zeph-tui 0.21.4

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

use std::fmt::Write as _;

use ratatui::Frame;
use ratatui::layout::Rect;
use ratatui::style::{Color, Style};
use ratatui::text::{Line, Span};
use ratatui::widgets::Paragraph;
use zeph_common::format_tokens;

use crate::app::{App, InputMode};
use crate::metrics::MetricsSnapshot;
use crate::theme::Theme;

/// Priority level for a status bar segment.
///
/// Lower numeric value = higher importance. `Critical` segments are never dropped;
/// lower-priority segments are dropped LIFO (last pushed = first dropped) within
/// a priority level when the status bar width is exceeded.
#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
enum Priority {
    Critical = 1,
    High = 2,
    Medium = 3,
    Low = 4,
}

struct Segment {
    spans: Vec<Span<'static>>,
    priority: Priority,
    width: u16,
}

struct SegmentList {
    segments: Vec<Segment>,
}

impl SegmentList {
    fn new() -> Self {
        Self {
            segments: Vec::new(),
        }
    }

    fn push(&mut self, priority: Priority, spans: Vec<Span<'static>>) {
        // TODO: use unicode_width for correct CJK/emoji column count
        let width: u16 = spans.iter().fold(0u16, |acc, s| {
            acc.saturating_add(u16::try_from(s.content.chars().count()).unwrap_or(u16::MAX))
        });
        self.segments.push(Segment {
            spans,
            priority,
            width,
        });
    }

    /// Iteratively drop the last-pushed segment among those with the highest (lowest importance)
    /// priority level until total fits within `max_width`, never dropping Critical.
    fn layout(mut self, max_width: u16) -> Vec<Span<'static>> {
        loop {
            let total: u16 = self
                .segments
                .iter()
                .fold(0u16, |a, s| a.saturating_add(s.width));
            if total <= max_width {
                break;
            }
            // Find the worst (highest) priority among non-Critical segments.
            let worst = self
                .segments
                .iter()
                .filter(|s| s.priority != Priority::Critical)
                .map(|s| s.priority)
                .max();
            let Some(worst_priority) = worst else {
                // Only Critical segments remain — truncate the last one's spans if needed.
                break;
            };
            // Drop the last-pushed segment at that priority level (LIFO).
            let drop_idx = self
                .segments
                .iter()
                .enumerate()
                .rev()
                .find(|(_, s)| s.priority == worst_priority)
                .map(|(i, _)| i);
            if let Some(idx) = drop_idx {
                self.segments.remove(idx);
            } else {
                break;
            }
        }

        // If Critical segments still overflow, truncate the last Critical span's content.
        let total: u16 = self
            .segments
            .iter()
            .fold(0u16, |a, s| a.saturating_add(s.width));
        if total > max_width && !self.segments.is_empty() {
            let overflow = total.saturating_sub(max_width) as usize;
            if let Some(last_span) = self
                .segments
                .last_mut()
                .and_then(|seg| seg.spans.last_mut())
            {
                let chars: Vec<char> = last_span.content.chars().collect();
                let keep = chars.len().saturating_sub(overflow);
                let truncated: String = chars[..keep].iter().collect();
                last_span.content = truncated.into();
            }
        }

        self.segments
            .into_iter()
            .flat_map(Segment::into_spans)
            .collect()
    }
}

impl Segment {
    fn into_spans(self) -> Vec<Span<'static>> {
        self.spans
    }
}

pub fn render(app: &App, metrics: &MetricsSnapshot, frame: &mut Frame, area: Rect) {
    let theme = Theme::default();
    let list = build_segment_list(app, metrics, &theme);
    let spans = list.layout(area.width);
    let line = Line::from(spans);
    let paragraph = Paragraph::new(line).style(theme.status_bar);
    frame.render_widget(paragraph, area);
}

fn build_segment_list(app: &App, metrics: &MetricsSnapshot, theme: &Theme) -> SegmentList {
    let mode = match app.input_mode() {
        InputMode::Normal => "Normal",
        InputMode::Insert => "Insert",
    };

    let mut list = SegmentList::new();

