package kafka

import (
	"context"
	"fmt"

	"git.loafle.net/commons/logging-go"
	occe "git.loafle.net/overflow/commons-go/config/external"
	"github.com/segmentio/kafka-go"
)

var (
	kafkaWriters map[string]*kafka.Writer
	kafkaReaders map[string]*kafka.Reader
)

func InitPackage(config *occe.Kafka) {
	if nil == config {
		return
	}

	if nil != config.Producers || 0 < len(config.Producers) {
		kafkaWriters = make(map[string]*kafka.Writer)
		for n, c := range config.Producers {
			wc := kafka.WriterConfig{
				Brokers:           c.Brokers,
				Topic:             c.Topic,
				Balancer:          &kafka.LeastBytes{},
				MaxAttempts:       c.MaxAttempts,
				QueueCapacity:     c.QueueCapacity,
				BatchSize:         c.BatchSize,
				BatchTimeout:      c.BatchTimeout,
				ReadTimeout:       c.ReadTimeout,
				WriteTimeout:      c.WriteTimeout,
				RebalanceInterval: c.RebalanceInterval,
				RequiredAcks:      c.RequiredAcks,
				Async:             c.Async,
			}
			kafkaWriters[n] = kafka.NewWriter(wc)
		}
	}

	if nil != config.Consumers || 0 < len(config.Consumers) {
		kafkaReaders = make(map[string]*kafka.Reader)
		for n, c := range config.Consumers {
			rc := kafka.ReaderConfig{
				Brokers:           c.Brokers,
				GroupID:           c.GroupID,
				Topic:             c.Topic,
				QueueCapacity:     c.QueueCapacity,
				MinBytes:          c.MaxBytes,
				MaxBytes:          c.MaxBytes,
				MaxWait:           c.MaxWait,
				ReadLagInterval:   c.ReadLagInterval,
				HeartbeatInterval: c.HeartbeatInterval,
				CommitInterval:    c.CommitInterval,
				SessionTimeout:    c.SessionTimeout,
				RebalanceTimeout:  c.RebalanceTimeout,
				RetentionTime:     c.RetentionTime,
			}
			kafkaReaders[n] = kafka.NewReader(rc)
		}
	}
}

func StartPackage(config *occe.Kafka) {
	if nil == config {
		return
	}

}

func StopPackage(config *occe.Kafka) {
	if nil == config {
		return
	}

}

func DestroyPackage(config *occe.Kafka) {
	if nil == config {
		return
	}

	for _, w := range kafkaWriters {
		if err := w.Close(); nil != err {
			logging.Logger().Errorf("%v", err)
		}
	}
}

func Writer(name string) *kafka.Writer {
	if nil == kafkaWriters {
		return nil
	}
	return kafkaWriters[name]
}

func Reader(name string) *kafka.Reader {
	if nil == kafkaReaders {
		return nil
	}
	return kafkaReaders[name]
}

func Write(name string, key []byte, value []byte) error {
	if nil == kafkaWriters {
		return fmt.Errorf("Kafka client is not valid")
	}

	w, ok := kafkaWriters[name]
	if !ok {
		return fmt.Errorf("Kafka client is not valid")
	}

	err := w.WriteMessages(context.Background(),
		kafka.Message{
			Key:   key,
			Value: value,
		},
	)

	return err
}