// Copyright 2024 Patial Tech (Ankit Patial).
//
// This file is part of code.patial.tech/go/appcore, which is MIT licensed.
// See http://opensource.org/licenses/MIT

package validate

import (
	"errors"
	"fmt"
	"reflect"
	"strings"

	"github.com/go-playground/validator/v10"
)

var validate *validator.Validate

func init() {
	validate = validator.New()
	// register function to get tag name from json tags.
	validate.RegisterTagNameFunc(func(fld reflect.StructField) string {
		name := strings.SplitN(fld.Tag.Get("json"), ",", 2)[0]
		if name == "-" {
			return ""
		}
		return name
	})

}

// RegisterAlias for single/multuple tags
func RegisterAlias(alias, tags string) {
	validate.RegisterAlias(alias, tags)
}

func RegisterValidation(tagName string, fn validator.Func, callValidationEvenIfNull ...bool) {
	validate.RegisterValidation(tagName, fn, callValidationEvenIfNull...)
}

// Struct validator
func Struct(s any) error {
	err := validate.Struct(s)
	if IsInvalidValidationError(err) {
		return err
	}

	var valErrs validator.ValidationErrors
	if !errors.As(err, &valErrs) {
		return err
	}

	var sb strings.Builder
	for _, err := range valErrs {
		switch err.Tag() {
		case "required":
			sb.WriteString(fmt.Sprintf("%s: is required.\n", err.Field()))
		case "email":
			sb.WriteString(fmt.Sprintf("%s: is invalid.\n", err.Field()))
		default:
			sb.WriteString(fmt.Sprintf("%s: %q validation failed.\n", err.Field(), err.Tag()))
		}
	}

	return errors.New(sb.String())
}

// Map validator
func Map(data map[string]any, rules map[string]any) map[string]any {
	return validate.ValidateMap(data, rules)
}

func IsInvalidValidationError(err error) bool {
	var v *validator.InvalidValidationError
	return errors.As(err, &v)
}