cargo-port 0.1.1

use std::path::Path;

#[cfg(test)]
use crossterm::event::KeyEvent;
use tui_pane::FocusedPane;
use tui_pane::FrameworkFocusId;
#[cfg(test)]
use tui_pane::KeyBind as TuiKeyBind;
use tui_pane::TrackedItem;
use tui_pane::Viewport;

use super::BuildMode;
use super::CargoGroup;
use super::CiFetchKind;
use super::GitRow;
use super::PackageRow;
use super::PaneId;
use super::PendingCiFetch;
use super::PendingExampleRun;
use super::RunningListRow;
use super::TargetsData;
use super::build_running_list;
use super::build_running_rows;
use super::build_target_list_from_data;
use super::outline_subtree_len;
use super::resolve_kill_request;
use crate::lint;
use crate::project;
use crate::project::AbsolutePath;
use crate::project::ProjectCiData;
use crate::project::ProjectCiInfo;
use crate::scan;
use crate::tui::app::App;
use crate::tui::app::CiRunDisplayMode;
use crate::tui::app::CleanSelection;
use crate::tui::input;
use crate::tui::integration;
use crate::tui::integration::AppPaneId;
use crate::tui::integration::NavAction;
use crate::tui::keymap::CiRunsAction;
use crate::tui::keymap::GitAction;
#[cfg(test)]
use crate::tui::keymap::KeyBind;
use crate::tui::keymap::LintsAction;
use crate::tui::keymap::PackageAction;
use crate::tui::keymap::TargetsAction;
use crate::tui::render;

fn handle_target_action(app: &mut App, mode: BuildMode) {
    let Some(targets_data) = app.panes.targets.content().cloned() else {
        return;
    };
    let entries = build_target_list_from_data(&targets_data);
    // The table's rows map 1:1 to entries; a highlight in the Running box
    // sits past them and runs nothing.
    if let Some(entry) = entries.get(app.panes.targets.viewport.pos()) {
        app.inflight.set_pending_example_run(PendingExampleRun {
            abs_path:          entry.project_path.display().to_string(),
            target_name:       entry.name.clone(),
            package_name:      Some(entry.package_name.clone()),
            kind:              entry.kind,
            build_mode:        mode,
            required_features: entry.required_features.clone(),
        });
    }
}

pub(super) fn dispatch_package_action(action: PackageAction, app: &mut App) {
    match action {
        PackageAction::Activate => handle_detail_enter(app),
    }
}

pub(super) fn dispatch_git_action(action: GitAction, app: &mut App) {
    match action {
        GitAction::Activate => handle_detail_enter(app),
    }
}

pub(super) fn dispatch_targets_action(action: TargetsAction, app: &mut App) {
    match action {
        TargetsAction::Activate => handle_detail_enter(app),
        TargetsAction::ReleaseBuild => handle_target_action(app, BuildMode::Release),
        TargetsAction::Kill => handle_target_kill(app),
    }
}

/// Open a confirm dialog to `SIGTERM` the running instance under the
/// selected Running row. A no-op while the highlight is on a table row
/// or the `cargo` group header — per-instance kill only exists on
/// instance rows in the Running box.
fn handle_target_kill(app: &mut App) {
    let table_len = targets_table_len(app);
    let running_rows = build_running_rows(app.panes.running_targets.snapshot());
    let list = build_running_list(
        &running_rows,
        app.panes.targets.cargo_group(),
        app.panes.targets.expanded_parents(),
    );
    let request = resolve_kill_request(
        table_len,
        &running_rows,
        &list,
        app.panes.targets.viewport.pos(),
    );
    if let Some(request) = request {
        app.request_kill_confirm(request.label, request.pid, request.create_time);
    }
}

/// The Targets table's row count — zero when the selected project has no
/// targets (the Running list still renders below the empty table).
fn targets_table_len(app: &App) -> usize {
    app.panes
        .targets
        .content()
        .map_or(0, TargetsData::target_count)
}

/// The Running-list row under the highlight — `None` while the highlight
/// is in the table or past the list's end.
fn running_row_under_highlight(app: &App) -> Option<RunningListRow> {
    let table_len = targets_table_len(app);
    let running_rows = build_running_rows(app.panes.running_targets.snapshot());
    let list = build_running_list(
        &running_rows,
        app.panes.targets.cargo_group(),
        app.panes.targets.expanded_parents(),
    );
    app.panes
        .targets
        .viewport
        .pos()
        .checked_sub(table_len)
        .and_then(|local| list.get(local).copied())
}

