restructure the API and update the admin script

api/config/option.go

@@ -0,0 +1,49 @@
+package config
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+)
+
+const (
+	OPTION_TYPE_STR  = 0
+	OPTION_TYPE_BOOL = 1
+	OPTION_TYPE_URL  = 2
+)
+
+type Option struct {
+	Name      string
+	Value     string
+	Required  bool
+	Type      uint8
+	TypeValue struct {
+		URL  *url.URL
+		Str  string
+		Bool bool
+	}
+}
+
+func (o *Option) Env() string {
+	return strings.ToUpper(fmt.Sprintf("API_%s", o.Name))
+}
+
+func (o *Option) Load() (err error) {
+	err = nil
+
+	switch o.Type {
+	case OPTION_TYPE_STR:
+		o.TypeValue.Str = o.Value
+
+	case OPTION_TYPE_BOOL:
+		o.TypeValue.Bool = "1" == o.Value || "true" == strings.ToLower(o.Value)
+
+	case OPTION_TYPE_URL:
+		o.TypeValue.URL, err = url.Parse(o.Value)
+
+	default:
+		return fmt.Errorf("invalid option type")
+	}
+
+	return err
+}