    push_critical_segments(&mut list, metrics, mode, theme);
    list.push(
        Priority::High,
        vec![Span::styled(" | ? for help", theme.status_bar)],
    );
    push_medium_segments(&mut list, app, metrics, theme);
    push_low_segments(&mut list, app, metrics, theme);

    list
}

fn push_critical_segments(
    list: &mut SegmentList,
    metrics: &MetricsSnapshot,
    mode: &str,
    theme: &Theme,
) {
    list.push(
        Priority::Critical,
        vec![Span::styled(format!(" [{mode}]"), theme.status_bar)],
    );
    if !metrics.model_name.is_empty() {
        list.push(
            Priority::Critical,
            vec![Span::styled(
                format!(" | {}", metrics.model_name),
                theme.status_bar,
            )],
        );
    }
    if metrics.context_max_tokens > 0 {
        let pct = context_pct(metrics.context_tokens, metrics.context_max_tokens);
        list.push(
            Priority::Critical,
            vec![Span::styled(format!(" | ctx:{pct}%"), theme.status_bar)],
        );
    }
}

fn push_medium_segments(
    list: &mut SegmentList,
    app: &App,
    metrics: &MetricsSnapshot,
    theme: &Theme,
) {
    let plan_seg = plan_mode_segment(app, metrics);
    if !plan_seg.is_empty() {
        list.push(
            Priority::Medium,
            vec![Span::styled(plan_seg.to_owned(), theme.status_bar)],
        );
    }
    let subagent_seg = subagent_view_segment(app);
    if !subagent_seg.is_empty() {
        list.push(
            Priority::Medium,
            vec![Span::styled(subagent_seg, theme.status_bar)],
        );
    }
    if !metrics.active_channel.is_empty() {
        list.push(
            Priority::Medium,
            vec![Span::styled(
                format!(" | ch:{}", metrics.active_channel),
                theme.status_bar,
            )],
        );
    }
    list.push(
        Priority::Medium,
        vec![Span::styled(
            format!(
                " | Skills: {} active / {} loaded",
                metrics.active_skills.len(),
                metrics.total_skills,
            ),
            theme.status_bar,
        )],
    );
}

#[allow(clippy::too_many_lines)]
fn push_low_segments(list: &mut SegmentList, app: &App, metrics: &MetricsSnapshot, theme: &Theme) {
    let token_str = if metrics.reasoning_tokens > 0 {
        format!(
            " | Tokens: {} (R: {})",
            format_tokens(metrics.total_tokens),
            format_tokens(metrics.reasoning_tokens)
        )
    } else {
        format!(" | Tokens: {}", format_tokens(metrics.total_tokens))
    };
    list.push(
        Priority::Low,
        vec![Span::styled(token_str, theme.status_bar)],
    );
    if metrics.cost_spent_cents > 0.0 {
        list.push(
            Priority::Low,
            vec![Span::styled(
                format!(" | ${:.4}", metrics.cost_spent_cents / 100.0),
                theme.status_bar,
            )],
        );
    }
    list.push(
        Priority::Low,
        vec![Span::styled(
            format!(" | API: {}", metrics.api_calls),
            theme.status_bar,
        )],
    );
    list.push(
        Priority::Low,
        vec![Span::styled(
            format!(" | {}", format_uptime(metrics.uptime_seconds)),
            theme.status_bar,
        )],
    );
    if !metrics.shell_background_runs.is_empty() {
        list.push(
            Priority::Low,
            vec![Span::styled(
                format!(" | sh:{}", metrics.shell_background_runs.len()),
                theme.status_bar,
            )],
        );
    }
    if let Some(cocoon_seg) = build_cocoon_spans(metrics, app.show_balance(), theme) {
        list.push(Priority::Low, cocoon_seg);
    }
    if metrics.bg_enrichment_inflight > 0 || metrics.bg_telemetry_inflight > 0 {
        list.push(
            Priority::Low,
            vec![Span::styled(
                format!(
                    " | bg: {} enrich, {} telem",
                    metrics.bg_enrichment_inflight, metrics.bg_telemetry_inflight,
                ),
                theme.status_bar,
            )],
        );
    }
    if metrics.server_compaction_events > 0 {
        list.push(
            Priority::Low,
            vec![
                Span::styled(" | ", theme.status_bar),
                Span::styled(
                    format!("[SC: {}]", metrics.server_compaction_events),
                    Style::default().fg(Color::Cyan),
                ),
            ],
        );
    }
    if let Some(ref snap) = metrics.active_goal {
        list.push(Priority::Low, build_goal_spans(snap, theme));
    }
    if metrics.filter_applications > 0 {
        list.push(
            Priority::Low,
            vec![Span::styled(build_filter_text(metrics), theme.status_bar)],
        );
    }
    let security_spans = build_security_spans(metrics, theme);
    if !security_spans.is_empty() {
        list.push(Priority::Low, security_spans);
    }
    if app.is_agent_busy() && app.input_mode() == InputMode::Normal {
        list.push(
            Priority::Low,
            vec![Span::styled(" | [Esc to cancel]", theme.status_bar)],
        );
    }
}

