config: add load/save config file

config/config.go

@@ -2,7 +2,10 @@ package config
 
 import (
 	"fmt"
+	"os"
 	"strings"
+
+	"gopkg.in/yaml.v3"
 )
 
 type Config struct {
@@ -107,3 +110,34 @@ func Init() {
 		NanoKVMUISupport: true,
 	}
 }
+
+func Load(fname string) error {
+	yamlData, err := os.ReadFile(fname)
+	if err != nil {
+		return fmt.Errorf("config: couldn't read config file: %w", err)
+	}
+
+	var cfg Config
+	err = yaml.Unmarshal(yamlData, &cfg)
+	if err != nil {
+		return fmt.Errorf("config: couldn't parse config file: %w", err)
+	}
+
+	c = cfg
+
+	return nil
+}
+
+func Save(fname string) error {
+	data, err := yaml.Marshal(c)
+	if err != nil {
+		return fmt.Errorf("config: failed to marshal config: %w", err)
+	}
+
+	err = os.WriteFile(fname, data, 0o660)
+	if err != nil {
+		return fmt.Errorf("config: failed to write config: %w", err)
+	}
+
+	return nil
+}