From f9f6d101f037cfa2ab58a0d85497b35b498a59c2 Mon Sep 17 00:00:00 2001
From: Sam Hofius <sam@samhofi.us>
Date: Thu, 28 Oct 2021 10:29:17 -0600
Subject: [PATCH 1/8] Add template support

---
 webhookbot/db.sql                |  4 +-
 webhookbot/main.go               | 39 +++++++++++++++++-
 webhookbot/webhookbot/db.go      | 33 +++++++++++----
 webhookbot/webhookbot/handler.go | 71 +++++++++++++++++++++++++++++++-
 webhookbot/webhookbot/http.go    | 66 ++++++++++++++++++++---------
 5 files changed, 180 insertions(+), 33 deletions(-)

diff --git a/webhookbot/db.sql b/webhookbot/db.sql
index eb62a95a..5c0233fa 100644
--- a/webhookbot/db.sql
+++ b/webhookbot/db.sql
@@ -2,6 +2,8 @@ CREATE TABLE `hooks` (
   `id` varchar(100) NOT NULL,
   `name` varchar(100) NOT NULL,
   `conv_id` varchar(100) NOT NULL,
+  `template` varchar(10000) NOT NULL,
+  CONSTRAINT hook UNIQUE (`name`,`conv_id`),
   PRIMARY KEY (`id`),
   KEY `conv_id` (`conv_id`)
-) ENGINE=InnoDB DEFAULT CHARSET=utf8;
\ No newline at end of file
+) ENGINE=InnoDB DEFAULT CHARSET=utf8;
diff --git a/webhookbot/main.go b/webhookbot/main.go
index 51add8a7..6ff09f64 100644
--- a/webhookbot/main.go
+++ b/webhookbot/main.go
@@ -48,7 +48,30 @@ func (s *BotServer) makeAdvertisement() kbchat.Advertisement {
 	createExtended := fmt.Sprintf(`Create a new webhook for sending messages into the current conversation. You must supply a name as well to identify the webhook. To use a webhook URL, supply a %smsg%s URL parameter, or a JSON POST body with a field %smsg%s.
 
 	Example:%s
-		!webhook create alerts%s`, back, back, back, back, backs, backs)
+		!webhook create alerts%s
+
+	Example (using custom template):%s
+		!webhook create alerts *{{.title}}*
+		%s{{.body}}%s%s
+
+	Templates:
+		Information about creating templates, and some examples can be found at %shttps://pkg.go.dev/text/template%s
+		You can test your templates against your JSON data at %shttps://play.golang.org/p/vC06kRCQDfX%s
+
+		There are 2 custom variables you can use in your templates (see the default template below for example usage):
+		  - %s$webhookName%s: The name you gave the webhook
+		  - %s$webhookMethod%s: Whether GET or POST was used when the webhook endpoint was fetched
+
+		If you don't provide a template, this is the default:%s
+		[hook: *{{$webhookName}}*]
+
+		{{if eq $webhookMethod "POST"}}{{.msg}}{{else}}{{index .msg 0}}{{end}}%s`,
+		back, back, back, back, backs, backs, backs, back, back, backs, back, back, back, back, back, back, back, back, backs, backs)
+	updateExtended := fmt.Sprintf(`Update an existing webhook's template. Leave the template field empty to use the default template. For more information about templates, see the help text for %s!webhook create%s.
+
+	Example:%s
+		!webhook update alerts *New Alert: {{.title}}*
+		%s{{.body}}%s%s`, back, back, backs, back, back, backs)
 	removeExtended := fmt.Sprintf(`Remove a webhook from the current conversation. You must supply the name of the webhook.
 