/// The `cargo` group's state while the highlight sits on its header row —
/// `None` anywhere else.
fn cargo_header_under_highlight(app: &App) -> Option<CargoGroup> {
    matches!(
        running_row_under_highlight(app)?,
        RunningListRow::CargoHeader { .. }
    )
    .then(|| app.panes.targets.cargo_group())
}

/// Toggle the Running list's `cargo` group when the highlight sits on its
/// header row. Returns whether the toggle consumed the `Enter`.
fn toggle_cargo_group(app: &mut App) -> bool {
    let on_header = cargo_header_under_highlight(app).is_some();
    if on_header {
        app.panes.targets.toggle_cargo_group();
    }
    on_header
}

/// `Right` on the collapsed `cargo` header expands the group — the same
/// key the project list's rows expand with. Returns whether it consumed
/// the move.
fn expand_cargo_group(app: &mut App) -> bool {
    let on_collapsed_header = matches!(
        cargo_header_under_highlight(app),
        Some(CargoGroup::Collapsed)
    );
    if on_collapsed_header {
        app.panes.targets.toggle_cargo_group();
    }
    on_collapsed_header
}

/// `Left` collapses the `cargo` group: on its expanded header directly,
/// and on a grouped instance row by handing the highlight back to the
/// header — the project list's collapse idiom. Returns whether it
/// consumed the move.
fn collapse_cargo_group(app: &mut App) -> bool {
    if matches!(
        cargo_header_under_highlight(app),
        Some(CargoGroup::Expanded)
    ) {
        app.panes.targets.toggle_cargo_group();
        return true;
    }
    let table_len = targets_table_len(app);
    let running_rows = build_running_rows(app.panes.running_targets.snapshot());
    let list = build_running_list(
        &running_rows,
        app.panes.targets.cargo_group(),
        app.panes.targets.expanded_parents(),
    );
    let Some(RunningListRow::CargoHeader { count }) = list.first().copied() else {
        return false;
    };
    let on_grouped_instance = app
        .panes
        .targets
        .viewport
        .pos()
        .checked_sub(table_len)
        .and_then(|local| list.get(local))
        .is_some_and(|row| matches!(row, RunningListRow::Instance(i) if *i < count));
    if on_grouped_instance {
        app.panes.targets.toggle_cargo_group();
        app.panes.targets.viewport.set_pos(table_len);
        app.panes.targets.set_running_cursor_pid(None);
    }
    on_grouped_instance
}

/// The outline parent under the highlight — a Running instance row with
/// sub-process children — as `(row_index, pid)`. `None` on leaves, the
/// `cargo` header, and table rows.
fn outline_parent_under_highlight(app: &App) -> Option<(usize, u32)> {
    let RunningListRow::Instance(index) = running_row_under_highlight(app)? else {
        return None;
    };
    let running_rows = build_running_rows(app.panes.running_targets.snapshot());
    (outline_subtree_len(&running_rows, index) > 0)
        .then(|| running_rows.get(index).map(|row| (index, row.pid)))
        .flatten()
}

/// Toggle the outline parent under the highlight between expanded and
/// collapsed. Returns whether the toggle consumed the `Enter`.
fn toggle_running_parent(app: &mut App) -> bool {
    let Some((_, pid)) = outline_parent_under_highlight(app) else {
        return false;
    };
    app.panes.targets.toggle_expanded_parent(pid);
    true
}

/// `Right` on a collapsed outline parent expands its subtree — the same
/// key the project list's rows expand with. Returns whether it consumed
/// the move.
fn expand_running_parent(app: &mut App) -> bool {
    let Some((_, pid)) = outline_parent_under_highlight(app) else {
        return false;
    };
    let collapsed = !app.panes.targets.expanded_parents().contains(&pid);
    if collapsed {
        app.panes.targets.toggle_expanded_parent(pid);
    }
    collapsed
}

/// `Left` collapses the outline: on an expanded parent directly, and on a
/// row inside a parent's subtree by collapsing that parent and handing it
/// the highlight — the project list's collapse idiom. Returns whether it
/// consumed the move.
fn collapse_running_parent(app: &mut App) -> bool {
    if let Some((_, pid)) = outline_parent_under_highlight(app)
        && app.panes.targets.expanded_parents().contains(&pid)
    {
        app.panes.targets.collapse_parent(pid);
        return true;
    }
    let Some(RunningListRow::Instance(index)) = running_row_under_highlight(app) else {
        return false;
    };
    let running_rows = build_running_rows(app.panes.running_targets.snapshot());
    let Some(parent_pid) = running_rows.get(index).and_then(|row| row.parent_pid) else {
        return false;
    };
    let Some(parent_index) = running_rows.iter().position(|row| row.pid == parent_pid) else {
        return false;
    };
    app.panes.targets.collapse_parent(parent_pid);
    // The child row is gone from the list; hand the highlight to the
    // now-collapsed parent.
    let list = build_running_list(
        &running_rows,
        app.panes.targets.cargo_group(),
        app.panes.targets.expanded_parents(),
    );
    if let Some(list_index) = list
        .iter()
        .position(|row| matches!(row, RunningListRow::Instance(i) if *i == parent_index))
    {
        let table_len = targets_table_len(app);
        app.panes.targets.viewport.set_pos(table_len + list_index);
        app.panes.targets.set_running_cursor_pid(Some(parent_pid));
    }
    true
}

