.agent_cx.clone(),
                repository: self.session_store.clone(),
                oauth_credential_store: self.oauth_store.clone(),
                active_agent: AgentKey::Default,
                specs,
                runtime_factory: factory,
                transcript: Vec::new(),
                replay: false,
                modes: Modes::default(),
                config: SessionConfigState::with_selection(model.to_string(), None, None),
            })
            .await;
    }

    pub fn append_stored_session(&self, session_id: &str, created_at: &str) {
        self.append_stored_session_in(session_id, created_at, std::path::Path::new("/tmp"));
    }

    pub fn append_stored_session_in(&self, session_id: &str, created_at: &str, cwd: &std::path::Path) {
        let meta = SessionMeta {
            session_id: session_id.to_string(),
            cwd: cwd.to_path_buf(),
            model: "anthropic:claude-sonnet-4-5".to_string(),
            selected_mode: None,
            created_at: created_at.to_string(),
        };

        self.session_store.append_meta(session_id, &meta).expect("stored session meta appends");
    }

    pub fn append_stored_prompt(&self, session_id: &str, prompt: &str) {
        self.append_stored_event(
            session_id,
            &SessionEvent::User(UserEvent::Message {
                message_id: llm::MessageId::new(),
                content: vec![llm::ContentBlock::text(prompt)],
                display_content: None,
            }),
        );
    }

    pub fn append_stored_user_blocks(&self, session_id: &str, blocks: Vec<llm::ContentBlock>) {
        self.append_stored_event(
            session_id,
            &SessionEvent::User(UserEvent::Message {
                message_id: llm::MessageId::new(),
                content: blocks,
                display_content: None,
            }),
        );
    }

    pub fn append_stored_agent_turn(&self, session_id: &str, text: &str) {
        self.append_stored_agent_text(session_id, text);
        self.append_stored_event(
            session_id,
            &SessionEvent::Agent(AgentEvent::Turn(TurnEvent::Ended { outcome: TurnOutcome::Completed })),
        );
    }

    pub fn append_stored_agent_text(&self, session_id: &str, text: &str) {
        self.append_stored_event(
            session_id,
            &SessionEvent::Agent(AgentEvent::Message(MessageEvent::Text {
                message_id: MessageId::new(),
                chunk: text.to_string(),
                is_complete: true,
            })),
        );
    }

    async fn insert_switching_session(
        &self,
        acp_session_id: SessionId,
        events: Vec<SessionEvent>,
        selected_mode: Option<String>,
        serverless_coder: bool,
    ) -> FakeAgentSwitchingSession {
        let (planner_def, planner) = fake_agent("Planner", "planner-mcp", "plan", PLANNER_REPLY);
        let (mut coder_def, coder) = fake_agent("Coder", "coder-mcp", "edit", CODER_REPLY);
        if serverless_coder {
            coder_def.mcp = None;
        }

        let mut catalog_specs = Vec::new();
        let mut agents = HashMap::new();
        for def in [planner_def, coder_def] {
            catalog_specs.push(def.spec.clone());
            agents.insert(def.spec.name.clone(), def);
        }
        let specs = SessionAgents::new(AgentCatalog::new(PathBuf::from("/tmp"), catalog_specs, None));

        let factory =
            Arc::new(FakeRuntimeFactory { cwd: PathBuf::from("/tmp"), agents, control: self.runtime_control.clone() });
        let initial_agent = selected_mode.clone().unwrap_or_else(|| "Planner".to_string());

        self.state
            .register_session(SessionActorInit {
                cwd: PathBuf::from("/tmp"),
                mcp_servers: Vec::new(),
                session_id: acp_session_id.clone(),
                connection: self.agent_cx.clone(),
                repository: self.session_store.clone(),
                oauth_credential_store: self.oauth_store.clone(),
                active_agent: AgentKey::Named(initial_agent),
                specs,
                runtime_factory: factory,
                transcript: events,
                replay: false,
                modes: switching_modes(),
                config: SessionConfigState::with_selection(
                    "anthropic:claude-sonnet-4-5".to_string(),
                    selected_mode,
                    None,
                ),
            })
            .await;
        FakeAgentSwitchingSession { session_id: acp_session_id, planner, coder }
    }

    pub fn append_stored_event(&self, session_id: &str, event: &SessionEvent) {
        self.session_store.append_event(session_id, event).expect("stored session event appends");
    }
}

impl FakeAgentSwitchingSession {
    pub fn session_id(&self) -> &SessionId {
        &self.session_id
    }

    pub fn planner(&self) -> &FakeAcpAgent {
        &self.planner
    }

    pub fn coder(&self) -> &FakeAcpAgent {
        &self.coder
    }
}

impl FakeAcpAgent {
    /// Asserts the agent's most recent turn saw a conversation containing each
    /// of `expected` (user or assistant text), in addition to anything else.
    pub fn assert_saw(&self, expected: &[&str]) {
        let seen = self.latest_conversation();
        for text in expected {
            assert!(seen.iter().any(|m| m == text), "{} should have seen {text:?}; saw {seen:?}", self.name);
        }
    }

