package integrations

import (
	MQTT "github.com/eclipse/paho.mqtt.golang"
)

type MQTTIntegration struct{}

type MQTTEvent struct {
	Type    string
	Topic   string
	Payload []byte
}

type MQTTListeningClient struct {
	Client  MQTT.Client
	Channel chan MQTTEvent
}

func (s *MQTTIntegration) Publish(server string, username string, password string, clientId string, retain bool, qos byte, topic string, message string) error {
	opts := MQTT.NewClientOptions()
	opts.AddBroker(server)
	opts.SetUsername(username)
	opts.SetPassword(password)
	opts.SetClientID(clientId)

	client := MQTT.NewClient(opts)
	if token := client.Connect(); token.Wait() && token.Error() != nil {
		return token.Error()
	}

	token := client.Publish(topic, qos, retain, message)
	token.Wait()

	client.Disconnect(250)

	return nil
}

func (s *MQTTIntegration) Listen(server string, username string, password string, clientId string, topics map[string]byte) (*MQTTListeningClient, error) {
	channel := make(chan MQTTEvent)

	opts := MQTT.NewClientOptions()
	opts.AddBroker(server)
	opts.SetUsername(username)
	opts.SetPassword(password)
	opts.SetClientID(clientId)
	opts.SetDefaultPublishHandler(func(client MQTT.Client, msg MQTT.Message) {
		channel <- MQTTEvent{
			Type:    "message",
			Topic:   msg.Topic(),
			Payload: msg.Payload(),
		}
	})

	client := MQTT.NewClient(opts)
	if token := client.Connect(); token.Wait() && token.Error() != nil {
		return nil, token.Error()
	}

	if token := client.SubscribeMultiple(topics, nil); token.Wait() && token.Error() != nil {
		return nil, token.Error()
	}

	return &MQTTListeningClient{
		Client:  client,
		Channel: channel,
	}, nil
}

func (c *MQTTListeningClient) Close() {
	c.Channel <- MQTTEvent{
		Type: "close",
	}

	c.Client.Disconnect(250)
	close(c.Channel)
}