 	Example:%s
@@ -57,14 +80,26 @@ func (s *BotServer) makeAdvertisement() kbchat.Advertisement {
 	cmds := []chat1.UserBotCommandInput{
 		{
 			Name:        "webhook create",
+			Usage:       "<name> [<template>]",
 			Description: "Create a new webhook for sending into the current conversation",
 			ExtendedDescription: &chat1.UserBotExtendedDescription{
-				Title: `*!webhook create* <name>
+				Title: `*!webhook create* <name> [<template>]
 Create a webhook`,
 				DesktopBody: createExtended,
 				MobileBody:  createExtended,
 			},
 		},
+		{
+			Name:        "webhook update",
+			Usage:       "<name> [<template>]",
+			Description: "Update the template of an existing webhook in the current conversation",
+			ExtendedDescription: &chat1.UserBotExtendedDescription{
+				Title: `*!webhook update* <name> [<template>]
+Update a webhook's template`,
+				DesktopBody: updateExtended,
+				MobileBody:  updateExtended,
+			},
+		},
 		{
 			Name:        "webhook list",
 			Description: "List active webhooks in the current conversation",
diff --git a/webhookbot/webhookbot/db.go b/webhookbot/webhookbot/db.go
index 88c12006..83fd6b0a 100644
--- a/webhookbot/webhookbot/db.go
+++ b/webhookbot/webhookbot/db.go
@@ -35,7 +35,7 @@ func (d *DB) makeID(name string, convID chat1.ConvIDStr) (string, error) {
 	return base.URLEncoder().EncodeToString(h.Sum(nil)[:20]), nil
 }
 
-func (d *DB) Create(name string, convID chat1.ConvIDStr) (string, error) {
+func (d *DB) Create(name, template string, convID chat1.ConvIDStr) (string, error) {
 	id, err := d.makeID(name, convID)
 	if err != nil {
 		return "", err
@@ -43,10 +43,10 @@ func (d *DB) Create(name string, convID chat1.ConvIDStr) (string, error) {
 	err = d.RunTxn(func(tx *sql.Tx) error {
 		if _, err := tx.Exec(`
 			INSERT INTO hooks
-			(id, name, conv_id)
+			(id, name, template, conv_id)
 			VALUES
-			(?, ?, ?)
-		`, id, name, convID); err != nil {
+			(?, ?, ?, ?)
+		`, id, name, template, convID); err != nil {
 			return err
 		}
 		return nil
@@ -54,20 +54,35 @@ func (d *DB) Create(name string, convID chat1.ConvIDStr) (string, error) {
 	return id, err
 }
 
+func (d *DB) Update(name, template string, convID chat1.ConvIDStr) error {
+	err := d.RunTxn(func(tx *sql.Tx) error {
+		if _, err := tx.Exec(`
+			UPDATE hooks
+			SET template = ?
+			WHERE conv_id = ? AND name = ?
+		`, template, convID, name); err != nil {
+			return err
+		}
+		return nil
+	})
+	return err
+}
+
 func (d *DB) GetHook(id string) (res webhook, err error) {
 	row := d.DB.QueryRow(`
-		SELECT conv_id, name FROM hooks WHERE id = ?
+		SELECT conv_id, name, template FROM hooks WHERE id = ?
 	`, id)
-	if err := row.Scan(&res.convID, &res.name); err != nil {
+	if err := row.Scan(&res.convID, &res.name, &res.template); err != nil {
 		return res, err
 	}
 	return res, nil
 }
 
 type webhook struct {
-	id     string
-	convID chat1.ConvIDStr
-	name   string
+	id       string
+	convID   chat1.ConvIDStr
+	name     string
+	template string
 }
 
 func (d *DB) List(convID chat1.ConvIDStr) (res []webhook, err error) {
diff --git a/webhookbot/webhookbot/handler.go b/webhookbot/webhookbot/handler.go
index f49e8c38..05130c05 100644
--- a/webhookbot/webhookbot/handler.go
+++ b/webhookbot/webhookbot/handler.go
@@ -1,9 +1,11 @@
 package webhookbot
 
 import (
+	"database/sql"
 	"errors"
 	"fmt"
 	"strings"
+	"text/template"
 
 	_ "github.com/go-sql-driver/mysql"
 	"github.com/keybase/go-keybase-chat-bot/kbchat"
@@ -11,6 +13,8 @@ import (
 	"github.com/keybase/managed-bots/base"
 )
 
+const defaultTemplate = "[hook: *{{$webhookName}}*]\n\n{{if eq $webhookMethod \"POST\"}}{{.msg}}{{else}}{{index .msg 0}}{{end}}"
+
 type Handler struct {
 	*base.DebugOutput
 
