chore: initial commit

command_list.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"io"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+)
+
+func listCommand() (*cobra.Command, error) {
+	cmd := &cobra.Command{
+		Use: "list",
+		Short: "List all Emacs versions found in " +
+			"`$EVM_ROOT/versions/*'",
+		Aliases:           []string{"ls", "versions"},
+		Args:              cobra.ExactArgs(0),
+		ValidArgsFunction: listValidArgs,
+		RunE:              listRunE,
+	}
+
+	cmd.Flags().StringP("format", "f", "", "output format (yaml or json)")
+	err := viper.BindPFlag("list.format", cmd.Flags().Lookup("format"))
+	if err != nil {
+		return nil, err
+	}
+
+	return cmd, nil
+}
+
+func listRunE(cmd *cobra.Command, _ []string) error {
+	conf, err := getConfig()
+	if err != nil {
+		return err
+	}
+
+	format := viper.GetString("list.format")
+
+	versions, err := newEmacsVersions(conf)
+	if err != nil {
+		return err
+	}
+
+	results := &listResults{
+		Current:  conf.Current.Version,
+		Versions: versions,
+	}
+
+	return render(cmd.OutOrStdout(), format, results)
+}
+
+func listValidArgs(
+	_ *cobra.Command,
+	args []string,
+	toComplete string,
+) ([]string, cobra.ShellCompDirective) {
+	return nil, cobra.ShellCompDirectiveNoFileComp
+}
+
+type listResults struct {
+	Current  string        `yaml:"current" json:"current"`
+	Versions emacsVersions `yaml:"versions" json:"versions"`
+}
+
+func (lr *listResults) WriteTo(w io.Writer) (int64, error) {
+	var b []byte
+
+	for _, ver := range lr.Versions {
+		if lr.Current == ver.Version {
+			b = append(b, []byte("* ")...)
+		} else {
+			b = append(b, []byte("  ")...)
+		}
+
+		b = append(b, []byte(ver.Version)...)
+		b = append(b, byte('\n'))
+	}
+
+	n, err := w.Write(b)
+
+	return int64(n), err
+}