//! Settings UI: command palette, settings modal, toggles, resets, and rollback.

use super::setters::{
    pr13_effective_default, set_ask_user_question_timeout_enabled_inner, set_auto_dark_theme_inner,
    set_auto_light_theme_inner, set_auto_update_inner, set_collapsed_edit_blocks_inner,
    set_compact_mode, set_compact_mode_inner, set_contextual_hint_inner,
    set_default_selected_permission_inner, set_display_refresh_auto_cadence_inner,
    set_fork_secondary_model_inner, set_group_tool_verbs_inner, set_hunk_tracker_mode_inner,
    set_invert_scroll_inner, set_keep_text_selection_inner, set_max_thoughts_width_inner,
    set_multiline_mode, set_prompt_suggestions_inner, set_remember_tool_approvals_inner,
    set_render_mermaid_inner, set_respect_manual_folds_inner, set_screen_mode_inner,
    set_scroll_lines_inner, set_scroll_mode_inner, set_scroll_speed_inner,
    set_show_thinking_blocks_inner, set_show_tips_inner, set_simple_mode_inner, set_theme_inner,
    set_timeline_inner, set_timestamps, set_timestamps_inner, set_vim_mode_inner,
};
use crate::app::actions::{Action, Effect};
use crate::app::app_view::{ActiveView, AppView};
use crate::app::dispatch::ctx::with_active_agent;
use crate::app::dispatch::modes::{set_yolo_mode_inner, sync_active_auto_flag};
use crate::app::dispatch::router::dispatch;
use crate::app::dispatch::turn::apply_cancel_subagents_preference_global;
use crate::scrollback::block::RenderBlock;
use agent_client_protocol as acp;

/// Format a "✓ Label: value" success toast.
pub(in crate::app::dispatch) fn save_success_toast(label: &str, on: bool) -> String {
    let value = if on { "on" } else { "off" };
    format!("\u{2713} {label}: {value}")
}

/// Refresh every open settings modal's `ui_snapshot` + `pager_snapshot`
/// so the next render reads the latest live state. The modal stores
/// snapshots by value; without this, toggles would appear stuck.
pub(crate) fn refresh_open_settings_modals(app: &mut AppView) {
    use crate::views::modal::ActiveModal;
    // Early exit when no settings modal is open (common case).
    if !app.agents.values().any(|a| {
        matches!(
            a.active_modal,
            Some(ActiveModal::Settings { .. } | ActiveModal::ResetSettingsConfirm { .. })
        )
    }) {
        return;
    }
    let ui_snapshot = app.current_ui.clone();
    // Capture app-level fields before the mut-borrow loop.
    let show_tips_from_app = app.show_tips;
    let auto_update_from_app = app.auto_update;
    let respect_manual_folds_from_app = app.appearance.scrollback.scroll.respect_manual_folds;
    let auto_mode_gate_from_app = app.auto_mode_gate;
    let ask_user_question_timeout_enabled_from_app = app.ask_user_question_timeout_enabled;
    for agent in app.agents.values_mut() {
        // Walk both `Settings` and `ResetSettingsConfirm` — the
        // confirm dialog embeds settings state that must stay fresh
        // through async persist failures.
        let state_opt = match agent.active_modal.as_mut() {
            Some(ActiveModal::Settings { state }) => Some(state.as_mut()),
            Some(ActiveModal::ResetSettingsConfirm { settings_state, .. }) => {
                Some(settings_state.as_mut())
            }
            _ => None,
        };
        if let Some(state) = state_opt {
            state.rebuild_rows();
            state.ui_snapshot = ui_snapshot.clone();
            state.pager_snapshot = crate::settings::PagerLocalSnapshot {
                multiline_mode: agent.multiline_mode,
                yolo_mode: agent.session.is_yolo(),
                auto_mode: agent.session.is_auto(),
                current_model_name: agent.session.models.current_model_name(),
                available_models: agent
                    .session
                    .models
                    .available
                    .iter()
                    .map(|(id, info)| (info.name.clone(), id.clone()))
                    .collect(),
                // Prefer optimistic pending over confirmed active.
                plan_mode_active: agent.plan_mode_pending.unwrap_or(agent.plan_mode_active),
                show_tips: show_tips_from_app,
                auto_update: auto_update_from_app,
                vim_mode: crate::appearance::cache::load_vim_mode(),
                scroll_speed: crate::appearance::cache::load_scroll_speed(),
                respect_manual_folds: respect_manual_folds_from_app,
                auto_mode_gate: auto_mode_gate_from_app,
                ask_user_question_timeout_enabled: ask_user_question_timeout_enabled_from_app,
            };
        }
    }
}

/// Open the command palette (the `/help` slash command path). Mirrors the
/// keybinding handler (`ActionId::CommandPalette`); toggles closed if already
/// open. Hosted inline in minimal mode by the overlay app-modal host.
pub(in crate::app::dispatch) fn dispatch_open_command_palette(app: &mut AppView) -> Vec<Effect> {
    use crate::views::modal::ActiveModal;
    let ActiveView::Agent(id) = app.active_view else {
        return vec![];
    };
    let Some(agent) = app.agents.get_mut(&id) else {
        return vec![];
    };
    if matches!(
        &agent.active_modal,
        Some(ActiveModal::CommandPalette { .. })
    ) {
        agent.active_modal = None;
        return vec![];
    }
    agent.active_modal = Some(ActiveModal::CommandPalette {
        entries: crate::views::modal::default_palette_entries(),
        // Type-to-find: open in input mode (matches Ctrl+P).
        state: crate::views::picker::PickerState::input_active(),
        window: crate::views::modal_window::ModalWindowState::new(),
    });
    vec![]
}