fn context_pct(context_tokens: u64, context_max_tokens: u64) -> u64 {
    #[allow(clippy::cast_precision_loss)]
    let ratio = (context_tokens as f64 / context_max_tokens as f64 * 100.0).clamp(0.0, 100.0);
    #[allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)]
    let pct = ratio as u64;
    pct
}

fn build_cocoon_spans(
    metrics: &MetricsSnapshot,
    show_balance: bool,
    theme: &Theme,
) -> Option<Vec<Span<'static>>> {
    match metrics.cocoon_connected {
        None => None,
        Some(true) => {
            let mut text = format!(
                " | Cocoon: healthy ({} models, {} workers)",
                metrics.cocoon_model_count, metrics.cocoon_worker_count,
            );
            if let Some(balance) = metrics.cocoon_ton_balance {
                if show_balance {
                    let _ = write!(text, ", {balance:.2} TON");
                } else {
                    text.push_str(", *** TON");
                }
            }
            Some(vec![Span::styled(text, theme.status_bar)])
        }
        Some(false) => Some(vec![Span::styled(
            " | Cocoon: sidecar unreachable".to_owned(),
            theme.status_bar,
        )]),
    }
}

fn build_goal_spans(snap: &crate::metrics::GoalSnapshot, theme: &Theme) -> Vec<Span<'static>> {
    use crate::metrics::GoalStatus;
    let (icon, color) = match snap.status {
        GoalStatus::Active => ("▶", Color::Green),
        GoalStatus::Paused => ("⏸", Color::Yellow),
        GoalStatus::Completed => ("✓", Color::Cyan),
        GoalStatus::Cleared => ("✗", Color::Red),
        _ => ("?", Color::DarkGray),
    };
    let label = if snap.text.is_empty() {
        format!(" {icon} goal")
    } else {
        let short: String = snap.text.chars().take(30).collect();
        let truncated = if snap.text.chars().count() > 30 {
            format!("{short}…")
        } else {
            short
        };
        format!(" {icon} {truncated}")
    };
    vec![
        Span::styled(" | ", theme.status_bar),
        Span::styled(label, Style::default().fg(color)),
    ]
}

fn build_security_spans(metrics: &MetricsSnapshot, theme: &Theme) -> Vec<Span<'static>> {
    let injection_flags = metrics.sanitizer_injection_flags;
    let exfil_total = metrics.exfiltration_images_blocked
        + metrics.exfiltration_tool_urls_flagged
        + metrics.exfiltration_memory_guards;

    let mut spans: Vec<Span<'static>> = Vec::new();

    if injection_flags > 0 || exfil_total > 0 {
        spans.push(Span::styled(" | ", theme.status_bar));
        if injection_flags > 0 {
            spans.push(Span::styled(
                format!("SEC: {injection_flags} flags"),
                Style::default().fg(Color::Yellow),
            ));
        }
        if exfil_total > 0 {
            if injection_flags > 0 {
                spans.push(Span::styled(" ", theme.status_bar));
            }
            spans.push(Span::styled(
                format!("{exfil_total} blocked"),
                Style::default().fg(Color::Red),
            ));
        }
    }
    if metrics.guardrail_enabled {
        spans.push(Span::styled(" | ", theme.status_bar));
        let (label, color) = if metrics.guardrail_warn_mode {
            ("GRD:warn", Color::Yellow)
        } else {
            ("GRD:on", Color::Green)
        };
        spans.push(Span::styled(label, Style::default().fg(color)));
    }