/// Send `SIGTERM` to the confirmed instance — verified against its create
/// time immediately before the signal — and drop it from the running
/// snapshot so its row collapses on the next render. The highlight's PID
/// anchor hands the cursor to the adjacent Running row (or back into the
/// table) on that render.
pub(super) fn execute_target_kill(app: &mut App, pid: u32, create_time: u64) {
    app.panes.running_targets.kill(pid, create_time);
    app.panes.running_targets.drop_instances(&[pid]);
}

/// Re-derive the Running-box PID anchor from the row the highlight sits
/// on (D2). Called after every user-driven cursor move (navigation,
/// click, wheel); the render pass then follows the anchored instance as
/// the Running rows reorder between moves. The `cargo` group header has
/// no PID — it anchors by its stable list position instead.
pub(super) fn sync_running_cursor_pid(app: &mut App) {
    let table_len = app
        .panes
        .targets
        .content()
        .map_or(0, TargetsData::target_count);
    let running_rows = build_running_rows(app.panes.running_targets.snapshot());
    let list = build_running_list(
        &running_rows,
        app.panes.targets.cargo_group(),
        app.panes.targets.expanded_parents(),
    );
    let pid = app
        .panes
        .targets
        .viewport
        .pos()
        .checked_sub(table_len)
        .and_then(|local| list.get(local))
        .and_then(|row| match row {
            RunningListRow::Instance(index) => running_rows.get(*index).map(|r| r.pid),
            RunningListRow::CargoHeader { .. } => None,
        });
    app.panes.targets.set_running_cursor_pid(pid);
}

pub(super) fn dispatch_lints_action(action: LintsAction, app: &mut App) {
    match action {
        LintsAction::Activate => open_lint_run_output(app),
        LintsAction::ClearHistory => clear_lint_history(app),
    }
}

pub(super) fn dispatch_ci_runs_action(action: CiRunsAction, app: &mut App) {
    match action {
        CiRunsAction::Activate => handle_ci_enter(app),
        CiRunsAction::FetchMore => handle_ci_fetch_more(app),
        CiRunsAction::ShowBranch => set_ci_display_mode(app, CiRunDisplayMode::BranchOnly),
        CiRunsAction::ShowAll => set_ci_display_mode(app, CiRunDisplayMode::All),
        CiRunsAction::ClearCache => {
            if let Some(path) = app.project_list.selected_ci_path() {
                clear_ci_cache(app, &path);
            }
        },
    }
}

fn set_ci_display_mode(app: &mut App, mode: CiRunDisplayMode) {
    if let Some(path) = app
        .project_list
        .selected_project_path()
        .map(Path::to_path_buf)
    {
        app.set_ci_display_mode_for(&path, mode);
    }
}

pub(super) fn dispatch_navigation_action(
    action: NavAction,
    focused: FocusedPane<AppPaneId>,
    app: &mut App,
) {
    let edge_advance = edge_scroll_probe(action, focused, app);

    match focused {
        FocusedPane::App(AppPaneId::ProjectList) => navigate_project_list(app, action),
        FocusedPane::App(AppPaneId::Package) => navigate_package_detail(app, action),
        FocusedPane::App(AppPaneId::Lang | AppPaneId::Cpu | AppPaneId::Git) => {
            navigate_detail(app, action);
        },
        FocusedPane::App(AppPaneId::Targets) => navigate_targets(app, action),
        FocusedPane::App(AppPaneId::Lints) => navigate_lints(app, action),
        FocusedPane::App(AppPaneId::CiRuns) => navigate_ci_runs(app, action),
        FocusedPane::App(AppPaneId::Output) => navigate_output(app, action),
        FocusedPane::App(AppPaneId::Finder) => {},
        FocusedPane::Framework(FrameworkFocusId::Toasts) => navigate_toasts(app, action),
    }

