package kafka

import (
	"context"
	"fmt"
	"time"

	"fiskerinc.com/modules/utils/envtool"

	"github.com/confluentinc/confluent-kafka-go/v2/kafka"
	"github.com/pkg/errors"
)

// AdminClient interface
type AdminClient interface {
	CreateTopics(ctx context.Context, topics []kafka.TopicSpecification, options ...kafka.CreateTopicsAdminOption) ([]kafka.TopicResult, error)
}

// Global
var (
	Admin      AdminClient
	kafkaHosts string = envtool.GetEnv("KAFKA_HOSTS", "localhost:9093")
)

func init() {
	Admin, _ = kafka.NewAdminClient(&kafka.ConfigMap{"bootstrap.servers": kafkaHosts})
}

// EnsureTopicsExist checks Kafka for topic, if it doesn't exist it creates topic
func EnsureTopicsExist(topics []string) error {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	s := fmt.Sprintf("%vs", envtool.GetEnvInt("KAFKA_TIMEOUT", 30))
	maxDur, err := time.ParseDuration(s)
	if err != nil {
		return errors.WithStack(err)
	}

	ts := make([]kafka.TopicSpecification, len(topics))
	for i, t := range topics {
		ts[i] = kafka.TopicSpecification{
			Topic:             t,
			NumPartitions:     envtool.GetEnvInt("KAFKA_TOPIC_PARTITIONS", 1),
			ReplicationFactor: envtool.GetEnvInt("KAFKA_TOPIC_REPLICATION_FACTOR", 1),
		}
	}

	_, err = Admin.CreateTopics(ctx, ts, kafka.SetAdminOperationTimeout(maxDur))
	if err != nil {
		return errors.WithStack(err)
	}

	return nil
}