From ea82282de5592749e0c07428dd4a9d028a895947 Mon Sep 17 00:00:00 2001
From: "Jorge L. Fatta" <jorge.fatta@auth0.com>
Date: Fri, 22 Jan 2021 01:06:31 -0300
Subject: [PATCH] feat: support JSON

---
 internal/cli/cli.go         |  9 +++++++++
 internal/cli/root.go        |  5 ++++-
 internal/display/clients.go | 28 ++++++++++++++++++++++------
 internal/display/display.go | 37 ++++++++++++++++++++++++++++++++++++-
 4 files changed, 71 insertions(+), 8 deletions(-)

diff --git a/internal/cli/cli.go b/internal/cli/cli.go
index 63a81b0a2..338183a9a 100644
--- a/internal/cli/cli.go
+++ b/internal/cli/cli.go
@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path"
+	"strings"
 	"sync"
 
 	"github.com/auth0/auth0-cli/internal/display"
@@ -33,6 +34,7 @@ type cli struct {
 
 	verbose bool
 	tenant  string
+	format  string
 
 	initOnce sync.Once
 	path     string
@@ -96,9 +98,16 @@ func (c *cli) init() error {
 			c.tenant = c.data.DefaultTenant
 		}
 
+		format := strings.ToLower(c.format)
+		if format != "" && format != string(display.OutputFormatJSON) {
+			err = fmt.Errorf("Invalid format. Use `--format=json` or ommit this option to use the default format.")
+			return
+		}
+
 		c.renderer = &display.Renderer{
 			Tenant: c.tenant,
 			Writer: os.Stdout,
+			Format: display.OutputFormat(format),
 		}
 	})
 
diff --git a/internal/cli/root.go b/internal/cli/root.go
index 62496f639..359639a9e 100644
--- a/internal/cli/root.go
+++ b/internal/cli/root.go
@@ -39,11 +39,14 @@ func Execute() {
 
 	rootCmd.SetUsageTemplate(namespaceUsageTemplate())
 	rootCmd.PersistentFlags().StringVar(&cli.tenant,
-		"tenant", "", "Specific tenant to use")
+		"tenant", "", "Specific tenant to use.")
 
 	rootCmd.PersistentFlags().BoolVar(&cli.verbose,
 		"verbose", false, "Enable verbose mode.")
 
+	rootCmd.PersistentFlags().StringVar(&cli.format,
+		"format", "", "Command output format. Options: json.")
+
 	rootCmd.AddCommand(clientsCmd(cli))
 	rootCmd.AddCommand(logsCmd(cli))
 
diff --git a/internal/display/clients.go b/internal/display/clients.go
index 35f068f81..58ef7fccf 100644
--- a/internal/display/clients.go
+++ b/internal/display/clients.go
@@ -6,21 +6,37 @@ import (
 	"gopkg.in/auth0.v5/management"
 )
 
+type clientView struct {
+	Name     string
+	Type     string
+	ClientID string
+}
+
+func (v *clientView) AsTableHeader() []string {
+	return []string{"Name", "Type", "ClientID"}
+}
+
+func (v *clientView) AsTableRow() []string {
+	return []string{v.Name, v.Type, ansi.Faint(v.ClientID)}
+}
+
 func (r *Renderer) ClientList(clients []*management.Client) {
 	r.Heading(ansi.Bold(r.Tenant), "clients\n")
 
-	var rows [][]string
+	var res []View
 	for _, c := range clients {
 		if auth0.StringValue(c.Name) == deprecatedAppName {
 			continue
 		}
-		rows = append(rows, []string{
-			auth0.StringValue(c.Name),
-			appTypeFor(c.AppType),
-			ansi.Faint(auth0.StringValue(c.ClientID)),
+		res = append(res, &clientView{
+			Name:     auth0.StringValue(c.Name),
+			Type:     appTypeFor(c.AppType),
+			ClientID: auth0.StringValue(c.ClientID),
 		})
+
 	}
-	r.Table([]string{"Name", "Type", "ClientID"}, rows)
+
+	r.Results(res)
 }
 
 // TODO(cyx): determine if there's a better way to filter this out.
diff --git a/internal/display/display.go b/internal/display/display.go
index f1eb84a13..d694932b3 100644
--- a/internal/display/display.go
+++ b/internal/display/display.go
@@ -1,6 +1,7 @@
 package display
 
 import (
+	"encoding/json"
 	"fmt"
 	"io"
 	"os"
@@ -13,11 +14,19 @@ import (
 	"github.com/olekukonko/tablewriter"
 )
 
+type OutputFormat string
+
+const (
+	OutputFormatJSON OutputFormat = "json"
+)
+
 type Renderer struct {
 	Tenant string
 
 	Writer io.Writer
 
+	Format OutputFormat
+
 	initOnce sync.Once
 }
 
@@ -54,7 +63,33 @@ func (r *Renderer) Heading(text ...string) {
 	fmt.Fprintf(r.Writer, "%s %s\n", ansi.Faint("==="), strings.Join(text, " "))
 }
 
-func (r *Renderer) Table(header []string, data [][]string) {
+type View interface {
+	AsTableHeader() []string
+	AsTableRow() []string
+}
+
+func (r *Renderer) Results(data []View) {
+	if len(data) > 0 {
+		switch r.Format {
+		case OutputFormatJSON:
+			b, err := json.MarshalIndent(data, "", "    ")
+			if err != nil {
+				r.Errorf("couldn't marshal results as JSON: %v", err)
+				return
+			}
+			fmt.Fprint(r.Writer, string(b))
+
+		default:
+			rows := make([][]string, len(data))
+			for i, d := range data {
+				rows[i] = d.AsTableRow()
+			}
+			r.table(data[0].AsTableHeader(), rows)
+		}
+	}
+}
+
+func (r *Renderer) table(header []string, data [][]string) {
 	tableString := &strings.Builder{}
 	table := tablewriter.NewWriter(tableString)
 	table.SetHeader(header)