Add multi-disk copy workflow

internal/watcher/watcher.go

@@ -2,6 +2,8 @@ package watcher
 
 import (
 	"context"
+	"path/filepath"
+	"sort"
 	"sync"
 	"time"
 
@@ -10,7 +12,7 @@ import (
 
 type DiskEvent struct {
 	Info disk.DiskInfo
-	Prev disk.DiskState
+	Prev disk.DiskInfo
 }
 
 type Handler func(event DiskEvent)
@@ -20,8 +22,8 @@ type Watcher struct {
 	interval  time.Duration
 	handler   Handler
 
-	mu      sync.RWMutex
-	current disk.DiskInfo
+	mu    sync.RWMutex
+	disks map[string]disk.DiskInfo
 }
 
 func New(mountPath string, interval time.Duration, handler Handler) *Watcher {
@@ -29,13 +31,42 @@ func New(mountPath string, interval time.Duration, handler Handler) *Watcher {
 		mountPath: mountPath,
 		interval:  interval,
 		handler:   handler,
+		disks:     make(map[string]disk.DiskInfo),
 	}
 }
 
-func (w *Watcher) CurrentDisk() disk.DiskInfo {
+func (w *Watcher) ListDisks() []disk.DiskInfo {
 	w.mu.RLock()
 	defer w.mu.RUnlock()
-	return w.current
+
+	items := make([]disk.DiskInfo, 0, len(w.disks))
+	for _, info := range w.disks {
+		items = append(items, info)
+	}
+	sort.Slice(items, func(i, j int) bool { return items[i].MountPath < items[j].MountPath })
+	return items
+}
+
+func (w *Watcher) DiskByMountPath(mountPath string) (disk.DiskInfo, bool) {
+	w.mu.RLock()
+	defer w.mu.RUnlock()
+	info, ok := w.disks[mountPath]
+	return info, ok
+}
+
+func (w *Watcher) DiskByID(diskID string) (disk.DiskInfo, bool) {
+	w.mu.RLock()
+	defer w.mu.RUnlock()
+	for _, info := range w.disks {
+		if info.DiskID == diskID {
+			return info, true
+		}
+	}
+	return disk.DiskInfo{}, false
+}
+
+func (w *Watcher) ProbeNow() {
+	w.probe()
 }
 
 func (w *Watcher) Run(ctx context.Context) {
@@ -56,15 +87,61 @@ func (w *Watcher) Run(ctx context.Context) {
 }
 
 func (w *Watcher) probe() {
-	info, _ := disk.Probe(w.mountPath)
+	next := discoverDisks(w.mountPath)
 
 	w.mu.Lock()
-	prev := w.current.State
-	changed := prev != info.State
-	w.current = info
+	prev := w.disks
+	w.disks = next
 	w.mu.Unlock()
 
-	if changed && w.handler != nil {
-		w.handler(DiskEvent{Info: info, Prev: prev})
+	if w.handler == nil {
+		return
+	}
+
+	seen := make(map[string]struct{}, len(prev)+len(next))
+	for mountPath, info := range next {
+		seen[mountPath] = struct{}{}
+		prevInfo := prev[mountPath]
+		if prevInfo.State != info.State || prevInfo.DiskID != info.DiskID {
+			w.handler(DiskEvent{Info: info, Prev: prevInfo})
+		}
+	}
+	for mountPath, prevInfo := range prev {
+		if _, ok := seen[mountPath]; ok {
+			continue
+		}
+		w.handler(DiskEvent{
+			Info: disk.DiskInfo{
+				State:     disk.DiskAbsent,
+				MountPath: mountPath,
+			},
+			Prev: prevInfo,
+		})
 	}
 }
+
+func discoverDisks(root string) map[string]disk.DiskInfo {
+	candidates := []string{root}
+
+	if entries, err := filepath.Glob(filepath.Join(root, "*")); err == nil {
+		for _, path := range entries {
+			candidates = append(candidates, path)
+		}
+	}
+
+	disks := make(map[string]disk.DiskInfo)
+	seen := make(map[string]struct{}, len(candidates))
+	for _, mountPath := range candidates {
+		if _, ok := seen[mountPath]; ok {
+			continue
+		}
+		seen[mountPath] = struct{}{}
+
+		info, _ := disk.Probe(mountPath)
+		if info.State == disk.DiskAbsent {
+			continue
+		}
+		disks[mountPath] = info
+	}
+	return disks
+}