package mqtt

import (
	"crypto/tls"
	"fmt"
	"log"
	"net/url"
	"strconv"
	"strings"

	"mqttListener/Config"
	"mqttListener/models"
	"regexp"
	"time"

	MQTT "github.com/eclipse/paho.mqtt.golang"

	"encoding/json"
)

/*
 URI = mqtt://<user>:<pass>@<server>:<port>
*/

/* TODO: This options are just a suggestion
Options:
 [-help]                      Display help
 [-customer]                  Customer- or project number
 [-device]                    Device number
 [-uri <uri>]                 Broker URI
*/

var client MQTT.Client
var opts *MQTT.ClientOptions
var topic string
var uri url.URL

func Connect() {
	client = MQTT.NewClient(opts)
	token := client.Connect()
	for !token.WaitTimeout(3 * time.Second) {
	}
	if err := token.Error(); err != nil {
		log.Fatal(err)
		return
	}
	fmt.Println("connected to broker, topic = ", topic)
}

func Listen() {
	if !client.IsConnected() {
		log.Fatal("Client is not connected")
		return
	}

	client.Subscribe(topic, 0, subscriptionHandler)
	/*
		client.Subscribe(topic, 0, func(client MQTT.Client, msg MQTT.Message) {
			fmt.Printf("---------------------------------------------------\n")
			fmt.Printf("TOPIC: %s\n", msg.Topic())
			fmt.Printf("MSG: \n%s\n", msg.Payload())
			//fmt.Printf("* [%s] %s\n", msg.Topic(), string(msg.Payload()))
		})
	*/
}

func Setup() {

	scheme := "tcp://"
	if Config.EnableTLS {
		scheme = "ssl://"
	}

	urlString := scheme
	urlString += Config.BrokerUsername + ":" + Config.BrokerPassword + "@"
	urlString += Config.BrokerAddress + ":"
	urlString += strconv.FormatInt(Config.BrokerPort, 10)

	fmt.Println("broker urlString: ", urlString)

	uri, err := url.Parse(urlString)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println("broker URI: ", *uri)
	//fmt.Println("customer: ", *customer)
	//fmt.Println("device: ", *device)

	topic = "/ATB/#"

	opts = createClientOptions(Config.BrokerClientId, uri)

}

func createClientOptions(ClientID string, uri *url.URL) *MQTT.ClientOptions {
	opts := MQTT.NewClientOptions()
	opts.AddBroker(uri.Scheme + "://" + uri.Host)
	opts.SetUsername(uri.User.Username())
	password, _ := uri.User.Password()
	opts.SetPassword(password)
	opts.SetClientID(ClientID)
	opts.SetDefaultPublishHandler(f)
	if Config.EnableTLS {
		tlsConfig := &tls.Config{InsecureSkipVerify: true, ClientAuth: tls.NoClientCert}
		opts.SetTLSConfig(tlsConfig)
	}

	return opts
}

func Disconnect() {
	client.Disconnect(250)
}

var f MQTT.MessageHandler = func(client MQTT.Client, msg MQTT.Message) {
	fmt.Printf("---------------------------------------------------\n")
	fmt.Printf("Default Message Handler:\n")
	fmt.Printf("TOPIC: %s\n", msg.Topic())
	fmt.Printf("MSG: %s\n", msg.Payload())
}

var subscriptionHandler = func(client MQTT.Client, msg MQTT.Message) {
	// DEBUG
	fmt.Printf("---------------------------------------------------\n")
	fmt.Printf("TOPIC: %s\n", msg.Topic())
	fmt.Printf("MSG: \n%s\n", msg.Payload())
	//fmt.Printf("* [%s] %s\n", msg.Topic(), string(msg.Payload()))

	//-------------------------------------------------------------------
	// create ID from topic
	regexpWithType := "\\/ATB\\/[A-Z]+\\/[0-9]+\\/[0-9]+\\/mo"
	regexpDefault := "\\/ATB\\/[0-9]+\\/[0-9]+\\/[0-9]+\\/[0-9]+\\/mo"

	topicSlice := strings.Split(msg.Topic(), "/")

	matchedWithType, err := regexp.MatchString(regexpWithType, msg.Topic())
	if err != nil {
		log.Printf("ERROR: matchedWithType: %s", err.Error())
	}
	matchedDefault, err := regexp.MatchString(regexpDefault, msg.Topic())
	if err != nil {
		log.Printf("ERROR: matchedDefault: %s", err.Error())
	}

	var deviceID string
	if matchedWithType {
		fmt.Printf("Topic matched regexpWithType\n")
		deviceID = topicSlice[2] + "_" + topicSlice[3] + "_" + topicSlice[4]
	} else if matchedDefault {
		fmt.Printf("Topic matched regexpDefault\n")
		deviceID = topicSlice[2] + "_" + topicSlice[3] + "_" + topicSlice[4] + "_" + topicSlice[5]
	} else {
		log.Printf("ERROR: no matching topic: %s", msg.Topic())
		return
	}

	fmt.Printf("Generated deviceID = %s\n", deviceID)

	var device models.Device
	device.ID = deviceID
	device.MAC = "t.b.d."
	device.SN = "t.b.d."
	device.LastMsg = "t.b.d"

	//-------------------------------------------------------------------
	// extract data from payload
	bytes := []byte(msg.Payload())
	mo := models.Mo{}
	err = json.Unmarshal(bytes, &mo)
	if err != nil {
		fmt.Println(err.Error())
		return
	}

	device.MAC = mo.ID.PTU4_MAC
	device.SN = mo.ID.PTU4_SN

	fmt.Printf("Device MAC = %s\n", device.MAC)
	fmt.Printf("Device SN  = %s\n", device.SN)

	// TODO: store this device in database
}