package example_test

import (
	"fmt"
	"net/url"
	"os"

	"github.com/huin/goupnp"
	"github.com/huin/goupnp/dcps/internetgateway1"
)

// Use discovered WANPPPConnection1 services to find external IP addresses.
func Example_WANPPPConnection1_GetExternalIPAddress() {
	clients, errors, err := internetgateway1.NewWANPPPConnection1Clients()
	extIPClients := make([]GetExternalIPAddresser, len(clients))
	for i, client := range clients {
		extIPClients[i] = client
	}
	DisplayExternalIPResults(extIPClients, errors, err)
	// Output:
}

// Use discovered WANIPConnection services to find external IP addresses.
func Example_WANIPConnection_GetExternalIPAddress() {
	clients, errors, err := internetgateway1.NewWANIPConnection1Clients()
	extIPClients := make([]GetExternalIPAddresser, len(clients))
	for i, client := range clients {
		extIPClients[i] = client
	}
	DisplayExternalIPResults(extIPClients, errors, err)
	// Output:
}

type GetExternalIPAddresser interface {
	GetExternalIPAddress() (NewExternalIPAddress string, err error)
	GetServiceClient() *goupnp.ServiceClient
}

func DisplayExternalIPResults(clients []GetExternalIPAddresser, errors []error, err error) {
	if err != nil {
		fmt.Fprintln(os.Stderr, "Error discovering service with UPnP: ", err)
		return
	}

	if len(errors) > 0 {
		fmt.Fprintf(os.Stderr, "Error discovering %d services:\n", len(errors))
		for _, err := range errors {
			fmt.Println("  ", err)
		}
	}

	fmt.Fprintf(os.Stderr, "Successfully discovered %d services:\n", len(clients))
	for _, client := range clients {
		device := &client.GetServiceClient().RootDevice.Device

		fmt.Fprintln(os.Stderr, "  Device:", device.FriendlyName)
		if addr, err := client.GetExternalIPAddress(); err != nil {
			fmt.Fprintf(os.Stderr, "    Failed to get external IP address: %v\n", err)
		} else {
			fmt.Fprintf(os.Stderr, "    External IP address: %v\n", addr)
		}
	}
}

func Example_ReuseDiscoveredDevice() {
	var allMaybeRootDevices []goupnp.MaybeRootDevice
	for _, urn := range []string{internetgateway1.URN_WANPPPConnection_1, internetgateway1.URN_WANIPConnection_1} {
		maybeRootDevices, err := goupnp.DiscoverDevices(internetgateway1.URN_WANPPPConnection_1)
		if err != nil {
			fmt.Fprintf(os.Stderr, "Could not discover %s devices: %v\n", urn, err)
		}
		allMaybeRootDevices = append(allMaybeRootDevices, maybeRootDevices...)
	}
	locations := make([]*url.URL, 0, len(allMaybeRootDevices))
	fmt.Fprintf(os.Stderr, "Found %d devices:\n", len(allMaybeRootDevices))
	for _, maybeRootDevice := range allMaybeRootDevices {
		if maybeRootDevice.Err != nil {
			fmt.Fprintln(os.Stderr, "  Failed to probe device at ", maybeRootDevice.Location.String())
		} else {
			locations = append(locations, maybeRootDevice.Location)
			fmt.Fprintln(os.Stderr, "  Successfully probed device at ", maybeRootDevice.Location.String())
		}
	}
	fmt.Fprintf(os.Stderr, "Attempt to re-acquire %d devices:\n", len(locations))
	for _, location := range locations {
		if _, err := goupnp.DeviceByURL(location); err != nil {
			fmt.Fprintf(os.Stderr, "  Failed to reacquire device at %s: %v\n", location.String(), err)
		} else {
			fmt.Fprintf(os.Stderr, "  Successfully reacquired device at %s\n", location.String())
		}
	}
	// Output:
}