/// Open the How-to Guides doc picker (`/docs`). Toggles closed if already open.
pub(in crate::app::dispatch) fn dispatch_open_howto_guides(app: &mut AppView) -> Vec<Effect> {
    use crate::views::modal::ActiveModal;
    let ActiveView::Agent(id) = app.active_view else {
        return vec![];
    };
    let Some(agent) = app.agents.get_mut(&id) else {
        return vec![];
    };
    if matches!(&agent.active_modal, Some(ActiveModal::DocPicker { .. })) {
        agent.active_modal = None;
        return vec![];
    }
    agent.active_modal = Some(crate::views::modal::howto_list_modal(None));
    vec![]
}

/// Open the settings modal. Reads the live `UiConfig` snapshot
/// (sans-IO). Single-instance: `debug_assert!` catches routing bugs.
pub(in crate::app::dispatch) fn dispatch_open_settings(app: &mut AppView) -> Vec<Effect> {
    use crate::views::modal::ActiveModal;
    use crate::views::settings_modal::SettingsModalState;

    let ActiveView::Agent(id) = app.active_view else {
        return vec![];
    };
    // Snapshot the registry + UiConfig + pager-local state BEFORE the
    // mutable borrow on `agent` so the borrow checker is happy.
    let registry = app.settings_registry.clone();
    let ui_snapshot = app.current_ui.clone();
    // Capture app-level fields before the mut-borrow on the agent.
    let show_tips_from_app = app.show_tips;
    let auto_update_from_app = app.auto_update;
    let respect_manual_folds_from_app = app.appearance.scrollback.scroll.respect_manual_folds;
    let auto_mode_gate_from_app = app.auto_mode_gate;
    let ask_user_question_timeout_enabled_from_app = app.ask_user_question_timeout_enabled;

    let Some(agent) = app.agents.get_mut(&id) else {
        return vec![];
    };

    debug_assert!(
        !matches!(&agent.active_modal, Some(ActiveModal::Settings { .. })),
        "OpenSettings dispatched while settings modal is already open — input routing bug"
    );
    // Defensive close in release builds: silent no-op risk is higher
    // than the cost of a single extra branch on a hot path that isn't
    // hot. Mirrors the shortcuts-cheatsheet precedent at
    // `views/shortcuts_help.rs:336-340`.
    if matches!(&agent.active_modal, Some(ActiveModal::Settings { .. })) {
        agent.active_modal = None;
        return vec![];
    }

    tracing::info!(target: "settings", "opened modal");

    let pager_snapshot = crate::settings::PagerLocalSnapshot {
        multiline_mode: agent.multiline_mode,
        yolo_mode: agent.session.is_yolo(),
        auto_mode: agent.session.is_auto(),
        current_model_name: agent.session.models.current_model_name(),
        available_models: agent
            .session
            .models
            .available
            .iter()
            .map(|(id, info)| (info.name.clone(), id.clone()))
            .collect(),
        // Prefer optimistic pending over confirmed active.
        plan_mode_active: agent.plan_mode_pending.unwrap_or(agent.plan_mode_active),
        show_tips: show_tips_from_app,
        auto_update: auto_update_from_app,
        vim_mode: crate::appearance::cache::load_vim_mode(),
        scroll_speed: crate::appearance::cache::load_scroll_speed(),
        respect_manual_folds: respect_manual_folds_from_app,
        auto_mode_gate: auto_mode_gate_from_app,
        ask_user_question_timeout_enabled: ask_user_question_timeout_enabled_from_app,
    };
    let state = Box::new(SettingsModalState::new(
        registry,
        ui_snapshot,
        pager_snapshot,
    ));
    agent.active_modal = Some(ActiveModal::Settings { state });
    vec![]
}

/// Open the reset-settings confirmation modal.
///
/// **Modal stack contract.** The current `ActiveModal::Settings`
/// state is moved out and stored inside the new
/// `ActiveModal::ResetSettingsConfirm { settings_state, key, .. }`
/// variant — preserving the user's filter, scroll position, and
/// selection across the confirm dialog. Both `ConfirmResetSetting`
/// branches (Reset / Cancel) move the state back out, restoring
/// `ActiveModal::Settings`. The box keeps the move a pointer swap.
///
/// **Routing precondition.** This action is only emitted from the
/// settings modal's `d` keystroke (`views/settings_modal.rs::handle_browse`),
/// which guarantees the active modal IS `ActiveModal::Settings` at
/// this point. We `debug_assert!` to catch a routing regression in
/// debug builds; in release we treat the mismatch as a no-op (a
/// foreign caller dispatching `OpenResetConfirm` without an open
/// Settings modal would otherwise crash).
pub(in crate::app::dispatch) fn dispatch_open_reset_confirm(
    app: &mut AppView,
    key: crate::settings::SettingKey,
) -> Vec<Effect> {
    use crate::views::modal::{ActiveModal, ModalConfirmation};

    let ActiveView::Agent(id) = app.active_view else {
        return vec![];
    };
    let Some(agent) = app.agents.get_mut(&id) else {
        return vec![];
    };

    // Take the Settings modal state out so we can move it into the
    // confirmation variant. If the active modal is anything else
    // (routing bug), restore the original modal and bail. The
    // debug_assert surfaces the bug in tests; release builds degrade
    // to a silent no-op rather than a panic.
    let prior = agent.active_modal.take();
    let settings_state = match prior {
        Some(ActiveModal::Settings { state }) => state,
        other => {
            debug_assert!(
                matches!(other, Some(ActiveModal::Settings { .. })),
                "OpenResetConfirm dispatched without an open Settings modal — input routing bug",
            );
            agent.active_modal = other;
            return vec![];
        }
    };

    // debug! level — per-keystroke logging would flood production.
    tracing::debug!(target: "settings", key, "opened reset-confirm modal");
    agent.active_modal = Some(ActiveModal::ResetSettingsConfirm {
        modal: ModalConfirmation::reset_settings(),
        key,
        settings_state,
    });
    vec![]
}