@@ -112,7 +116,7 @@ func (h *Handler) handleList(cmd string, msg chat1.MsgSummary) (err error) {
 func (h *Handler) handleCreate(cmd string, msg chat1.MsgSummary) (err error) {
 	convID := msg.ConvID
 	toks := strings.Split(cmd, " ")
-	if len(toks) != 3 {
+	if len(toks) < 3 {
 		h.ChatEcho(convID, "invalid number of arguments, must specify a name")
 		return nil
 	}
@@ -128,7 +132,23 @@ func (h *Handler) handleCreate(cmd string, msg chat1.MsgSummary) (err error) {
 
 	h.stats.Count("create")
 	name := toks[2]
-	id, err := h.db.Create(name, convID)
+
+	// template is whatever remains after removing "!webhook create <name>", and trimming spaces.
+	// if the template is empty, we'll set a default one
+	templateSrc := strings.Replace(cmd, "!webhook create", "", 1)
+	templateSrc = strings.Replace(templateSrc, name, "", 1)
+	templateSrc = strings.TrimSpace(templateSrc)
+	if templateSrc == "" {
+		templateSrc = defaultTemplate
+	}
+	tWithVars := injectTemplateVars("testhook1", "POST", templateSrc)
+	_, err = template.New("").Parse(tWithVars)
+	if err != nil {
+		h.ChatEcho(convID, "failed to parse template: %v", err)
+		return fmt.Errorf("handleCreate: failed to parse template: %s", err)
+	}
+
+	id, err := h.db.Create(name, templateSrc, convID)
 	if err != nil {
 		return fmt.Errorf("handleCreate: failed to create webhook: %s", err)
 	}
@@ -139,6 +159,51 @@ func (h *Handler) handleCreate(cmd string, msg chat1.MsgSummary) (err error) {
 	return nil
 }
 
+func (h *Handler) handleUpdate(cmd string, msg chat1.MsgSummary) (err error) {
+	convID := msg.ConvID
+	toks := strings.Split(cmd, " ")
+	if len(toks) < 3 {
+		h.ChatEcho(convID, "invalid number of arguments, must specify a name")
+		return nil
+	}
+	err = h.checkAllowed(msg)
+	switch err {
+	case nil:
+	case errNotAllowed:
+		h.ChatEcho(convID, err.Error())
+		return nil
+	default:
+		return err
+	}
+	h.stats.Count("update")
+	name := toks[2]
+	// template is whatever remains after removing "!webhook create <name>", and trimming spaces.
+	// if the template is empty, we'll set a default one
+	templateSrc := strings.Replace(cmd, "!webhook update", "", 1)
+	templateSrc = strings.Replace(templateSrc, name, "", 1)
+	templateSrc = strings.TrimSpace(templateSrc)
+	if templateSrc == "" {
+		templateSrc = defaultTemplate
+	}
+	tWithVars := injectTemplateVars("testhook1", "POST", templateSrc)
+	_, err = template.New("").Parse(tWithVars)
+	if err != nil {
+		h.ChatEcho(convID, "failed to parse template")
+		return nil
+	}
+
+	err = h.db.Update(name, templateSrc, convID)
+	switch err {
+	case nil:
+	case sql.ErrNoRows:
+	default:
+		h.ChatEcho(convID, "failed to update template: no webhook with that name exists in this conversation")
+		return nil
+	}
+	h.ChatEcho(convID, "Success!")
+	return nil
+}
+
 func (h *Handler) HandleNewConv(conv chat1.ConvSummary) error {
 	welcomeMsg := "I can create generic webhooks into Keybase! Try `!webhook create` to get started."
 	return base.HandleNewTeam(h.stats, h.DebugOutput, h.kbc, conv, welcomeMsg)
@@ -156,6 +221,8 @@ func (h *Handler) HandleCommand(msg chat1.MsgSummary) error {
 		return h.handleList(cmd, msg)
 	case strings.HasPrefix(cmd, "!webhook remove"):
 		return h.handleRemove(cmd, msg)
+	case strings.HasPrefix(cmd, "!webhook update"):
+		return h.handleUpdate(cmd, msg)
 	}
 	return nil
 }
diff --git a/webhookbot/webhookbot/http.go b/webhookbot/webhookbot/http.go
index cefe511c..7ccdf63f 100644
--- a/webhookbot/webhookbot/http.go
+++ b/webhookbot/webhookbot/http.go
@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"os"
 	"strings"
+	"text/template"
 	"time"
 