    spans
}

fn subagent_view_segment(app: &App) -> String {
    if let Some(name) = app.view_target().subagent_name() {
        format!(" | Viewing: {name}")
    } else {
        String::new()
    }
}

fn plan_mode_segment<'a>(app: &App, metrics: &MetricsSnapshot) -> &'a str {
    if metrics
        .orchestration_graph
        .as_ref()
        .is_some_and(|s| !s.is_stale())
    {
        if app.plan_view_active() {
            " | [Agents]"
        } else {
            " | [Plan]"
        }
    } else {
        ""
    }
}

#[allow(clippy::cast_precision_loss)]
fn build_filter_text(metrics: &MetricsSnapshot) -> String {
    let savings = if metrics.filter_raw_tokens > 0 {
        metrics.filter_saved_tokens as f64 / metrics.filter_raw_tokens as f64 * 100.0
    } else {
        0.0
    };
    format!(
        " | Filters: {}/{} ({savings:.0}% saved)",
        metrics.filter_filtered_commands, metrics.filter_total_commands,
    )
}

fn format_uptime(secs: u64) -> String {
    let m = secs / 60;
    let s = secs % 60;
    if m > 0 {
        format!("{m}m {s:02}s")
    } else {
        format!("{s}s")
    }
}

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

    #[test]
    fn format_tokens_small() {
        assert_eq!(format_tokens(500), "500");
    }

    #[test]
    fn format_tokens_thousands() {
        assert_eq!(format_tokens(4200), "4.2k");
    }

    #[test]
    fn format_tokens_millions() {
        assert_eq!(format_tokens(1_500_000), "1.5M");
    }

    #[test]
    fn format_uptime_seconds_only() {
        assert_eq!(format_uptime(45), "45s");
    }

    #[test]
    fn format_uptime_minutes_and_seconds() {
        assert_eq!(format_uptime(135), "2m 15s");
    }

    #[test]
    fn segment_list_drops_low_before_high() {
        let theme = Theme::default();
        let mut list = SegmentList::new();
        // Critical: 10 chars
        list.push(
            Priority::Critical,
            vec![Span::styled("0123456789", theme.status_bar)],
        );
        // High: 10 chars
        list.push(
            Priority::High,
            vec![Span::styled("ABCDEFGHIJ", theme.status_bar)],
        );
        // Low: 10 chars — should be dropped first
        list.push(
            Priority::Low,
            vec![Span::styled("xxxxxxxxxx", theme.status_bar)],
        );
        // max_width = 20: Critical + High fit (20 chars), Low is dropped
        let spans = list.layout(20);
        let text: String = spans.iter().map(|s| s.content.as_ref()).collect();
        assert!(text.contains("0123456789"), "Critical must survive");
        assert!(text.contains("ABCDEFGHIJ"), "High must survive");
        assert!(!text.contains("xxxxxxxxxx"), "Low must be dropped");
    }

    #[test]
    fn segment_list_lifo_among_equal_priority() {
        let theme = Theme::default();
        let mut list = SegmentList::new();
        // Critical: 10 chars
        list.push(
            Priority::Critical,
            vec![Span::styled("0123456789", theme.status_bar)],
        );
        // Two Low segments: the last-pushed (B) should be dropped first
        list.push(
            Priority::Low,
            vec![Span::styled("AAAAAAAAAA", theme.status_bar)],
        );
        list.push(
            Priority::Low,
            vec![Span::styled("BBBBBBBBBB", theme.status_bar)],
        );
        // max_width = 20: Critical + A fit, B is dropped (LIFO)
        let spans = list.layout(20);
        let text: String = spans.iter().map(|s| s.content.as_ref()).collect();
        assert!(text.contains("0123456789"), "Critical must survive");
        assert!(text.contains("AAAAAAAAAA"), "First Low must survive");
        assert!(
            !text.contains("BBBBBBBBBB"),
            "Second Low (LIFO) must be dropped"
        );
    }

