11

tui/internal/cc/session_watcher.go

@@ -0,0 +1,110 @@
+package cc
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/fsnotify/fsnotify"
+)
+
+// EncodeCwdForProjectsDir converts an absolute path to claude's projects-dir
+// encoding: both '/' and '.' are replaced with '-'.
+func EncodeCwdForProjectsDir(absPath string) string {
+	return strings.NewReplacer("/", "-", ".", "-").Replace(absPath)
+}
+
+// ClaudeProjectsDir returns the claude transcript directory for a given cwd:
+// <homeDir>/.claude/projects/<encoded-cwd>.
+func ClaudeProjectsDir(homeDir, cwd string) string {
+	return filepath.Join(homeDir, ".claude", "projects", EncodeCwdForProjectsDir(cwd))
+}
+
+// SessionWatchOpts configures WatchForNewSession.
+type SessionWatchOpts struct {
+	ProjectsDir string
+	Timeout     time.Duration
+}
+
+// WatchForNewSession watches ProjectsDir for the first new .jsonl file that
+// appears after the call, returning its basename without the .jsonl suffix
+// (the claude session id). Returns ("", nil) on timeout or context cancellation,
+// mirroring the TypeScript null-on-timeout semantics. MkdirAll ensures the
+// target dir exists so a missing claude projects dir is handled symmetrically
+// with the codex watcher — the first session is captured even if the dir was
+// absent at call time.
+func WatchForNewSession(ctx context.Context, opts SessionWatchOpts) (string, error) {
+	// Ensure the target dir exists before snapshotting and watching.
+	if err := os.MkdirAll(opts.ProjectsDir, 0o755); err != nil {
+		return "", nil
+	}
+
+	// Snapshot existing .jsonl files so we only react to truly new ones.
+	snapshot, err := snapshotJSONL(opts.ProjectsDir)
+	if err != nil {
+		return "", nil
+	}
+
+	watcher, err := fsnotify.NewWatcher()
+	if err != nil {
+		return "", nil
+	}
+	defer watcher.Close()
+
+	if err := watcher.Add(opts.ProjectsDir); err != nil {
+		return "", nil
+	}
+
+	timer := time.NewTimer(opts.Timeout)
+	defer timer.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return "", nil
+		case <-timer.C:
+			return "", nil
+		case event, ok := <-watcher.Events:
+			if !ok {
+				return "", nil
+			}
+			if event.Op&(fsnotify.Create|fsnotify.Rename) == 0 {
+				continue
+			}
+			name := filepath.Base(event.Name)
+			if !strings.HasSuffix(name, ".jsonl") {
+				continue
+			}
+			if snapshot[name] {
+				continue
+			}
+			// Confirm the file actually exists (rename fires for deletes too).
+			if _, err := os.Stat(event.Name); err != nil {
+				continue
+			}
+			return strings.TrimSuffix(name, ".jsonl"), nil
+		case _, ok := <-watcher.Errors:
+			if !ok {
+				return "", nil
+			}
+			// Non-fatal watcher error; keep watching.
+		}
+	}
+}
+
+// snapshotJSONL returns the set of .jsonl filenames currently in dir.
+func snapshotJSONL(dir string) (map[string]bool, error) {
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return nil, err
+	}
+	snap := make(map[string]bool, len(entries))
+	for _, e := range entries {
+		if !e.IsDir() && strings.HasSuffix(e.Name(), ".jsonl") {
+			snap[e.Name()] = true
+		}
+	}
+	return snap, nil
+}