package selector

import (
	"context"
	"git.diulo.com/mogfee/kit/errors"
	"google.golang.org/grpc/balancer"
)

var ErrNoAvailable = errors.ServiceUnavailable("no_available_node", "")

type Selector interface {
	Rebalancer
	Select(ctx context.Context, opts ...SelectOption) (selected WeightedNode, di DoneFunc, err error)
}
type Rebalancer interface {
	Apply(nodes []Node)
}
type Builder interface {
	Build() Selector
}
type Node interface {
	Scheme() string
	Address() string
	ServerName() string
	InitialWeight() *int64
	Version() string
	Metadata() map[string]string
}
type DoneInfo struct {
	Err           error
	ReplyMD       ReplyMD
	BytesSent     bool
	BytesReceived bool
}
type ReplyMD interface {
	Get(key string) string
}

type DoneFunc func(ctx context.Context, di balancer.DoneInfo)