Add new "module" command

- "module list" will list all modules and their descriptions
- "module info [module names or 'all']" will list detailed info about modules including their parameters

cmd/module.go

@@ -0,0 +1,110 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"text/tabwriter"
+
+	"github.com/asmaloney/gactar/actr/modules"
+	"github.com/asmaloney/gactar/util/chalk"
+	"github.com/spf13/cobra"
+)
+
+var modulesCmd = &cobra.Command{
+	Use:   "module",
+	Short: "Get info about available modules",
+	RunE: func(cmd *cobra.Command, args []string) (err error) {
+		err = errRequiresSubcommand{command: "module"}
+		chalk.PrintErr(err)
+
+		return
+	},
+}
+
+var infoCmd = &cobra.Command{
+	Use:   "info",
+	Short: "Get detailed info about modules by name (list of names or 'all')",
+	Run: func(cmd *cobra.Command, args []string) {
+		info(args)
+	},
+}
+
+var listCmd = &cobra.Command{
+	Use:   "list",
+	Short: "Output module names and their descriptions",
+	Run: func(cmd *cobra.Command, args []string) {
+		list()
+	},
+}
+
+type errUnknownModule struct {
+	module string
+}
+
+func (e errUnknownModule) Error() string {
+	message := fmt.Sprintf("module not found: %q", e.module)
+	return chalk.ErrorBold(message)
+}
+
+func init() {
+	modulesCmd.AddCommand(infoCmd)
+	modulesCmd.AddCommand(listCmd)
+
+	rootCmd.AddCommand(modulesCmd)
+}
+
+func info(args []string) {
+	if len(args) == 1 && args[0] == "all" {
+		args = modules.ModuleNames()
+	}
+
+	for _, name := range args {
+		mod := modules.FindModule(name)
+		if mod == nil {
+			err := errUnknownModule{module: name}
+			chalk.PrintErr(err)
+
+			continue
+		}
+
+		fmt.Printf("%s: %s (%s)\n", chalk.Bold("Module"), mod.ModuleName(), mod.ModuleVersion())
+		fmt.Println(chalk.Header(" Description"))
+		fmt.Printf("  %s\n", mod.ModuleDescription())
+
+		if mod.HasParameters() {
+			fmt.Println(chalk.Header(" Parameters"))
+			writer := tabwriter.NewWriter(os.Stdout, 1, 1, 2, ' ', 0)
+
+			for _, paramName := range mod.ParameterNames() {
+				fmt.Fprintf(writer, "\t%s", chalk.Italic(paramName))
+
+				info := mod.ParameterInfo(paramName)
+				if info != nil {
+					fmt.Fprintf(writer, "\t%s", info.Description)
+				}
+
+				fmt.Fprintln(writer, "")
+
+			}
+			writer.Flush()
+		}
+
+		fmt.Println("")
+	}
+}
+
+func list() {
+	writer := tabwriter.NewWriter(os.Stdout, 1, 1, 2, ' ', 0)
+
+	for _, module := range modules.AllModules() {
+		version := module.ModuleVersion()
+
+		if version == modules.BuiltIn {
+			version = chalk.Italic(version)
+		}
+
+		fmt.Fprintf(writer, "%s\t%s\t%s\n", chalk.Bold(module.ModuleName()), version, module.ModuleDescription())
+	}
+
+	writer.Flush()
+}