    // When the cursor could not move — the list was already at its edge —
    // roll focus to the adjacent pane in tab order instead of stopping.
    if let Some((advance, cursor_before)) = edge_advance
        && list_cursor(focused, app) == Some(cursor_before)
    {
        match advance {
            EdgeAdvance::Next => tui_pane::focus_next(app),
            EdgeAdvance::Prev => tui_pane::focus_prev(app),
        }
    }
}

/// Direction to roll focus when a vertical scroll runs off a list edge.
enum EdgeAdvance {
    Next,
    Prev,
}

/// Decide whether this navigation should advance the focused pane on a
/// no-op edge hit, and capture the cursor position to compare against
/// afterward. Returns `None` when the edge-scroll setting is off, the
/// action is not a single vertical step, or the focused pane has no
/// participating list.
fn edge_scroll_probe(
    action: NavAction,
    focused: FocusedPane<AppPaneId>,
    app: &App,
) -> Option<(EdgeAdvance, usize)> {
    if !app.config.edge_scroll().advances_pane() {
        return None;
    }
    let advance = match action {
        NavAction::Up => EdgeAdvance::Prev,
        NavAction::Down => EdgeAdvance::Next,
        NavAction::Left
        | NavAction::Right
        | NavAction::Home
        | NavAction::End
        | NavAction::PageUp
        | NavAction::PageDown
        | NavAction::HalfPageUp
        | NavAction::HalfPageDown => return None,
    };
    list_cursor(focused, app).map(|cursor| (advance, cursor))
}

/// Current cursor row for the focused pane's list, or `None` for panes
/// that do not take part in edge-scroll focus advance (text input,
/// static output, and non-list framework panes).
fn list_cursor(focused: FocusedPane<AppPaneId>, app: &App) -> Option<usize> {
    match focused {
        FocusedPane::App(AppPaneId::ProjectList) => Some(app.project_list.cursor()),
        FocusedPane::App(AppPaneId::Package) => Some(app.panes.package.viewport.pos()),
        FocusedPane::App(
            AppPaneId::Lang | AppPaneId::Cpu | AppPaneId::Git | AppPaneId::Targets,
        ) => Some(active_detail_viewport(app).pos()),
        FocusedPane::App(AppPaneId::Lints) => Some(app.lint.viewport.pos()),
        FocusedPane::App(AppPaneId::CiRuns) => Some(app.ci.viewport.pos()),
        FocusedPane::Framework(FrameworkFocusId::Toasts) => app
            .framework
            .toasts
            .has_active()
            .then_some(app.framework.toasts.viewport.pos()),
        FocusedPane::App(AppPaneId::Output | AppPaneId::Finder) => None,
    }
}

fn navigate_project_list(app: &mut App, action: NavAction) {
    let include_non_rust = app.config.include_non_rust().includes_non_rust();
    match action {
        NavAction::Up => app.project_list.move_up(),
        NavAction::Down => app.project_list.move_down(),
        NavAction::Home => app.project_list.move_to_top(),
        NavAction::End => app.project_list.move_to_bottom(),
        NavAction::PageUp => {
            if let Some(step) = project_list_page_step(app) {
                app.project_list.move_up_by(step);
            }
        },
        NavAction::PageDown => {
            if let Some(step) = project_list_page_step(app) {
                app.project_list.move_down_by(step);
            }
        },
        NavAction::HalfPageUp => {
            if let Some(step) = project_list_half_page_step(app) {
                app.project_list.move_up_by(step);
            }
        },
        NavAction::HalfPageDown => {
            if let Some(step) = project_list_half_page_step(app) {
                app.project_list.move_down_by(step);
            }
        },
        NavAction::Right => {
            if !app.expand() {
                app.project_list.move_down();
            }
        },
        NavAction::Left => {
            if !app.project_list.collapse(include_non_rust) {
                app.project_list.move_up();
            }
        },
    }
}

fn navigate_detail(app: &mut App, action: NavAction) {
    let pane = active_detail_pane(app);
    navigate_viewport(pane, action);
}

