trusty-common 0.4.6

//! Service-specific terminal UI for the trusty-memory daemon.
//!
//! Why: operators of the trusty-memory daemon want a focused terminal surface
//! — a palace list with aggregate counts, a streaming activity log of dream /
//! drawer / recall events, and a recall query bar — rather than the generic
//! two-daemon dashboard. Living in `trusty-common` behind the `monitor-tui`
//! feature keeps the pure state / rendering testable (issue #34).
//! What: a ratatui app with a 3-zone layout (title bar, PALACES + ACTIVITY
//! split, RECALL input bar). It polls the daemon every 2 seconds, subscribes
//! to the `/sse` event stream on startup, runs cross-palace recalls from the
//! input bar on `[Enter]`, and triggers a dream cycle on `[d]`.
//! Test: `cargo test -p trusty-common --features monitor-tui` covers the pure
//! state, palace row formatting, and dream-event logging; `trusty-memory
//! monitor tui` launches the live UI.

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

use crossterm::{
    event::{self, Event, KeyCode, KeyEventKind, KeyModifiers},
    execute,
    terminal::{EnterAlternateScreen, LeaveAlternateScreen, disable_raw_mode, enable_raw_mode},
};
use ratatui::{
    Frame, Terminal,
    backend::CrosstermBackend,
    layout::{Constraint, Direction, Layout},
    style::{Color, Modifier, Style},
    text::{Line, Span},
    widgets::{Block, Borders, Clear, List, ListItem, Paragraph},
};
use tokio::sync::mpsc;

use crate::monitor::dashboard::{MemoryData, PalaceRow, format_count};
use crate::monitor::memory_client::{MemoryClient, MemoryEvent, resolve_memory_url};
use crate::monitor::utils::{ActivityLog, DaemonStatus};

/// Data-refresh interval: how often the daemon is polled.
const REFRESH_INTERVAL: Duration = Duration::from_millis(2000);

/// Input-poll interval: how often the keyboard is checked.
const INPUT_POLL: Duration = Duration::from_millis(50);

/// Number of results requested per recall query.
const RECALL_TOP_K: usize = 5;

/// Maximum width (in columns) of the left PALACES panel.
const LEFT_PANEL_MAX: u16 = 28;

/// Crate version, surfaced in the title bar.
pub const VERSION: &str = env!("CARGO_PKG_VERSION");

/// One-line key hint shown along the bottom of the UI.
pub const KEY_HINT: &str =
    "[Tab] focus  [d] dream  [↑↓] select  [Enter] recall  [q] quit  [?] help";

/// Which zone of the memory UI currently holds keyboard focus.
///
/// Why: `[Tab]` cycles focus; the palace list and the recall bar consume keys
/// differently (navigation vs. text entry).
/// What: `List` (the default — the PALACES panel) or `Input` (the RECALL bar).
/// Test: `test_toggle_focus`.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub enum MemoryFocus {
    /// The PALACES list panel has focus; arrows move the selection.
    #[default]
    List,
    /// The RECALL input bar has focus; typed characters edit the query.
    Input,
}

/// All mutable state the memory UI renders and mutates.
///
/// Why: the event loop polls the daemon, streams `/sse` events, and handles
/// input — keeping every piece of state in one struct keeps the loop terse and
/// the rendering a pure function of this snapshot.
/// What: the daemon URL and status, the aggregate stats, the palace list and
/// selection cursor, the bounded activity log, the query buffer, the focused
/// zone, and the help flag.
/// Test: `test_selected_clamp`, `test_toggle_focus`, `test_palace_row_display`.
#[derive(Debug, Clone)]
pub struct MemoryTuiState {
    /// The trusty-memory daemon base URL being monitored.
    pub base_url: String,
    /// The daemon's current liveness state.
    pub daemon_status: DaemonStatus,
    /// The latest aggregate stats, or `None` before the first poll.
    pub status: Option<MemoryData>,
    /// One row per palace.
    pub palaces: Vec<PalaceRow>,
    /// Cursor into [`Self::palaces`] for the selected row.
    pub selected: usize,
    /// Bounded, timestamped log of dream / drawer / recall activity.
    pub log: ActivityLog,
    /// The in-progress recall query buffer.
    pub input: String,
    /// Which zone currently holds keyboard focus.
    pub focus: MemoryFocus,
    /// Whether the help overlay is visible (toggled with `?`).
    pub show_help: bool,
}