/// Resolve the reset-settings confirmation modal.
///
/// Both Reset and Cancel branches:
///   1. Take the `ResetSettingsConfirm` variant out of `active_modal`.
///   2. Restore `ActiveModal::Settings { state }` from the
///      preserved `settings_state` so the underlying modal is
///      visible again with its filter/scroll/selection intact.
///
/// Reset additionally:
///   3. Looks up the registered default for the target setting via
///      `crate::settings::default_value_for(meta)`.
///   4. If the current value already equals the default (idempotent
///      reset), shows an "Already at default" toast and skips dispatch.
///   5. Otherwise maps the default value to the matching typed
///      `Action::SetX(default)` via `action_for_reset` and dispatches
///      it recursively. The recursive dispatch runs the full set_X
///      pipeline (persist → toast → refresh open modal snapshots),
///      so the modal indicator reflects the new value on the next
///      frame.
///
/// **Why dispatch recursively rather than call `set_X(app, default)`
/// directly?** Each typed setter's `set_X(app, new)` function is
/// `fn` (not `pub fn`) — they're internal to dispatch.rs. The
/// alternative would be to either (a) expose every setter publicly,
/// or (b) duplicate the routing match here. Recursive dispatch is
/// the lowest-coupling option: when a new setting lands, the
/// `Action::SetX → set_X(app, v)` arm is added to dispatch's top-
/// level match (one line) AND an `action_for_reset` arm is added
/// (one line); no new public API surface. The recursion depth is
/// at most 2 `dispatch` frames.
pub(in crate::app::dispatch) fn dispatch_confirm_reset_setting(
    app: &mut AppView,
    choice: crate::views::modal::ResetSettingsResult,
) -> Vec<Effect> {
    use crate::views::modal::{ActiveModal, ResetSettingsResult};

    let ActiveView::Agent(id) = app.active_view else {
        return vec![];
    };
    let Some(agent) = app.agents.get_mut(&id) else {
        return vec![];
    };

    // Take the ResetSettingsConfirm modal out and restore Settings.
    // Take the ResetSettingsConfirm modal out and capture the
    // target key from the variant (single source of truth — the
    // Action does NOT carry the key, eliminating the desync risk
    // a future emitter could introduce).
    let prior = agent.active_modal.take();
    let (key, settings_state) = match prior {
        Some(ActiveModal::ResetSettingsConfirm {
            key,
            settings_state,
            ..
        }) => (key, settings_state),
        other => {
            debug_assert!(
                matches!(other, Some(ActiveModal::ResetSettingsConfirm { .. })),
                "ConfirmResetSetting dispatched without an open ResetSettingsConfirm modal — \
                 input routing bug",
            );
            agent.active_modal = other;
            return vec![];
        }
    };
    agent.active_modal = Some(ActiveModal::Settings {
        state: settings_state,
    });

    match choice {
        ResetSettingsResult::Cancel => {
            tracing::debug!(target: "settings", key, "reset confirmation cancelled");
            vec![]
        }
        ResetSettingsResult::Reset => {
            let registry_arc = app.settings_registry.clone();
            let Some(meta) = registry_arc.find(key) else {
                tracing::error!(
                    target: "settings",
                    key,
                    "reset target points at unregistered key — registry/dispatch skew",
                );
                return vec![];
            };
            let default_value = crate::settings::default_value_for(meta);

            // Gate idempotent reset: already-at-default → toast only.
            let pager_snapshot = build_pager_snapshot(app);
            let current_value =
                crate::settings::current_value_for(key, &app.current_ui, &pager_snapshot);
            if current_value.as_ref() == Some(&default_value) {
                tracing::debug!(
                    target: "settings",
                    key,
                    ?default_value,
                    "reset skipped — setting already at default",
                );
                with_active_agent(app, |agent| {
                    agent.show_toast(&format!("{}: already at default", meta.label));
                });
                return vec![];
            }

            let Some(action) = action_for_reset(key, &default_value) else {
                tracing::error!(
                    target: "settings",
                    key,
                    ?default_value,
                    "reset has no action_for_reset arm — registry/dispatch skew",
                );
                return vec![];
            };
            tracing::info!(
                target: "settings",
                key,
                ?default_value,
                "resetting setting to default",
            );
            // Recursive dispatch — runs the full set_X pipeline.
            // See the docstring above for why recursion is the
            // right tool here. Max depth: 2 dispatch frames.
            dispatch(action, app)
        }
    }
}

/// Toggle multiline input mode (Ctrl+M keybinding path). Delegates
/// to `set_multiline_mode` (PAGER-OWNED, per-agent ephemeral).
pub(in crate::app::dispatch) fn dispatch_toggle_multiline(app: &mut AppView) -> Vec<Effect> {
    let ActiveView::Agent(id) = app.active_view else {
        return vec![];
    };
    let Some(agent) = app.agents.get(&id) else {
        return vec![];
    };
    let new = !agent.multiline_mode;
    set_multiline_mode(app, new)
}

/// Toggle compact mode (keybinding path). Delegates to the
/// registry-driven `set_compact_mode` so the cache, modal snapshot,
/// and `Effect::PersistSetting` all flow through one path.
pub(in crate::app::dispatch) fn dispatch_toggle_compact_mode(app: &mut AppView) -> Vec<Effect> {
    // Toggle the USER value: `appearance.prompt.compact` is the derived render
    // value, which auto-compact forces on short terminals regardless of it.
    let new = !app.current_ui.compact_mode;
    set_compact_mode(app, new)
}