/// Drive the Targets cursor through the shared viewport navigation, then
/// re-derive the Running-box PID anchor from the row it landed on.
fn navigate_targets(app: &mut App, action: NavAction) {
    // `Right`/`Left` (and vim `l`/`h`, which the navigation scope maps to
    // the same actions) expand/collapse the Running list's `cargo` group
    // and outline parents first — the project list's row idiom, innermost
    // group first on `Left` — and fall through to the ordinary row move
    // everywhere else.
    let consumed = match action {
        NavAction::Right => expand_cargo_group(app) || expand_running_parent(app),
        NavAction::Left => collapse_running_parent(app) || collapse_cargo_group(app),
        _ => false,
    };
    if consumed {
        return;
    }
    navigate_viewport(&mut app.panes.targets.viewport, action);
    sync_running_cursor_pid(app);
}

fn navigate_viewport(pane: &mut Viewport, action: NavAction) {
    match action {
        NavAction::Up | NavAction::Left => pane.up(),
        NavAction::Down | NavAction::Right => pane.down(),
        NavAction::Home => pane.home(),
        NavAction::End => pane.end(),
        NavAction::PageUp => pane.page_up(),
        NavAction::PageDown => pane.page_down(),
        NavAction::HalfPageUp => pane.half_page_up(),
        NavAction::HalfPageDown => pane.half_page_down(),
    }
}

pub(super) fn navigate_package_detail(app: &mut App, action: NavAction) {
    let Some(package) = app.panes.package.content() else {
        navigate_viewport(&mut app.panes.package.viewport, action);
        return;
    };

    let rows = super::package_rows_from_data(package);
    let current = app
        .panes
        .package
        .viewport
        .pos()
        .min(rows.len().saturating_sub(1));
    let target = match action {
        NavAction::Up | NavAction::Left => {
            super::package_selectable_row_at_or_before(&rows, current.saturating_sub(1))
                .or_else(|| super::package_first_selectable_row(&rows))
        },
        NavAction::Down | NavAction::Right => {
            super::package_selectable_row_at_or_after(&rows, current.saturating_add(1))
                .or_else(|| super::package_last_selectable_row(&rows))
        },
        NavAction::Home => super::package_first_selectable_row(&rows),
        NavAction::End => super::package_last_selectable_row(&rows),
        NavAction::PageUp => {
            let step = app
                .panes
                .package
                .viewport
                .visible_rows()
                .saturating_sub(1)
                .max(1);
            let target = current.saturating_sub(step);
            super::package_selectable_row_at_or_before(&rows, target)
                .or_else(|| super::package_selectable_row_at_or_after(&rows, target))
        },
        NavAction::PageDown => {
            let step = app
                .panes
                .package
                .viewport
                .visible_rows()
                .saturating_sub(1)
                .max(1);
            let target = current
                .saturating_add(step)
                .min(rows.len().saturating_sub(1));
            super::package_selectable_row_at_or_after(&rows, target)
                .or_else(|| super::package_selectable_row_at_or_before(&rows, target))
        },
        NavAction::HalfPageUp => {
            let step = (app.panes.package.viewport.visible_rows() / 2).max(1);
            let target = current.saturating_sub(step);
            super::package_selectable_row_at_or_before(&rows, target)
                .or_else(|| super::package_selectable_row_at_or_after(&rows, target))
        },
        NavAction::HalfPageDown => {
            let step = (app.panes.package.viewport.visible_rows() / 2).max(1);
            let target = current
                .saturating_add(step)
                .min(rows.len().saturating_sub(1));
            super::package_selectable_row_at_or_after(&rows, target)
                .or_else(|| super::package_selectable_row_at_or_before(&rows, target))
        },
    };
    if let Some(pos) = target {
        app.panes.package.viewport.set_pos(pos);
    }
}

fn navigate_lints(app: &mut App, action: NavAction) {
    match action {
        NavAction::Up | NavAction::Left => app.lint.viewport.up(),
        NavAction::Down | NavAction::Right => app.lint.viewport.down(),
        NavAction::Home => app.lint.viewport.home(),
        NavAction::End => app.lint.viewport.end(),
        NavAction::PageUp => app.lint.viewport.page_up(),
        NavAction::PageDown => app.lint.viewport.page_down(),
        NavAction::HalfPageUp => app.lint.viewport.half_page_up(),
        NavAction::HalfPageDown => app.lint.viewport.half_page_down(),
    }
}

fn navigate_ci_runs(app: &mut App, action: NavAction) {
    match action {
        NavAction::Up | NavAction::Left => app.ci.viewport.up(),
        NavAction::Down | NavAction::Right => app.ci.viewport.down(),
        NavAction::Home => app.ci.viewport.home(),
        NavAction::End => app.ci.viewport.end(),
        NavAction::PageUp => app.ci.viewport.page_up(),
        NavAction::PageDown => app.ci.viewport.page_down(),
        NavAction::HalfPageUp => app.ci.viewport.half_page_up(),
        NavAction::HalfPageDown => app.ci.viewport.half_page_down(),
    }
}

