refactor(grafanabackuper): add restore function

pkg/git/project.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"errors"
 	"io"
+	"path/filepath"
+	"strings"
 
 	"github.com/go-git/go-billy/v5"
 	"github.com/go-git/go-billy/v5/memfs"
@@ -214,3 +216,36 @@ func (p *Project) Push(ctx context.Context) error {
 
 	return p.repository.PushContext(ctx, &pushOpts)
 }
+
+func (p *Project) ListJSONFiles(directory string) ([]string, error) {
+	files, err := p.fs.ReadDir(directory)
+	if err != nil {
+		return nil, err
+	}
+
+	var allFiles []string
+	for _, file := range files {
+		if file.IsDir() {
+			var childFiles []string
+			childFiles, err = p.ListJSONFiles(filepath.Join(directory, file.Name()))
+			if err != nil {
+				return nil, err
+			}
+			allFiles = append(allFiles, childFiles...)
+		} else if strings.HasSuffix(file.Name(), ".json") {
+			allFiles = append(allFiles, filepath.Join(directory, file.Name()))
+		}
+	}
+
+	return allFiles, nil
+}
+
+func (p *Project) ReadFile(filepath string) ([]byte, error) {
+	file, err := p.fs.Open(filepath)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	return io.ReadAll(file)
+}