 	"github.com/gorilla/mux"
@@ -32,33 +33,56 @@ func NewHTTPSrv(stats *base.StatsRegistry, debugConfig *base.ChatDebugOutputConf
 	return h
 }
 
-type msgPayload struct {
-	Msg string
+func injectTemplateVars(webhookName, webhookMethod, template string) string {
+	return fmt.Sprintf("{{$webhookName := %q}}{{$webhookMethod := %q}} %s", webhookName, webhookMethod, template)
 }
 
-func (h *HTTPSrv) getMessage(r *http.Request) (string, error) {
-	msg := r.URL.Query().Get("msg")
-	if len(msg) > 0 {
-		return msg, nil
+func (h *HTTPSrv) getMessage(r *http.Request, hook webhook) (string, error) {
+	if r.Method == http.MethodGet && len(hook.template) == 0 {
+		j, err := json.Marshal(r.URL.Query())
+		if err != nil {
+			return "", err
+		}
+		return string(j), nil
 	}
 
-	defer r.Body.Close()
-	body, err := ioutil.ReadAll(r.Body)
+	if r.Method == http.MethodPost && len(hook.template) == 0 {
+		defer r.Body.Close()
+		body, err := ioutil.ReadAll(r.Body)
+		if err != nil {
+			return "", err
+		}
+		return string(body), nil
+	}
+
+	tWithVars := injectTemplateVars(hook.name, r.Method, hook.template)
+	t, err := template.New("").Parse(tWithVars)
 	if err != nil {
-		return "", err
+		return "`Error: failed to parse template: " + err.Error() + "`", nil
 	}
 
-	var payload msgPayload
-	decoder := json.NewDecoder(bytes.NewReader(body))
-	if err := decoder.Decode(&payload); err == nil && len(payload.Msg) > 0 {
-		return payload.Msg, nil
+	if r.Method == http.MethodGet {
+		buf := new(bytes.Buffer)
+		if err := t.Execute(buf, r.URL.Query()); err == nil {
+			return buf.String(), nil
+		}
 	}
 
-	msg = string(body)
-	if len(msg) > 0 {
-		return msg, nil
+	if r.Method == http.MethodPost {
+		defer r.Body.Close()
+		body, err := ioutil.ReadAll(r.Body)
+
+		m := map[string]interface{}{}
+		err = json.Unmarshal(body, &m)
+		if err != nil {
+			return "", err
+		}
+		buf := new(bytes.Buffer)
+		if err := t.Execute(buf, m); err == nil && len(buf.String()) > 0 {
+			return buf.String(), nil
+		}
 	}
-	return "`Error: no body found. To use a webhook URL, supply a 'msg' URL parameter, or a JSON POST body with a field 'msg'`", nil
+	return "", nil
 }
 
 func (h *HTTPSrv) handleHook(w http.ResponseWriter, r *http.Request) {
@@ -71,15 +95,19 @@ func (h *HTTPSrv) handleHook(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusNotFound)
 		return
 	}
-	msg, err := h.getMessage(r)
+	msg, err := h.getMessage(r, hook)
 	if err != nil {
 		h.Stats.Count("handle - no message")
 		h.Errorf("handleHook: failed to find message: %s", err)
 		w.WriteHeader(http.StatusBadRequest)
 		return
 	}
+	if strings.TrimSpace(msg) == "" {
+		h.Stats.Count("handle - empty msg")
+		return
+	}
 	h.Stats.Count("handle - success")
-	if _, err := h.Config().KBC.SendMessageByConvID(hook.convID, "[hook: *%s*]\n\n%s", hook.name, msg); err != nil {
+	if _, err := h.Config().KBC.SendMessageByConvID(hook.convID, " %s", msg); err != nil {
 		if base.IsDeletedConvError(err) {
 			h.Debug("ChatEcho: failed to send echo message: %s", err)
 			return

From 602af770afedb2bb17801cd5a63d76b73e024171 Mon Sep 17 00:00:00 2001
From: Sam Hofius <sam@samhofi.us>
Date: Mon, 15 Nov 2021 13:25:38 -0700
Subject: [PATCH 2/8] handle error when reading http body

