cache

type Cache interface {
	// Dirty reports whether the cache has been mutated since being loaded
	// or initialized.
	Dirty() bool

	// Channel reports the release channel the cache is subscribed to.
	Channel() string

	// SetChannel sets the channel to the one corresponding to the given
	// string. It reports the value the channel was actually set to.
	//
	// Calling SetChannel on a Cache set to a different channel, zeroes out
	// the Cache's release & timestamp information.
	SetChannel(string) string

	// LastCheckedAt reports the last time SetLatestRelease with a non-nil
	// value was called on the Cache.
	LastCheckedAt() time.Time

	// LatestRelease reports the latest release the cache is aware of.
	LatestRelease() *update.Release

	// SetLatestRelease sets the latest release for the given channel.
	//
	// Calling SetLatestRelease for a different channel than the one the Cache
	// is set to has no effect.
	SetLatestRelease(channel string, r *update.Release)

	// SetCurrentVersionInvalid sets the current version of flyctl as invalid
	// because of the given error.
	SetCurrentVersionInvalid(err error)

	// IsCurrentVersionInvalid returns an error message if the given version
	// of flyctl is currently invalid. If not, it returns an empty string.
	IsCurrentVersionInvalid() string

	// Save writes the YAML-encoded representation of c to the named file path via
	// os.WriteFile.
	Save(path string) error
}