    #[test]
    fn segment_list_critical_never_dropped() {
        let theme = Theme::default();
        let mut list = SegmentList::new();
        list.push(
            Priority::Critical,
            vec![Span::styled("CRITICAL_SEGMENT_DATA", theme.status_bar)],
        );
        list.push(
            Priority::Low,
            vec![Span::styled("lowpri", theme.status_bar)],
        );
        // Extremely narrow — Low must be dropped, Critical survives (possibly truncated).
        let spans = list.layout(5);
        let text: String = spans.iter().map(|s| s.content.as_ref()).collect();
        assert!(
            !text.contains("lowpri"),
            "Low must be dropped under pressure"
        );
    }

    #[test]
    fn status_bar_snapshot() {
        use insta::assert_snapshot;
        use tokio::sync::mpsc;

        use crate::app::App;
        use crate::metrics::MetricsSnapshot;
        use crate::test_utils::render_to_string;

        let (user_tx, _) = mpsc::channel(1);
        let (_, agent_rx) = mpsc::channel(1);
        let app = App::new(user_tx, agent_rx);
        let metrics = MetricsSnapshot {
            total_tokens: 4200,
            api_calls: 12,
            active_skills: vec!["web".into(), "code".into()],
            total_skills: 5,
            qdrant_available: true,
            vector_backend: "qdrant".into(),
            uptime_seconds: 135,
            ..MetricsSnapshot::default()
        };

        let output = render_to_string(100, 1, |frame, area| {
            super::render(&app, &metrics, frame, area);
        });
        assert_snapshot!(output);
    }

    #[test]
    fn status_bar_shows_sec_flags_when_injection_flags_nonzero() {
        use tokio::sync::mpsc;

        use crate::app::App;
        use crate::metrics::MetricsSnapshot;
        use crate::test_utils::render_to_string;

        let (user_tx, _) = mpsc::channel(1);
        let (_, agent_rx) = mpsc::channel(1);
        let app = App::new(user_tx, agent_rx);
        let metrics = MetricsSnapshot {
            sanitizer_injection_flags: 2,
            ..MetricsSnapshot::default()
        };

        let output = render_to_string(180, 1, |frame, area| {
            super::render(&app, &metrics, frame, area);
        });
        assert!(
            output.contains("SEC: 2 flags"),
            "expected SEC indicator with flag count"
        );
    }

    #[test]
    fn status_bar_shows_blocked_when_exfiltration_nonzero() {
        use tokio::sync::mpsc;

        use crate::app::App;
        use crate::metrics::MetricsSnapshot;
        use crate::test_utils::render_to_string;

        let (user_tx, _) = mpsc::channel(1);
        let (_, agent_rx) = mpsc::channel(1);
        let app = App::new(user_tx, agent_rx);
        let metrics = MetricsSnapshot {
            exfiltration_images_blocked: 1,
            ..MetricsSnapshot::default()
        };

        let output = render_to_string(180, 1, |frame, area| {
            super::render(&app, &metrics, frame, area);
        });
        assert!(
            output.contains("1 blocked"),
            "expected blocked count in status bar"
        );
    }

    #[test]
    fn status_bar_shows_channel_when_active_channel_set() {
        use tokio::sync::mpsc;

        use crate::app::App;
        use crate::metrics::MetricsSnapshot;
        use crate::test_utils::render_to_string;

        let (user_tx, _) = mpsc::channel(1);
        let (_, agent_rx) = mpsc::channel(1);
        let app = App::new(user_tx, agent_rx);
        let metrics = MetricsSnapshot {
            active_channel: "tui".into(),
            ..MetricsSnapshot::default()
        };

        let output = render_to_string(180, 1, |frame, area| {
            super::render(&app, &metrics, frame, area);
        });
        assert!(
            output.contains("ch:tui"),
            "expected ch:tui in status bar; got: {output:?}"
        );
    }

    #[test]
    fn status_bar_shows_model_name_when_set() {
        use tokio::sync::mpsc;

        use crate::app::App;
        use crate::metrics::MetricsSnapshot;
        use crate::test_utils::render_to_string;

        let (user_tx, _) = mpsc::channel(1);
        let (_, agent_rx) = mpsc::channel(1);
        let app = App::new(user_tx, agent_rx);
        let metrics = MetricsSnapshot {
            model_name: "claude-sonnet-4-6".into(),
            ..MetricsSnapshot::default()
        };

        let output = render_to_string(180, 1, |frame, area| {
            super::render(&app, &metrics, frame, area);
        });
        assert!(
            output.contains("claude-sonnet-4-6"),
            "expected model name in status bar; got: {output:?}"
        );
    }

