package main

import (
	"crypto/tls"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"time"

	_ "github.com/mattn/go-sqlite3"
	rabbitmq "github.com/rabbitmq/amqp091-go"
)

func failOnError(err error, msg string) {
	if err != nil {
		log.Panicf("%s: %s", err, msg)
	}
}

type Message struct {
	Topic string
	Body  []byte
}

var messageQueue chan Message

func PublicMessage(giteaWebhookType, giteaOrg string, msgBody io.Reader) error {
	if messageQueue == nil {
		return fmt.Errorf("Queue not initialized")
	}

	data, err := io.ReadAll(msgBody)
	if err != nil {
		return fmt.Errorf("Error reading JSON data. Err: %v", err)
	}

	if !json.Valid(data) {
		return fmt.Errorf("Invalid JSON in request")
	}

	messageQueue <- Message{
		Topic: fmt.Sprintf("opensuse.gitea.%s.%s", giteaOrg, giteaWebhookType),
		Body:  data,
	}
	return nil
}

func ConnectToExchangeForPublish(host, username, password string) {
	defer func() {
		if r := recover(); r != nil {
			log.Print("recovering... reconnecting...\n")
			time.Sleep(5 * time.Second)
			go ConnectToExchangeForPublish(host, username, password)
		}
	}()

	if messageQueue == nil {
		messageQueue = make(chan Message, 10240)
	}

	auth := ""
	if len(username) > 0 && len(password) > 0 {
		auth = username + ":" + password + "@"
	}

	connection, err := rabbitmq.DialTLS("amqps://"+auth+host, &tls.Config{
		ServerName: host,
	})
	failOnError(err, "Cannot connect to rabbit.opensuse.org")
	defer connection.Close()

	ch, err := connection.Channel()
	failOnError(err, "Cannot create a channel")
	defer ch.Close()

	err = ch.ExchangeDeclarePassive("pubsub", "topic", true, false, false, false, nil)
	failOnError(err, "Cannot find pubsub exchange")

	for {
		msg, ok := <-messageQueue
		if !ok {
			log.Printf("Shutdown ... \n")
			return
		}

		err = ch.Publish("pubsub", msg.Topic, false, false, rabbitmq.Publishing{
			ContentType: "application/json",
			AppId:       RabbitForwarderPath,
			Body:        []byte(msg.Body),
		})

		if err != nil {
			if connection.IsClosed() {
				select {
				case messageQueue <- msg:
					log.Printf("requed ...")
				default:
					log.Printf("queue full... message lost")
				}
				// reconnect
				log.Printf("reconnecting...")
				time.Sleep(5 * time.Second)
				go ConnectToExchangeForPublish(host, username, password)
				return
			} else {
				log.Printf("Error sending request. %v", err)
			}
		}
	}
}