// Package mq define message queue operation functions
package mq

import (
	"context"
	"fmt"
	"net/url"
	"sync"
	"time"

	"eventRT/config"
	"eventRT/logger"

	amqp "github.com/rabbitmq/amqp091-go"
)

var (
	_globalRabbitMQProxy *RabbitMQProxy
	rabbitMQOnce         sync.Once
)

// RabbitMQProxy define stuct of rabbitMQ connection proxy
type RabbitMQProxy struct {
	Conn *amqp.Connection
	mu   sync.Mutex
}

// GetConn define func to return the rabbitMQ connection
func GetConn() *amqp.Connection {
	_globalRabbitMQProxy.mu.Lock()
	defer _globalRabbitMQProxy.mu.Unlock()
	return _globalRabbitMQProxy.Conn
}

// InitRabbitProxy return instance of rabbitMQ connection
func InitRabbitProxy(ctx context.Context, rCfg config.RabbitMQConfig) *RabbitMQProxy {
	amqpURI := generateRabbitMQURI(rCfg)
	rabbitMQOnce.Do(func() {
		conn := initRabbitMQ(ctx, amqpURI)
		_globalRabbitMQProxy = &RabbitMQProxy{Conn: conn}
		go _globalRabbitMQProxy.handleReconnect(ctx, amqpURI)
	})
	return _globalRabbitMQProxy
}

// initRabbitMQ return instance of rabbitMQ connection
func initRabbitMQ(ctx context.Context, rabbitMQURI string) *amqp.Connection {
	logger.Info(ctx, fmt.Sprintf("connecting to rabbitMQ server at: %s", rabbitMQURI))
	conn, err := amqp.Dial(rabbitMQURI)
	if err != nil {
		panic(fmt.Errorf("failed to connect to rabbitMQ: %w", err))
	}

	return conn
}

func (p *RabbitMQProxy) handleReconnect(ctx context.Context, rabbitMQURI string) {
	for {
		closeChan := make(chan *amqp.Error)
		GetConn().NotifyClose(closeChan)

		err, ok := <-closeChan

		if !ok {
			logger.Info(ctx, "rabbitMQ notify channel closed, stopping solicitor")
			break
		}

		if err != nil {
			logger.Warn(ctx, "rabbitMQ connection closed by error", "reason", err)
		} else {
			logger.Info(ctx, "rabbitMQ connection closed normally (nil err)")
		}

		for {
			time.Sleep(5 * time.Second)
			newConn, err := amqp.Dial(rabbitMQURI)
			if err == nil {
				p.mu.Lock()
				p.Conn = newConn
				p.mu.Unlock()
				logger.Info(ctx, "rabbitMQ reconnected successfully")
				break
			}
			logger.Error(ctx, "rabbitMQ reconnect failed", "err", err)
		}
	}
}

func generateRabbitMQURI(rCfg config.RabbitMQConfig) string {
	user := url.QueryEscape(rCfg.User)
	password := url.QueryEscape(rCfg.Password)

	amqpURI := fmt.Sprintf("amqp://%s:%s@%s:%d/",
		user,
		password,
		rCfg.Host,
		rCfg.Port,
	)
	return amqpURI
}