/// Drive the output pane cursor through the shared viewport navigation —
/// the same handler every scroll pane uses, so vim keys and page/half-page
/// motions come for free. Follow-vs-frozen is derived from the cursor:
/// moving up off the last row frees the view, returning to it (Down at the
/// tail, `End`) follows again. While a selection is active the same motions
/// extend the range against the frozen snapshot (the cursor is one end, the
/// anchor the other).
fn navigate_output(app: &mut App, action: NavAction) {
    // Plain motions move the single-row selection (or grow it while in
    // vim visual-line mode); `navigate` keeps the anchor, snapshot, and
    // follow state in sync with the cursor.
    let live = app.inflight.example_output().to_vec();
    app.panes
        .output
        .navigate(&live, |viewport| navigate_viewport(viewport, action));
}

fn navigate_toasts(app: &mut App, action: NavAction) {
    let active_count = app.framework.toasts.active_now().len();
    app.framework.toasts.viewport.set_len(active_count);
    match action {
        NavAction::Up | NavAction::Left => app.framework.toasts.viewport.up(),
        NavAction::Down | NavAction::Right => app.framework.toasts.viewport.down(),
        NavAction::Home => app.framework.toasts.viewport.home(),
        NavAction::PageUp => app.framework.toasts.viewport.page_up(),
        NavAction::PageDown => app.framework.toasts.viewport.page_down(),
        NavAction::HalfPageUp => app.framework.toasts.viewport.half_page_up(),
        NavAction::HalfPageDown => app.framework.toasts.viewport.half_page_down(),
        NavAction::End => {
            let last_index = active_count.saturating_sub(1);
            app.framework.toasts.viewport.set_pos(last_index);
        },
    }
}

fn project_list_page_step(app: &App) -> Option<usize> {
    let rows = app.panes.project_list.viewport.visible_rows();
    (rows > 0).then(|| rows.saturating_sub(1).max(1))
}

fn project_list_half_page_step(app: &App) -> Option<usize> {
    let rows = app.panes.project_list.viewport.visible_rows();
    (rows > 0).then(|| (rows / 2).max(1))
}

pub(super) fn request_clean(app: &mut App) {
    // Gated through App::clean_selection — the single source of truth
    // for clean eligibility, regardless of which pane currently owns
    // focus.
    if let Some(selection) = app.project_list.clean_selection() {
        match selection {
            CleanSelection::Project { root } => {
                app.request_clean_confirm(root);
            },
            CleanSelection::WorktreeGroup { primary, linked } => {
                app.request_clean_group_confirm(primary, linked);
            },
        }
    }
}

/// Return a mutable reference to the pane that owns the cursor for the
/// currently active detail column.
fn active_detail_pane(app: &mut App) -> &mut Viewport {
    match app.base_focus() {
        PaneId::Targets => &mut app.panes.targets.viewport,
        PaneId::Lang => &mut app.panes.lang.viewport,
        PaneId::Cpu => &mut app.panes.cpu.viewport,
        PaneId::Git => &mut app.panes.git.viewport,
        PaneId::Package
        | PaneId::ProjectList
        | PaneId::Lints
        | PaneId::CiRuns
        | PaneId::Output
        | PaneId::Toasts
        | PaneId::Settings
        | PaneId::Finder
        | PaneId::Keymap
        | PaneId::Sccache => &mut app.panes.package.viewport,
    }
}

/// Shared-reference counterpart to [`active_detail_pane`], used to read
/// the cursor row without taking a mutable borrow.
fn active_detail_viewport(app: &App) -> &Viewport {
    match app.base_focus() {
        PaneId::Targets => &app.panes.targets.viewport,
        PaneId::Lang => &app.panes.lang.viewport,
        PaneId::Cpu => &app.panes.cpu.viewport,
        PaneId::Git => &app.panes.git.viewport,
        PaneId::Package
        | PaneId::ProjectList
        | PaneId::Lints
        | PaneId::CiRuns
        | PaneId::Output
        | PaneId::Toasts
        | PaneId::Settings
        | PaneId::Finder
        | PaneId::Keymap
        | PaneId::Sccache => &app.panes.package.viewport,
    }
}

