package main

import (
    "fmt"
    mqtt "github.com/eclipse/paho.mqtt.golang"
    "time"
    "os/exec"
    "os"
    "flag"
)

//mqtt Event listener
var messagePubHandler mqtt.MessageHandler = func(client mqtt.Client, msg mqtt.Message) {
    fmt.Printf("Received message: %s from topic: %s\n", msg.Payload(), msg.Topic())
    RecievedPayload := string(msg.Payload())
    cmd := exec.Command("ir-ctl","-S" + RecievedPayload)
    out, err := cmd.Output()
    if err != nil {
        fmt.Println("could not run command: ", err)
    }
    fmt.Println("Output: ", string(out))
}

var connectHandler mqtt.OnConnectHandler = func(client mqtt.Client) {
    fmt.Println("Connected")
}

var connectLostHandler mqtt.ConnectionLostHandler = func(client mqtt.Client, err error) {
    fmt.Printf("Connect lost: %v", err)
}

func main() {
    //Set variables
    var DeviceName string
    var broker = "192.168.1.4"
    var port = 1883
    var CoreTopic = "KodiIR"
    //Get the hostname as sane default for mqtt topic/device id
    hostname, err := os.Hostname()
	if err != nil {
		panic(err)
	}
    //innput flag -DeviceName
    flag.StringVar(&DeviceName, "DeviceName", hostname, "The name that will be used as the topic an mqtt DeviceID")
    flag.Parse()
    //Set Mqtt Client options
    opts := mqtt.NewClientOptions()
    opts.AddBroker(fmt.Sprintf("tcp://%s:%d", broker, port))
    opts.SetClientID(DeviceName)
    opts.SetDefaultPublishHandler(messagePubHandler)
    opts.SetWill(CoreTopic + "/" + DeviceName + "/status", "Offline", 0, true)
    opts.OnConnect = connectHandler
    opts.OnConnectionLost = connectLostHandler

    client := mqtt.NewClient(opts)
    if token := client.Connect(); token.Wait() && token.Error() != nil {
        panic(token.Error())
    }
    //Subscribe to command toptic
    client.Subscribe(CoreTopic + "/" + DeviceName + "/cmd", 1, nil).Wait()
    //Publish connect msg
    client.Publish(CoreTopic + "/" + DeviceName + "/status", 0, true, "Online")
    //Print status
    fmt.Printf("Mqtt subscribed")
    //Loop so the program keeps running
    for {
        time.Sleep(time.Hour)
    }

    //Publish disconnect msg
    client.Publish(CoreTopic + "/" + DeviceName + "/status", 0, true, "Offline")
    client.Disconnect(250)
}