package main

import (
	"fmt"
	"log"
	"net"
	"time"

	"github.com/grandcat/zeroconf"
	"golang.org/x/net/context"
)

type Device struct {
	IP   net.IP
	Name string
}

func discoverHueBridge() ([]Device, error) {
	// Create a new resolver
	resolver, err := zeroconf.NewResolver(nil)
	if err != nil {
		log.Fatalf("Failed to initialize resolver: %v", err)
	}

	// Instantiate a new devices slice
	devices := make([]Device, 0)

	// Set up a context with a timeout
	ctx, cancel := context.WithTimeout(context.Background(), time.Second*3)
	defer cancel()

	// Channel to recive the results
	entries := make(chan *zeroconf.ServiceEntry)

	// Start the lookup for the Hue Bridge
	go func() {
		err = resolver.Browse(ctx, "_hue._tcp", "local.", entries)
		if err != nil {
			log.Fatalf("Failed to browse for Hue Bridge: %v", err)
		}
	}()

	// Process the results
	go func() {
		for entry := range entries {
			devices = append(devices, Device{IP: entry.AddrIPv4[0], Name: entry.HostName})
		}
	}()

	// Wait for the context to expire
	<-ctx.Done()
	fmt.Println("mDNS query finished")
	fmt.Printf("Number of devices found: %d\n", len(devices))
	for _, device := range devices {
		fmt.Printf("Device: %s\n", device.Name)
		fmt.Printf("IP Address: %s\n", device.IP)
	}
	return devices, nil
}

func main() {
	discoverHueBridge()
}