package store

// TypeGetter is a func used to determine the concrete type of a context or
// endpoint metadata by returning a pointer to an instance of the object
// eg: for a context of type DockerContext, the corresponding TypeGetter should return new(DockerContext)
type TypeGetter func() interface{}

// NamedTypeGetter is a TypeGetter associated with a name
type NamedTypeGetter struct {
	name       string
	typeGetter TypeGetter
}

// EndpointTypeGetter returns a NamedTypeGetter with the spcecified name and getter
func EndpointTypeGetter(name string, getter TypeGetter) NamedTypeGetter {
	return NamedTypeGetter{
		name:       name,
		typeGetter: getter,
	}
}

// Config is used to configure the metadata marshaler of the context store
type Config struct {
	contextType   TypeGetter
	endpointTypes map[string]TypeGetter
}

// NewConfig creates a config object
func NewConfig(contextType TypeGetter, endpoints ...NamedTypeGetter) Config {
	res := Config{
		contextType:   contextType,
		endpointTypes: make(map[string]TypeGetter),
	}
	for _, e := range endpoints {
		res.endpointTypes[e.name] = e.typeGetter
	}
	return res
}