package processor

import (
	"context"
	"errors"
	"fmt"

	"github.com/jwetzell/showbridge-go/internal/common"
	"github.com/jwetzell/showbridge-go/internal/config"
)

type MQTTMessage struct {
	topic    string
	qos      byte
	payload  []byte
	retained bool
}

type MQTTMessageCreate struct {
	config   config.ProcessorConfig
	Topic    string
	QoS      byte
	Retained bool
	Payload  []byte
}

func NewMQTTMessage(topic string, qos byte, retained bool, payload []byte) MQTTMessage {
	return MQTTMessage{
		topic:    topic,
		qos:      qos,
		retained: retained,
		payload:  payload,
	}
}

func (mm MQTTMessage) Duplicate() bool {
	// TODO(jwetzell): implement?
	return false
}

func (mm MQTTMessage) Qos() byte {
	return mm.qos
}

func (mm MQTTMessage) Retained() bool {
	return mm.retained
}

func (mm MQTTMessage) Topic() string {
	return mm.topic
}

func (mm MQTTMessage) MessageID() uint16 {
	// TODO(jwetzell): implement?
	return 0
}

func (mm MQTTMessage) Payload() []byte {
	return mm.payload
}

func (mm MQTTMessage) Ack() {}

func (mmc *MQTTMessageCreate) Process(ctx context.Context, wrappedPayload common.WrappedPayload) (common.WrappedPayload, error) {
	// TODO(jwetzell): support templating

	wrappedPayload.Payload = MQTTMessage{
		topic:    mmc.Topic,
		qos:      mmc.QoS,
		retained: mmc.Retained,
		payload:  mmc.Payload,
	}

	return wrappedPayload, nil
}

func (mmc *MQTTMessageCreate) Type() string {
	return mmc.config.Type
}

func init() {
	RegisterProcessor(ProcessorRegistration{
		Type: "mqtt.message.create",
		New: func(processorConfig config.ProcessorConfig) (Processor, error) {
			params := processorConfig.Params
			topicString, err := params.GetString("topic")
			if err != nil {
				return nil, fmt.Errorf("mqtt.message.create topic error: %w", err)
			}

			qosByte, err := params.GetInt("qos")
			if err != nil {
				return nil, fmt.Errorf("mqtt.message.create qos error: %w", err)
			}

			retainedBool, err := params.GetBool("retained")
			if err != nil {
				return nil, fmt.Errorf("mqtt.message.create retained error: %w", err)
			}

			//TODO(jwetzell): convert payload into []byte or string for sending
			payloadString, err := params.GetString("payload")
			if err != nil {
				if errors.Is(err, config.ErrParamNotString) {
					payloadBytes, err := params.GetByteSlice("payload")
					if err != nil {
						return nil, fmt.Errorf("mqtt.message.create payload error: %w", err)
					}
					return &MQTTMessageCreate{config: processorConfig, Topic: topicString, QoS: byte(qosByte), Retained: retainedBool, Payload: payloadBytes}, nil
				} else {
					return nil, fmt.Errorf("mqtt.message.create payload error: %w", err)
				}
			}

			payloadBytes := []byte(payloadString)

			return &MQTTMessageCreate{config: processorConfig, Topic: topicString, QoS: byte(qosByte), Retained: retainedBool, Payload: payloadBytes}, nil
		},
	})
}