package nsqclient

import (
	"context"
	"fmt"
	"time"

	nsq "github.com/nsqio/go-nsq"
)

type NsqConsumer struct {
	consumer *nsq.Consumer
	// handler   nsq.Handler
	handler   func([]byte) error
	ctx       context.Context
	ctxCancel context.CancelFunc
	topic     string
	channel   string
}

func NewNsqConsumer(ctx context.Context, topic, channel string, options ...func(*nsq.Config)) (*NsqConsumer, error) {
	conf := nsq.NewConfig()
	conf.MaxAttempts = 0
	conf.MsgTimeout = 10 * time.Minute         // 默认一个消息最多能处理十分钟，否则就会重新丢入队列
	conf.LookupdPollInterval = 3 * time.Second // 调整consumer的重连间隔时间为3秒
	for _, option := range options {
		option(conf)
	}

	consumer, err := nsq.NewConsumer(topic, channel, conf)
	if err != nil {
		return nil, err
	}
	return &NsqConsumer{
		consumer: consumer,
		ctx:      ctx,
		topic:    topic,
		channel:  channel,
	}, nil
}

func DestroyNsqConsumer(c *NsqConsumer) {
	if c != nil {
		if c.ctxCancel != nil {
			c.ctxCancel()
		}
	}
}

// func (n *NsqConsumer) AddHandler(handler nsq.Handler) {
// 	n.handler = handler
// }

func (n *NsqConsumer) AddHandler(handler func([]byte) error) {
	n.handler = handler
}

func (n *NsqConsumer) Run(qaddr string, concurrency int) error {
	return n.RunDistributed([]string{qaddr}, nil, concurrency)
}

func (n *NsqConsumer) RunLookupd(lookupAddr string, concurrency int) error {
	return n.RunDistributed(nil, []string{lookupAddr}, concurrency)
}

func (n *NsqConsumer) RunDistributed(qAddr, lAddr []string, concurrency int) error {
	n.consumer.ChangeMaxInFlight(concurrency)
	// n.consumer.AddConcurrentHandlers(n.handler, concurrency)
	n.consumer.AddConcurrentHandlers(nsq.HandlerFunc(func(msg *nsq.Message) error {
		return n.handler(msg.Body)
		// return nil
	}), concurrency)

	var err error
	if len(qAddr) > 0 {
		err = n.consumer.ConnectToNSQDs(qAddr)
	} else if len(lAddr) > 0 {
		err = n.consumer.ConnectToNSQLookupds(lAddr)
	} else {
		err = fmt.Errorf("Addr Must NOT Empty")
	}
	if err != nil {
		return err
	}

	if n.ctx == nil {
		n.ctx, n.ctxCancel = context.WithCancel(context.Background())
	}

	for {
		select {
		case <-n.ctx.Done():
			fmt.Println("[%s] %s,%s", "stop consumer", n.topic, n.channel)
			n.consumer.Stop()
			fmt.Println("[%s] %s,%s", "stop consumer success", n.topic, n.channel)
			return nil
		}
	}
}