#![cfg_attr(rustfmt, rustfmt::skip)]
    use super::*;

    /// Regression: a machine-wide `kigi/models/update` broadcast
    /// carries each model's static catalog-default effort (`high`), not the
    /// session's chosen `xhigh`, and must not clobber the per-session choice.
    #[test]
    fn models_update_preserves_user_reasoning_effort() {
        use kigi_shell::sampling::types::ReasoningEffort;
        let mut app = make_app_with_agent("sess-1");

        let agent = app.agents.get_mut(&AgentId(0)).unwrap();
        let id = acp::ModelId::new(std::sync::Arc::from("reason-model"));
        let mut info = make_model_info("reason-model");
        info.meta = serde_json::json!({
            "supportsReasoningEffort": true,
            "reasoningEffort": "high",
        })
        .as_object()
        .cloned();
        agent.session.models.available.insert(id.clone(), info);
        agent
            .session
            .models
            .set_current(id, Some(ReasoningEffort::Xhigh));
        assert_eq!(
            agent.session.models.reasoning_effort,
            Some(ReasoningEffort::Xhigh)
        );

        let notif = make_reasoning_models_update_notif("reason-model", "high");
        assert!(handle_models_update(&notif, &mut app));

        let agent = app.agents.get(&AgentId(0)).unwrap();
        assert_eq!(
            agent.session.models.reasoning_effort,
            Some(ReasoningEffort::Xhigh),
            "models/update broadcast must not clobber a user-set per-session effort"
        );
    }

    #[test]
    fn models_update_preserves_active_agent_model() {
        let mut app = make_app_with_agent("sess-1");

        let agent = app.agents.get_mut(&AgentId(0)).unwrap();
        let id_3 = acp::ModelId::new(std::sync::Arc::from("kigi-3"));
        agent
            .session
            .models
            .available
            .insert(id_3.clone(), make_model_info("kigi-3"));
        agent.session.models.current = Some(id_3);

        let notif = make_models_update_notif("kigi-4", &["kigi-3", "kigi-4"]);
        handle_models_update(&notif, &mut app);

        assert_eq!(
            app.models.current.as_ref().map(|id| id.0.as_ref()),
            Some("kigi-3"),
            "app.models.current must preserve active agent's model, not remote settings default"
        );

        let agent = app.agents.get(&AgentId(0)).unwrap();
        assert_eq!(
            agent
                .session
                .models
                .current
                .as_ref()
                .map(|id| id.0.as_ref()),
            Some("kigi-3"),
            "agent's per-session model must be preserved"
        );
    }

    #[test]
    fn models_update_uses_shell_default_when_agent_model_removed() {
        let mut app = make_app_with_agent("sess-1");

        let agent = app.agents.get_mut(&AgentId(0)).unwrap();
        let id_3 = acp::ModelId::new(std::sync::Arc::from("kigi-3"));
        agent
            .session
            .models
            .available
            .insert(id_3.clone(), make_model_info("kigi-3"));
        agent.session.models.current = Some(id_3);

        // kigi-3 removed from catalog.
        let notif = make_models_update_notif("kigi-4.3", &["kigi-4.3", "kigi-4.5"]);
        handle_models_update(&notif, &mut app);

        assert_eq!(
            app.models.current.as_ref().map(|id| id.0.as_ref()),
            Some("kigi-4.3"),
            "app.models.current must use shell default when agent model removed"
        );

        let agent = app.agents.get(&AgentId(0)).unwrap();
        assert_eq!(
            agent
                .session
                .models
                .current
                .as_ref()
                .map(|id| id.0.as_ref()),
            Some("kigi-4.3"),
            "agent must fall back to shell default when its model is removed"
        );
    }

    fn seed_windowed_models(agent: &mut AgentView) {
        for (slug, window) in [("wide", 1_000_000u64), ("narrow", 262_144)] {
            let mut info = make_model_info(slug);
            info.meta = serde_json::json!({ "totalContextTokens": window })
                .as_object()
                .cloned();
            agent
                .session
                .models
                .available
                .insert(acp::ModelId::new(std::sync::Arc::from(slug)), info);
        }
        agent
            .session
            .models
            .set_current(acp::ModelId::new(std::sync::Arc::from("wide")), None);
        agent.apply_context_used(15_000, 1_000_000);
    }