---
 webhookbot/webhookbot/http.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/webhookbot/webhookbot/http.go b/webhookbot/webhookbot/http.go
index 7ccdf63f..5b17c84b 100644
--- a/webhookbot/webhookbot/http.go
+++ b/webhookbot/webhookbot/http.go
@@ -71,6 +71,9 @@ func (h *HTTPSrv) getMessage(r *http.Request, hook webhook) (string, error) {
 	if r.Method == http.MethodPost {
 		defer r.Body.Close()
 		body, err := ioutil.ReadAll(r.Body)
+		if err != nil {
+			return "", err
+		}
 
 		m := map[string]interface{}{}
 		err = json.Unmarshal(body, &m)

From fe491bf39de751dac5c3c338992d4fa35297980e Mon Sep 17 00:00:00 2001
From: Sam Hofius <sam@samhofi.us>
Date: Mon, 15 Nov 2021 17:32:32 -0700
Subject: [PATCH 3/8] Move template validation to a helper func

---
 webhookbot/webhookbot/handler.go | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/webhookbot/webhookbot/handler.go b/webhookbot/webhookbot/handler.go
index 05130c05..9ecb16bd 100644
--- a/webhookbot/webhookbot/handler.go
+++ b/webhookbot/webhookbot/handler.go
@@ -113,6 +113,15 @@ func (h *Handler) handleList(cmd string, msg chat1.MsgSummary) (err error) {
 	return nil
 }
 
+func validateTemplate(templateSrc string) error {
+	tWithVars := injectTemplateVars("testhook1", "POST", templateSrc)
+	_, err := template.New("").Parse(tWithVars)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 func (h *Handler) handleCreate(cmd string, msg chat1.MsgSummary) (err error) {
 	convID := msg.ConvID
 	toks := strings.Split(cmd, " ")
@@ -141,8 +150,7 @@ func (h *Handler) handleCreate(cmd string, msg chat1.MsgSummary) (err error) {
 	if templateSrc == "" {
 		templateSrc = defaultTemplate
 	}
-	tWithVars := injectTemplateVars("testhook1", "POST", templateSrc)
-	_, err = template.New("").Parse(tWithVars)
+	err = validateTemplate(templateSrc)
 	if err != nil {
 		h.ChatEcho(convID, "failed to parse template: %v", err)
 		return fmt.Errorf("handleCreate: failed to parse template: %s", err)
@@ -177,7 +185,7 @@ func (h *Handler) handleUpdate(cmd string, msg chat1.MsgSummary) (err error) {
 	}
 	h.stats.Count("update")
 	name := toks[2]
-	// template is whatever remains after removing "!webhook create <name>", and trimming spaces.
+	// template is whatever remains after removing "!webhook update <name>", and trimming spaces.
 	// if the template is empty, we'll set a default one
 	templateSrc := strings.Replace(cmd, "!webhook update", "", 1)
 	templateSrc = strings.Replace(templateSrc, name, "", 1)
@@ -185,11 +193,10 @@ func (h *Handler) handleUpdate(cmd string, msg chat1.MsgSummary) (err error) {
 	if templateSrc == "" {
 		templateSrc = defaultTemplate
 	}
-	tWithVars := injectTemplateVars("testhook1", "POST", templateSrc)
-	_, err = template.New("").Parse(tWithVars)
+	err = validateTemplate(templateSrc)
 	if err != nil {
-		h.ChatEcho(convID, "failed to parse template")
-		return nil
+		h.ChatEcho(convID, "failed to parse template: %v", err)
+		return fmt.Errorf("handleCreate: failed to parse template: %s", err)
 	}
 
 	err = h.db.Update(name, templateSrc, convID)

From 29adb8e7b3b5e2deb091ee90e9e836bae335152e Mon Sep 17 00:00:00 2001
From: Sam Hofius <sam@samhofi.us>
Date: Mon, 15 Nov 2021 17:35:15 -0700
Subject: [PATCH 4/8] Direct user to webhook create command when updating
 non-existant hook

---
 webhookbot/webhookbot/handler.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/webhookbot/webhookbot/handler.go b/webhookbot/webhookbot/handler.go
index 9ecb16bd..da3df049 100644
--- a/webhookbot/webhookbot/handler.go
+++ b/webhookbot/webhookbot/handler.go
@@ -204,7 +204,7 @@ func (h *Handler) handleUpdate(cmd string, msg chat1.MsgSummary) (err error) {
 	case nil:
 	case sql.ErrNoRows:
 	default:
-		h.ChatEcho(convID, "failed to update template: no webhook with that name exists in this conversation")
+		h.ChatEcho(convID, "failed to update template: no webhook with that name exists in this conversation. a new webhook can be created with the `!webhook create` command.")
 		return nil
 	}
 	h.ChatEcho(convID, "Success!")

