package discovery

import (
	"context"
	"sig-pub/pkg/zlog"
	"strconv"

	"google.golang.org/grpc/resolver"
)

type Registry interface {
	// Registry server instance
	Registry(ctx context.Context, server Server) (err error)
}

type GrpcResolver interface {
	DialUrl(serviceName string) string
	// Resolver get grpc dial resolver
	Resolver() (builder resolver.Builder, err error)
}

type Resolver interface {
	// ResolveAll get service all instance
	ResolveAll(ctx context.Context, serviceName string) (servers []Server, err error)
	// Watch when service instance change, send current all instances to channel
	Watch(ctx context.Context, serviceName string) (ch chan []Server, err error)
}

type Discovery interface {
	Registry
	Resolver
	GrpcResolver
}

// Server registry format
type Server struct {
	Name   string            `json:"name"`
	Addr   string            `json:"addr"` // 地址
	NodeId int               `json:"nodeId"`
	Attrs  map[string]string `json:"attrs"` // attributes
}

func (s Server) GetWeight() (weight int) {
	weight = 1
	if len(s.Attrs) == 0 {
		return
	}

	v, ok := s.Attrs["weight"]
	if !ok {
		return
	}
	w, err := strconv.Atoi(v)
	if err != nil {
		zlog.Warning("failed parse discovery server attr weight: ", v)
		return
	}
	weight = w
	return
}