    /// Asserts the agent's most recent turn saw *exactly* `expected` and nothing
    /// else — used to prove a freshly-activated agent started with no prior
    /// transcript.
    pub fn assert_saw_exactly(&self, expected: &[&str]) {
        let seen = self.latest_conversation();
        let expected: Vec<String> = expected.iter().map(|t| (*t).to_string()).collect();
        assert_eq!(seen, expected, "{} conversation mismatch", self.name);
    }

    pub fn assert_saw_user_content(&self, expected: &[llm::ContentBlock]) {
        let contexts = self.captured_contexts.lock().expect("captured contexts lock is healthy");
        let latest = contexts.last().expect("agent should have run a turn");
        assert!(
            latest
                .messages()
                .iter()
                .any(|message| { matches!(message, ChatMessage::User { content, .. } if content == expected) }),
            "{} should have seen user content {expected:?}",
            self.name
        );
    }

    /// Asserts the agent never ran a turn (its LLM was never invoked).
    pub fn assert_never_ran(&self) {
        let contexts = self.captured_contexts.lock().expect("captured contexts lock is healthy");
        assert!(contexts.is_empty(), "{} should not have run; captured {} context(s)", self.name, contexts.len());
    }

    fn latest_conversation(&self) -> Vec<String> {
        let contexts = self.captured_contexts.lock().expect("captured contexts lock is healthy");
        let latest = contexts.last().unwrap_or_else(|| panic!("{} should have run a turn", self.name));
        conversation_texts(latest)
    }
}

struct HarnessConnection {
    client_cx: ConnectionTo<Agent>,
    agent_cx: ConnectionTo<Client>,
    peer: TestPeer,
    initialize_response: InitializeResponse,
    auth_updates: mpsc::UnboundedReceiver<acp_utils::notifications::AuthMethodsUpdatedParams>,
    tasks: HarnessConnectionTasks,
}

struct HarnessConnectionTasks {
    stop: CancellationToken,
    tasks: JoinSet<Result<(), agent_client_protocol::Error>>,
}

impl HarnessConnectionTasks {
    async fn shutdown(mut self) {
        self.stop.cancel();
        while let Some(result) = self.tasks.join_next().await {
            result.expect("connection task joins").expect("connection cleanup completes");
        }
    }
}

async fn connect_client(state: Arc<AcpState>) -> HarnessConnection {
    let (peer, client_builder) = TestPeer::new();
    let (auth_tx, auth_updates) = mpsc::unbounded_channel();
    let client_builder = client_builder.on_receive_notification(
        async move |notification: AuthMethodsUpdatedParams, _cx| {
            let _ = auth_tx.send(notification);
            Ok(())
        },
        on_receive_notification!(),
    );
    let (agent_transport, client_transport) = duplex_pair();
    let (send_agent_connection, agent_ready) = oneshot::channel();
    let (send_client_connection, client_ready) = oneshot::channel();
    let stop = state.stop_token().child_token();
    let mut tasks = JoinSet::new();
    let agent_stop = stop.clone();
    tasks.spawn_local(async move { state.serve_with(agent_transport, agent_stop, send_agent_connection).await });
    tasks.spawn_local(async move {
        client_builder
            .with_runner(acp_utils::testing::CaptureConnection(send_client_connection))
            .connect_to(client_transport)
            .await
    });
    let agent_cx = agent_ready.await.expect("agent connection");
    let client_cx = client_ready.await.expect("client connection");
    let initialize_response =
        client_cx.send_request(initialize_request()).block_task().await.expect("initialize harness");
    HarnessConnection {
        client_cx,
        agent_cx,
        peer,
        initialize_response,
        auth_updates,
        tasks: HarnessConnectionTasks { stop, tasks },
    }
}

