package locator

import (
	"errors"

	"g.activething.com/go/DateKeys/extension"
	"g.activething.com/go/DateKeys/profile"
	"g.activething.com/go/DateKeys/provider"
)

// OpenLocator opens the sealed locator of the extension with the release of
// the round of its own DateKey, in the profile that DateKey names: a locator
// for another round or another chain does not open, and is unusable (spec
// v0.11, §44.1). It fails when the extension has no locator.
func (i *Info) OpenLocator(reg profile.Registry, release provider.Release) (*Locator, error) {
	if i.Sealed == nil {
		return nil, errors.New("locator: the extension has no locator")
	}
	p, ok := reg.Lookup(i.DateKey.ProfileID)
	if !ok {
		return nil, errors.New("locator: the profile of the DateKey is not pinned")
	}
	return Open(p, i.DateKey.Round, release, i.Sealed)
}

// Standard returns the registry of the extensions of spec v0.11 with the
// data of datekeys.capsule validated by ParseInfo, as spec §54 asks of a
// reader that knows an extension.
func Standard() extension.Standard {
	return extension.Standard{ValidateCapsule: func(e extension.Extension) error {
		_, err := ParseInfo(e)
		return err
	}}
}