package xmlrpc

import (

	"fmt"

	"regexp"

)

var (

	faultRx = regexp.MustCompile(`<fault>(\s|\S)+</fault>`)

)

// FaultError is returned from the server when an invalid call is made

type FaultError struct {

	Code   int    `xmlrpc:"faultCode"`

	String string `xmlrpc:"faultString"`

}

// Error implements the error interface

func (e FaultError) Error() string {

	return fmt.Sprintf("Fault(%d): %s", e.Code, e.String)

}

type Response []byte

func (r Response) Err() error {

	if !faultRx.Match(r) {

		return nil

	}

	var fault FaultError

	if err := unmarshal(r, &fault); err != nil {

		return err

	}

	return fault

}

func (r Response) Unmarshal(v interface{}) error {

	if err := unmarshal(r, v); err != nil {

		return err

	}

	return nil

}