/// Spawns each agent's runtime through the real [`AgentRuntime`] wiring, but
/// backed by a [`FakeLlmProvider`] and an in-memory MCP server instead of a
/// network LLM and external MCP processes.
struct FakeRuntimeFactory {
    cwd: PathBuf,
    agents: HashMap<String, FakeAgentDef>,
    control: Arc<Mutex<FakeRuntimeControl>>,
}

#[derive(Default)]
struct FakeRuntimeControl {
    agents: Vec<mpsc::Sender<Command>>,
    pending: Option<(oneshot::Sender<()>, oneshot::Receiver<bool>)>,
    prompt_gate: Option<(Arc<tokio::sync::Notify>, Arc<tokio::sync::Notify>)>,
    elicitation_results: Option<mpsc::UnboundedSender<rmcp::model::ElicitResult>>,
}

struct FakeAgentDef {
    spec: AgentSpec,
    provider: Arc<dyn StreamingModelProvider>,
    mcp: Option<(String, String)>,
}

#[async_trait::async_trait]
impl RuntimeFactory for FakeRuntimeFactory {
    async fn spawn(
        &self,
        _agent: AgentKey,
        spec: &AgentSpec,
        initial_messages: Vec<ChatMessage>,
        usage_seed: Option<SessionUsageEvent>,
    ) -> Result<AgentRuntime, SessionError> {
        let pending = self.control.lock().unwrap().pending.take();
        if let Some((started, proceed)) = pending {
            let _ = started.send(());
            if !proceed.await.unwrap_or(false) {
                return Err(SessionError::AgentNotFound("injected startup failure".to_string()));
            }
        }
        let def = self
            .agents
            .get(&spec.name)
            .or_else(|| self.agents.values().next())
            .ok_or_else(|| SessionError::AgentNotFound(spec.name.clone()))?;
        let provider = def.provider.clone();

        let mut mcp_builder = mcp(&self.cwd).with_tool_filter(spec.tools.clone());
        if let Some((server_name, prompt_name)) = &def.mcp {
            let factory_name = server_name.clone();
            let prompt_name = prompt_name.clone();
            let gate = self.control.lock().unwrap().prompt_gate.clone();
            let elicitation_results = self.control.lock().unwrap().elicitation_results.clone();
            let factory: ServerFactory = Box::new(move |_spec, _services| {
                let prompt_name = prompt_name.clone();
                let gate = gate.clone();
                let elicitation_results = elicitation_results.clone();
                async move {
                    FakePromptMcp::new(&prompt_name).with_gate(gate).with_elicitation(elicitation_results).into_dyn()
                }
                .boxed()
            });
            mcp_builder = mcp_builder.register_in_memory_server(factory_name.clone(), factory).with_servers(vec![
                McpServer::new(
                    server_name.clone(),
                    McpTransport::InMemory {
                        spec: InMemoryServerSpec { factory: factory_name, args: Vec::new(), input: None },
                    },
                    ToolExposure::ModelVisible,
                ),
            ]);
        }
        let mut spawn =
            mcp_builder.spawn().await.map_err(|e| SessionError::Build(CliError::McpError(e.to_string())))?;
        spawn.block_until_ready().await.ok_or(SessionError::McpStartupStopped)?;
        let mcp_handle = spawn.handle().clone();
        let mut builder = AgentBuilder::new(provider).max_auto_continues(0);
        if let Some(last) = &usage_seed {
            builder = builder.resume_usage(last);
        }
        for prompt in &spec.prompts {
            builder = builder.system_prompt(prompt.clone());
        }
        let (agent_tx, agent_rx, agent_handle) = builder
            .tools(mcp_handle, Vec::new())
            .messages(initial_messages)
            .spawn()
            .await
            .map_err(|e| SessionError::Build(CliError::AgentError(e.to_string())))?;
        self.control.lock().unwrap().agents.push(agent_tx.clone());
        let (mcp_runtime, event_rx) = spawn.connect_agent(agent_tx.clone()).await.split();

        Ok(AgentRuntime::new(agent_tx, agent_rx, Some(agent_handle), event_rx, mcp_runtime))
    }
}

struct StubRuntimeFactory {
    cwd: PathBuf,
    agent_parts: Mutex<Option<StubAgentParts>>,
}

struct StubAgentParts {
    tx: mpsc::Sender<Command>,
    rx: mpsc::Receiver<AgentEvent>,
    handle: AgentHandle,
}

