package natsio

import (
	"errors"
	"fmt"

	"github.com/nats-io/nats.go"
)

func generateStreamConfig(stream string, subjects []string) *nats.StreamConfig {
	cfg := nats.StreamConfig{
		Name:         stream,
		Subjects:     subjects,
		Retention:    nats.WorkQueuePolicy,
		MaxConsumers: -1,
		MaxMsgSize:   -1,
		MaxMsgs:      -1,
		NoAck:        false,
	}
	return &cfg
}

// GetStreamInfo ...
func (js JetStream) GetStreamInfo() (*nats.StreamInfo, error) {
	return js.instance.StreamInfo(js.streamName)
}

// addStream add new stream, with default config
func (js JetStream) addStream() {
	// get info about the stream
	stream, _ := js.GetStreamInfo()

	// if stream not found, create new
	if stream == nil {
		_, err := js.instance.AddStream(generateStreamConfig(js.streamName, []string{}))
		if err != nil {
			fmt.Printf("[natsio.JetStream] add stream %s error: %s \n", js.streamName, err.Error())
		}
	}
}

// DeleteStream ...
func (js JetStream) DeleteStream() error {
	if err := js.instance.DeleteStream(js.streamName); err != nil {
		msg := fmt.Sprintf("[natsio.JetStream] delete stream %s error: %s", js.streamName, err.Error())
		return errors.New(msg)
	}

	return nil
}

// AddSubjects ...
func (js JetStream) AddSubjects(subjects []string) error {
	// get stream info
	stream, _ := js.GetStreamInfo()
	if stream == nil {
		msg := fmt.Sprintf("[natsio.JetStream] error when adding stream #%s subjects: stream not found", js.streamName)
		return errors.New(msg)
	}

	// merge current and new subjects
	newSubjects := mergeAndUniqueArrayStrings(subjects, stream.Config.Subjects)

	// update
	_, err := js.instance.UpdateStream(generateStreamConfig(js.streamName, newSubjects))
	if err != nil {
		msg := fmt.Sprintf("[natsio.JetStream] add subject to stream #%s error: %s", js.streamName, err.Error())
		return errors.New(msg)
	}

	return nil
}