impl MemoryTuiState {
    /// Build a fresh memory UI state targeting `base_url`.
    ///
    /// Why: the event loop seeds the state at startup before the first poll.
    /// What: stores the URL, sets the daemon `Connecting`, and starts with no
    /// stats, an empty palace list, empty log, empty query, and list focus.
    /// Test: `test_new_state_defaults`.
    pub fn new(base_url: impl Into<String>) -> Self {
        Self {
            base_url: base_url.into(),
            daemon_status: DaemonStatus::Connecting,
            status: None,
            palaces: Vec::new(),
            selected: 0,
            log: ActivityLog::new(),
            input: String::new(),
            focus: MemoryFocus::List,
            show_help: false,
        }
    }

    /// Cycle keyboard focus between the palace list and the recall bar.
    ///
    /// Why: `[Tab]` decides whether arrows navigate the list or whether typed
    /// characters edit the recall query.
    /// What: flips [`Self::focus`] between [`MemoryFocus::List`] and
    /// [`MemoryFocus::Input`].
    /// Test: `test_toggle_focus`.
    pub fn toggle_focus(&mut self) {
        self.focus = match self.focus {
            MemoryFocus::List => MemoryFocus::Input,
            MemoryFocus::Input => MemoryFocus::List,
        };
    }

    /// Move the palace selection up one row, saturating at the top.
    ///
    /// Why: `↑` navigates the PALACES list when it has focus.
    /// What: decrements [`Self::selected`], never below zero.
    /// Test: `test_selected_clamp`.
    pub fn select_up(&mut self) {
        self.selected = self.selected.saturating_sub(1);
    }

    /// Move the palace selection down one row, clamped to the last palace.
    ///
    /// Why: `↓` navigates the PALACES list when it has focus.
    /// What: increments [`Self::selected`] but never past the last row.
    /// Test: `test_selected_clamp`.
    pub fn select_down(&mut self) {
        let last = self.palaces.len().saturating_sub(1);
        if self.selected < last {
            self.selected += 1;
        }
    }

    /// Clamp the selection cursor to the current palace count.
    ///
    /// Why: a poll can shrink the palace list leaving the cursor past the end;
    /// this keeps it valid before rendering.
    /// What: caps [`Self::selected`] at `palaces.len().saturating_sub(1)`; an
    /// empty list resets the cursor to zero.
    /// Test: `test_selected_clamp`.
    pub fn clamp_selection(&mut self) {
        let last = self.palaces.len().saturating_sub(1);
        if self.selected > last {
            self.selected = last;
        }
    }

    /// The id of the currently selected palace, if any.
    ///
    /// Why: `[d]` dreams over every palace but `[Enter]` recalls and the log
    /// labels the selected palace; both need its id.
    /// What: returns `Some(id)` for the row at [`Self::selected`], or `None`
    /// when the palace list is empty.
    /// Test: `test_selected_id`.
    pub fn selected_id(&self) -> Option<&str> {
        self.palaces.get(self.selected).map(|p| p.id.as_str())
    }
}

/// Run the trusty-memory monitor TUI.
///
/// Why: the single entry point the `monitor tui` subcommand of `trusty-memory`
/// calls.
/// What: resolves the daemon URL from the service lock file and delegates to
/// [`run_with_url`].
/// Test: the pure pieces are unit-tested; this thin glue is exercised by
/// launching the UI.
pub async fn run() -> anyhow::Result<()> {
    run_with_url(resolve_memory_url()).await
}

/// Run the memory TUI against an explicit daemon URL.
///
/// Why: separated from [`run`] so a future CLI flag can override the resolved
/// address, and so terminal setup/teardown lives in one place.
/// What: builds the client and state, enters raw mode + the alternate screen,
/// runs [`run_loop`], and unconditionally restores the terminal even on error.
/// Test: terminal glue is exercised by launching the UI.
pub async fn run_with_url(base_url: String) -> anyhow::Result<()> {
    let mut client = MemoryClient::new(base_url.clone());
    let mut state = MemoryTuiState::new(base_url);

    enable_raw_mode()?;
    let mut stdout = std::io::stdout();
    execute!(stdout, EnterAlternateScreen)?;
    let backend = CrosstermBackend::new(stdout);
    let mut terminal = Terminal::new(backend)?;

    let result = run_loop(&mut terminal, &mut state, &mut client).await;

    disable_raw_mode()?;
    execute!(terminal.backend_mut(), LeaveAlternateScreen)?;
    terminal.show_cursor()?;
    result
}

