par-term 0.49.0

//! Status bar system for displaying session and system information.
//!
//! The status bar is a configurable panel that can display widgets such as
//! the current time, username, git branch, CPU/memory usage, and more.
//!
//! # Widget Architecture
//!
//! The current architecture uses a **data-driven, direct-call approach** rather
//! than a formal registration mechanism:
//!
//! - Widget identifiers (`WidgetId`) and their configuration are defined in
//!   `par-term-config/src/status_bar.rs`.
//! - The `widgets` submodule (`src/status_bar/widgets/`) contains the rendering
//!   logic: `widget_text()` dispatches on `WidgetId` to produce the display string,
//!   and `sorted_widgets_for_section()` filters and orders widgets for each bar section.
//! - `StatusBarUI::render()` in this file drives the egui layout for left/center/right
//!   sections and calls into the widgets module.
//! - Background data (system metrics, git status) is polled on dedicated threads
//!   (`SystemMonitor`, `GitBranchPoller`) and surfaced via `WidgetContext`.
//!
//! # Adding a New Widget
//!
//! 1. Add a variant to `WidgetId` in `par-term-config/src/status_bar.rs`.
//! 2. Add a `widget_text()` arm in `src/status_bar/widgets/`.
//! 3. If the widget needs background data, extend `WidgetContext` and add
//!    a poller in this file following the `GitBranchPoller` pattern.
//! 4. Update `default_widgets()` in `par-term-config` to include the new widget.
//! 5. Update search keywords in `par-term-settings-ui/src/settings_ui/sidebar.rs`.
//!
//! # Future: Formal Widget Registry
//!
//! The current dispatch-on-enum approach scales well to ~20 widgets but becomes
//! harder to extend as the widget set grows. A future improvement could introduce
//! a `StatusBarWidget` trait and a registry (e.g., `HashMap<WidgetId, Box<dyn StatusBarWidget>>`)
//! so that third-party or plugin-style widgets can be registered without modifying
//! the central dispatch function. This is tracked as ARC-009 in AUDIT.md.

pub mod disk_monitor;
pub mod git_poller;
pub mod plugins_upkeep;
pub mod system_monitor;
pub mod widgets;

#[cfg(test)]
mod widget_click_tests;

use std::collections::HashMap;
use std::time::{Duration, Instant};

use crate::agent_usage::store::UsageStore;
use crate::agent_usage::update::UpdateRunner;
use crate::badge::SessionVariables;
use crate::config::{Config, StatusBarPosition, StatusBarSection, StatusBarWidgetConfig};
use disk_monitor::DiskMonitor;
use git_poller::GitBranchPoller;
use par_term_scripting::plugin_manager::{PluginHost, WarnOnce};
use system_monitor::SystemMonitor;
use widgets::{WidgetContext, sorted_widgets_for_section, widget_text};

pub use git_poller::GitStatus;

/// Floor for the configured agent-usage refresh interval.
const AGENT_USAGE_MIN_REFRESH: Duration = Duration::from_secs(30);

/// Actions that the status bar can request from the window.
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum StatusBarAction {
    /// User clicked the update-available widget.
    ShowUpdateDialog,
    /// User clicked the agent-usage widget.
    OpenAgentUsagePanel,
    /// User clicked the agent-roster widget; opens the command palette (the
    /// roster's list surface, per the A2b design — not a separate panel).
    OpenAgentPalette,
}

