feat(cmd): add a "register" command

Running go-hass-agent register with appropriate options allows for
registering without a GUI.

cmd/register.go

@@ -0,0 +1,70 @@
+// Copyright (c) 2023 Joshua Rich <[email protected]>
+//
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+package cmd
+
+import (
+	"context"
+	"net/url"
+	"os"
+
+	"fyne.io/fyne/v2/data/binding"
+	"github.com/joshuar/go-hass-agent/internal/agent"
+	"github.com/joshuar/go-hass-agent/internal/device"
+	"github.com/joshuar/go-hass-agent/internal/hass"
+	"github.com/rs/zerolog/log"
+	"github.com/spf13/cobra"
+)
+
+var (
+	providedURL, providedToken string
+)
+
+// registerCmd represents the register command
+var registerCmd = &cobra.Command{
+	Use:   "register",
+	Short: "Register this device with Home Assistant",
+	Long:  `Register will attempt to register this device with Home Assistant. A URL for a Home Assistant instance and long-lived access token is required to be provided.`,
+	Run: func(cmd *cobra.Command, args []string) {
+		agentCtx, cancelfunc := context.WithCancel(context.Background())
+		agentCtx = device.SetupContext(agentCtx)
+		log.Info().Msg("Starting registration process.")
+		agent := agent.NewAgent()
+		agent.SetupLogging()
+		agent.Load(agentCtx, registrationFetcher)
+		cancelfunc()
+		log.Info().Msg("Device registered with Home Assistant.")
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(registerCmd)
+	registerCmd.PersistentFlags().StringVar(&providedURL,
+		"url", "http://localhost:8123",
+		"URL to Home Assistant instance (e.g. https://somehost:someport)")
+	registerCmd.PersistentFlags().StringVar(&providedToken,
+		"token", "",
+		"Long-lived token (e.g. 123456)")
+	registerCmd.MarkPersistentFlagRequired("token")
+}
+
+func registrationFetcher(ctx context.Context) *hass.RegistrationHost {
+	u, err := url.Parse(providedURL)
+	if err != nil {
+		log.Error().Err(err).
+			Msg("Cannot parse provided URL.")
+		os.Exit(-1)
+	}
+	registrationInfo := agent.NewRegistration()
+	registrationInfo.Token = binding.BindString(&providedToken)
+	registrationInfo.Server = binding.BindString(&u.Host)
+	registrationInfo.UseTLS = binding.NewBool()
+	if u.Scheme == "https" {
+		registrationInfo.UseTLS.Set(true)
+	} else {
+		registrationInfo.UseTLS.Set(false)
+	}
+	return registrationInfo
+}