package rabbitmq

import (
	"errors"
	"fmt"
	amqp "github.com/rabbitmq/amqp091-go"
	"sync"
	"time"
)

var Rabbitmq = &rabbitmq{}

type rabbitmq struct {
	config Config
	Conn   *amqp.Connection
	mu     sync.RWMutex
	ch     *amqp.Channel
}

type Config struct {
	Host         string
	Port         int
	User         string
	Password     string
	ReConnSecond int  // 重连间隔秒数
	ReConn       bool // 是否断线重连
}

// InitRabbitmq @Title 初始化rabbitmq
func InitRabbitmq(config Config) (err error) {
	Rabbitmq.config = config
	return getConn()
}

// @Title 获取连接
func getConn() (err error) {
	Rabbitmq.Conn, err = amqp.Dial(fmt.Sprintf("amqp://%s:%s@%s:%d/", Rabbitmq.config.User, Rabbitmq.config.Password, Rabbitmq.config.Host, Rabbitmq.config.Port))
	if err != nil {
		return err
	}
	// 断线重连
	if Rabbitmq.config.ReConn {
		cc := make(chan *amqp.Error)
		closeChan := Rabbitmq.Conn.NotifyClose(cc)
		go func() {
			select {
			case <-closeChan:
				if Rabbitmq.config.ReConn {
					reConn()
				}
			}
		}()
	}
	return
}

// @Title 自动重连
func reConn() {
	if err := getConn(); err != nil {
		// 延时重连
		time.Sleep(time.Duration(Rabbitmq.config.ReConnSecond) * time.Second)
		reConn()
	}
}

// GetChannel @Title 获取连接
func (r *rabbitmq) GetChannel() (*amqp.Channel, error) {
	if r.ch != nil && !r.ch.IsClosed() {
		return r.ch, nil
	}
	r.mu.Lock()
	defer r.mu.Unlock()
	if r.ch != nil && !r.ch.IsClosed() {
		return r.ch, nil
	}
	if r.Conn == nil || r.Conn.IsClosed() {
		return nil, errors.New("rabbitmq not connect")
	}
	var err error
	r.ch, err = r.Conn.Channel()
	if err != nil {
		return nil, err
	}
	return r.ch, nil
}

// Publish @Title 发送消息
// @Param exchangeName string true "指定发送的交换机"
// @Param msg string true "发送消息内容"
// @Param delay int64 false "延时发送秒数"
func (r *rabbitmq) Publish(exchangeName, msg string, delay ...int64) error {
	ch, err := r.GetChannel()
	if err != nil {
		return err
	}
	header := amqp.Table{}
	if len(delay) > 0 && delay[0] > 0 {
		header["x-delay"] = delay[0] * 1000
	}
	return ch.Publish(
		exchangeName, //交换
		"",           //队列名称
		false,        //强制为
		false,        //立即
		amqp.Publishing{
			ContentType: "text/plain",
			Body:        []byte(msg),
			Headers:     header,
		})
}

// Consume @Title 消费队列
// @Param queueName string true "队列名称"
// @Param autoAck bool true "是否自动确认"
// @Param prefetchCount int 0 "预消费数量"
// @Param callback func(amqp.Delivery)) true "回调处理"
func (r *rabbitmq) Consume(queueName string, autoAck bool, prefetchCount int, callback func(amqp.Delivery)) error {
	ch, err := r.GetChannel()
	if err != nil {
		return err
	}
	defer ch.Close()
	if prefetchCount > 0 {
		if err := ch.Qos(prefetchCount, 0, false); err != nil {
			return err
		}
	}
	//消费队列
	msgs, err := ch.Consume(
		queueName, //队列名称
		"",        //消费者
		autoAck,   //自动确认
		false,     //排他
		false,
		false,
		nil,
	)
	if err != nil {
		return err
	}

	cc := make(chan *amqp.Error)
	closeChan := ch.NotifyClose(cc)

	for {
		select {
		case d := <-msgs:
			if d.Acknowledger == nil {
				return errors.New("delivery not initialized")
			}
			callback(d)
		case <-closeChan:
			// 连接断开
			return errors.New("rabbitmq channel close")
		}
	}
}

// Close @Title 关闭资源
func (r *rabbitmq) Close() {
	Rabbitmq.config.ReConn = false
	defer Rabbitmq.Conn.Close()
}