feat: add update command

cmd/update.go

@@ -0,0 +1,75 @@
+package cmd
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+
+	"github.com/mathismqn/godeez/internal/buildinfo"
+	"github.com/mathismqn/godeez/internal/updater"
+	"github.com/spf13/cobra"
+)
+
+var updateOpts struct {
+	checkOnly bool
+	force     bool
+}
+
+var updateCmd = &cobra.Command{
+	Use:   "update",
+	Short: "Update GoDeez to the latest version",
+	Args:  cobra.NoArgs,
+	RunE: func(cmd *cobra.Command, args []string) error {
+		err := runUpdate(cmd.Context())
+		if errors.Is(err, context.Canceled) {
+			return nil
+		}
+
+		return err
+	},
+}
+
+func runUpdate(ctx context.Context) error {
+	if err := updater.CheckUpdatable(); err != nil {
+		return err
+	}
+
+	u := updater.New()
+	u.Out = os.Stdout
+	current := buildinfo.Version()
+
+	release, err := u.Latest(ctx)
+	if err != nil {
+		return fmt.Errorf("failed to check for updates: %w", err)
+	}
+
+	latest := release.Version()
+	fmt.Printf("Current: %s\nLatest:  %s\n", current, latest)
+
+	if !updater.IsNewer(current, latest) && !updateOpts.force {
+		fmt.Println("Already up to date.")
+
+		return nil
+	}
+
+	if updateOpts.checkOnly {
+		fmt.Printf("Run `godeez update` to install %s.\n", latest)
+
+		return nil
+	}
+
+	if err := u.Apply(ctx, release); err != nil {
+		return err
+	}
+	fmt.Printf("Updated to %s.\n", latest)
+
+	return nil
+}
+
+func init() {
+	RootCmd.AddCommand(updateCmd)
+
+	updateCmd.Flags().BoolVar(&updateOpts.checkOnly, "check", false, "only report whether an update is available")
+	updateCmd.Flags().BoolVar(&updateOpts.force, "force", false, "reinstall even if already up to date")
+}