    /// A follower mirrors a remote switch and installs the effective window
    /// the broadcast carries, like the invoking client does.
    #[test]
    fn model_changed_broadcast_installs_the_reported_context_window() {
        let mut app = make_app_with_agent("sess-1");
        seed_windowed_models(app.agents.get_mut(&AgentId(0)).unwrap());

        let notif = model_changed_ext("sess-1", "narrow", None, Some(262_144));
        assert!(handle_ext_notification(&notif, &mut app));

        let snap = app.agents[&AgentId(0)].context_state.as_ref().unwrap();
        assert_eq!((snap.used, snap.total, snap.usage_pct), (15_000, 262_144, 6));
    }

    /// Same model, same effort, new effective window (the catalog was
    /// reloaded and re-applied): the follower must still request a redraw.
    #[test]
    fn model_changed_same_model_new_window_requests_redraw() {
        let mut app = make_app_with_agent("sess-1");
        seed_windowed_models(app.agents.get_mut(&AgentId(0)).unwrap());

        let notif = model_changed_ext("sess-1", "wide", None, Some(2_000_000));
        assert!(handle_ext_notification(&notif, &mut app));

        let snap = app.agents[&AgentId(0)].context_state.as_ref().unwrap();
        assert_eq!((snap.used, snap.total), (15_000, 2_000_000));

        let again = model_changed_ext("sess-1", "wide", None, Some(2_000_000));
        assert!(!handle_ext_notification(&again, &mut app));
    }

    /// A broadcast from a leader that predates the field carries no window;
    /// the snapshot is left for the next streaming update to refresh.
    #[test]
    fn model_changed_broadcast_without_window_keeps_the_snapshot() {
        let mut app = make_app_with_agent("sess-1");
        seed_windowed_models(app.agents.get_mut(&AgentId(0)).unwrap());

        let notif = model_changed_ext("sess-1", "narrow", None, None);
        assert!(handle_ext_notification(&notif, &mut app));

        let snap = app.agents[&AgentId(0)].context_state.as_ref().unwrap();
        assert_eq!((snap.used, snap.total), (15_000, 1_000_000));
    }

    #[test]
    fn models_update_without_active_agent_uses_shell_default() {
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();
        let mut app = AppView::new(tx, ModelState::default(), Vec::new());

        let notif = make_models_update_notif("kigi-4", &["kigi-3", "kigi-4"]);
        handle_models_update(&notif, &mut app);

        assert_eq!(
            app.models.current.as_ref().map(|id| id.0.as_ref()),
            Some("kigi-4"),
            "without an active agent, shell default must be used"
        );
    }

    #[test]
    fn models_update_noop_when_agent_matches_shell_default() {
        let mut app = make_app_with_agent("sess-1");

        let agent = app.agents.get_mut(&AgentId(0)).unwrap();
        let id_4 = acp::ModelId::new(std::sync::Arc::from("kigi-4"));
        agent
            .session
            .models
            .available
            .insert(id_4.clone(), make_model_info("kigi-4"));
        agent.session.models.current = Some(id_4);

        let notif = make_models_update_notif("kigi-4", &["kigi-3", "kigi-4"]);
        handle_models_update(&notif, &mut app);

        assert_eq!(
            app.models.current.as_ref().map(|id| id.0.as_ref()),
            Some("kigi-4"),
            "app.models.current must be kigi-4 when agent and shell agree"
        );
        let agent = app.agents.get(&AgentId(0)).unwrap();
        assert_eq!(
            agent
                .session
                .models
                .current
                .as_ref()
                .map(|id| id.0.as_ref()),
            Some("kigi-4"),
            "agent model must remain kigi-4"
        );
    }

    #[test]
    fn models_update_non_active_agent_uses_shell_fallback_not_active_model() {
        let mut app = make_app_with_agent("sess-A");
        insert_agent(&mut app, AgentId(1), Some("sess-B"));

        {
            let agent_a = app.agents.get_mut(&AgentId(0)).unwrap();
            let id_3 = acp::ModelId::new(std::sync::Arc::from("kigi-3"));
            agent_a
                .session
                .models
                .available
                .insert(id_3.clone(), make_model_info("kigi-3"));
            agent_a.session.models.current = Some(id_3);
        }

        {
            let agent_b = app.agents.get_mut(&AgentId(1)).unwrap();
            let id_5 = acp::ModelId::new(std::sync::Arc::from("kigi-4.5"));
            agent_b
                .session
                .models
                .available
                .insert(id_5.clone(), make_model_info("kigi-4.5"));
            agent_b.session.models.current = Some(id_5);
        }

