feat: implement WYSIWYG markdown editor with Go backend and React frontend

backend/internal/storage/storage.go

@@ -0,0 +1,111 @@
+package storage
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"path/filepath"
+
+	"github.com/sirupsen/logrus"
+)
+
+type Storage interface {
+	ListFiles() ([]string, error)
+	ReadFile(filename string) ([]byte, error)
+	WriteFile(filename string, content []byte) error
+	DeleteFile(filename string) error
+	FileExists(filename string) bool
+}
+
+type FileStorage struct {
+	dataDir string
+	logger  *logrus.Logger
+}
+
+func NewFileStorage(dataDir string) (*FileStorage, error) {
+	// Create data directory if it doesn't exist
+	if err := os.MkdirAll(dataDir, 0755); err != nil {
+		return nil, err
+	}
+
+	log := logrus.New()
+	log.SetOutput(os.Stdout)
+	log.SetFormatter(&logrus.TextFormatter{
+		ForceColors:   true,
+		FullTimestamp: true,
+	})
+	log.SetLevel(logrus.InfoLevel)
+
+	return &FileStorage{
+		dataDir: dataDir,
+		logger:  log,
+	}, nil
+}
+
+func (s *FileStorage) ListFiles() ([]string, error) {
+	files, err := os.ReadDir(s.dataDir)
+	if err != nil {
+		return nil, err
+	}
+
+	var markdownFiles []string
+	for _, file := range files {
+		if !file.IsDir() && filepath.Ext(file.Name()) == ".md" {
+			markdownFiles = append(markdownFiles, file.Name())
+		}
+	}
+
+	return markdownFiles, nil
+}
+
+func (s *FileStorage) ReadFile(filename string) ([]byte, error) {
+	if !s.FileExists(filename) {
+		return nil, errors.New("file not found")
+	}
+
+	content, err := os.ReadFile(filepath.Join(s.dataDir, filename))
+	if err != nil {
+		return nil, err
+	}
+
+	return content, nil
+}
+
+func (s *FileStorage) WriteFile(filename string, content []byte) error {
+	// Ensure the file has .md extension
+	if filepath.Ext(filename) != ".md" {
+		filename += ".md"
+	}
+
+	filepath := filepath.Join(s.dataDir, filename)
+	err := os.WriteFile(filepath, content, 0644)
+	if err != nil {
+		return err
+	}
+
+	s.logger.Infof("Saved file: %s", filename)
+	return nil
+}
+
+func (s *FileStorage) DeleteFile(filename string) error {
+	filepath := filepath.Join(s.dataDir, filename)
+	err := os.Remove(filepath)
+	if err != nil {
+		if errors.Is(err, fs.ErrNotExist) {
+			return errors.New("file not found")
+		}
+		return err
+	}
+
+	s.logger.Infof("Deleted file: %s", filename)
+	return nil
+}
+
+func (s *FileStorage) FileExists(filename string) bool {
+	filepath := filepath.Join(s.dataDir, filename)
+	info, err := os.Stat(filepath)
+	if err != nil {
+		return false
+	}
+	return !info.IsDir()
+}