// Copyright 2022 The OpenZipkin Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package model

import (
	"encoding/json"
	"net"
	"strings"
)

// Endpoint holds the network context of a node in the service graph.
type Endpoint struct {
	ServiceName string
	IPv4        net.IP
	IPv6        net.IP
	Port        uint16
}

// MarshalJSON exports our Endpoint into the correct format for the Zipkin V2 API.
func (e Endpoint) MarshalJSON() ([]byte, error) {
	return json.Marshal(&struct {
		ServiceName string `json:"serviceName,omitempty"`
		IPv4        net.IP `json:"ipv4,omitempty"`
		IPv6        net.IP `json:"ipv6,omitempty"`
		Port        uint16 `json:"port,omitempty"`
	}{
		strings.ToLower(e.ServiceName),
		e.IPv4,
		e.IPv6,
		e.Port,
	})
}

// Empty returns if all Endpoint properties are empty / unspecified.
func (e *Endpoint) Empty() bool {
	return e == nil ||
		(e.ServiceName == "" && e.Port == 0 && len(e.IPv4) == 0 && len(e.IPv6) == 0)
}