        // kigi-4.5 removed from catalog.
        let notif = make_models_update_notif("kigi-4", &["kigi-3", "kigi-4"]);
        handle_models_update(&notif, &mut app);

        assert_eq!(
            app.models.current.as_ref().map(|id| id.0.as_ref()),
            Some("kigi-3"),
        );
        let agent_a = app.agents.get(&AgentId(0)).unwrap();
        assert_eq!(
            agent_a
                .session
                .models
                .current
                .as_ref()
                .map(|id| id.0.as_ref()),
            Some("kigi-3"),
            "agent A's model must be preserved"
        );

        // B's kigi-4.5 was removed — must fall back to shell's kigi-4, not A's kigi-3.
        let agent_b = app.agents.get(&AgentId(1)).unwrap();
        assert_eq!(
            agent_b
                .session
                .models
                .current
                .as_ref()
                .map(|id| id.0.as_ref()),
            Some("kigi-4"),
            "inactive agent must fall back to shell default, not active agent's model"
        );
    }

    /// A follower client (no in-flight switch of its own) receives the
    /// leader's `ModelChanged` broadcast and silently mirrors the new model
    /// into its local state — no scrollback entry, no toast, just enough
    /// state for the status bar / `/model` dropdown to render correctly.
    #[test]
    fn model_changed_updates_state_silently_on_follower() {
        let mut app = make_app_with_agent("sess-1");
        let agent = app.agents.get_mut(&AgentId(0)).unwrap();
        seed_models(agent, "kigi-3", &["kigi-3", "kigi-4"]);
        let scrollback_before = agent.scrollback.len();
        assert!(!agent.session.model_switch_pending);

        let notif = model_changed_ext("sess-1", "kigi-4", None, None);
        let changed = handle_ext_notification(&notif, &mut app);
        assert!(
            changed,
            "follower's state changed → handler must request a redraw"
        );

        let agent = app.agents.get(&AgentId(0)).unwrap();
        assert_eq!(
            agent
                .session
                .models
                .current
                .as_ref()
                .map(|id| id.0.as_ref()),
            Some("kigi-4"),
            "follower must mirror the remote switch into its local model state",
        );
        assert_eq!(
            agent.scrollback.len(),
            scrollback_before,
            "follower must NOT push a 'Switched to' scrollback entry — that is \
             the invoking client's job (SwitchModelComplete owns the system message)"
        );
        assert!(
            !agent.session.model_switch_pending,
            "follower's pending flag must stay false (no local switch was issued)"
        );
    }

    /// A live remote `ModelChanged` (leader-mode fan-out from another client)
    /// must apply even when this client already has a local
    /// `user_model_preference` — otherwise the status bar desyncs from the
    /// gateway session. Preference is updated to track the new live model.
    /// (History-replay silent-revert is suppressed on the shell side via
    /// `ReconnectState::user_selected_model`, not by permanently blocking
    /// remote ModelChanged here.)
    #[test]
    fn model_changed_applies_and_updates_user_model_preference() {
        let mut app = make_app_with_agent("sess-1");
        let agent = app.agents.get_mut(&AgentId(0)).unwrap();
        seed_models(agent, "heavy", &["auto", "heavy"]);
        agent.session.user_model_preference =
            Some(acp::ModelId::new(std::sync::Arc::from("heavy")));
        assert!(!agent.session.model_switch_pending);

        let notif = model_changed_ext("sess-1", "auto", None, None);
        let changed = handle_ext_notification(&notif, &mut app);
        assert!(
            changed,
            "remote live ModelChanged must apply despite prior local preference"
        );

        let agent = app.agents.get(&AgentId(0)).unwrap();
        assert_eq!(
            agent
                .session
                .models
                .current
                .as_ref()
                .map(|id| id.0.as_ref()),
            Some("auto"),
            "selector must mirror the remote switch"
        );
        assert_eq!(
            agent
                .session
                .user_model_preference
                .as_ref()
                .map(|id| id.0.as_ref()),
            Some("auto"),
            "preference must track the applied remote switch"
        );
    }

