added obsidian note api

backend/services/notes.go

@@ -0,0 +1,65 @@
+package services
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+type NotesConfig struct {
+	Dir string
+}
+
+type Note struct {
+	Filename   string    `json:"title"`
+	Contents   string    `json:"contents"`
+	LastEdited time.Time `json:"last_edited"`
+}
+
+type Notes struct {
+	Config NotesConfig
+}
+
+func InitNotes(config *NotesConfig) *Notes {
+	return &Notes{
+		Config: *config,
+	}
+}
+
+var ErrPathTraversal = errors.New("invalid path")
+
+func (notes *Notes) GetNote(path string) (*Note, error) {
+	baseDir, err := filepath.Abs(notes.Config.Dir)
+	if err != nil {
+		return nil, err
+	}
+
+	fullPath := filepath.Join(baseDir, path)
+	fullPath, err = filepath.Abs(fullPath)
+	if err != nil {
+		return nil, err
+	}
+
+	// Enforce directory boundary
+	if !strings.HasPrefix(fullPath, baseDir+string(os.PathSeparator)) {
+		return nil, ErrPathTraversal
+	}
+
+	data, err := os.ReadFile(fullPath)
+	if err != nil {
+		return nil, err
+	}
+
+	info, err := os.Stat(fullPath)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Note{
+		Filename:   info.Name(),
+		Contents:   string(data),
+		LastEdited: info.ModTime(),
+	}, nil
+}