package producer

import (
	"fmt"
	"git.beejay.kim/tool/service"
	"github.com/confluentinc/confluent-kafka-go/v2/kafka"
	"github.com/google/uuid"
	"github.com/rs/zerolog/log"
	"strings"
	"sync"
	"time"
)

type _producer struct {
	config  *Config
	session *kafka.Producer
}

func New(cfg *Config) (service.Producer, error) {
	var (
		p   = new(_producer)
		err error
	)

	if cfg == nil {
		return nil, fmt.Errorf("config must be provided")
	}

	p.config = cfg
	opts := &kafka.ConfigMap{
		"bootstrap.servers": strings.Join(p.config.Hosts, ","),
	}

	if p.session, err = kafka.NewProducer(opts); err != nil {
		return nil, err
	}

	go func() {
		for e := range p.session.Events() {
			switch ev := e.(type) {
			case kafka.Error:
				// Generic client instance-level errors, such as
				// broker connection failures, authentication issues, etc.
				//
				// These errors should generally be considered informational
				// as the underlying client will automatically try to
				// recover from any errors encountered, the application
				// does not need to take action on them.
				log.Debug().Str("service", "producer").Err(ev).Send()
			default:
				log.Debug().Str("service", "producer").Msgf("ignored event: %s", ev)
			}
		}
	}()

	return p, nil
}

func (p *_producer) ID() uuid.UUID {
	return uuid.NewSHA1(uuid.NameSpaceDNS, []byte("producer.kafka"))
}

func (p *_producer) Close() error {
	var wg sync.WaitGroup
	wg.Add(1)

	go func() {
		defer wg.Done()

		if p.session != nil {
			time.Sleep(time.Second)
			p.session.Close() //nolint:errcheck
		}
	}()

	wg.Wait()
	return nil
}

func (p *_producer) Produce(message *kafka.Message) error {
	var (
		delivery = make(chan kafka.Event)
		err      error
	)

	defer close(delivery)

	if message.TopicPartition.Topic == nil {
		return fmt.Errorf("illegal message: at least one topic name must be provided")
	}

	if err = p.session.Produce(message, delivery); err != nil {
		return err
	}

	e := <-delivery
	m := e.(*kafka.Message)

	if m.TopicPartition.Error != nil {
		return fmt.Errorf("delivery failed: %v", m.TopicPartition.Error)
	}

	return nil
}