/// Poll the trusty-memory daemon and fold the result into `state`.
///
/// Why: keeps the per-poll I/O out of the event loop so the loop can re-poll
/// on demand as well as on its timer.
/// What: re-resolves the URL when the daemon is offline, calls `fetch_all`, and
/// updates the status, aggregate stats, palace list, and selection clamp.
/// Test: thin I/O glue; the pure clamp is unit-tested.
async fn poll_daemon(state: &mut MemoryTuiState, client: &mut MemoryClient) {
    if !state.daemon_status.is_online() {
        let resolved = resolve_memory_url();
        if resolved != client.base_url() {
            client.set_base_url(resolved.clone());
            state.base_url = resolved;
        }
    }
    match client.fetch_all().await {
        Ok(data) => {
            state.daemon_status = DaemonStatus::Online {
                version: data.version.clone(),
                uptime_secs: 0,
            };
            state.palaces = data.palaces.clone();
            state.status = Some(data);
            state.clamp_selection();
        }
        Err(e) => {
            state.daemon_status = DaemonStatus::Offline {
                last_error: e.to_string(),
            };
        }
    }
}

/// Run a cross-palace recall and append the hits to the activity log.
///
/// Why: pressing `[Enter]` in the recall bar runs a memory recall; the
/// operator sees the results inline in the ACTIVITY panel.
/// What: calls `client.recall`, appends a `recall "<q>" → N results` summary
/// plus one indented `· <snippet>` continuation line per hit. An empty query
/// is a no-op; a transport error is logged.
/// Test: thin I/O glue; result projection is tested in `memory_client`.
async fn run_recall(state: &mut MemoryTuiState, client: &MemoryClient) {
    let query = state.input.trim().to_string();
    if query.is_empty() {
        return;
    }
    match client.recall(&query, RECALL_TOP_K).await {
        Ok(hits) => {
            state
                .log
                .push(format!("recall \"{query}\" → {} results", hits.len()));
            for hit in &hits {
                state.log.push_raw(format!("  · {}", hit.snippet));
            }
        }
        Err(e) => state.log.push(format!("recall \"{query}\" failed: {e}")),
    }
    state.input.clear();
}

/// Append a streamed `/sse` event to the activity log.
///
/// Why: the SSE task forwards [`MemoryEvent`]s through a channel; the event
/// loop drains them and this turns each into a human-readable log entry.
/// What: `DreamCompleted` records a header plus an indented merge/prune/compact
/// line; drawer and palace events record a single line each.
/// Test: `test_log_append_dream`, `test_apply_memory_event`.
pub fn apply_memory_event(state: &mut MemoryTuiState, event: MemoryEvent) {
    match event {
        MemoryEvent::DreamCompleted {
            merged,
            pruned,
            compacted,
        } => {
            state.log.push("SSE: dream_completed");
            state.log.push_raw(format!(
                "  merged: {merged}  pruned: {pruned}  compacted: {compacted}"
            ));
        }
        MemoryEvent::DrawerAdded {
            palace_id,
            drawer_count,
        } => {
            state
                .log
                .push(format!("SSE: drawer added → {palace_id} ({drawer_count})"));
        }
        MemoryEvent::DrawerDeleted {
            palace_id,
            drawer_count,
        } => {
            state.log.push(format!(
                "SSE: drawer deleted → {palace_id} ({drawer_count})"
            ));
        }
        MemoryEvent::PalaceCreated { name } => {
            state.log.push(format!("SSE: palace created → {name}"));
        }
    }
}