/// Toggle vim-style scrollback keybindings (`/vim-mode` slash command path).
///
/// When OFF (default): bare-letter and Shift+letter scrollback bindings
/// (j/k/h/l/g/G/y/Y/o/O/r/x/e/E/L/H plus the `i` FocusPrompt alt) are
/// suppressed; users get a "letter pressed in scrollback jumps to prompt
/// and types the character" behaviour instead. Arrow/Tab/Esc/Space/PgUp/
/// PgDn and all Ctrl+letter bindings remain active in both modes.
///
/// Delegates to the registry-driven `set_vim_mode` so the cache, modal
/// snapshot, toast, and `Effect::PersistSetting` (which writes
/// `[ui].vim_mode` to config.toml) all flow through one path — matching
/// the `dispatch_toggle_multiline` / `dispatch_toggle_compact_mode` /
/// `dispatch_toggle_timestamps` pattern.
pub(in crate::app::dispatch) fn dispatch_toggle_vim_mode(app: &mut AppView) -> Vec<Effect> {
    // Toggle the EFFECTIVE value (the pager cache) so `/vim-mode` works
    // from ANY view — including the session-less dashboard. Previously
    // this early-returned unless an agent was active, so running
    // `/vim-mode` on the dashboard was a silent no-op and the overview's
    // j/k navigation (which is gated on vim-mode) never turned on.
    let prev = crate::appearance::cache::load_vim_mode();
    let enabled = !prev;
    // Propagate to every agent AND every nested subagent view (so
    // background + open subagent views pick up the change without a
    // restart) and mirror the pager cache. Shares `set_vim_mode_inner`
    // with the `SetVimMode` settings path.
    set_vim_mode_inner(app, enabled);
    refresh_open_settings_modals(app);
    let msg = if enabled {
        "Vim mode: on"
    } else {
        "Vim mode: off"
    };
    tracing::info!(vim_mode = enabled, "Vim mode toggled");
    match app.active_view {
        ActiveView::Agent(id) => {
            if let Some(agent) = app.agents.get_mut(&id) {
                agent
                    .scrollback
                    .push_block(RenderBlock::system(msg.to_string()));
            }
        }
        ActiveView::AgentDashboard => {
            // On the dashboard, j/k navigate the overview only when it
            // holds focus. Turning vim ON focuses the overview so the
            // user can navigate immediately (mirroring the agent view's
            // "normal mode"); turning it OFF returns focus to the input.
            // No agents → nothing to navigate, so stay on the input. The
            // focus shift (overview highlighted, input dimmed, footer
            // flips to nav hints) is the feedback — a toast would route
            // to the dashboard's red error slot.
            let has_agents = !app.agents.is_empty();
            if let Some(d) = app.dashboard.as_mut() {
                d.list_focused = enabled && has_agents;
            }
        }
        _ => {
            app.show_toast(msg);
        }
    }
    // Persist like the shared setter so `/vim-mode` survives a restart
    // (writes `[ui].vim_mode` to config.toml).
    vec![Effect::PersistSetting {
        key: "vim_mode",
        value: crate::settings::SettingValue::Bool(enabled),
        rollback_value: crate::settings::SettingValue::Bool(prev),
    }]
}

/// Toggle timestamps (Ctrl+? keybinding path). Delegates to the
/// registry-driven `set_timestamps` so persistence + cache + UI
/// reconciliation all flow through a single code path.
pub(in crate::app::dispatch) fn dispatch_toggle_timestamps(app: &mut AppView) -> Vec<Effect> {
    let show = !app.appearance.show_timestamps;
    set_timestamps(app, show)
}

/// Toggle terminal mouse reporting (crossterm mouse capture) at the user's
/// discretion. Disabling it lets the terminal handle native click-drag text
/// selection and copy/paste; re-enabling restores in-app mouse handling
/// (click-to-focus, scrollback selection, scrollbar drag, etc.).
///
/// The on-wire enable/disable sequences mirror the auth-screen toggle in
/// [`AppView::draw`]; the process-wide [`MOUSE_CAPTURE_ENABLED`] atomic is
/// the single source of truth that teardown / panic paths read to decide
/// whether to emit the reset sequence.
///
/// [`MOUSE_CAPTURE_ENABLED`]: crate::app::MOUSE_CAPTURE_ENABLED
pub(in crate::app::dispatch) fn dispatch_toggle_mouse_capture(app: &mut AppView) {
    use std::sync::atomic::Ordering;

    let was_enabled = crate::app::MOUSE_CAPTURE_ENABLED.load(Ordering::Acquire);
    let enable = !was_enabled;
    crate::unified_log::info(
        "mouse_reporting_toggle.toggle",
        None,
        Some(serde_json::json!({
            "was_enabled": was_enabled,
            "now_enabled": enable,
            "active_view": format!("{:?}", app.active_view),
        })),
    );
    kigi_shell::util::with_locked_stderr(|stderr| {
        let _ = if enable {
            crossterm::execute!(stderr, crossterm::event::EnableMouseCapture)
        } else {
            crossterm::execute!(stderr, crossterm::event::DisableMouseCapture)
        };
    });
    // On legacy conhost, DisableMouseCapture restores the *pre-capture* stdin
    // mode, which may itself have QuickEdit off (per-window profile or a
    // stale mode from a crashed run) — assert it so "mouse off" actually
    // hands the terminal native drag-select, the whole point of the toggle.
    #[cfg(windows)]
    if !enable {
        crate::app::win_native_selection::enable_native_selection();
    }
    crate::app::MOUSE_CAPTURE_ENABLED.store(enable, Ordering::Release);
    // Use with_active_agent (not app.show_toast) so the toast lands on the
    // visible surface — same path as copy-to-clipboard toasts, including
    // when a subagent view is active.
    //
    // Off state: sticky banner on every agent/subagent view (capture is
    // process-wide; toast must survive subagent open/close and copy toasts).
    // On state: clear sticky everywhere + transient confirmation on active view.
    // Stored in the scrollback form; `AgentView::active_toast_message` swaps it
    // to the `/toggle-mouse-reporting` form at render time when the prompt is
    // focused (Ctrl+R only re-enables from scrollback).
    let mut toast_applied = false;
    if enable {
        for agent in app.agents.values_mut() {
            agent.set_sticky_toast_recursive(None);
        }
        with_active_agent(app, |agent| {
            toast_applied = true;
            agent.show_toast("Mouse reporting on");
        });
    } else {
        for agent in app.agents.values_mut() {
            agent.set_sticky_toast_recursive(Some(crate::app::MOUSE_OFF_HINT_SCROLLBACK));
            toast_applied = true;
        }
    }
    crate::unified_log::info(
        "mouse_reporting_toggle.toggle_done",
        None,
        Some(serde_json::json!({
            "now_enabled": enable,
            "toast_applied": toast_applied,
        })),
    );
}

