feat(v0.4): add FormatActiveWarning and FormatStaleCleanupNotice

internal/session/lease.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"os/user"
 	"path/filepath"
+	"strings"
 	"time"
 )
 
@@ -155,3 +156,76 @@ func CleanupStaleLease(path string, staleAfter time.Duration) (*Lease, error) {
 	}
 	return &l, nil
 }
+
+// FormatActiveWarning renders the human-readable warning printed when a
+// fresh active lease is detected on session start.
+func FormatActiveWarning(l *Lease, now time.Time) string {
+	startedAgo := now.Sub(l.StartedAt)
+	lastSeenAgo := now.Sub(l.LastHeartbeatAt)
+
+	var b strings.Builder
+	b.WriteString("[ctask] This workspace has an active session:\n")
+	fmt.Fprintf(&b, "  Session:   %s\n", l.SessionID)
+	fmt.Fprintf(&b, "  Host:      %s\n", l.Hostname)
+	fmt.Fprintf(&b, "  Agent:     %s\n", l.Agent)
+	fmt.Fprintf(&b, "  Started:   %s (%s ago)\n",
+		l.StartedAt.Local().Format("2006-01-02 15:04"),
+		FormatAgo(startedAgo))
+	fmt.Fprintf(&b, "  Last seen: %s ago\n", FormatAgoShort(lastSeenAgo))
+	b.WriteString("\n")
+	b.WriteString("  Opening a second session may cause conflicts.\n")
+	b.WriteString("  Continue anyway? [y/N] ")
+	return b.String()
+}
+
+// FormatStaleCleanupNotice renders the single-line notice printed when a
+// stale lease has been removed during session start.
+func FormatStaleCleanupNotice(l *Lease, now time.Time) string {
+	return fmt.Sprintf("[ctask] Cleaned up stale session from %s (started %s, last seen %s ago)\n",
+		l.Hostname,
+		l.StartedAt.Local().Format("2006-01-02 15:04"),
+		FormatAgo(now.Sub(l.LastHeartbeatAt)))
+}
+
+// FormatAgo renders a coarse "2h 15m" / "3m" / "45s" for the active warning.
+func FormatAgo(d time.Duration) string {
+	if d < 0 {
+		d = 0
+	}
+	h := int(d.Hours())
+	m := int(d.Minutes()) % 60
+	if h > 0 {
+		return fmt.Sprintf("%dh %dm", h, m)
+	}
+	if m > 0 {
+		return fmt.Sprintf("%dm", m)
+	}
+	return fmt.Sprintf("%ds", int(d.Seconds()))
+}
+
+// FormatAgoShort renders "12 seconds" / "3 minutes" / "2 hours" for the
+// Last seen line, which the spec shows with a noun suffix.
+func FormatAgoShort(d time.Duration) string {
+	if d < 0 {
+		d = 0
+	}
+	s := int(d.Seconds())
+	if s < 60 {
+		if s == 1 {
+			return "1 second"
+		}
+		return fmt.Sprintf("%d seconds", s)
+	}
+	m := int(d.Minutes())
+	if m < 60 {
+		if m == 1 {
+			return "1 minute"
+		}
+		return fmt.Sprintf("%d minutes", m)
+	}
+	h := int(d.Hours())
+	if h == 1 {
+		return "1 hour"
+	}
+	return fmt.Sprintf("%d hours", h)
+}