feat: scanner for directory reconciliation

internal/scanner/scanner.go

@@ -0,0 +1,109 @@
+package scanner
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"os"
+	"path/filepath"
+	"time"
+	"yoresee_dropbox/internal/store"
+)
+
+type Scanner struct {
+	store     *store.Store
+	workspace string
+	interval  time.Duration
+	stopCh    chan struct{}
+}
+
+func New(s *store.Store, workspace string, interval time.Duration) *Scanner {
+	return &Scanner{
+		store:     s,
+		workspace: workspace,
+		interval:  interval,
+		stopCh:    make(chan struct{}),
+	}
+}
+
+func (sc *Scanner) Start() {
+	go sc.run()
+}
+
+func (sc *Scanner) Stop() {
+	close(sc.stopCh)
+}
+
+func (sc *Scanner) run() {
+	ticker := time.NewTicker(sc.interval)
+	defer ticker.Stop()
+
+	sc.scan()
+	for {
+		select {
+		case <-sc.stopCh:
+			return
+		case <-ticker.C:
+			sc.scan()
+		}
+	}
+}
+
+func (sc *Scanner) scan() {
+	sc.scanDir("inbox")
+	sc.scanDir("outbox")
+}
+
+func (sc *Scanner) scanDir(dir string) {
+	dirPath := filepath.Join(sc.workspace, dir)
+	entries, err := os.ReadDir(dirPath)
+	if err != nil {
+		return
+	}
+
+	dbFiles, err := sc.store.FileList(dir)
+	if err != nil {
+		return
+	}
+
+	dbMap := make(map[string]*store.File)
+	for _, f := range dbFiles {
+		dbMap[f.StorageName] = f
+	}
+
+	diskMap := make(map[string]bool)
+	for _, entry := range entries {
+		if entry.IsDir() {
+			continue
+		}
+		info, err := entry.Info()
+		if err != nil {
+			continue
+		}
+		diskMap[entry.Name()] = true
+
+		if _, exists := dbMap[entry.Name()]; !exists {
+			id := generateUUID()
+			f := &store.File{
+				ID:           id,
+				OriginalName: entry.Name(),
+				StorageName:  entry.Name(),
+				Dir:          dir,
+				Size:         info.Size(),
+				CreatedAt:    time.Now().Unix(),
+			}
+			sc.store.FileCreate(f)
+		}
+	}
+
+	for name, f := range dbMap {
+		if !diskMap[name] {
+			sc.store.FileDelete(f.ID)
+		}
+	}
+}
+
+func generateUUID() string {
+	b := make([]byte, 16)
+	rand.Read(b)
+	return hex.EncodeToString(b)
+}