/// Helper to read the active agent's `multiline_mode` for the
/// pager-local snapshot used in idempotent-reset detection. Returns
/// `false` if no active agent (no Settings modal would be open in
/// that state, so the value doesn't matter — but the helper has to
/// return SOMETHING).
fn agent_multiline_mode(app: &AppView) -> bool {
    if let ActiveView::Agent(id) = app.active_view
        && let Some(agent) = app.agents.get(&id)
    {
        return agent.multiline_mode;
    }
    false
}

/// Helper to read the active agent's `yolo_mode`. See
/// [`agent_multiline_mode`] for the no-agent fallback rationale.
fn agent_yolo_mode(app: &AppView) -> bool {
    if let ActiveView::Agent(id) = app.active_view
        && let Some(agent) = app.agents.get(&id)
    {
        return agent.session.is_yolo();
    }
    false
}

/// Helper to read the active agent's `auto_mode`. See
/// [`agent_multiline_mode`] for the no-agent fallback rationale.
fn agent_auto_mode(app: &AppView) -> bool {
    if let ActiveView::Agent(id) = app.active_view
        && let Some(agent) = app.agents.get(&id)
    {
        return agent.session.is_auto();
    }
    false
}

/// Effective `plan_mode` for the active agent
/// (`pending.unwrap_or(active)`).
fn agent_plan_mode(app: &AppView) -> bool {
    if let ActiveView::Agent(id) = app.active_view
        && let Some(agent) = app.agents.get(&id)
    {
        return agent.plan_mode_pending.unwrap_or(agent.plan_mode_active);
    }
    false
}

/// Helper to read the active agent's currently-selected model
/// display name. Returns `None` when no agent is active OR when the
/// catalog hasn't loaded yet (e.g. early startup). See
/// [`agent_multiline_mode`] for the no-agent fallback rationale.
///
/// Used by the `default_model` row's `current_value_for`.
fn agent_current_model_name(app: &AppView) -> Option<String> {
    if let ActiveView::Agent(id) = app.active_view
        && let Some(agent) = app.agents.get(&id)
    {
        return agent.session.models.current_model_name();
    }
    None
}

/// Helper to clone the `(display_name, ModelId)` pairs from the
/// active agent's catalog. Returns an empty `Vec` when no agent is
/// active OR when the catalog is empty.
///
/// Used by the `KnownModel` validator and "resolve user input to
/// ModelId" path.
fn agent_available_models(app: &AppView) -> Vec<(String, acp::ModelId)> {
    if let ActiveView::Agent(id) = app.active_view
        && let Some(agent) = app.agents.get(&id)
    {
        return agent
            .session
            .models
            .available
            .iter()
            .map(|(id, info)| (info.name.clone(), id.clone()))
            .collect();
    }
    Vec::new()
}

/// Build a `PagerLocalSnapshot` from the current `AppView`.
pub(crate) fn build_pager_snapshot(app: &AppView) -> crate::settings::PagerLocalSnapshot {
    crate::settings::PagerLocalSnapshot {
        multiline_mode: agent_multiline_mode(app),
        yolo_mode: agent_yolo_mode(app),
        auto_mode: agent_auto_mode(app),
        current_model_name: agent_current_model_name(app),
        available_models: agent_available_models(app),
        plan_mode_active: agent_plan_mode(app),
        show_tips: app.show_tips,
        auto_update: app.auto_update,
        vim_mode: crate::appearance::cache::load_vim_mode(),
        scroll_speed: crate::appearance::cache::load_scroll_speed(),
        respect_manual_folds: app.appearance.scrollback.scroll.respect_manual_folds,
        auto_mode_gate: app.auto_mode_gate,
        ask_user_question_timeout_enabled: app.ask_user_question_timeout_enabled,
    }
}