/// The memory TUI event loop: poll, render, handle input, drain SSE events.
///
/// Why: kept separate from [`run_with_url`] so terminal setup/teardown wraps it
/// cleanly.
/// What: polls the daemon immediately and spawns the `/sse` subscription task,
/// then renders every frame while polling the keyboard every 50 ms; re-polls on
/// the 2 s timer and drains SSE events via `try_recv`. `[d]` triggers a dream
/// cycle, `[Enter]` runs a recall; `Tab`, arrows, `?`, `q`/`Esc`, and `Ctrl-C`
/// behave per [`KEY_HINT`].
/// Test: the pure pieces (state, log, rendering helpers) are unit-tested.
async fn run_loop<B: ratatui::backend::Backend>(
    terminal: &mut Terminal<B>,
    state: &mut MemoryTuiState,
    client: &mut MemoryClient,
) -> anyhow::Result<()> {
    poll_daemon(state, client).await;
    let mut last_poll = Instant::now();

    // Subscribe to the daemon's /sse stream on a background task.
    let (sse_tx, mut sse_rx) = mpsc::channel::<MemoryEvent>(64);
    let sse_client = client.clone();
    tokio::spawn(async move {
        sse_client.sse_stream(sse_tx).await;
    });

    loop {
        terminal.draw(|f| render(f, state))?;

        // Drain any SSE events the subscription task produced since last frame.
        while let Ok(event) = sse_rx.try_recv() {
            apply_memory_event(state, event);
        }

        let key = if event::poll(INPUT_POLL)? {
            match event::read()? {
                Event::Key(key) => Some(key),
                _ => None,
            }
        } else {
            None
        };
        if let Some(key) = key
            && key.kind != KeyEventKind::Release
        {
            // Ctrl-C always quits, regardless of focus or the help overlay.
            if key.modifiers.contains(KeyModifiers::CONTROL) && key.code == KeyCode::Char('c') {
                return Ok(());
            }
            if state.show_help {
                if matches!(key.code, KeyCode::Char('?') | KeyCode::Esc) {
                    state.show_help = false;
                } else if key.code == KeyCode::Char('q') {
                    return Ok(());
                }
                continue;
            }
            match (state.focus, key.code) {
                (_, KeyCode::Char('?')) => state.show_help = true,
                (_, KeyCode::Tab) => state.toggle_focus(),
                (_, KeyCode::Esc) => return Ok(()),
                // List-focus bindings.
                (MemoryFocus::List, KeyCode::Char('q')) => return Ok(()),
                (MemoryFocus::List, KeyCode::Up) => state.select_up(),
                (MemoryFocus::List, KeyCode::Down) => state.select_down(),
                (MemoryFocus::List, KeyCode::Char('d')) => {
                    state.log.push("dream cycle triggered");
                    match client.dream_run().await {
                        Ok(stats) => state.log.push_raw(format!(
                            "  merged: {}  pruned: {}  compacted: {}",
                            stats.merged, stats.pruned, stats.compacted
                        )),
                        Err(e) => state.log.push(format!("dream failed: {e}")),
                    }
                    poll_daemon(state, client).await;
                    last_poll = Instant::now();
                }
                // Input-focus bindings.
                (MemoryFocus::Input, KeyCode::Enter) => {
                    run_recall(state, client).await;
                }
                (MemoryFocus::Input, KeyCode::Backspace) => {
                    state.input.pop();
                }
                (MemoryFocus::Input, KeyCode::Char(c)) => state.input.push(c),
                _ => {}
            }
        }

        if last_poll.elapsed() >= REFRESH_INTERVAL {
            poll_daemon(state, client).await;
            last_poll = Instant::now();
        }
    }
}

/// The body text for the help overlay, one binding per line.
///
/// Why: kept separate so a test can assert every binding is documented.
/// What: returns the multi-line help string.
/// Test: `test_help_text_lists_bindings`.
pub fn help_text() -> String {
    [
        "  Tab     switch focus between the palace list and the recall bar",
        "  ↑ / ↓   move the palace selection (when the list has focus)",
        "  d       run a dream cycle across every palace",
        "  Enter   run a recall query (recall bar)",
        "  ?       toggle this help overlay",
        "  q / Esc quit",
    ]
    .join("\n")
}

/// Compute the width of the left PALACES panel for a given terminal width.
///
/// Why: the layout caps the palace panel so the activity log gets the bulk of
/// the width on wide terminals.
/// What: returns `min(LEFT_PANEL_MAX, width / 3)`.
/// Test: `test_left_panel_width`.
pub fn left_panel_width(width: u16) -> u16 {
    LEFT_PANEL_MAX.min(width / 3)
}