    #[test]
    fn cocoon_segment_none_is_empty() {
        let metrics = MetricsSnapshot::default();
        let theme = Theme::default();
        assert!(build_cocoon_spans(&metrics, true, &theme).is_none());
    }

    #[test]
    fn cocoon_segment_healthy() {
        let theme = Theme::default();
        let metrics = MetricsSnapshot {
            cocoon_connected: Some(true),
            cocoon_worker_count: 12,
            cocoon_model_count: 3,
            cocoon_ton_balance: Some(42.5),
            ..MetricsSnapshot::default()
        };
        let spans = build_cocoon_spans(&metrics, true, &theme).expect("should be Some");
        let text: String = spans.iter().map(|s| s.content.as_ref()).collect();
        assert!(text.contains("healthy"), "got: {text}");
        assert!(text.contains("3 models"), "got: {text}");
        assert!(text.contains("12 workers"), "got: {text}");
        assert!(text.contains("42.50 TON"), "got: {text}");
    }

    #[test]
    fn cocoon_segment_unreachable() {
        let theme = Theme::default();
        let metrics = MetricsSnapshot {
            cocoon_connected: Some(false),
            ..MetricsSnapshot::default()
        };
        let spans = build_cocoon_spans(&metrics, true, &theme).expect("should be Some");
        let text: String = spans.iter().map(|s| s.content.as_ref()).collect();
        assert!(
            text.contains("unreachable"),
            "expected 'unreachable' in segment"
        );
    }

    #[test]
    fn cocoon_segment_balance_redacted_when_show_balance_false() {
        let theme = Theme::default();
        let metrics = MetricsSnapshot {
            cocoon_connected: Some(true),
            cocoon_worker_count: 4,
            cocoon_model_count: 2,
            cocoon_ton_balance: Some(99.9),
            ..MetricsSnapshot::default()
        };
        let spans = build_cocoon_spans(&metrics, false, &theme).expect("should be Some");
        let text: String = spans.iter().map(|s| s.content.as_ref()).collect();
        assert!(text.contains("*** TON"), "balance must be redacted: {text}");
        assert!(
            !text.contains("99.9"),
            "real balance must not appear: {text}"
        );
    }

    #[test]
    fn status_bar_omits_sec_when_all_zero() {
        use tokio::sync::mpsc;

        use crate::app::App;
        use crate::metrics::MetricsSnapshot;
        use crate::test_utils::render_to_string;

        let (user_tx, _) = mpsc::channel(1);
        let (_, agent_rx) = mpsc::channel(1);
        let app = App::new(user_tx, agent_rx);
        let metrics = MetricsSnapshot::default();

        let output = render_to_string(180, 1, |frame, area| {
            super::render(&app, &metrics, frame, area);
        });
        assert!(
            !output.contains("SEC:"),
            "SEC indicator must be hidden when all counters are zero"
        );
    }

    #[test]
    fn status_bar_full_width_120() {
        use insta::assert_snapshot;
        use tokio::sync::mpsc;

        use crate::app::App;
        use crate::metrics::MetricsSnapshot;
        use crate::test_utils::render_to_string;

        let (user_tx, _) = mpsc::channel(1);
        let (_, agent_rx) = mpsc::channel(1);
        let app = App::new(user_tx, agent_rx);
        let metrics = MetricsSnapshot {
            model_name: "claude-sonnet-4-6".into(),
            context_tokens: 8_000,
            context_max_tokens: 100_000,
            total_tokens: 12_500,
            uptime_seconds: 300,
            api_calls: 7,
            active_skills: vec!["code".into()],
            total_skills: 3,
            ..MetricsSnapshot::default()
        };

        let output = render_to_string(120, 1, |frame, area| {
            super::render(&app, &metrics, frame, area);
        });
        assert_snapshot!(output);
    }
}