zesdex/src/view/sidebar.rs

//! Persistent right-hand dashboard sidebar: Workflow, Tasks, and Usage
//! widgets stacked in three vertical thirds — the "glance" view that
//! complements the `Overlay::Todo` / `Overlay::Usage` "expand" views in
//! `view/mod.rs`.

use ratatui::layout::{Constraint, Direction, Layout, Rect};
use ratatui::style::{Style, Modifier};
use ratatui::text::{Line, Span};
use ratatui::widgets::{Block, Borders, Paragraph};
use ratatui::Frame;
use super::theme::Theme;

/// Render the persistent right-hand dashboard: Workflow, Tasks, and Usage
/// widgets stacked in three roughly-equal vertical thirds.
pub fn draw_sidebar(frame: &mut Frame, area: Rect, state: &crate::app::state::rest::AppStateRest) {
    let chunks = Layout::default()
        .direction(Direction::Vertical)
        .constraints([
            Constraint::Ratio(1, 3),
            Constraint::Ratio(1, 3),
            Constraint::Ratio(1, 3),
        ])
        .split(area);

    super::workflow::draw_workflow_widget(frame, chunks[0], state);
    draw_tasks_widget(frame, chunks[1], state);
    draw_usage_widget(frame, chunks[2], state);
}

/// Compact Tasks widget: `misc.todo_content` split into lines, truncated
/// to whatever fits with a trailing "+N more" hint pointing at `/todo`.
fn draw_tasks_widget(frame: &mut Frame, area: Rect, state: &crate::app::state::rest::AppStateRest) {
    let block = Block::default()
        .title(Span::styled(" Tasks ", Style::default().fg(Theme::ACCENT_PURPLE).add_modifier(Modifier::BOLD)))
        .borders(Borders::ALL)
        .border_style(Style::default().fg(Theme::BORDER));
    let budget = (block.inner(area).height as usize).max(1);

    let content = &state.misc.todo_content;
    let task_lines: Vec<&str> = content.lines().filter(|l| !l.trim().is_empty()).collect();

    let lines: Vec<Line> = if task_lines.is_empty() {
        vec![Line::from(Span::styled(" No tasks yet.", Style::default().fg(Theme::TEXT_DIM)))]
    } else {
        let show_hint = task_lines.len() > budget;
        let item_budget = if show_hint { budget.saturating_sub(1).max(1) } else { budget };
        let (visible, hidden) = super::split_for_display(&task_lines, item_budget);
        let mut lines: Vec<Line> = visible.iter()
            .map(|l| Line::from(Span::styled(format!(" {l}"), Style::default().fg(Theme::TEXT))))
            .collect();
        if show_hint {
            lines.push(super::overflow_hint_line(hidden, "/todo"));
        }
        lines
    };

    let paragraph = Paragraph::new(lines).block(block);
    frame.render_widget(paragraph, area);
}

/// Compact Usage widget: main/self-learning token split, API call count,
/// and session clock. Always fits (the summary is a fixed handful of
/// lines), so there is no overflow hint — the `Overlay::Usage` "expand"
/// view adds edit/review/lesson activity counters on top of this same
/// summary rather than showing more of a truncated list.
fn draw_usage_widget(frame: &mut Frame, area: Rect, state: &crate::app::state::rest::AppStateRest) {
    let block = Block::default()
        .title(Span::styled(" Usage ", Style::default().fg(Theme::INFO).add_modifier(Modifier::BOLD)))
        .borders(Borders::ALL)
        .border_style(Style::default().fg(Theme::BORDER));

    let lines: Vec<Line> = if let Some(ref rt) = state.session_runtime {
        let now_ms = chrono::Utc::now().timestamp_millis();
        let summary = compute_usage_summary(&rt.usage, rt.session_start, now_ms);
        vec![
            Line::from(Span::styled(
                format!(" {} tok ({} main / {} learn)", summary.total_tokens, summary.main_tokens, summary.self_learning_tokens),
                Style::default().fg(Theme::TEXT).add_modifier(Modifier::BOLD),
            )),
            Line::from(Span::styled(
                format!(" {} API calls", summary.api_calls),
                Style::default().fg(Theme::TEXT_DIM),
            )),
            Line::from(Span::styled(
                format!(" {}h {}m {}s", summary.elapsed_hours, summary.elapsed_minutes, summary.elapsed_seconds),
                Style::default().fg(Theme::TEXT_DIM),
            )),
        ]
    } else {
        vec![Line::from(Span::styled(" No active session.", Style::default().fg(Theme::TEXT_DIM)))]
    };

    let paragraph = Paragraph::new(lines).block(block);
    frame.render_widget(paragraph, area);
}

/// Derived, display-ready usage numbers shared by the compact Usage
/// widget and the `Overlay::Usage` expand view.
pub(crate) struct UsageSummary {
    pub main_tokens: u64,
    pub self_learning_tokens: u64,
    pub total_tokens: u64,
    pub api_calls: u64,
    pub elapsed_hours: i64,
    pub elapsed_minutes: i64,
    pub elapsed_seconds: i64,
}

/// Compute display-ready usage numbers from raw session counters.
///
/// Flow: total = `tokens_in` + `tokens_out` → main = total - `review_tokens`
/// (the self-learning share) → elapsed = `now_ms` - `session_start`, split
/// into h/m/s.
///
/// Why `now_ms` is a parameter instead of reading the clock internally:
/// keeps this function pure and deterministic for testing.
pub(crate) fn compute_usage_summary(
    usage: &crate::app::state::runtime::UsageStats,
    session_start: i64,
    now_ms: i64,
) -> UsageSummary {
    let total_tokens = usage.tokens_in.saturating_add(usage.tokens_out);
    let self_learning_tokens = usage.review_tokens;
    let main_tokens = total_tokens.saturating_sub(self_learning_tokens);
    let elapsed_ms = now_ms.saturating_sub(session_start);
    let elapsed_hours = elapsed_ms / 3_600_000;
    let elapsed_minutes = (elapsed_ms % 3_600_000) / 60_000;
    let elapsed_seconds = (elapsed_ms % 60_000) / 1000;
    UsageSummary {
        main_tokens,
        self_learning_tokens,
        total_tokens,
        api_calls: usage.api_calls,
        elapsed_hours,
        elapsed_minutes,
        elapsed_seconds,
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::app::state::runtime::UsageStats;

    #[test]
    fn compute_usage_summary_splits_main_and_self_learning_tokens() {
        let usage = UsageStats {
            tokens_in: 100,
            tokens_out: 50,
            review_tokens: 30,
            api_calls: 4,
            ..UsageStats::default()
        };
        let summary = compute_usage_summary(&usage, 0, 0);
        assert_eq!(summary.total_tokens, 150);
        assert_eq!(summary.self_learning_tokens, 30);
        assert_eq!(summary.main_tokens, 120);
        assert_eq!(summary.api_calls, 4);
    }

    #[test]
    fn compute_usage_summary_splits_elapsed_time() {
        let usage = UsageStats::default();
        // 1h 2m 3s = 3_600_000 + 120_000 + 3_000 ms
        let summary = compute_usage_summary(&usage, 0, 3_723_000);
        assert_eq!(summary.elapsed_hours, 1);
        assert_eq!(summary.elapsed_minutes, 2);
        assert_eq!(summary.elapsed_seconds, 3);
    }
}