Show session lengths in ten categories

The Focus view grouped sessions into six buckets, too coarse to see a
rhythm. There are now ten: under 5m, 5-15m, 15-25m, 25-45m, 45m-1h,
1h-1h30m, 1h30m-2h, 2-3h, 3-4h and 4h or more. 25 minutes is a classic
pomodoro, and the long end separates 3-4h stretches from 4h+ hyperfocus.

Ten labelled columns don't fit side by side, so the chart is now drawn
with horizontal bars: every label stays readable at any width.

The buckets are one constant (analysis::focus::SESSION_BUCKETS); a new
test pins down where sessions land, including an exact boundary.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/analysis/focus.rs

@@ -10,9 +10,21 @@ use super::{days_in, median};
 use crate::domain::WorkDay;
 use crate::time::DateRange;
 
-/// Session lengths are counted in these buckets: (label, upper limit in minutes).
+/// Session lengths are counted in these buckets: (label, upper limit in
-pub const SESSION_BUCKETS: [(&str, i64); 6] =
+/// minutes). 25 minutes is a classic pomodoro. Change them freely: the
-    [("<15m", 15), ("15-30m", 30), ("30m-1h", 60), ("1-2h", 120), ("2-3h", 180), ("3h+", i64::MAX)];
+/// Insights screen follows.
+pub const SESSION_BUCKETS: [(&str, i64); 10] = [
+    ("under 5m", 5),
+    ("5-15m", 15),
+    ("15-25m", 25),
+    ("25-45m", 45),
+    ("45m-1h", 60),
+    ("1h-1h30m", 90),
+    ("1h30m-2h", 120),
+    ("2-3h", 180),
+    ("3-4h", 240),
+    ("4h or more", i64::MAX),
+];
 
 #[derive(Debug, Clone, PartialEq)]
 pub struct Focus {
@@ -73,3 +85,32 @@ pub fn focus(days: &[WorkDay], range: DateRange, zone: &TimeZone, long_session:
         past_midnight,
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::domain::{Journal, Segment, ShiftState};
+    use jiff::civil::date;
+
+    #[test]
+    fn sessions_land_in_the_right_bucket() {
+        // Sessions of 3m, 20m, exactly 25m, 50m and 5h, with 10m breaks.
+        let lengths = [3, 20, 25, 50, 300];
+        let mut start = date(2026, 9, 24).at(8, 0, 0, 0).to_zoned(TimeZone::UTC).unwrap().timestamp();
+        let mut segments = Vec::new();
+        for minutes in lengths {
+            let end = start + SignedDuration::from_mins(minutes);
+            segments.push(Segment::new(start, end).unwrap());
+            start = end + SignedDuration::from_mins(10);
+        }
+        let journal = Journal::from_parts(vec![(date(2026, 9, 24), segments)], ShiftState::Idle).unwrap();
+        let days = journal.snapshot(start);
+        let range = DateRange::last_days(date(2026, 9, 24), 7);
+
+        let result = focus(&days, range, &TimeZone::UTC, SignedDuration::from_hours(2));
+        // under 5m, 5-15m, 15-25m, 25-45m, 45m-1h, ..., 4h or more
+        assert_eq!(result.session_counts, [1, 0, 1, 1, 1, 0, 0, 0, 0, 1]);
+        assert_eq!(result.long_sessions, 1);
+        assert_eq!(result.breaks, 4);
+    }
+}

src/ui/screens/insights.rs

@@ -12,7 +12,7 @@ use jiff::civil::{Date, Weekday};
 use jiff::{SignedDuration, ToSpan};
 use ratatui::Frame;
 use ratatui::crossterm::event::{MouseButton, MouseEvent, MouseEventKind};
-use ratatui::layout::{Constraint, Layout, Position, Rect};
+use ratatui::layout::{Constraint, Direction, Layout, Position, Rect};
 use ratatui::style::{Modifier, Style};
 use ratatui::symbols::Marker;
 use ratatui::text::{Line, Span};
@@ -375,14 +375,16 @@ impl Insights {
                     .style(Style::new().fg(ctx.theme.working))
             })
             .collect();
-        let bar_width = (chart_area.width.saturating_sub(2) / SESSION_BUCKETS.len() as u16)
+        // Horizontal bars, one row each, so every label fits; a blank row
-            .saturating_sub(2)
+        // between bars when there's room.
-            .clamp(3, 12);
+        let rows = chart_area.height.saturating_sub(2);
+        let gap = u16::from(rows >= 2 * SESSION_BUCKETS.len() as u16 - 1);
         frame.render_widget(
             BarChart::new(bars)
+                .direction(Direction::Horizontal)
                 .block(section(" How long your sessions last ", ctx))
-                .bar_width(bar_width)
+                .bar_width(1)
-                .bar_gap(2)
+                .bar_gap(gap)
                 .value_style(Style::new().fg(ratatui::style::Color::Black).bg(ctx.theme.working)),
             chart_area,
         );