/// Format one palace as a fixed-width table row.
///
/// Why: the PALACES panel lists every palace with its vector count in aligned
/// columns; isolating the formatter makes the alignment unit-testable.
/// What: returns `> <name padded to 10>  <count>v`, where the leading marker
/// is `>` for the selected row and a space otherwise.
/// Test: `test_palace_row_display`.
pub fn palace_row(palace: &PalaceRow, selected: bool) -> String {
    let marker = if selected { ">" } else { " " };
    let label = if palace.name.is_empty() {
        &palace.id
    } else {
        &palace.name
    };
    format!(
        "{marker} {:<10} {:>7}v",
        truncate(label, 10),
        format_count(palace.vector_count),
    )
}

/// Build the lines for the PALACES panel body.
///
/// Why: separating line construction from the ratatui widgets lets a test
/// assert the rendered content without a terminal backend.
/// What: returns one `(text, selected)` pair per palace, then a blank spacer
/// and three aggregate-count lines; an empty list shows a placeholder.
/// Test: `test_palace_lines`.
pub fn palace_lines(state: &MemoryTuiState) -> Vec<(String, bool)> {
    let mut lines: Vec<(String, bool)> = Vec::new();
    if state.palaces.is_empty() {
        lines.push(("(no palaces)".to_string(), false));
    } else {
        for (i, palace) in state.palaces.iter().enumerate() {
            lines.push((palace_row(palace, i == state.selected), i == state.selected));
        }
    }
    lines.push((String::new(), false));
    let stats = state.status.clone().unwrap_or_default();
    lines.push((
        format!("vectors:  {}", format_count(stats.total_vectors)),
        false,
    ));
    lines.push((
        format!("drawers:  {}", format_count(stats.total_drawers)),
        false,
    ));
    lines.push((
        format!("kg:       {}", format_count(stats.total_kg_triples)),
        false,
    ));
    lines
}

/// Truncate a string to `max` characters, appending an ellipsis when cut.
///
/// Why: palace names can be long; the fixed-width left panel needs bounded
/// labels.
/// What: returns `s` unchanged when short enough, else its first `max - 1`
/// characters plus `…`.
/// Test: `test_truncate`.
pub fn truncate(s: &str, max: usize) -> String {
    if s.chars().count() <= max {
        s.to_string()
    } else {
        let kept: String = s.chars().take(max.saturating_sub(1)).collect();
        format!("{kept}…")
    }
}

/// Build the title-bar line for the memory UI.
///
/// Why: the top row shows the daemon name, version, and liveness badge at a
/// glance; isolating it keeps `render` terse and the text testable.
/// What: returns `trusty-memory vX  [●] <status>` — the daemon's reported
/// version is appended when it is online.
/// Test: `test_title_line`.
pub fn title_line(state: &MemoryTuiState) -> String {
    let (glyph, label) = state.daemon_status.badge();
    match &state.daemon_status {
        DaemonStatus::Online { version, .. } => {
            format!("trusty-memory v{version}  [{glyph}] {label}")
        }
        _ => format!(
            "trusty-memory v{VERSION}  [{glyph}] {label}  {}",
            state.base_url
        ),
    }
}

/// Draw the memory TUI frame.
///
/// Why: the single entry point the event loop calls each tick.
/// What: a 4-row vertical layout — title bar, the PALACES/ACTIVITY split, the
/// RECALL input bar, and the key-hint footer. A centred help overlay floats on
/// top when `show_help` is set.
/// Test: line content is unit-tested via the `*_lines` helpers; this glue is
/// exercised by `test_render_smoke`.
pub fn render(frame: &mut Frame, state: &MemoryTuiState) {
    let area = frame.area();
    let rows = Layout::default()
        .direction(Direction::Vertical)
        .constraints([
            Constraint::Length(1), // title bar
            Constraint::Min(4),    // panels
            Constraint::Length(3), // recall input
            Constraint::Length(1), // key hint
        ])
        .split(area);

    // Title bar.
    frame.render_widget(
        Paragraph::new(Line::from(Span::styled(
            title_line(state),
            Style::default()
                .fg(Color::Cyan)
                .add_modifier(Modifier::BOLD),
        ))),
        rows[0],
    );

