package atom

import (
	"encoding/xml"
	"errors"
	"fmt"
)

type ID struct {
	XMLName xml.Name `xml:"id"`
	*CommonAttributes
	URI string `xml:",chardata"` // IRI
}

// NewID creates a new ID. It returns a *ID.
func NewID(uri string) *ID {
	return &ID{
		CommonAttributes: NewCommonAttributes(),
		URI:              uri,
	}
}

// Check checks the ID for incompatibilities with RFC4287. It returns an error.
func (i *ID) Check() error {
	if i.URI == "" {
		return errors.New("uri element of id empty")
	} else {
		if !isValidIRI(i.URI) {
			return fmt.Errorf("uri element of id %v not correctly formatted", i)
		}
	}

	return nil
}