/// Map a `(SettingKey, SettingValue)` to the matching typed
/// `Action::SetX(value)`. Used by the reset path to turn the
/// registered default into a dispatchable Action. CI test
/// `every_setting_has_action_for_reset_arm` pins correctness.
pub(in crate::app::dispatch) fn action_for_reset(
    key: crate::settings::SettingKey,
    value: &crate::settings::SettingValue,
) -> Option<Action> {
    use crate::settings::SettingValue;
    match (key, value) {
        ("compact_mode", SettingValue::Bool(b)) => Some(Action::SetCompactMode(*b)),
        ("show_timestamps", SettingValue::Bool(b)) => Some(Action::SetTimestamps(*b)),
        ("show_timeline", SettingValue::Bool(b)) => Some(Action::SetTimeline(*b)),
        ("simple_mode", SettingValue::Bool(b)) => Some(Action::SetSimpleMode(*b)),
        ("contextual_hints.undo", SettingValue::Bool(b)) => Some(Action::SetContextualHintUndo(*b)),
        ("contextual_hints.plan_mode", SettingValue::Bool(b)) => {
            Some(Action::SetContextualHintPlanMode(*b))
        }
        ("contextual_hints.image_input", SettingValue::Bool(b)) => {
            Some(Action::SetContextualHintImageInput(*b))
        }
        ("contextual_hints.send_now", SettingValue::Bool(b)) => {
            Some(Action::SetContextualHintSendNow(*b))
        }
        ("contextual_hints.small_screen", SettingValue::Bool(b)) => {
            Some(Action::SetContextualHintSmallScreen(*b))
        }
        ("contextual_hints.word_select", SettingValue::Bool(b)) => {
            Some(Action::SetContextualHintWordSelect(*b))
        }
        ("multiline_mode", SettingValue::Bool(b)) => Some(Action::SetMultilineMode(*b)),
        ("render_mermaid", SettingValue::Enum(s)) => {
            crate::appearance::RenderMermaid::from_canonical(s).map(Action::SetRenderMermaid)
        }
        ("vim_mode", SettingValue::Bool(b)) => Some(Action::SetVimMode(*b)),
        ("remember_tool_approvals", SettingValue::Bool(b)) => {
            Some(Action::SetRememberToolApprovals(*b))
        }
        ("toolset.ask_user_question.timeout_enabled", SettingValue::Bool(b)) => {
            Some(Action::SetAskUserQuestionTimeoutEnabled(*b))
        }
        ("keep_text_selection", SettingValue::Enum(s)) => {
            crate::appearance::TextSelection::from_canonical(s).map(Action::SetKeepTextSelection)
        }
        ("scroll_speed", SettingValue::Int(v)) => Some(Action::SetScrollSpeed(*v)),
        ("scroll_mode", SettingValue::Enum(s)) => {
            crate::appearance::ScrollMode::from_canonical(s).map(Action::SetScrollMode)
        }
        ("invert_scroll", SettingValue::Bool(b)) => Some(Action::SetInvertScroll(*b)),
        ("scroll_lines", SettingValue::Int(v)) => Some(Action::SetScrollLines(*v)),
        ("show_thinking_blocks", SettingValue::Bool(b)) => Some(Action::SetShowThinkingBlocks(*b)),
        ("group_tool_verbs", SettingValue::Bool(b)) => Some(Action::SetGroupToolVerbs(*b)),
        ("collapsed_edit_blocks", SettingValue::Bool(b)) => {
            Some(Action::SetCollapsedEditBlocks(*b))
        }
        ("prompt_suggestions", SettingValue::Bool(b)) => Some(Action::SetPromptSuggestions(*b)),
        ("respect_manual_folds", SettingValue::Bool(b)) => Some(Action::SetRespectManualFolds(*b)),
        ("default_selected_permission", SettingValue::Enum(s)) => {
            Some(Action::SetDefaultSelectedPermission((*s).to_owned()))
        }
        ("theme", SettingValue::Enum(s)) => Some(Action::SetTheme((*s).to_owned())),
        ("auto_dark_theme", SettingValue::Enum(s)) => {
            Some(Action::SetAutoDarkTheme((*s).to_owned()))
        }
        ("auto_light_theme", SettingValue::Enum(s)) => {
            Some(Action::SetAutoLightTheme((*s).to_owned()))
        }
        // Three explicit arms, one per
        // canonical, all dispatched through the typed
        // `Action::SetPermissionMode(kind)` (NOT the legacy
        // `Action::SetYoloMode(bool)`). The reset path IS modal-
        // initiated (the `d` reset key is part of the
        // settings modal), so it falls under the same "modal commit
        // ↦ typed setter" rule as the picker Enter path.
        //
        // **Why all three arms (not just "ask").** The registered
        // default is "ask" today (defs.rs:`SettingKind::Enum { default:
        // "ask", ... }`), so only the "ask" arm is reachable in
        // production through the normal reset flow. The other two
        // arms exist as forcing functions:
        //   - If the registered default changes to
        //     "default" or "always-approve", the matching arm fires
        //     correctly — no silent collapse onto SetYoloMode.
        //   - The arms exercise the same canonical→kind mapping that
        //     `action_for_enum_commit` uses, so the dispatch surface
        //     stays consistent across modal entry points.
        //
        // The drift guard
        // `pr11_permission_mode_kind_canonical_strings_match_choices_catalog`
        // pins `len == 3` on `PERMISSION_MODE_CHOICES`, so a future
        // 4th canonical without a matching arm here would fail the
        // catalog drift test (the registered default would still be
        // one of the existing arms — but a fresh test
        // `pr11_action_for_reset_covers_every_permission_mode_canonical`
        // pins exhaustivity directly).
        ("permission_mode", SettingValue::Enum("always-approve")) => Some(
            Action::SetPermissionMode(crate::app::actions::PermissionModeKind::AlwaysApprove),
        ),
        ("permission_mode", SettingValue::Enum("ask")) => Some(Action::SetPermissionMode(
            crate::app::actions::PermissionModeKind::Ask,
        )),
        ("permission_mode", SettingValue::Enum("auto")) => Some(Action::SetPermissionMode(
            crate::app::actions::PermissionModeKind::Auto,
        )),
        ("permission_mode", SettingValue::Enum("default")) => Some(Action::SetPermissionMode(
            crate::app::actions::PermissionModeKind::Default,
        )),
        // default_model: empty string → ClearDefaultModel; non-empty
        // is a registry/dispatch skew guard.
        ("default_model", SettingValue::String(s)) => {
            if s.is_empty() {
                Some(Action::ClearDefaultModel)
            } else {
                tracing::error!(
                    target: "settings",
                    value = %s,
                    "action_for_reset(default_model) received non-empty default — \
                     registry/dispatch skew (default should be empty string)",
                );
                None
            }
        }
        // max_thoughts_width: direct round-trip.
        ("max_thoughts_width", SettingValue::Int(i)) => Some(Action::SetMaxThoughtsWidth(*i)),
        // plan_mode: "on" / "off" → PlanModeKind.
        // "on" arm is a skew guard (default is "off").
        ("plan_mode", SettingValue::Enum("off")) => {
            Some(Action::SetPlanMode(crate::app::actions::PlanModeKind::Off))
        }
        ("plan_mode", SettingValue::Enum("on")) => {
            Some(Action::SetPlanMode(crate::app::actions::PlanModeKind::On))
        }
        // show_tips / auto_update / display_refresh_auto_cadence: direct bool.
        ("show_tips", SettingValue::Bool(b)) => Some(Action::SetShowTips(*b)),
        ("auto_update", SettingValue::Bool(b)) => Some(Action::SetAutoUpdate(*b)),
        ("display_refresh_auto_cadence", SettingValue::Bool(b)) => {
            Some(Action::SetDisplayRefreshAutoCadence(*b))
        }
        // hunk_tracker_mode: canonical enum string round-trip.
        ("hunk_tracker_mode", SettingValue::Enum(s)) => {
            Some(Action::SetHunkTrackerMode((*s).to_string()))
        }
        ("screen_mode", SettingValue::Enum(s)) => Some(Action::SetScreenMode((*s).to_string())),
        // fork_secondary_model: empty → Clear, non-empty is skew guard.
        ("fork_secondary_model", SettingValue::String(s)) => {
            if s.is_empty() {
                Some(Action::ClearForkSecondaryModel)
            } else {
                tracing::error!(
                    target: "settings",
                    value = %s,
                    "action_for_reset(fork_secondary_model) received non-empty default — \
                     registry/dispatch skew (default should be empty string)",
                );
                None
            }
        }

