// Sources for https://watermill.io/learn/getting-started/
package main

import (
	"context"
	"log"
	"time"

	"github.com/ThreeDotsLabs/watermill"
	"github.com/ThreeDotsLabs/watermill-redisstream/pkg/redisstream"
	"github.com/ThreeDotsLabs/watermill/message"
	"github.com/redis/go-redis/v9"
)

func main() {
	subClient := redis.NewClient(&redis.Options{
		Addr: "redis:6379",
		DB:   0,
	})
	subscriber, err := redisstream.NewSubscriber(
		redisstream.SubscriberConfig{
			Client:        subClient,
			Unmarshaller:  redisstream.DefaultMarshallerUnmarshaller{},
			ConsumerGroup: "test_consumer_group",
		},
		watermill.NewStdLogger(false, false),
	)
	if err != nil {
		panic(err)
	}

	messages, err := subscriber.Subscribe(context.Background(), "example.topic")
	if err != nil {
		panic(err)
	}

	go process(messages)

	pubClient := redis.NewClient(&redis.Options{
		Addr: "redis:6379",
		DB:   0,
	})
	publisher, err := redisstream.NewPublisher(
		redisstream.PublisherConfig{
			Client:     pubClient,
			Marshaller: redisstream.DefaultMarshallerUnmarshaller{},
		},
		watermill.NewStdLogger(false, false),
	)
	if err != nil {
		panic(err)
	}

	publishMessages(publisher)
}

func publishMessages(publisher message.Publisher) {
	for {
		msg := message.NewMessage(watermill.NewUUID(), []byte("Hello, world!"))

		if err := publisher.Publish("example.topic", msg); err != nil {
			panic(err)
		}

		time.Sleep(time.Second)
	}
}

func process(messages <-chan *message.Message) {
	for msg := range messages {
		log.Printf("received message: %s, payload: %s", msg.UUID, string(msg.Payload))

		// we need to Acknowledge that we received and processed the message,
		// otherwise, it will be resent over and over again.
		msg.Ack()
	}
}