feat: migrate codes from previous project

internal/config/config.go

@@ -0,0 +1,46 @@
+package config
+
+import (
+	"strings"
+
+	"github.com/spf13/viper"
+)
+
+func LoadConfig() (*Config, error) {
+	v := viper.New()
+
+	v.AutomaticEnv()
+
+	v.SetConfigName("config")
+	v.SetConfigType("yaml")
+	v.AddConfigPath("./config")
+	v.AddConfigPath(".")
+
+	if err := v.ReadInConfig(); err != nil {
+		return nil, err
+	}
+
+	v.SetConfigName(".env")
+	v.SetConfigType("env")
+
+	if err := v.MergeInConfig(); err != nil {
+		return nil, err
+	}
+
+	for _, key := range v.AllKeys() {
+		if strings.Contains(key, "_") {
+			nestedKey := strings.Replace(key, "_", ".", 1)
+
+			if !v.IsSet(nestedKey) || v.Get(nestedKey) == "" {
+				v.Set(nestedKey, v.Get(key))
+			}
+		}
+	}
+
+	var cfg Config
+	if err := v.Unmarshal(&cfg); err != nil {
+		return nil, err
+	}
+
+	return &cfg, nil
+}