From b6419dbaed4642b55f6e2b0facd4aeedb821610d Mon Sep 17 00:00:00 2001
From: Sam Hofius <sam@samhofi.us>
Date: Tue, 16 Nov 2021 23:22:14 -0700
Subject: [PATCH 5/8] Use strings.Fields instead of strings.Split

---
 webhookbot/webhookbot/handler.go | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/webhookbot/webhookbot/handler.go b/webhookbot/webhookbot/handler.go
index da3df049..d76275cf 100644
--- a/webhookbot/webhookbot/handler.go
+++ b/webhookbot/webhookbot/handler.go
@@ -58,7 +58,7 @@ func (h *Handler) checkAllowed(msg chat1.MsgSummary) error {
 
 func (h *Handler) handleRemove(cmd string, msg chat1.MsgSummary) (err error) {
 	convID := msg.ConvID
-	toks := strings.Split(cmd, " ")
+	toks := strings.Fields(cmd)
 	if len(toks) != 3 {
 		h.ChatEcho(convID, "invalid number of arguments, must specify a name")
 		return nil
@@ -124,7 +124,7 @@ func validateTemplate(templateSrc string) error {
 
 func (h *Handler) handleCreate(cmd string, msg chat1.MsgSummary) (err error) {
 	convID := msg.ConvID
-	toks := strings.Split(cmd, " ")
+	toks := strings.Fields(cmd)
 	if len(toks) < 3 {
 		h.ChatEcho(convID, "invalid number of arguments, must specify a name")
 		return nil
@@ -169,7 +169,7 @@ func (h *Handler) handleCreate(cmd string, msg chat1.MsgSummary) (err error) {
 
 func (h *Handler) handleUpdate(cmd string, msg chat1.MsgSummary) (err error) {
 	convID := msg.ConvID
-	toks := strings.Split(cmd, " ")
+	toks := strings.Fields(cmd)
 	if len(toks) < 3 {
 		h.ChatEcho(convID, "invalid number of arguments, must specify a name")
 		return nil

From a3a1c8ae5f29e9b89d2f967e42301f78c0440f5e Mon Sep 17 00:00:00 2001
From: Sam Hofius <sam@samhofi.us>
Date: Tue, 16 Nov 2021 23:41:08 -0700
Subject: [PATCH 6/8] Move command cleanup to template validation helper

---
 webhookbot/webhookbot/handler.go | 51 +++++++++++++++++---------------
 1 file changed, 27 insertions(+), 24 deletions(-)

diff --git a/webhookbot/webhookbot/handler.go b/webhookbot/webhookbot/handler.go
index d76275cf..5c272f11 100644
--- a/webhookbot/webhookbot/handler.go
+++ b/webhookbot/webhookbot/handler.go
@@ -113,13 +113,33 @@ func (h *Handler) handleList(cmd string, msg chat1.MsgSummary) (err error) {
 	return nil
 }
 
-func validateTemplate(templateSrc string) error {
+func validateTemplate(cmd string) (templateSrc string, err error) {
+	toks := strings.Fields(cmd)
+
+	var trigger string
+	switch toks[1] {
+	case "create":
+		trigger = "!webhook create"
+	case "update":
+		trigger = "!webhook update"
+	}
+
+	// templateSrc is whatever remains after removing the trigger (i.e `!webhook create` or
+	// `!webhook update`) followed by the template name, and trimming spaces. if the template
+	// is empty, we'll set a default one
+	name := toks[2]
+	templateSrc = strings.Replace(cmd, trigger, "", 1)
+	templateSrc = strings.Replace(templateSrc, name, "", 1)
+	templateSrc = strings.TrimSpace(templateSrc)
+	if templateSrc == "" {
+		templateSrc = defaultTemplate
+	}
 	tWithVars := injectTemplateVars("testhook1", "POST", templateSrc)
-	_, err := template.New("").Parse(tWithVars)
+	_, err = template.New("").Parse(tWithVars)
 	if err != nil {
-		return err
+		return "", err
 	}
-	return nil
+	return templateSrc, nil
 }
 
