package protocol

import (
	"context"

	"github.com/pkg/errors"
)

type Registry struct {
	protocols map[Identifier]Protocol
}

func (r *Registry) Register(protocol Protocol) {
	r.protocols[protocol.Identifier()] = protocol
}

func (r *Registry) Availables(ctx context.Context, addr string) ([]Protocol, error) {
	availables := make([]Protocol, 0)

	for _, proto := range r.protocols {
		available, err := proto.Available(ctx, addr)
		if err != nil {
			return nil, errors.WithStack(err)
		}

		if !available {
			continue
		}

		availables = append(availables, proto)
	}

	return availables, nil
}

func NewRegistry() *Registry {
	return &Registry{
		protocols: make(map[Identifier]Protocol),
	}
}

var defaultRegistry = NewRegistry()

func DefaultRegistry() *Registry {
	return defaultRegistry
}

func Register(protocol Protocol) {
	defaultRegistry.Register(protocol)
}

func Availables(ctx context.Context, addr string) ([]Protocol, error) {
	return defaultRegistry.Availables(ctx, addr)
}