zeph-tui 0.21.2

// SPDX-FileCopyrightText: 2026 Andrei G <bug-ops>
// SPDX-License-Identifier: MIT OR Apache-2.0

//! TUI fleet panel: shows a live table of all agent sessions (#3884).

use ratatui::Frame;
use ratatui::layout::Rect;
use ratatui::style::{Color, Modifier, Style};
use ratatui::text::{Line, Span};
use ratatui::widgets::{Block, Borders, List, ListItem, ListState};
use zeph_common::format_tokens;
use zeph_memory::store::agent_sessions::{AgentSessionRow, SessionStatus};

use crate::theme::Theme;

/// Cached fleet data loaded from the database by the background refresh task.
#[derive(Debug, Clone, Default)]
pub struct FleetSnapshot {
    /// Sessions ordered by `last_active_at` descending.
    pub sessions: Vec<AgentSessionRow>,
}

fn status_color(status: SessionStatus) -> Color {
    match status {
        SessionStatus::Active => Color::Green,
        SessionStatus::Completed => Color::DarkGray,
        SessionStatus::Failed => Color::Red,
        SessionStatus::Cancelled => Color::Yellow,
        SessionStatus::Unknown => Color::Magenta,
    }
}

fn build_session_item(row: &AgentSessionRow, selected: bool) -> ListItem<'static> {
    let color = status_color(row.status);
    let base = if selected {
        Style::default().add_modifier(Modifier::REVERSED)
    } else {
        Style::default()
    };

    let id_short: String = row.id.chars().take(8).collect();

    let model_short = if row.model.chars().count() > 20 {
        format!("{}…", row.model.chars().take(19).collect::<String>())
    } else {
        row.model.clone()
    };

    let tokens = format!(
        "{}/{}",
        format_tokens(row.prompt_tokens),
        format_tokens(row.completion_tokens)
    );
    let cost = if row.cost_cents > 0.0 {
        format!("${:.4}", row.cost_cents / 100.0)
    } else {
        "—".to_owned()
    };

    let line = Line::from(vec![
        Span::styled(format!(" {id_short}  "), base),
        Span::styled(format!("{:<12}", row.kind), base.fg(color)),
        Span::styled(format!("{:<11}", row.status), base.fg(color)),
        Span::styled(format!("{:<5}", row.channel), base),
        Span::styled(format!("{model_short:<22}"), base),
        Span::styled(format!("{:>5}  ", row.turns), base),
        Span::styled(format!("{tokens:<15}"), base),
        Span::styled(cost, base),
    ]);
    ListItem::new(line)
}

/// Render the fleet panel.
///
/// `list_state` is used for scroll position tracking.
pub fn render(snapshot: &FleetSnapshot, frame: &mut Frame, area: Rect, list_state: &mut ListState) {
    let theme = Theme::default();

    let block = Block::default()
        .borders(Borders::ALL)
        .border_style(theme.panel_border)
        .title(Span::styled(
            " Fleet [f] ",
            Style::default().add_modifier(Modifier::BOLD),
        ));

    if snapshot.sessions.is_empty() {
        let inner = block.inner(area);
        frame.render_widget(block, area);
        let msg = ratatui::widgets::Paragraph::new("No agent sessions recorded.")
            .style(Style::default().fg(Color::DarkGray));
        frame.render_widget(msg, inner);
        return;
    }

    let header = ListItem::new(Line::from(vec![Span::styled(
        format!(
            " {:<8}  {:<12}{:<11}{:<5}{:<22}{:>5}  {:<15}{}",
            "ID", "KIND", "STATUS", "CH", "MODEL", "TURNS", "P/C TOKENS", "COST"
        ),
        Style::default().add_modifier(Modifier::BOLD),
    )]));

    let mut items: Vec<ListItem> = vec![header];
    for (i, row) in snapshot.sessions.iter().enumerate() {
        let selected = list_state.selected() == Some(i + 1);
        items.push(build_session_item(row, selected));
    }

    let list = List::new(items)
        .block(block)
        .highlight_style(Style::default().add_modifier(Modifier::REVERSED));
    frame.render_stateful_widget(list, area, list_state);
}

#[cfg(test)]
mod tests {
    use super::format_tokens;

    #[test]
    fn format_tokens_zero() {
        assert_eq!(format_tokens(0), "0");
    }

    #[test]
    fn format_tokens_below_1k() {
        assert_eq!(format_tokens(999), "999");
    }

    #[test]
    fn format_tokens_exactly_1k() {
        assert_eq!(format_tokens(1_000), "1.0k");
    }

    #[test]
    fn format_tokens_below_1m() {
        assert_eq!(format_tokens(999_999), "1000.0k");
    }

    #[test]
    fn format_tokens_exactly_1m() {
        assert_eq!(format_tokens(1_000_000), "1.0M");
    }
}