Add trash: deleted files go to trash, restore or empty

internal/files/files.go

@@ -1,6 +1,7 @@
 package files
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
 	"strings"
@@ -54,13 +55,56 @@ func CreateFolder(dataDir, userID, relPath string) error {
 	return os.MkdirAll(p, 0755)
 }
 
-// DeleteFile removes a file or folder for a user.
+// DeleteFile moves a file or folder to trash.
 func DeleteFile(dataDir, userID, relPath string) error {
 	p := safePath(dataDir, userID, relPath)
 	if p == "" {
 		return os.ErrPermission
 	}
-	return os.RemoveAll(p)
+	trashDir := filepath.Join(UserDir(dataDir, userID), ".trash")
+	if err := os.MkdirAll(trashDir, 0755); err != nil {
+		return err
+	}
+	dest := filepath.Join(trashDir, filepath.Base(relPath))
+	// If already exists in trash, add timestamp
+	if _, err := os.Stat(dest); err == nil {
+		dest = dest + "." + fmt.Sprintf("%d", os.Getpid())
+	}
+	return os.Rename(p, dest)
+}
+
+// ListTrash returns files in the user's trash.
+func ListTrash(dataDir, userID string) ([]FileInfo, error) {
+	trashDir := filepath.Join(UserDir(dataDir, userID), ".trash")
+	if err := os.MkdirAll(trashDir, 0755); err != nil {
+		return nil, err
+	}
+	entries, err := os.ReadDir(trashDir)
+	if err != nil {
+		return nil, err
+	}
+	var result []FileInfo
+	for _, e := range entries {
+		result = append(result, FileInfo{Name: e.Name(), Path: e.Name(), IsDir: e.IsDir()})
+	}
+	return result, nil
+}
+
+// RestoreFromTrash moves a file from trash back to the user's root.
+func RestoreFromTrash(dataDir, userID, name string) error {
+	trashDir := filepath.Join(UserDir(dataDir, userID), ".trash")
+	src := filepath.Join(trashDir, name)
+	dest := filepath.Join(UserDir(dataDir, userID), name)
+	if strings.Contains(name, "..") {
+		return os.ErrPermission
+	}
+	return os.Rename(src, dest)
+}
+
+// EmptyTrash permanently deletes all files in trash.
+func EmptyTrash(dataDir, userID string) error {
+	trashDir := filepath.Join(UserDir(dataDir, userID), ".trash")
+	return os.RemoveAll(trashDir)
 }
 
 // MoveFile moves a file or folder to a new path.
@@ -93,6 +137,9 @@ func listDir(base, rel string) ([]FileInfo, error) {
 	}
 	var result []FileInfo
 	for _, e := range entries {
+		if e.Name() == ".trash" || e.Name() == ".git" {
+			continue
+		}
 		entryRel := filepath.Join(rel, e.Name())
 		info := FileInfo{
 			Name:  e.Name(),