Adding storage to our data

storage.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"encoding/json"
+	"os"
+)
+
+type storage[T any] struct {
+	FileName string
+}
+
+func newStorage[T any](filename string) *storage[T] {
+	return &storage[T]{FileName: filename}
+}
+
+func (s *storage[T]) save(data T) error {
+	fileData, err := json.MarshalIndent(data, "", "    ")
+	if err != nil {
+		return err
+	}
+
+	return os.WriteFile(s.FileName, fileData, 0o644)
+}
+
+func (s *storage[T]) load(data *T) error {
+	fileData, err := os.ReadFile(s.FileName)
+	if err != nil {
+		return err
+	}
+
+	return json.Unmarshal(fileData, data)
+}