package nsq

import (
	"errors"
	"fmt"
	"github.com/nsqio/go-nsq"
	"time"
)

type Producer struct {
	nsqAddr  []string
	config   *nsq.Config
	producer *nsq.Producer
	size     int
	pos      int
}

func initProducer(p *Producer, nsqAddr string) error {
	var err error
	p.producer, err = nsq.NewProducer(nsqAddr, p.config)
	if err != nil {
		return err
	}
	p.producer.SetLogger(newNSQLogger(nsq.LogLevelError), nsq.LogLevelError)
	return nil
}

// 创建建生产者 nsqAddr:127.0.0.1:4150, 127.0.0.2:4150
func NewProducer(nsqAddr ...string) (*Producer, error) {
	var err error
	p := new(Producer)
	p.config = nsq.NewConfig()
	// 心跳设置
	p.config.HeartbeatInterval = 30 * time.Second

	p.nsqAddr = nsqAddr
	p.size = len(nsqAddr)
	p.pos = 0
	if len(nsqAddr) == 0 {
		return nil, errors.New("nsqAddr is empty")
	}

	err = initProducer(p, p.nsqAddr[0])
	return p, err
}

// 向主题发布消息
func (p *Producer) Publish(topic string, data []byte) error {
	var err error
	for {
		if p.producer != nil {
			err = p.producer.Publish(topic, data)
			if err == nil {
				break
			}
			// 切换ip重发
			p.producer.Stop()
		}

		p.pos = p.pos + 1
		if p.pos < p.size {
			err = initProducer(p, p.nsqAddr[p.pos])
		} else {
			p.pos = 0
			return fmt.Errorf("连接nsq：%v 失败", p.nsqAddr)
		}
	}
	return nil
}

func (p *Producer) Close() {
	if p.producer != nil {
		p.producer.Stop()
		p.producer = nil
	}
}