/// Status bar UI state and renderer.
pub struct StatusBarUI {
    /// Background system resource monitor.
    system_monitor: SystemMonitor,
    /// Background disk free-space monitor.
    disk_monitor: DiskMonitor,
    /// Git branch poller.
    git_poller: GitBranchPoller,
    /// Timestamp of the last mouse activity (for auto-hide).
    last_mouse_activity: Instant,
    /// Whether the status bar is currently visible.
    visible: bool,
    /// Last valid time format string (for fallback when user is mid-edit).
    last_valid_time_format: String,
    /// Available update version (set by WindowManager when update is detected)
    pub update_available_version: Option<String>,
    /// Agent-roster summary line for the status-bar widget (A2b task 2),
    /// refreshed by the render pipeline from the mux roster cache before the
    /// egui borrow. `None` (no mux session / empty roster) self-hides the
    /// widget.
    pub agent_roster_summary: Option<String>,
    /// Hover text for the agent-roster widget; `None` hides the tooltip.
    pub agent_roster_tooltip: Option<String>,
    /// Receiving pane count for the broadcast widget (V5), refreshed by
    /// the render pipeline; `None` while broadcast is off.
    pub broadcast_receivers: Option<usize>,
    /// Agent-usage records store (watched directory + snapshot). Lives here
    /// with the other background-data pollers; the popup panel reads it via
    /// [`StatusBarUI::usage_snapshot`].
    pub(crate) usage: UsageStore,
    /// Optional agent-usage update command, run on the refresh interval.
    usage_update: UpdateRunner,
    /// Window-scoped plugin host: discovery cache, supervised processes,
    /// and the last `SetWidget` text per plugin (v1 plugins are bar widgets).
    plugins: PluginHost,
    /// When the plugins root was last scanned; `None` until the first
    /// [`update_plugins`](StatusBarUI::update_plugins) call performs it.
    plugins_last_discovery: Option<Instant>,
    /// Warn-once gate for per-frame invalid-settings warnings (upkeep runs
    /// every render frame; a steady fault must not warn per frame).
    plugin_settings_warned: WarnOnce,
    /// Terminal-observer registrations for plugin event forwarders, keyed by
    /// (plugin id, tab id, terminal slot): `None` names the tab terminal,
    /// `Some(pane id)` a pane terminal of a mux tab. Reconciled every sweep
    /// by [`StatusBarUI::pump_plugin_events`]; an entry for a closed tab or
    /// pane is dropped with the map entry alone — its terminal, and the
    /// observer registry inside it, is gone with it.
    plugin_observer_ids: HashMap<
        (String, crate::tab::TabId, Option<crate::pane::PaneId>),
        par_term_emu_core_rust::observer::ObserverId,
    >,
}

impl StatusBarUI {
    /// Create a new status bar UI.
    pub fn new() -> Self {
        Self {
            system_monitor: SystemMonitor::new(),
            disk_monitor: DiskMonitor::new(),
            git_poller: GitBranchPoller::new(),
            last_mouse_activity: Instant::now(),
            visible: true,
            last_valid_time_format: "%H:%M:%S".to_string(),
            update_available_version: None,
            agent_roster_summary: None,
            agent_roster_tooltip: None,
            broadcast_receivers: None,
            usage: UsageStore::new(crate::agent_usage::default_records_dir()),
            usage_update: UpdateRunner::new(),
            plugins: PluginHost::new(),
            plugins_last_discovery: None,
            plugin_settings_warned: WarnOnce::default(),
            plugin_observer_ids: HashMap::new(),
        }
    }

    /// Read access to the agent-usage snapshot for the popup panel.
    pub(crate) fn usage_snapshot(&self) -> &crate::agent_usage::store::UsageSnapshot {
        self.usage.snapshot()
    }

    /// Rescan the usage records directory now (panel `r`), and give the
    /// optional update command its manual-refresh turn.
    pub(crate) fn refresh_usage_now(&mut self) {
        self.usage.refresh_now();
        self.usage_update.trigger_if_idle();
    }

    /// Signal all background threads to stop without waiting.
    /// Call early during shutdown so threads have time to notice before the Drop join.
    pub fn signal_shutdown(&self) {
        self.system_monitor.signal_stop();
        self.disk_monitor.signal_stop();
        self.git_poller.signal_stop();
    }

    /// Per-frame agent-usage upkeep: watcher events, config wiring, refresh
    /// tick, and the optional update command.
    ///
    /// Called unconditionally from the render pipeline every frame — NOT from
    /// [`StatusBarUI::render`], which the caller only reaches while the status
    /// bar is enabled. The usage panel must stay live with the bar off (it is
    /// opened by its own action), and a watcher event arriving while the bar
    /// is hidden must not wait for the bar to come back.
    pub(crate) fn update_agent_usage(&mut self, config: &Config) {
        if !config.agent_usage.agent_usage_enabled {
            return;
        }
        self.usage.poll();
        self.usage.set_hidden(config.agent_usage.hidden_set());
        // Extra records dirs (synced from other machines) merge into the
        // snapshot; same-set calls are a no-op inside the store.
        self.usage.set_extra_dirs(
            config
                .agent_usage
                .agent_usage_extra_records_dirs
                .iter()
                .map(|p| crate::agent_usage::expand_tilde(p))
                .collect(),
        );
        self.usage_update
            .configure(config.agent_usage.agent_usage_update_command.clone());
        let interval = Duration::from_secs(
            config
                .agent_usage
                .agent_usage_refresh_interval_sec
                .max(AGENT_USAGE_MIN_REFRESH.as_secs()),
        );
        if self.usage.tick(interval) {
            // The refresh interval elapsed: give the optional update
            // command its turn alongside the rescan.
            self.usage_update.trigger_if_idle();
        }
    }

