feat(v0.4): add DetectExternalChanges and stale-workspace warning

2026-04-21 17:08:46 -04:00
parent aabb7c6464
commit 77513aa5f8
2 changed files with 178 additions and 0 deletions
@@ -0,0 +1,73 @@
+package session
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// DetectExternalChanges compares the current workspace state against the
+// EndManifest recorded in .ctask/last-session-summary.json.
+//
+// Returns (nil, nil) if no summary exists (pre-v0.4 workspace or first
+// session ever) — callers should treat this as "silently skip the warning".
+//
+// Returns a non-nil diff with empty slices when nothing changed outside a
+// ctask session.
+func DetectExternalChanges(wsDir string) (*ManifestDiff, error) {
+	summary, err := ReadSummary(SummaryPath(wsDir))
+	if err != nil {
+		return nil, err
+	}
+	if summary == nil {
+		return nil, nil
+	}
+
+	previous := &Manifest{
+		CapturedAt: summary.EndedAt,
+		Files:      append([]FileEntry{}, summary.EndManifest...),
+	}
+	current, err := CaptureManifest(wsDir)
+	if err != nil {
+		return nil, err
+	}
+	return DiffManifests(previous, current), nil
+}
+
+// FormatStaleWarning renders the Layer-3 warning shown when the workspace
+// was modified outside a ctask session since the last session ended.
+func FormatStaleWarning(summary *SessionSummary, diff *ManifestDiff) string {
+	var b strings.Builder
+	b.WriteString("[ctask] Workspace modified since last session ended:\n\n")
+	fmt.Fprintf(&b, "  Last session: %s (%s, %s)\n\n",
+		summary.EndedAt.Local().Format("2006-01-02 15:04"),
+		summary.Hostname, summary.Agent)
+	b.WriteString("  Modified since then:\n")
+
+	lines := append([]string{}, diff.Modified...)
+	sort.Strings(lines)
+	for _, f := range lines {
+		fmt.Fprintf(&b, "    %s (modified)\n", f)
+	}
+	added := append([]string{}, diff.Added...)
+	sort.Strings(added)
+	for _, f := range added {
+		fmt.Fprintf(&b, "    %s (new file)\n", f)
+	}
+	deleted := append([]string{}, diff.Deleted...)
+	sort.Strings(deleted)
+	for _, f := range deleted {
+		fmt.Fprintf(&b, "    %s (deleted)\n", f)
+	}
+	b.WriteString("\n  These changes were not made during a ctask session.\n")
+	b.WriteString("  Review before continuing? [Y/n] ")
+	return b.String()
+}
+
+// HasChanges returns true if diff reports any added/modified/deleted entries.
+func HasChanges(d *ManifestDiff) bool {
+	if d == nil {
+		return false
+	}
+	return len(d.Added) > 0 || len(d.Modified) > 0 || len(d.Deleted) > 0
+}