        _ => None,
    }
}

/// Toast shown by the [`apply_setting_rollback`] catch-all when a persisted
/// setting has no rollback arm. Shared with `every_persisting_setting_has_rollback_arm`
/// so the guard can't be silently defeated by a wording edit.
pub(crate) const ROLLBACK_NO_ARM_TOAST: &str =
    "Settings rolled back, but local state may be out of sync — restart to reload";

/// Apply a rollback `SettingValue` to the in-memory cache. Does NOT
/// re-emit `PersistSetting` (avoids infinite loop on persistent
/// failure). Can emit companion effects (e.g. reverse `SwitchModel`).
///
/// New settings MUST add an arm here. Unknown keys log `error!` — the
/// silent data-vs-disk inconsistency is visible to the user.
pub(in crate::app::dispatch) fn apply_setting_rollback(
    app: &mut AppView,
    key: crate::settings::SettingKey,
    rollback_value: &crate::settings::SettingValue,
) -> Vec<Effect> {
    use crate::settings::SettingValue;
    let companion_effects: Vec<Effect> = Vec::new();
    match (key, rollback_value) {
        ("compact_mode", SettingValue::Bool(b)) => set_compact_mode_inner(app, *b),
        ("show_timestamps", SettingValue::Bool(b)) => set_timestamps_inner(app, *b),
        ("show_timeline", SettingValue::Bool(b)) => set_timeline_inner(app, *b),
        ("simple_mode", SettingValue::Bool(b)) => set_simple_mode_inner(app, *b),
        ("contextual_hints.undo", SettingValue::Bool(b)) => {
            set_contextual_hint_inner(app, |h, v| h.undo = v, *b)
        }
        ("contextual_hints.plan_mode", SettingValue::Bool(b)) => {
            set_contextual_hint_inner(app, |h, v| h.plan_mode = v, *b)
        }
        ("contextual_hints.image_input", SettingValue::Bool(b)) => {
            set_contextual_hint_inner(app, |h, v| h.image_input = v, *b)
        }
        ("contextual_hints.send_now", SettingValue::Bool(b)) => {
            set_contextual_hint_inner(app, |h, v| h.send_now = v, *b)
        }
        ("contextual_hints.small_screen", SettingValue::Bool(b)) => {
            set_contextual_hint_inner(app, |h, v| h.small_screen = v, *b)
        }
        ("contextual_hints.word_select", SettingValue::Bool(b)) => {
            set_contextual_hint_inner(app, |h, v| h.word_select = v, *b)
        }
        ("respect_manual_folds", SettingValue::Bool(b)) => set_respect_manual_folds_inner(app, *b),
        ("theme", SettingValue::Enum(s)) => set_theme_inner(app, s),
        ("default_selected_permission", SettingValue::Enum(s)) => {
            set_default_selected_permission_inner(
                app,
                crate::appearance::permission_cursor::DefaultSelectedPermission::from_config_value(
                    s,
                ),
            )
        }
        ("cancel_subagents_on_turn_cancel", SettingValue::Enum("ask")) => {
            app.current_ui.cancel_subagents_on_turn_cancel = None;
            for agent in app.agents.values_mut() {
                agent.cancel_subagents_preference = None;
            }
        }
        ("cancel_subagents_on_turn_cancel", SettingValue::Enum("always_stop")) => {
            apply_cancel_subagents_preference_global(app, true);
        }
        ("cancel_subagents_on_turn_cancel", SettingValue::Enum("always_continue")) => {
            apply_cancel_subagents_preference_global(app, false);
        }
        // Rollback for corrupted auto-* = "auto" — clear to None.
        ("auto_dark_theme", SettingValue::Enum("auto")) => {
            app.current_ui.auto_dark_theme = None;
            crate::theme::cache::invalidate_auto_theme_config();
            tracing::warn!(
                target: "settings",
                key = "auto_dark_theme",
                "rolled back to `auto` (invalid) — cleared in-memory override to None",
            );
        }
        ("auto_light_theme", SettingValue::Enum("auto")) => {
            app.current_ui.auto_light_theme = None;
            crate::theme::cache::invalidate_auto_theme_config();
            tracing::warn!(
                target: "settings",
                key = "auto_light_theme",
                "rolled back to `auto` (invalid) — cleared in-memory override to None",
            );
        }
        ("auto_dark_theme", SettingValue::Enum(s)) => set_auto_dark_theme_inner(app, s),
        ("auto_light_theme", SettingValue::Enum(s)) => set_auto_light_theme_inner(app, s),
        // permission_mode rollback: recover kind from canonical,
        // run inner, then restore the canonical the inner collapsed.
        ("permission_mode", SettingValue::Enum(s)) => {
            use crate::app::actions::PermissionModeKind;
            let kind = match PermissionModeKind::from_canonical(s) {
                Some(k) => k,
                None => {
                    tracing::warn!(
                        target: "settings",
                        key = "permission_mode",
                        value = *s,
                        "rollback received unknown canonical — defaulting to `ask`",
                    );
                    PermissionModeKind::Ask
                }
            };
            set_yolo_mode_inner(app, kind.is_always_approve());
            // Restore canonical (meaningful for `Default`).
            app.current_ui.permission_mode = Some(kind.as_canonical().to_string());
            // Sync the per-session auto flag ONLY for a permission_mode rollback;
            // other rollback arms must not clobber it from the global canonical.
            sync_active_auto_flag(app);
        }
        // default_model: deliberately NO revert. The session switch already
        // succeeded independently (its own failure path reports via
        // `handle_switch_model_complete`); this arm fires when only the