/// Handle the Enter key in the detail panel.
fn handle_detail_enter(app: &mut App) {
    if app.focus_is(PaneId::Targets) {
        // On the Running list's `cargo` header or an outline parent row,
        // Enter expands/collapses the group instead of running a target.
        if !toggle_cargo_group(app) && !toggle_running_parent(app) {
            handle_target_action(app, BuildMode::Debug);
        }
    } else if app.base_focus() == PaneId::Package {
        if let Some(pkg) = app.panes.package.content()
            && matches!(
                super::package_rows_from_data(pkg).get(app.panes.package.viewport.pos()),
                Some(PackageRow::CratesIo(_))
            )
        {
            open_url(&format!("https://crates.io/crates/{}", pkg.title_name));
        }
    } else if let Some(git) = app.panes.git.content() {
        let pos = app.panes.git.viewport.pos();
        if let Some(GitRow::PullRequest(pull_request)) = super::git_row_at(git, pos) {
            open_url(&pull_request.url);
            return;
        }
        if let Some(GitRow::Remote(remote)) = super::git_row_at(git, pos)
            && let Some(url) = remote.full_url.as_deref()
        {
            open_url(url);
        }
    }
}

fn open_url(url: &str) {
    let _ = std::process::Command::new(if cfg!(target_os = "macos") {
        "open"
    } else if cfg!(target_os = "windows") {
        "start"
    } else {
        "xdg-open"
    })
    .arg(url)
    .stdout(std::process::Stdio::null())
    .stderr(std::process::Stdio::null())
    .spawn();
}

#[cfg(test)]
pub fn handle_ci_runs_key(app: &mut App, event: &KeyEvent) {
    // Pane scope first — TOML rebinds win over navigation defaults.
    let bind = KeyBind::from_parts(event.code, event.modifiers);
    if let Some(action) = app.keymap.current().ci_runs.action_for(&bind) {
        match action {
            CiRunsAction::Activate => handle_ci_enter(app),
            CiRunsAction::FetchMore => handle_ci_fetch_more(app),
            CiRunsAction::ShowBranch => set_ci_display_mode(app, CiRunDisplayMode::BranchOnly),
            CiRunsAction::ShowAll => set_ci_display_mode(app, CiRunDisplayMode::All),
            CiRunsAction::ClearCache => {
                if let Some(path) = app.project_list.selected_ci_path() {
                    clear_ci_cache(app, &path);
                }
            },
        }
        return;
    }

    // Navigation scope.
    let dispatch_bind = TuiKeyBind::from_key_event(*event);
    if let Some(nav_scope) = app.framework_keymap.navigation()
        && let Some(nav_action) = nav_scope.action_for(&dispatch_bind)
    {
        match nav_action {
            NavAction::Up => app.ci.viewport.up(),
            NavAction::Down => app.ci.viewport.down(),
            NavAction::Home => app.ci.viewport.home(),
            NavAction::End => app.ci.viewport.end(),
            NavAction::PageUp => app.ci.viewport.page_up(),
            NavAction::PageDown => app.ci.viewport.page_down(),
            NavAction::HalfPageUp => app.ci.viewport.half_page_up(),
            NavAction::HalfPageDown => app.ci.viewport.half_page_down(),
            NavAction::Left | NavAction::Right => {},
        }
    }
}

fn handle_ci_enter(app: &App) {
    let visible_runs = app
        .ci
        .content()
        .map(|data| data.runs.clone())
        .unwrap_or_default();
    let cursor_pos = app.ci.viewport.pos();
    if let Some(run) = visible_runs.get(cursor_pos) {
        open_url(&run.url);
    }
}

fn handle_ci_fetch_more(app: &mut App) {
    let is_fetching = app
        .project_list
        .selected_project_path()
        .is_some_and(|path| app.ci.fetch_tracker.is_fetching(path));
    if is_fetching {
        return;
    }
    let Some(ci_path) = app.project_list.selected_ci_path() else {
        return;
    };
    let project_name = app
        .project_list
        .selected_project_path()
        .and_then(|path| {
            app.project_list
                .iter()
                .find(|item| item.path() == path)
                .and_then(|item| item.name().map(str::to_string))
        })
        .unwrap_or_else(|| project::home_relative_path(&ci_path));
    // Always start with Sync: pick up runs newer than the cached set. If
    // Sync surfaces nothing, `poll_ci_fetches` automatically chains a
    // FetchOlder using the cached tail as the cursor.
    app.inflight.set_pending_ci_fetch(PendingCiFetch {
        project_path:      ci_path.display().to_string(),
        ci_run_count:      app.config.ci_run_count(),
        oldest_created_at: None,
        kind:              CiFetchKind::Sync,
    });
    let task_id = app
        .framework
        .toasts
        .start_task("Fetching CI", &project_name);
    let item = TrackedItem {
        label:        project_name,
        key:          integration::path_key(&ci_path),
        started_at:   Some(std::time::Instant::now()),
        completed_at: None,
    };
    app.set_task_tracked_items(task_id, &[item]);
    app.ci.set_fetch_toast(Some(task_id));
}

