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

import (
	"context"
	"log"
	"net/url"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	amazonsqs "github.com/aws/aws-sdk-go-v2/service/sqs"
	transport "github.com/aws/smithy-go/endpoints"
	"github.com/samber/lo"

	"github.com/ThreeDotsLabs/watermill"
	"github.com/ThreeDotsLabs/watermill-aws/sqs"
	"github.com/ThreeDotsLabs/watermill/message"
)

func main() {
	logger := watermill.NewStdLogger(false, false)

	sqsOpts := []func(*amazonsqs.Options){
		amazonsqs.WithEndpointResolverV2(sqs.OverrideEndpointResolver{
			Endpoint: transport.Endpoint{
				URI: *lo.Must(url.Parse("http://localstack:4566")),
			},
		}),
	}

	subscriberConfig := sqs.SubscriberConfig{
		AWSConfig: aws.Config{
			Credentials: aws.AnonymousCredentials{},
		},
		OptFns: sqsOpts,
	}

	subscriber, err := sqs.NewSubscriber(subscriberConfig, logger)
	if err != nil {
		panic(err)
	}

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

	go process(messages)

	publisherConfig := sqs.PublisherConfig{
		AWSConfig: aws.Config{
			Credentials: aws.AnonymousCredentials{},
		},
		OptFns: sqsOpts,
	}

	publisher, err := sqs.NewPublisher(publisherConfig, logger)
	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()
	}
}