#[async_trait::async_trait]
impl RuntimeFactory for StubRuntimeFactory {
    async fn spawn(
        &self,
        _agent: AgentKey,
        _spec: &AgentSpec,
        _initial_messages: Vec<ChatMessage>,
        _usage_seed: Option<SessionUsageEvent>,
    ) -> Result<AgentRuntime, SessionError> {
        let parts = self
            .agent_parts
            .lock()
            .expect("stub agent parts lock is healthy")
            .take()
            .expect("stub runtime spawned more than once");

        let mut spawn =
            mcp(&self.cwd).spawn().await.map_err(|e| SessionError::Build(CliError::McpError(e.to_string())))?;
        spawn.block_until_ready().await.ok_or(SessionError::McpStartupStopped)?;
        let (mcp_runtime, event_rx) = spawn.connect_agent(parts.tx.clone()).await.split();

        Ok(AgentRuntime::new(parts.tx, parts.rx, Some(parts.handle), event_rx, mcp_runtime))
    }
}

fn fake_agent(name: &str, server_name: &str, prompt_name: &str, reply: &str) -> (FakeAgentDef, FakeAcpAgent) {
    const TURNS_BEFORE_AND_AFTER_REATTACH: usize = 2;
    let provider = FakeLlmProvider::new(vec![
        vec![LlmResponse::Start, LlmResponse::text(reply), LlmResponse::done()];
        TURNS_BEFORE_AND_AFTER_REATTACH
    ])
    .with_display_name(name);
    let captured_contexts = provider.captured_contexts();
    let def = FakeAgentDef {
        spec: fake_agent_spec(name),
        provider: Arc::new(provider),
        mcp: Some((server_name.to_string(), prompt_name.to_string())),
    };
    let observer = FakeAcpAgent { name: name.to_string(), captured_contexts };
    (def, observer)
}

struct FakeProviderLogin;

#[async_trait::async_trait]
impl super::state::ProviderLogin for FakeProviderLogin {
    async fn login(&self, store: &dyn OAuthCredentialStorage) -> Result<(), llm::LlmError> {
        store
            .save("codex", serde_json::json!({"access_token": "fake-access", "refresh_token": "fake-refresh"}))
            .await?;
        Ok(())
    }
}

fn switching_modes() -> Modes {
    Modes::new(vec![
        ValidatedMode {
            name: "Planner".to_string(),
            model: "anthropic:claude-sonnet-4-5".to_string(),
            reasoning_effort: None,
        },
        ValidatedMode {
            name: "Coder".to_string(),
            model: "deepseek:deepseek-v4-flash".to_string(),
            reasoning_effort: None,
        },
    ])
}

fn fake_agent_spec(name: &str) -> AgentSpec {
    let model: llm::catalog::LlmModel = "anthropic:claude-sonnet-4-5".parse().expect("test model parses");
    let mut spec = AgentSpec::bare(&model, None, vec![Prompt::text(&format!("{name} system prompt"))]);
    spec.name = name.to_string();
    spec.description = format!("{name} test agent");
    spec.exposure = AgentSpecExposure::user_only();
    spec
}

fn assert_available_commands(update: SessionUpdate, expected: &[&str], unexpected: &[&str]) {
    let SessionUpdate::AvailableCommandsUpdate(commands) = update else {
        panic!("expected available commands update");
    };
    let names = commands.available_commands.iter().map(|command| command.name.as_str()).collect::<Vec<_>>();
    for name in expected {
        assert!(names.contains(name), "expected command /{name} in {names:?}");
    }
    for name in unexpected {
        assert!(!names.contains(name), "did not expect command /{name} in {names:?}");
    }
}

fn assert_server_status(notification: McpNotification, expected: &[&str]) {
    let McpNotification::ServerStatus { servers } = notification;
    let names = servers.iter().map(|server| server.name.as_str()).collect::<Vec<_>>();
    for server_name in expected {
        assert!(names.contains(server_name), "expected server {server_name} in {names:?}");
    }
}

fn assert_server_status_exact(notification: McpNotification, expected: &[&str]) {
    let McpNotification::ServerStatus { servers } = notification;
    let names = servers.iter().map(|server| server.name.as_str()).collect::<Vec<_>>();
    assert_eq!(names, expected);
}

fn conversation_texts(context: &Context) -> Vec<String> {
    context
        .messages()
        .iter()
        .filter_map(|message| match message {
            ChatMessage::User { content, .. } => llm::ContentBlock::first_text(content).map(str::to_string),
            ChatMessage::Assistant { content, .. } if !content.is_empty() => Some(content.clone()),
            _ => None,
        })
        .collect()
}