    /// Compute the effective height consumed by the status bar.
    ///
    /// Returns 0 if the status bar is hidden or disabled.
    pub fn height(&self, config: &Config, is_fullscreen: bool) -> f32 {
        if !config.status_bar.status_bar_enabled || self.should_hide(config, is_fullscreen) {
            0.0
        } else {
            config.status_bar.status_bar_height
        }
    }

    /// Determine whether the status bar should be hidden right now.
    pub fn should_hide(&self, config: &Config, is_fullscreen: bool) -> bool {
        if !config.status_bar.status_bar_enabled {
            return true;
        }
        if config.status_bar.status_bar_auto_hide_fullscreen && is_fullscreen {
            return true;
        }
        if config.status_bar.status_bar_auto_hide_mouse_inactive {
            let elapsed = self.last_mouse_activity.elapsed().as_secs_f32();
            if elapsed > config.status_bar.status_bar_mouse_inactive_timeout {
                return true;
            }
        }
        false
    }

    /// Record mouse activity (resets auto-hide timer).
    pub fn on_mouse_activity(&mut self) {
        self.last_mouse_activity = Instant::now();
        self.visible = true;
    }

    /// Start or stop the system monitor and git poller based on enabled widgets.
    pub fn sync_monitor_state(&self, config: &Config) {
        if !config.status_bar.status_bar_enabled {
            if self.system_monitor.is_running() {
                self.system_monitor.stop();
            }
            if self.disk_monitor.is_running() {
                self.disk_monitor.stop();
            }
            if self.git_poller.is_running() {
                self.git_poller.stop();
            }
            return;
        }

        // System monitor
        let needs_monitor = config
            .status_bar
            .status_bar_widgets
            .iter()
            .any(|w| w.enabled && w.id.needs_system_monitor());

        if needs_monitor && !self.system_monitor.is_running() {
            self.system_monitor
                .start(config.status_bar.status_bar_system_poll_interval);
        } else if !needs_monitor && self.system_monitor.is_running() {
            self.system_monitor.stop();
        }

        // Disk free-space monitor
        let needs_disk = config
            .status_bar
            .status_bar_widgets
            .iter()
            .any(|w| w.enabled && w.id.needs_disk_monitor());

        self.disk_monitor
            .set_follow_cwd(config.status_bar.status_bar_disk_follow_cwd);

        if needs_disk && !self.disk_monitor.is_running() {
            self.disk_monitor
                .start(config.status_bar.status_bar_disk_poll_interval);
        } else if !needs_disk && self.disk_monitor.is_running() {
            self.disk_monitor.stop();
        }

        // Git branch poller
        let needs_git = config
            .status_bar
            .status_bar_widgets
            .iter()
            .any(|w| w.enabled && w.id == crate::config::WidgetId::GitBranch);

        if needs_git && !self.git_poller.is_running() {
            self.git_poller
                .start(config.status_bar.status_bar_git_poll_interval);
        } else if !needs_git && self.git_poller.is_running() {
            self.git_poller.stop();
        }
    }

    /// Render the status bar.
    ///
    /// Returns the height consumed by the status bar (0 if hidden) and an
    /// optional action requested by the user (e.g. clicking the update widget).
    pub fn render(
        &mut self,
        ctx: &egui::Context,
        config: &Config,
        session_vars: &SessionVariables,
        is_fullscreen: bool,
    ) -> (f32, Option<StatusBarAction>) {
        if !config.status_bar.status_bar_enabled || self.should_hide(config, is_fullscreen) {
            return (0.0, None);
        }

