refactor: use dtos in controllers

backend/internal/dto/validations.go

@@ -0,0 +1,39 @@
+package dto
+
+import (
+	"github.com/gin-gonic/gin/binding"
+	"github.com/go-playground/validator/v10"
+	"log"
+	"net/url"
+	"regexp"
+)
+
+var validateUrlList validator.Func = func(fl validator.FieldLevel) bool {
+	urls := fl.Field().Interface().([]string)
+	for _, u := range urls {
+		_, err := url.ParseRequestURI(u)
+		if err != nil {
+			return false
+		}
+	}
+	return true
+}
+
+var validateUsername validator.Func = func(fl validator.FieldLevel) bool {
+	regex := "^[a-z0-9_]*$"
+	matched, _ := regexp.MatchString(regex, fl.Field().String())
+	return matched
+}
+
+func init() {
+	if v, ok := binding.Validator.Engine().(*validator.Validate); ok {
+		if err := v.RegisterValidation("urlList", validateUrlList); err != nil {
+			log.Fatalf("Failed to register custom validation: %v", err)
+		}
+	}
+	if v, ok := binding.Validator.Engine().(*validator.Validate); ok {
+		if err := v.RegisterValidation("username", validateUsername); err != nil {
+			log.Fatalf("Failed to register custom validation: %v", err)
+		}
+	}
+}