 func (h *Handler) handleCreate(cmd string, msg chat1.MsgSummary) (err error) {
@@ -141,16 +161,7 @@ func (h *Handler) handleCreate(cmd string, msg chat1.MsgSummary) (err error) {
 
 	h.stats.Count("create")
 	name := toks[2]
-
-	// template is whatever remains after removing "!webhook create <name>", and trimming spaces.
-	// if the template is empty, we'll set a default one
-	templateSrc := strings.Replace(cmd, "!webhook create", "", 1)
-	templateSrc = strings.Replace(templateSrc, name, "", 1)
-	templateSrc = strings.TrimSpace(templateSrc)
-	if templateSrc == "" {
-		templateSrc = defaultTemplate
-	}
-	err = validateTemplate(templateSrc)
+	templateSrc, err := validateTemplate(cmd)
 	if err != nil {
 		h.ChatEcho(convID, "failed to parse template: %v", err)
 		return fmt.Errorf("handleCreate: failed to parse template: %s", err)
@@ -185,18 +196,10 @@ func (h *Handler) handleUpdate(cmd string, msg chat1.MsgSummary) (err error) {
 	}
 	h.stats.Count("update")
 	name := toks[2]
-	// template is whatever remains after removing "!webhook update <name>", and trimming spaces.
-	// if the template is empty, we'll set a default one
-	templateSrc := strings.Replace(cmd, "!webhook update", "", 1)
-	templateSrc = strings.Replace(templateSrc, name, "", 1)
-	templateSrc = strings.TrimSpace(templateSrc)
-	if templateSrc == "" {
-		templateSrc = defaultTemplate
-	}
-	err = validateTemplate(templateSrc)
+	templateSrc, err := validateTemplate(cmd)
 	if err != nil {
 		h.ChatEcho(convID, "failed to parse template: %v", err)
-		return fmt.Errorf("handleCreate: failed to parse template: %s", err)
+		return fmt.Errorf("handleUpdate: failed to parse template: %s", err)
 	}
 
 	err = h.db.Update(name, templateSrc, convID)

From 887d70d96b217dcaf789693e0ba3ea031e788ea9 Mon Sep 17 00:00:00 2001
From: Sam Hofius <sam@samhofi.us>
Date: Wed, 17 Nov 2021 00:06:45 -0700
Subject: [PATCH 7/8] Add help command

---
 webhookbot/main.go               | 25 ++++++++-----------------
 webhookbot/webhookbot/handler.go | 22 ++++++++++++++++++++++
 2 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/webhookbot/main.go b/webhookbot/main.go
index 6ff09f64..e1629049 100644
--- a/webhookbot/main.go
+++ b/webhookbot/main.go
@@ -45,29 +45,16 @@ const back = "`"
 const backs = "```"
 
 func (s *BotServer) makeAdvertisement() kbchat.Advertisement {
-	createExtended := fmt.Sprintf(`Create a new webhook for sending messages into the current conversation. You must supply a name as well to identify the webhook. To use a webhook URL, supply a %smsg%s URL parameter, or a JSON POST body with a field %smsg%s.
+	createExtended := fmt.Sprintf(`Create a new webhook for sending messages into the current conversation. You must supply a name as well to identify the webhook. To use a webhook URL, supply a %smsg%s URL parameter, or a JSON POST body with a field %smsg%s. You can also supply a template, which allows you to customize the message displayed by the webhook, and the URL and/or JSON fields it will accept. For more information on templates, use the %s!webhook help%s command.
 
