Add output formatting support to the 'show' and 'user ls' commands

This adds options to specify an output format for the commands in question. Supported formats are currently:
- 'plain': plaintext, stripped of all colors
- 'json': prints output as a json object

1 files changed, 65 insertions, 2 deletions

diff --git a/commands/user_ls.go b/commands/user_ls.go
index 609ff5a4..9d0eebf1 100644
--- a/commands/user_ls.go
+++ b/commands/user_ls.go
@@ -1,15 +1,19 @@
 package commands
 
 import (
+	"encoding/json"
 	"fmt"
-
 	"github.com/MichaelMure/git-bug/cache"
 	"github.com/MichaelMure/git-bug/util/colors"
 	"github.com/MichaelMure/git-bug/util/interrupt"
 	"github.com/spf13/cobra"
 )
 
-func runUserLs(cmd *cobra.Command, args []string) error {
+var (
+	userLsOutputFormat string
+)
+
+func runUserLs(_ *cobra.Command, _ []string) error {
 	backend, err := cache.NewRepoCache(repo)
 	if err != nil {
 		return err
@@ -17,6 +21,42 @@ func runUserLs(cmd *cobra.Command, args []string) error {
 	defer backend.Close()
 	interrupt.RegisterCleaner(backend.Close)
 
+	switch userLsOutputFormat {
+	case "json":
+		return userLsJsonFormatter(backend)
+	case "plain":
+		return userLsPlainFormatter(backend)
+	case "default":
+		return userLsDefaultFormatter(backend)
+	default:
+		return fmt.Errorf("unknown format %s", userLsOutputFormat)
+	}
+}
+
+type JSONIdentity struct {
+	Id      string `json:"id"`
+	HumanId string `json:"human_id"`
+	Name    string `json:"name"`
+	Login   string `json:"login"`
+}
+
+func userLsPlainFormatter(backend *cache.RepoCache) error {
+	for _, id := range backend.AllIdentityIds() {
+		i, err := backend.ResolveIdentityExcerpt(id)
+		if err != nil {
+			return err
+		}
+
+		fmt.Printf("%s %s\n",
+			i.Id.Human(),
+			i.DisplayName(),
+		)
+	}
+
+	return nil
+}
+
+func userLsDefaultFormatter(backend *cache.RepoCache) error {
 	for _, id := range backend.AllIdentityIds() {
 		i, err := backend.ResolveIdentityExcerpt(id)
 		if err != nil {
@@ -32,6 +72,27 @@ func runUserLs(cmd *cobra.Command, args []string) error {
 	return nil
 }
 
+func userLsJsonFormatter(backend *cache.RepoCache) error {
+	users := []JSONIdentity{}
+	for _, id := range backend.AllIdentityIds() {
+		i, err := backend.ResolveIdentityExcerpt(id)
+		if err != nil {
+			return err
+		}
+
+		users = append(users, JSONIdentity{
+			i.Id.String(),
+			i.Id.Human(),
+			i.Name,
+			i.Login,
+		})
+	}
+
+	jsonObject, _ := json.MarshalIndent(users, "", "    ")
+	fmt.Printf("%s\n", jsonObject)
+	return nil
+}
+
 var userLsCmd = &cobra.Command{
 	Use:     "ls",
 	Short:   "List identities.",
@@ -42,4 +103,6 @@ var userLsCmd = &cobra.Command{
 func init() {
 	userCmd.AddCommand(userLsCmd)
 	userLsCmd.Flags().SortFlags = false
+	userLsCmd.Flags().StringVarP(&userLsOutputFormat, "format", "f", "default",
+		"Select the output formatting style. Valid values are [default,plain,json]")
 }