feat(version): replace --version with 'version' command to print build information for uc and uncloudd

cmd/uncloudd/version.go

@@ -0,0 +1,82 @@
+package main
+
+import (
+	"bytes"
+	_ "embed"
+	"fmt"
+	"strings"
+	"text/template"
+
+	"github.com/psviderski/uncloud/internal/cli/tui"
+	"github.com/psviderski/uncloud/internal/version"
+	"github.com/spf13/cobra"
+)
+
+//go:embed art.txt
+var asciiArt string
+
+// newVersionCommand creates a new command to print the version and build information for the binary.
+func newVersionCommand() *cobra.Command {
+	var output string
+
+	cmd := &cobra.Command{
+		Use:   "version",
+		Short: "Show version and build information.",
+		Args:  cobra.NoArgs,
+		RunE: func(cmd *cobra.Command, _ []string) error {
+			info := version.GetInfo()
+			w := cmd.OutOrStdout()
+
+			switch output {
+			case "":
+				fmt.Fprint(w, humanVersion(info))
+			case "json":
+				s, err := info.JSONString()
+				if err != nil {
+					return err
+				}
+				fmt.Fprintln(w, s)
+			default:
+				s, err := templateVersion(output, info)
+				if err != nil {
+					return err
+				}
+				fmt.Fprint(w, s)
+			}
+
+			return nil
+		},
+	}
+
+	cmd.Flags().StringVarP(&output, "output", "o", "",
+		"Output format: 'json' or a Go template (e.g., '{{.Version}}').\n"+
+			"Run with '-o json' to discover the field names available to the template.\n"+
+			"(default is human-readable)")
+
+	return cmd
+}
+
+func humanVersion(info version.Info) string {
+	var b strings.Builder
+	b.WriteString(asciiArt)
+	b.WriteString("\n")
+	b.WriteString(fmt.Sprintf("uncloudd: Uncloud machine daemon (%s)",
+		tui.URLStyle.Render(version.WebsiteURL)))
+	b.WriteString("\n\n")
+	b.WriteString(info.String())
+	return b.String()
+}
+
+// templateVersion renders the version info using the provided Go template.
+func templateVersion(tmpl string, info version.Info) (string, error) {
+	t, err := template.New("version").Parse(tmpl)
+	if err != nil {
+		return "", fmt.Errorf("parse template: %w", err)
+	}
+
+	var buf bytes.Buffer
+	if err = t.Execute(&buf, info); err != nil {
+		return "", fmt.Errorf("execute template: %w", err)
+	}
+	return buf.String(), nil
+}