    // PALACES + ACTIVITY split.
    let split = Layout::default()
        .direction(Direction::Horizontal)
        .constraints([
            Constraint::Length(left_panel_width(area.width)),
            Constraint::Min(10),
        ])
        .split(rows[1]);

    let list_focused = state.focus == MemoryFocus::List;
    let palace_items: Vec<ListItem> = palace_lines(state)
        .into_iter()
        .map(|(text, selected)| {
            let style = if selected {
                Style::default()
                    .fg(Color::Black)
                    .bg(Color::Cyan)
                    .add_modifier(Modifier::BOLD)
            } else {
                Style::default()
            };
            ListItem::new(Line::from(Span::styled(text, style)))
        })
        .collect();
    frame.render_widget(
        List::new(palace_items).block(panel_block("PALACES", list_focused)),
        split[0],
    );

    // ACTIVITY panel — show the tail that fits the panel height.
    let activity_height = split[1].height.saturating_sub(2) as usize;
    let activity_items: Vec<ListItem> = if state.log.is_empty() {
        vec![ListItem::new("(no activity yet)")]
    } else {
        state
            .log
            .tail(activity_height.max(1))
            .map(|line| ListItem::new(line.as_str()))
            .collect()
    };
    frame.render_widget(
        List::new(activity_items).block(panel_block("ACTIVITY", false)),
        split[1],
    );

    // RECALL input bar.
    let input_focused = state.focus == MemoryFocus::Input;
    let cursor = if input_focused { "_" } else { "" };
    let input_style = if input_focused {
        Style::default().fg(Color::Cyan)
    } else {
        Style::default().fg(Color::DarkGray)
    };
    frame.render_widget(
        Paragraph::new(Line::from(vec![
            Span::styled("RECALL ▶ ", Style::default().fg(Color::Yellow)),
            Span::styled(format!("{}{cursor}", state.input), input_style),
        ]))
        .block(panel_block("RECALL", input_focused)),
        rows[2],
    );

    // Key-hint footer.
    frame.render_widget(
        Paragraph::new(Line::from(Span::styled(
            KEY_HINT,
            Style::default().fg(Color::DarkGray),
        ))),
        rows[3],
    );

    if state.show_help {
        render_help_overlay(frame);
    }
}

/// Build a bordered block for a UI panel, highlighting it when focused.
///
/// Why: the focused panel must be visually distinct; both panels share this.
/// What: returns a [`Block`] titled `name` with a thick cyan border when
/// `focused`, a dim gray border otherwise.
fn panel_block(name: &str, focused: bool) -> Block<'static> {
    let border_style = if focused {
        Style::default()
            .fg(Color::Cyan)
            .add_modifier(Modifier::BOLD)
    } else {
        Style::default().fg(Color::DarkGray)
    };
    Block::default()
        .borders(Borders::ALL)
        .border_style(border_style)
        .title(Span::styled(
            format!(" {name} "),
            Style::default()
                .fg(Color::Cyan)
                .add_modifier(Modifier::BOLD),
        ))
}

/// Render the centred help overlay listing every key binding.
///
/// Why: the `?` key shows a floating reference of every binding.
/// What: clears a centred rectangle and draws [`help_text`] in a block.
fn render_help_overlay(frame: &mut Frame) {
    let area = frame.area();
    let w = 60.min(area.width);
    let h = 9.min(area.height);
    let rect = ratatui::layout::Rect {
        x: area.x + area.width.saturating_sub(w) / 2,
        y: area.y + area.height.saturating_sub(h) / 2,
        width: w,
        height: h,
    };
    frame.render_widget(Clear, rect);
    frame.render_widget(
        Paragraph::new(help_text())
            .style(Style::default().fg(Color::White))
            .block(
                Block::default()
                    .borders(Borders::ALL)
                    .title(" Help — press ? or Esc to close "),
            ),
        rect,
    );
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::monitor::utils::timestamped;
    use ratatui::{Terminal, backend::TestBackend};

    /// A state with two palaces and aggregate stats for rendering tests.
    fn sample_state() -> MemoryTuiState {
        let mut state = MemoryTuiState::new("http://127.0.0.1:7070");
        state.daemon_status = DaemonStatus::Online {
            version: "0.1.54".into(),
            uptime_secs: 0,
        };
        state.palaces = vec![
            PalaceRow {
                id: "default".into(),
                name: "default".into(),
                vector_count: 8_400,
            },
            PalaceRow {
                id: "work".into(),
                name: "work".into(),
                vector_count: 0,
            },
        ];
        state.status = Some(MemoryData {
            version: "0.1.54".into(),
            palace_count: 2,
            total_drawers: 14,
            total_vectors: 8_400,
            total_kg_triples: 1_200,
            palaces: state.palaces.clone(),
        });
        state
    }