    /// The invoking client is also a subscriber to its own session and so
    /// receives the broadcast it triggered. Its in-flight
    /// `SetSessionModelResponse` is the authority for its local state +
    /// the single "Switched to X" scrollback entry, so the broadcast handler
    /// must be a no-op here — gated on `model_switch_pending == true`.
    ///
    /// Concretely we verify the broadcast does NOT touch
    /// `models.current` (preserving the pre-response snapshot) — that
    /// snapshot is what `SwitchModelComplete`'s `unchanged` check compares
    /// against to decide whether to render the "Switched to X" message. If
    /// the broadcast optimistically updated state here, the response
    /// handler would see `prev == new`, mark it unchanged, and suppress the
    /// user-facing message entirely.
    #[test]
    fn model_changed_skipped_when_local_switch_in_flight() {
        let mut app = make_app_with_agent("sess-1");
        let agent = app.agents.get_mut(&AgentId(0)).unwrap();
        seed_models(agent, "kigi-3", &["kigi-3", "kigi-4"]);
        agent.session.model_switch_pending = true;
        let scrollback_before = agent.scrollback.len();

        let notif = model_changed_ext("sess-1", "kigi-4", None, None);
        let changed = handle_ext_notification(&notif, &mut app);
        assert!(
            !changed,
            "broadcast must be a no-op while local switch is pending"
        );

        let agent = app.agents.get(&AgentId(0)).unwrap();
        assert_eq!(
            agent
                .session
                .models
                .current
                .as_ref()
                .map(|id| id.0.as_ref()),
            Some("kigi-3"),
            "models.current must stay at the pre-response snapshot — \
             SwitchModelComplete owns the final apply + system message"
        );
        assert_eq!(
            agent.scrollback.len(),
            scrollback_before,
            "broadcast must not push any scrollback entry on the invoker"
        );
        assert!(
            agent.session.model_switch_pending,
            "pending flag must remain set until SwitchModelComplete arrives"
        );
    }

    /// A `ModelChanged` broadcast carrying a model id the local catalog
    /// doesn't know about must be dropped — applying it would render an
    /// unresolvable id in the status bar and desync the `/model` dropdown.
    /// This can happen when leader and a follower client briefly disagree
    /// on the model catalog (etag drift, custom-model config skew).
    #[test]
    fn model_changed_dropped_when_model_unknown_to_catalog() {
        let mut app = make_app_with_agent("sess-1");
        let agent = app.agents.get_mut(&AgentId(0)).unwrap();
        seed_models(agent, "kigi-3", &["kigi-3", "kigi-4"]);

        let notif = model_changed_ext("sess-1", "kigi-99-unknown", None, None);
        let changed = handle_ext_notification(&notif, &mut app);
        assert!(
            !changed,
            "unknown model must NOT trigger a redraw — no state changed"
        );

        let agent = app.agents.get(&AgentId(0)).unwrap();
        assert_eq!(
            agent
                .session
                .models
                .current
                .as_ref()
                .map(|id| id.0.as_ref()),
            Some("kigi-3"),
            "models.current must stay on the previously-known model"
        );
    }

    /// `reasoning_effort` round-trips through the broadcast: the follower
    /// applies it alongside the model id so the prompt header / status bar
    /// show the right effort without waiting for a subsequent
    /// `kigi/models/update`.
    #[test]
    fn model_changed_applies_reasoning_effort_on_follower() {
        use kigi_shell::sampling::types::ReasoningEffort;
        let mut app = make_app_with_agent("sess-1");
        let agent = app.agents.get_mut(&AgentId(0)).unwrap();
        seed_models(agent, "kigi-3", &["kigi-3", "kigi-4"]);

        let notif = model_changed_ext("sess-1", "kigi-4", Some("high"), None);
        assert!(handle_ext_notification(&notif, &mut app));

        let agent = app.agents.get(&AgentId(0)).unwrap();
        assert_eq!(
            agent.session.models.reasoning_effort,
            Some(ReasoningEffort::High),
            "follower must mirror the broadcast's reasoning_effort"
        );
    }

    /// `ModelChanged` for a session this client doesn't own / hasn't loaded
    /// must be dropped — `find_session_match` returns `None`. The bug-flavored
    /// version of this would be: leader-mode A switches model on session X
    /// (which this client never opened) and we accidentally apply the change
    /// to the active agent.
    #[test]
    fn model_changed_dropped_for_unknown_session_id() {
        let mut app = make_app_with_agent("sess-1");
        let agent = app.agents.get_mut(&AgentId(0)).unwrap();
        seed_models(agent, "kigi-3", &["kigi-3", "kigi-4"]);

        let notif = model_changed_ext("sess-OTHER", "kigi-4", None, None);
        let changed = handle_ext_notification(&notif, &mut app);
        assert!(!changed);

        let agent = app.agents.get(&AgentId(0)).unwrap();
        assert_eq!(
            agent
                .session
                .models
                .current
                .as_ref()
                .map(|id| id.0.as_ref()),
            Some("kigi-3"),
            "unrelated-session broadcast must not touch this agent's model"
        );
    }