        // Update git poller cwd from active tab's path
        let cwd = if session_vars.path.is_empty() {
            None
        } else {
            Some(session_vars.path.as_str())
        };
        self.git_poller.set_cwd(cwd);
        self.disk_monitor.set_cwd(cwd);

        // Validate time format — update last-known-good on success, fall back on failure
        {
            use chrono::format::strftime::StrftimeItems;
            let valid = !config.status_bar.status_bar_time_format.is_empty()
                && StrftimeItems::new(&config.status_bar.status_bar_time_format)
                    .all(|item| !matches!(item, chrono::format::Item::Error));
            if valid {
                self.last_valid_time_format = config.status_bar.status_bar_time_format.clone();
            }
        }

        // Build widget context
        let git_status = self.git_poller.status();
        let disk_data = self.disk_monitor.data();
        let widget_ctx = WidgetContext {
            session_vars: session_vars.clone(),
            system_data: self.system_monitor.data(),
            git_branch: git_status.branch,
            git_ahead: git_status.ahead,
            git_behind: git_status.behind,
            git_dirty: git_status.dirty,
            git_show_status: config.status_bar.status_bar_git_show_status,
            time_format: self.last_valid_time_format.clone(),
            update_available_version: self.update_available_version.clone(),
            disk_free_percent: disk_data.free_percent,
            disk_free_bytes: disk_data.free_bytes,
            disk_total_bytes: disk_data.total_bytes,
            agent_usage_summary: self.usage.summary_line(),
            agent_roster_summary: self.agent_roster_summary.clone(),
            agent_roster_tooltip: self.agent_roster_tooltip.clone(),
            broadcast_receivers: self.broadcast_receivers,
            plugin_texts: self.plugins.widget_texts().clone(),
        };

        let bar_height = config.status_bar.status_bar_height;
        let [bg_r, bg_g, bg_b] = config.status_bar.status_bar_bg_color;
        let bg_alpha = (config.status_bar.status_bar_bg_alpha * 255.0) as u8;
        let bg_color = egui::Color32::from_rgba_unmultiplied(bg_r, bg_g, bg_b, bg_alpha);

        let [fg_r, fg_g, fg_b] = config.status_bar.status_bar_fg_color;
        let fg_color = egui::Color32::from_rgb(fg_r, fg_g, fg_b);
        let font_size = config.status_bar.status_bar_font_size;
        let separator = &config.status_bar.status_bar_separator;
        let sep_color = fg_color.linear_multiply(0.4);

        // Use an egui::Area with a fixed size so the status bar stops before
        // the scrollbar column.  TopBottomPanel always spans the full window
        // width and ignores every attempt to narrow it.
        let h_margin: f32 = 8.0; // left + right inner margin per side
        let v_margin: f32 = 2.0; // top + bottom inner margin per side
        let scrollbar_reserved = config.scrollbar.scrollbar_width + 2.0;
        let viewport = ctx.input(|i| i.viewport_rect());
        // Content width is the frame width minus both horizontal margins.
        let content_width = (viewport.width() - scrollbar_reserved - h_margin * 2.0).max(0.0);
        let content_height = (bar_height - v_margin * 2.0).max(0.0);

        let bar_pos = match config.status_bar.status_bar_position {
            StatusBarPosition::Top => egui::pos2(0.0, 0.0),
            StatusBarPosition::Bottom => egui::pos2(0.0, viewport.height() - bar_height),
        };

        let frame = egui::Frame::NONE
            .fill(bg_color)
            .inner_margin(egui::Margin::symmetric(h_margin as i8, v_margin as i8));

        let make_rich_text = |text: &str| -> egui::RichText {
            egui::RichText::new(text)
                .color(fg_color)
                .size(font_size)
                .monospace()
        };

        let make_sep = |sep: &str| -> egui::RichText {
            egui::RichText::new(sep)
                .color(sep_color)
                .size(font_size)
                .monospace()
        };