    #[test]
    fn test_new_state_defaults() {
        let state = MemoryTuiState::new("http://127.0.0.1:7070");
        assert_eq!(state.base_url, "http://127.0.0.1:7070");
        assert!(matches!(state.daemon_status, DaemonStatus::Connecting));
        assert!(state.status.is_none());
        assert!(state.palaces.is_empty());
        assert_eq!(state.selected, 0);
        assert!(state.log.is_empty());
        assert_eq!(state.focus, MemoryFocus::List);
        assert!(!state.show_help);
    }

    #[test]
    fn test_toggle_focus() {
        let mut state = MemoryTuiState::new("http://x");
        assert_eq!(state.focus, MemoryFocus::List);
        state.toggle_focus();
        assert_eq!(state.focus, MemoryFocus::Input);
        state.toggle_focus();
        assert_eq!(state.focus, MemoryFocus::List);
    }

    #[test]
    fn test_selected_clamp() {
        let mut state = sample_state();
        for _ in 0..10 {
            state.select_down();
        }
        assert_eq!(state.selected, 1, "clamped to palaces.len() - 1");
        for _ in 0..10 {
            state.select_up();
        }
        assert_eq!(state.selected, 0);
        // A shrunk palace list re-clamps the cursor.
        state.selected = 1;
        state.palaces.truncate(1);
        state.clamp_selection();
        assert_eq!(state.selected, 0);
        // An empty list resets the cursor.
        state.palaces.clear();
        state.selected = 9;
        state.clamp_selection();
        assert_eq!(state.selected, 0);
    }

    #[test]
    fn test_selected_id() {
        let mut state = sample_state();
        assert_eq!(state.selected_id(), Some("default"));
        state.select_down();
        assert_eq!(state.selected_id(), Some("work"));
        state.palaces.clear();
        state.clamp_selection();
        assert_eq!(state.selected_id(), None);
    }

    #[test]
    fn test_palace_row_display() {
        // The selected row is marked `>`; columns are aligned and the count
        // carries a trailing `v`.
        let palace = PalaceRow {
            id: "default".into(),
            name: "default".into(),
            vector_count: 8_400,
        };
        let selected = palace_row(&palace, true);
        assert!(selected.starts_with('>'), "selected marker: {selected}");
        assert!(selected.contains("default"));
        assert!(selected.contains("8,400v"));

        let unselected = palace_row(&palace, false);
        assert!(unselected.starts_with(' '), "unselected: {unselected}");

        // A nameless palace falls back to its id; a zero count still renders.
        let nameless = PalaceRow {
            id: "p-xyz".into(),
            name: String::new(),
            vector_count: 0,
        };
        let row = palace_row(&nameless, false);
        assert!(row.contains("p-xyz"));
        assert!(row.contains("0v"));

        // A long name is truncated with an ellipsis.
        let long = PalaceRow {
            id: "x".into(),
            name: "a-very-long-palace-name".into(),
            vector_count: 1,
        };
        assert!(palace_row(&long, false).contains('…'));
    }

    #[test]
    fn test_palace_lines() {
        let state = sample_state();
        let lines = palace_lines(&state);
        // Two palace rows + blank spacer + three aggregate lines.
        assert_eq!(lines.len(), 6);
        assert!(lines[0].0.contains("default") && lines[0].1);
        assert!(lines[1].0.contains("work") && !lines[1].1);
        assert!(lines[2].0.is_empty());
        assert!(
            lines
                .iter()
                .any(|(t, _)| t.contains("vectors:") && t.contains("8,400"))
        );
        assert!(
            lines
                .iter()
                .any(|(t, _)| t.contains("drawers:") && t.contains("14"))
        );
        assert!(
            lines
                .iter()
                .any(|(t, _)| t.contains("kg:") && t.contains("1,200"))
        );

        // An empty palace list shows a placeholder, still with the stats.
        let empty = MemoryTuiState::new("http://x");
        let lines = palace_lines(&empty);
        assert!(lines[0].0.contains("no palaces"));
    }

