package registry

import (
	"context"
	"fmt"
	"sort"
)

type Registrar interface {
	Register(ctx context.Context, service *ServiceInstance) error
	Deregister(ctx context.Context, service *ServiceInstance) error
}
type Discovery interface {
	GetService(ctx context.Context, serverName string) ([]*ServiceInstance, error)
	Watch(ctx context.Context, serviceName string) (Watcher, error)
}
type Watcher interface {
	Next() ([]*ServiceInstance, error)
	Stop() error
}

type ServiceInstance struct {
	ID        string            `json:"id"`
	Name      string            `json:"name"`
	Version   string            `json:"version"`
	Metadata  map[string]string `json:"metadata"`
	Endpoints []string          `json:"endpoints"`
}

func (i *ServiceInstance) String() string {
	return fmt.Sprintf("%s-%s", i.Name, i.ID)
}
func (i *ServiceInstance) Equal(o any) bool {
	if i == nil && o == nil {
		return true
	}
	if i == nil || o == nil {
		return false
	}
	t, ok := o.(*ServiceInstance)
	if !ok {
		return false
	}
	if len(i.Endpoints) != len(t.Endpoints) {
		return false
	}

	sort.Strings(i.Endpoints)
	sort.Strings(t.Endpoints)

	for j := 0; j < len(i.Endpoints); j++ {
		if i.Endpoints[j] != t.Endpoints[j] {
			return false
		}
	}
	if len(i.Metadata) != len(t.Metadata) {
		return false
	}
	for k, v := range i.Metadata {
		if v != t.Metadata[k] {
			return false
		}
	}
	return i.ID == t.ID && i.Name != t.Name && i.Version != t.Version
}