        // Widgets that open something on click get the same treatment in
        // every section; all other widgets render as plain labels.
        let roster_tooltip = self.agent_roster_tooltip.clone();
        let render_widget = |ui: &mut egui::Ui,
                             w: &StatusBarWidgetConfig,
                             text: &str|
         -> Option<StatusBarAction> {
            use crate::config::WidgetId;
            let (rich, action) = match w.id {
                WidgetId::UpdateAvailable => (
                    egui::RichText::new(text)
                        .color(egui::Color32::from_rgb(255, 200, 50))
                        .size(font_size)
                        .monospace(),
                    StatusBarAction::ShowUpdateDialog,
                ),
                WidgetId::AgentUsage => {
                    (make_rich_text(text), StatusBarAction::OpenAgentUsagePanel)
                }
                WidgetId::AgentRoster => (make_rich_text(text), StatusBarAction::OpenAgentPalette),
                _ => {
                    ui.label(make_rich_text(text));
                    return None;
                }
            };
            let response = ui.add(egui::Label::new(rich).sense(egui::Sense::click()));
            // The roster's hover carries the per-agent provenance detail the
            // bar text cannot fit.
            if w.id == WidgetId::AgentRoster
                && let Some(tooltip) = roster_tooltip.as_deref()
                && !tooltip.is_empty()
            {
                return response.on_hover_text(tooltip).clicked().then_some(action);
            }
            response.clicked().then_some(action)
        };

        let mut action: Option<StatusBarAction> = None;

        egui::Area::new(egui::Id::new("status_bar"))
            .fixed_pos(bar_pos)
            .order(egui::Order::Background)
            .interactable(true)
            .show(ctx, |ui| {
                // Constrain the outer UI so the frame cannot grow beyond the
                // intended total width (content + margins).
                ui.set_max_width(content_width + h_margin * 2.0);
                ui.set_max_height(bar_height);

                frame.show(ui, |ui| {
                    ui.set_min_size(egui::vec2(content_width, content_height));
                    ui.set_max_size(egui::vec2(content_width, content_height));

                    ui.horizontal_centered(|ui| {
                        // Clip widgets to the available content width so
                        // right-to-left layouts cannot expand past the bar edge.
                        ui.set_clip_rect(ui.max_rect());

                        // === Left section ===
                        let left_widgets = sorted_widgets_for_section(
                            &config.status_bar.status_bar_widgets,
                            StatusBarSection::Left,
                        );
                        let mut first = true;
                        for w in &left_widgets {
                            let text = widget_text(&w.id, &widget_ctx, w.format.as_deref());
                            if text.is_empty() {
                                continue;
                            }
                            if !first {
                                ui.label(make_sep(separator));
                            }
                            first = false;
                            if let Some(a) = render_widget(ui, w, &text) {
                                action = Some(a);
                            }
                        }

                        // === Center section ===
                        let center_widgets = sorted_widgets_for_section(
                            &config.status_bar.status_bar_widgets,
                            StatusBarSection::Center,
                        );
                        if !center_widgets.is_empty() {
                            ui.with_layout(
                                egui::Layout::centered_and_justified(egui::Direction::LeftToRight),
                                |ui| {
                                    let mut first = true;
                                    for w in &center_widgets {
                                        let text =
                                            widget_text(&w.id, &widget_ctx, w.format.as_deref());
                                        if text.is_empty() {
                                            continue;
                                        }
                                        if !first {
                                            ui.label(make_sep(separator));
                                        }
                                        first = false;
                                        if let Some(a) = render_widget(ui, w, &text) {
                                            action = Some(a);
                                        }
                                    }
                                },
                            );
                        }

                        // === Right section ===
                        let right_widgets = sorted_widgets_for_section(
                            &config.status_bar.status_bar_widgets,
                            StatusBarSection::Right,
                        );
                        if !right_widgets.is_empty() {
                            ui.with_layout(
                                egui::Layout::right_to_left(egui::Align::Center),
                                |ui| {
                                    let mut first = true;
                                    for w in right_widgets.iter().rev() {
                                        let text =
                                            widget_text(&w.id, &widget_ctx, w.format.as_deref());
                                        if text.is_empty() {
                                            continue;
                                        }
                                        if !first {
                                            ui.label(make_sep(separator));
                                        }
                                        first = false;
                                        if let Some(a) = render_widget(ui, w, &text) {
                                            action = Some(a);
                                        }
                                    }
                                },
                            );
                        }
                    });
                });
            });

        (bar_height, action)
    }
}

impl Default for StatusBarUI {
    fn default() -> Self {
        Self::new()
    }
}

impl Drop for StatusBarUI {
    fn drop(&mut self) {
        self.system_monitor.stop();
        self.disk_monitor.stop();
    }
}