    #[test]
    fn test_log_append_dream() {
        // A dream_completed SSE event appends a header line plus an indented
        // merge/prune/compact stats line.
        let mut state = MemoryTuiState::new("http://x");
        apply_memory_event(
            &mut state,
            MemoryEvent::DreamCompleted {
                merged: 3,
                pruned: 1,
                compacted: 0,
            },
        );
        let lines: Vec<&String> = state.log.iter().collect();
        assert_eq!(lines.len(), 2);
        assert!(lines[0].contains("SSE: dream_completed"));
        assert!(lines[0].starts_with('['), "header is timestamped");
        assert!(lines[1].contains("merged: 3"));
        assert!(lines[1].contains("pruned: 1"));
        assert!(lines[1].contains("compacted: 0"));
        // The continuation line is not timestamped — it reads as a sub-line.
        assert!(lines[1].starts_with("  "));
    }

    #[test]
    fn test_apply_memory_event() {
        let mut state = MemoryTuiState::new("http://x");
        apply_memory_event(
            &mut state,
            MemoryEvent::DrawerAdded {
                palace_id: "default".into(),
                drawer_count: 14,
            },
        );
        apply_memory_event(
            &mut state,
            MemoryEvent::DrawerDeleted {
                palace_id: "work".into(),
                drawer_count: 2,
            },
        );
        apply_memory_event(
            &mut state,
            MemoryEvent::PalaceCreated {
                name: "notes".into(),
            },
        );
        let lines: Vec<&String> = state.log.iter().collect();
        assert_eq!(lines.len(), 3);
        assert!(lines[0].contains("drawer added → default (14)"));
        assert!(lines[1].contains("drawer deleted → work (2)"));
        assert!(lines[2].contains("palace created → notes"));
    }

    #[test]
    fn test_log_capacity() {
        let mut state = MemoryTuiState::new("http://x");
        for i in 0..(ActivityLog::MAX_ENTRIES + 30) {
            state.log.push(format!("event {i}"));
        }
        assert_eq!(state.log.len(), ActivityLog::MAX_ENTRIES);
    }

    #[test]
    fn test_timestamped_format() {
        let line = timestamped("recall complete");
        assert!(line.starts_with('['));
        assert!(line.ends_with(" recall complete"));
        assert_eq!(line.as_bytes()[9], b']');
    }

    #[test]
    fn test_left_panel_width() {
        assert_eq!(left_panel_width(200), LEFT_PANEL_MAX);
        assert_eq!(left_panel_width(60), 20);
    }

    #[test]
    fn test_truncate() {
        assert_eq!(truncate("work", 10), "work");
        assert_eq!(truncate("a-very-long-palace", 8), "a-very-…");
    }

    #[test]
    fn test_title_line() {
        let state = sample_state();
        let title = title_line(&state);
        assert!(title.contains("trusty-memory v0.1.54"));
        assert!(title.contains("online"));

        let mut offline = MemoryTuiState::new("http://127.0.0.1:7070");
        offline.daemon_status = DaemonStatus::Offline {
            last_error: "refused".into(),
        };
        let title = title_line(&offline);
        assert!(title.contains("offline"));
        assert!(title.contains("http://127.0.0.1:7070"));
    }

    #[test]
    fn test_help_text_lists_bindings() {
        let text = help_text();
        for token in ["Tab", "d ", "Enter", "?", "q "] {
            assert!(text.contains(token), "help text missing {token}");
        }
    }

    #[test]
    fn test_render_smoke() {
        let mut state = sample_state();
        state.log.push("SSE: dream_completed");
        state.log.push("recall \"auth flow\" → 3 results");
        state.input = "auth flow".into();
        state.focus = MemoryFocus::Input;
        for (w, h) in [(120u16, 30u16), (80, 24)] {
            let backend = TestBackend::new(w, h);
            let mut terminal = Terminal::new(backend).expect("test terminal");
            terminal
                .draw(|f| render(f, &state))
                .expect("render must not panic");
        }
        state.show_help = true;
        state.daemon_status = DaemonStatus::Connecting;
        let backend = TestBackend::new(120, 30);
        let mut terminal = Terminal::new(backend).expect("test terminal");
        terminal
            .draw(|f| render(f, &state))
            .expect("help render must not panic");
    }
}