/// Clear CI cache for a project and remove its runs from the app.
fn clear_ci_cache(app: &mut App, abs: &Path) {
    let run_count = app
        .project_list
        .ci_data_for(abs)
        .and_then(ProjectCiData::info)
        .map_or(0, |info| info.runs.len());
    let (title, body) = if let Some(repo) = app.owner_repo_for_path(abs) {
        let dir = scan::ci_cache_dir_pub(repo.owner(), repo.repo());
        let result = std::fs::remove_dir_all(&dir);
        scan::clear_exhausted(repo.owner(), repo.repo());
        if let Ok(mut cache) = app.net.github.fetch_cache.lock() {
            cache.remove(&repo);
        }
        match result {
            Ok(()) => {
                let runs = if run_count == 1 { "run" } else { "runs" };
                (
                    "CI cache cleared",
                    format!("{}/{}: {run_count} {runs}", repo.owner(), repo.repo()),
                )
            },
            Err(err) => ("CI cache clear failed", format!("{}: {err}", dir.display())),
        }
    } else {
        (
            "CI cache clear failed",
            format!("no owner/repo for {}", abs.display()),
        )
    };
    let _ = app.framework.toasts.push_status(title, body);
    let prev_total = app
        .project_list
        .ci_data_for(abs)
        .map_or(0, ProjectCiData::github_total);
    app.project_list.replace_ci_data_for_path(
        abs,
        ProjectCiData::Loaded(ProjectCiInfo {
            runs:         Vec::new(),
            github_total: prev_total,
            exhausted:    false,
        }),
    );
    app.ci.fetch_tracker.complete(abs);
    app.ci.viewport.home();
    app.scan.bump_generation();
}

fn clear_lint_history(app: &mut App) {
    if !app.selected_row_owns_lint() {
        return;
    }
    // A worktree-group parent row aggregates every visible checkout's
    // history, so clearing it must clear each checkout — otherwise the
    // aggregate rebuild keeps re-showing the linked checkouts' runs.
    // Other rows clear their single selected path.
    let paths: Vec<AbsolutePath> = app
        .project_list
        .selected_worktree_group_checkout_paths()
        .unwrap_or_else(|| {
            app.project_list
                .selected_project_path()
                .map(AbsolutePath::from)
                .into_iter()
                .collect()
        });
    if paths.is_empty() {
        return;
    }
    // Tally before deleting: how many runs go away and the disk they held,
    // summing each run's archived-log bytes across every checkout being cleared.
    let mut run_count: usize = 0;
    let mut freed_bytes: u64 = 0;
    for abs_path in &paths {
        if let Some(lr) = app.lint_at_path(abs_path.as_path()) {
            for run in lr.runs() {
                run_count += 1;
                freed_bytes += lr.archive_bytes(&run.run_id).unwrap_or(0);
            }
        }
    }
    for abs_path in &paths {
        // Removes the per-project cache dir AND decrements the cache-size
        // index so the lint cache-usage total stays accurate. A bare
        // `remove_dir_all` would leave the index (at the cache root, outside
        // this dir) overcounting until the next walk-and-rewrite.
        lint::reclaim_project_cache(abs_path.as_path());

        if let Some(lr) = app.lint_at_path_mut(abs_path.as_path()) {
            lr.clear_runs();
        }
    }
    if run_count > 0 {
        let runs = if run_count == 1 { "run" } else { "runs" };
        let body = format!(
            "{run_count} {runs}, {} freed",
            render::format_bytes(freed_bytes)
        );
        let _ = app
            .framework
            .toasts
            .push_status("Lint history cleared", body);
    }
    app.lint.viewport.home();
    app.set_focus_to_pane(PaneId::ProjectList);
    app.refresh_lint_cache_usage_from_disk();
    app.scan.bump_generation();
}

fn open_lint_run_output(app: &App) {
    if !app.selected_row_owns_lint() {
        return;
    }
    let Some(data) = app.lint.content() else {
        return;
    };
    let pos = app.lint.viewport.pos();
    let Some(run) = data.runs.get(pos) else {
        return;
    };
    // Resolve logs against the checkout the run came from (the primary for
    // a single project, or the specific checkout for a worktree-group
    // aggregate), not the selected row's path.
    let Some(abs_path) = data.owner_path_for_run(pos) else {
        return;
    };

    let project_cache_dir = lint::project_dir(abs_path.as_path());
    let log_paths: Vec<AbsolutePath> = run
        .commands
        .iter()
        .map(|command| AbsolutePath::from(project_cache_dir.join(&command.log_file)))
        .filter(|path| path.exists())
        .collect();

    if log_paths.is_empty() {
        return;
    }

    for path in log_paths {
        let _ = input::open_paths_in_editor(app.config.editor(), [path.as_path()]);
    }
}