Premier commit déjà bien avancé

internal/watcher/watcher.go

@@ -0,0 +1,126 @@
+package watcher
+
+import (
+	"context"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/fsnotify/fsnotify"
+
+	"github.com/mathieu/project-notes/internal/indexer"
+)
+
+// Watcher observe les modifications dans le repertoire des notes et relance l indexation au besoin.
+type Watcher struct {
+	fs     *fsnotify.Watcher
+	idx    *indexer.Indexer
+	dir    string
+	logger *log.Logger
+	wg     sync.WaitGroup
+}
+
+// Start initialise le watcher et commence la surveillance dans une goroutine.
+func Start(ctx context.Context, dir string, idx *indexer.Indexer, logger *log.Logger) (*Watcher, error) {
+	fsWatcher, err := fsnotify.NewWatcher()
+	if err != nil {
+		return nil, err
+	}
+
+	w := &Watcher{
+		fs:     fsWatcher,
+		idx:    idx,
+		dir:    dir,
+		logger: logger,
+	}
+
+	if err := w.addDirRecursive(dir); err != nil {
+		fsWatcher.Close()
+		return nil, err
+	}
+
+	w.wg.Add(1)
+	go w.run(ctx)
+
+	return w, nil
+}
+
+// Close arrete le watcher et attend la fin des goroutines.
+func (w *Watcher) Close() error {
+	err := w.fs.Close()
+	w.wg.Wait()
+	return err
+}
+
+func (w *Watcher) run(ctx context.Context) {
+	defer w.wg.Done()
+
+	debounce := time.NewTimer(0)
+	if !debounce.Stop() {
+		<-debounce.C
+	}
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case event, ok := <-w.fs.Events:
+			if !ok {
+				return
+			}
+
+			if event.Op&fsnotify.Create != 0 {
+				if info, err := os.Stat(event.Name); err == nil && info.IsDir() {
+					if err := w.addDirRecursive(event.Name); err != nil {
+						w.logger.Printf("watcher: ajout repertoire %s impossible: %v", event.Name, err)
+					}
+				}
+			}
+
+			if w.shouldReindex(event.Name, event.Op) {
+				if !debounce.Stop() {
+					select {
+					case <-debounce.C:
+					default:
+					}
+				}
+				debounce.Reset(200 * time.Millisecond)
+			}
+		case err, ok := <-w.fs.Errors:
+			if !ok {
+				return
+			}
+			w.logger.Printf("watcher: erreur: %v", err)
+		case <-debounce.C:
+			w.logger.Printf("watcher: reindexation suite a modification")
+			if err := w.idx.Load(w.dir); err != nil {
+				w.logger.Printf("watcher: echec reindexation: %v", err)
+			}
+		}
+	}
+}
+
+func (w *Watcher) shouldReindex(path string, op fsnotify.Op) bool {
+	ext := strings.ToLower(filepath.Ext(path))
+	if ext != ".md" && op&fsnotify.Remove == 0 && op&fsnotify.Rename == 0 {
+		return false
+	}
+	return true
+}
+
+func (w *Watcher) addDirRecursive(root string) error {
+	return filepath.WalkDir(root, func(path string, entry os.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if entry.IsDir() {
+			if err := w.fs.Add(path); err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+}