 	Example:%s
 		!webhook create alerts%s
 
 	Example (using custom template):%s
 		!webhook create alerts *{{.title}}*
-		%s{{.body}}%s%s
-
-	Templates:
-		Information about creating templates, and some examples can be found at %shttps://pkg.go.dev/text/template%s
-		You can test your templates against your JSON data at %shttps://play.golang.org/p/vC06kRCQDfX%s
-
-		There are 2 custom variables you can use in your templates (see the default template below for example usage):
-		  - %s$webhookName%s: The name you gave the webhook
-		  - %s$webhookMethod%s: Whether GET or POST was used when the webhook endpoint was fetched
-
-		If you don't provide a template, this is the default:%s
-		[hook: *{{$webhookName}}*]
-
-		{{if eq $webhookMethod "POST"}}{{.msg}}{{else}}{{index .msg 0}}{{end}}%s`,
-		back, back, back, back, backs, backs, backs, back, back, backs, back, back, back, back, back, back, back, back, backs, backs)
-	updateExtended := fmt.Sprintf(`Update an existing webhook's template. Leave the template field empty to use the default template. For more information about templates, see the help text for %s!webhook create%s.
+		%s{{.body}}%s%s`,
+		back, back, back, back, back, back, backs, backs, backs, back, back, backs)
+	updateExtended := fmt.Sprintf(`Update an existing webhook's template. Leave the template field empty to use the default template. For more information on templates, use the %s!webhook help%s command.
 
 	Example:%s
 		!webhook update alerts *New Alert: {{.title}}*
@@ -114,6 +101,10 @@ Remove a webhook`,
 				MobileBody:  removeExtended,
 			},
 		},
+		{
+			Name:        "webhook help",
+			Description: "Get more information about using templates",
+		},
 		base.GetFeedbackCommandAdvertisement(s.kbc.GetUsername()),
 	}
 	return kbchat.Advertisement{
diff --git a/webhookbot/webhookbot/handler.go b/webhookbot/webhookbot/handler.go
index 5c272f11..aed38b42 100644
--- a/webhookbot/webhookbot/handler.go
+++ b/webhookbot/webhookbot/handler.go
@@ -214,6 +214,26 @@ func (h *Handler) handleUpdate(cmd string, msg chat1.MsgSummary) (err error) {
 	return nil
 }
 
+func (h *Handler) handleHelp(msg chat1.MsgSummary) (err error) {
+	back := "`"
+	backs := "```"
+	convID := msg.ConvID
+	h.ChatEcho(convID, `
+*Templates:*
+	- Information about creating templates, and some examples can be found at https://pkg.go.dev/text/template
+	- You can test your templates against your JSON data at https://play.golang.org/p/vC06kRCQDfX
+
+	There are 2 custom variables you can use in your templates (see the default template below for example usage):
+	  - %s$webhookName%s: The name you gave the webhook
+	  - %s$webhookMethod%s: Whether GET or POST was used when the webhook endpoint was fetched
+
+	If you don't provide a template, this is the default:%s
+	[hook: *{{$webhookName}}*]
+
+	{{if eq $webhookMethod "POST"}}{{.msg}}{{else}}{{index .msg 0}}{{end}}%s`, back, back, back, back, backs, backs)
+	return nil
+}
+
 func (h *Handler) HandleNewConv(conv chat1.ConvSummary) error {
 	welcomeMsg := "I can create generic webhooks into Keybase! Try `!webhook create` to get started."
 	return base.HandleNewTeam(h.stats, h.DebugOutput, h.kbc, conv, welcomeMsg)
@@ -233,6 +253,8 @@ func (h *Handler) HandleCommand(msg chat1.MsgSummary) error {
 		return h.handleRemove(cmd, msg)
 	case strings.HasPrefix(cmd, "!webhook update"):
 		return h.handleUpdate(cmd, msg)
+	case strings.HasPrefix(cmd, "!webhook help"):
+		return h.handleHelp(msg)
 	}
 	return nil
 }

From cc9a267266ef1a30795c0012699b3b0f90e7ee88 Mon Sep 17 00:00:00 2001
From: Sam Hofius <sam@samhofi.us>
Date: Wed, 17 Nov 2021 00:10:22 -0700
Subject: [PATCH 8/8] Add stats counter for help command

---
 webhookbot/webhookbot/handler.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/webhookbot/webhookbot/handler.go b/webhookbot/webhookbot/handler.go
index aed38b42..1e40fdb4 100644
--- a/webhookbot/webhookbot/handler.go
+++ b/webhookbot/webhookbot/handler.go
@@ -215,6 +215,7 @@ func (h *Handler) handleUpdate(cmd string, msg chat1.MsgSummary) (err error) {
 }
 
 func (h *Handler) handleHelp(msg chat1.MsgSummary) (err error) {
+	h.stats.Count("help")
 	back := "`"
 	backs := "```"
 	convID := msg.ConvID