        // DISK write of the next-launch default failed — which must not
        // undo a working switch. Same policy as `PersistPreferredModel`
        // ("still active for this session"). Regression: reverting here
        // (plus a reverse SwitchModel) made every picker selection appear
        // to not take on Windows, where AV/indexer file locks routinely
        // fail config.toml persists.
        ("default_model", SettingValue::String(prior)) => {
            tracing::warn!(
                target: "settings",
                key = "default_model",
                prior = %prior,
                "default-model persist failed; keeping the live session's \
                 model (the switch succeeded) — only the next-launch \
                 default is unsaved",
            );
        }
        // max_thoughts_width: direct inner call.
        ("max_thoughts_width", SettingValue::Int(i)) => set_max_thoughts_width_inner(app, *i),
        // scroll_speed: direct inner call (clamp handled by inner).
        ("scroll_speed", SettingValue::Int(i)) => set_scroll_speed_inner(app, *i as u8),
        // scroll_mode: restore the cache mirror to the canonical value.
        ("scroll_mode", SettingValue::Enum(s)) => {
            if let Some(mode) = crate::appearance::ScrollMode::from_canonical(s) {
                set_scroll_mode_inner(app, mode);
            }
        }
        // invert_scroll / scroll_lines: direct inner calls (clamp in inner).
        ("invert_scroll", SettingValue::Bool(b)) => set_invert_scroll_inner(app, *b),
        // Effective default is false → restore None (mirror stays disk-synced).
        ("display_refresh_auto_cadence", SettingValue::Bool(b)) => {
            if !*b {
                app.current_ui.display_refresh.auto_cadence_enabled = None;
            } else {
                set_display_refresh_auto_cadence_inner(app, *b);
            }
        }
        ("scroll_lines", SettingValue::Int(i)) => set_scroll_lines_inner(app, *i as u8),
        // vim_mode: direct inner call.
        ("vim_mode", SettingValue::Bool(b)) => set_vim_mode_inner(app, *b),
        ("remember_tool_approvals", SettingValue::Bool(b)) => {
            set_remember_tool_approvals_inner(app, *b)
        }
        // ask_user_question timeout: if rollback equals the effective
        // default, restore to None (keeps mirror in sync with disk).
        ("toolset.ask_user_question.timeout_enabled", SettingValue::Bool(b)) => {
            if Some(*b) == pr13_effective_default("toolset.ask_user_question.timeout_enabled") {
                app.ask_user_question_timeout_enabled = None;
            } else {
                set_ask_user_question_timeout_enabled_inner(app, *b);
            }
        }
        ("show_thinking_blocks", SettingValue::Bool(b)) => set_show_thinking_blocks_inner(app, *b),
        ("group_tool_verbs", SettingValue::Bool(b)) => set_group_tool_verbs_inner(app, *b),
        ("collapsed_edit_blocks", SettingValue::Bool(b)) => {
            set_collapsed_edit_blocks_inner(app, *b)
        }
        ("prompt_suggestions", SettingValue::Bool(b)) => set_prompt_suggestions_inner(app, *b),
        // keep_text_selection: restore the cache mirror to the canonical value.
        ("keep_text_selection", SettingValue::Enum(s)) => {
            if let Some(kind) = crate::appearance::TextSelection::from_canonical(s) {
                set_keep_text_selection_inner(kind);
            }
        }
        // render_mermaid: restore the cache mirror to the canonical value.
        ("render_mermaid", SettingValue::Enum(s)) => {
            if let Some(kind) = crate::appearance::RenderMermaid::from_canonical(s) {
                set_render_mermaid_inner(kind);
            }
        }
        // hunk_tracker_mode: restore the in-memory ui mirror.
        ("hunk_tracker_mode", SettingValue::Enum(s)) => {
            set_hunk_tracker_mode_inner(app, crate::settings::canonical_hunk_tracker_mode(Some(s)));
        }
        ("screen_mode", SettingValue::Enum(s)) => {
            set_screen_mode_inner(app, crate::settings::canonical_screen_mode(Some(s)));
        }
        // show_tips / auto_update: if rollback equals the effective
        // default, restore to None (keeps mirror in sync with disk).
        ("show_tips", SettingValue::Bool(b)) => {
            if Some(*b) == pr13_effective_default("show_tips") {
                app.show_tips = None;
            } else {
                set_show_tips_inner(app, *b);
            }
        }
        ("auto_update", SettingValue::Bool(b)) => {
            if Some(*b) == pr13_effective_default("auto_update") {
                app.auto_update = None;
            } else {
                set_auto_update_inner(app, *b);
            }
        }
        // fork_secondary_model: empty rollback restores baseline default.
        ("fork_secondary_model", SettingValue::String(s)) => {
            let restored = if s.is_empty() {
                kigi_shell::models::default_model().to_string()
            } else {
                s.clone()
            };
            set_fork_secondary_model_inner(app, restored);
        }

        _ => {
            tracing::error!(
                target: "settings",
                ?key,
                ?rollback_value,
                "rollback path has no arm for this setting key; in-memory cache is now \
                 inconsistent with the on-disk state (which already failed to write)"
            );
            app.show_toast(ROLLBACK_NO_ARM_TOAST);
            return companion_effects;
        }
    }
    // Refresh modal snapshots after rollback.
    refresh_open_settings_modals(app);
    companion_effects
}