Implement create and get incoming webhook endpoints for APIv4 (#5407)

* Implement POST /hooks/incoming endpoint for APIv4

* Implement GET /hooks/incoming endpoint for APIv4

* Updates per feedback

api4/webhook.go

@@ -0,0 +1,85 @@
+// Copyright (c) 2017 Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package api4
+
+import (
+	"net/http"
+
+	l4g "github.com/alecthomas/log4go"
+	"github.com/mattermost/platform/app"
+	"github.com/mattermost/platform/model"
+	"github.com/mattermost/platform/utils"
+)
+
+func InitWebhook() {
+	l4g.Debug(utils.T("api.webhook.init.debug"))
+
+	BaseRoutes.IncomingHooks.Handle("", ApiSessionRequired(createIncomingHook)).Methods("POST")
+	BaseRoutes.IncomingHooks.Handle("", ApiSessionRequired(getIncomingHooks)).Methods("GET")
+}
+
+func createIncomingHook(c *Context, w http.ResponseWriter, r *http.Request) {
+	hook := model.IncomingWebhookFromJson(r.Body)
+	if hook == nil {
+		c.SetInvalidParam("webhook")
+		return
+	}
+
+	channel, err := app.GetChannel(hook.ChannelId)
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	c.LogAudit("attempt")
+
+	if !app.SessionHasPermissionToTeam(c.Session, channel.TeamId, model.PERMISSION_MANAGE_WEBHOOKS) {
+		c.SetPermissionError(model.PERMISSION_MANAGE_WEBHOOKS)
+		return
+	}
+
+	if channel.Type != model.CHANNEL_OPEN && !app.SessionHasPermissionToChannel(c.Session, channel.Id, model.PERMISSION_READ_CHANNEL) {
+		c.LogAudit("fail - bad channel permissions")
+		c.SetPermissionError(model.PERMISSION_READ_CHANNEL)
+		return
+	}
+
+	if incomingHook, err := app.CreateIncomingWebhookForChannel(c.Session.UserId, channel, hook); err != nil {
+		c.Err = err
+		return
+	} else {
+		c.LogAudit("success")
+		w.Write([]byte(incomingHook.ToJson()))
+	}
+}
+
+func getIncomingHooks(c *Context, w http.ResponseWriter, r *http.Request) {
+	teamId := r.URL.Query().Get("team_id")
+
+	var hooks []*model.IncomingWebhook
+	var err *model.AppError
+
+	if len(teamId) > 0 {
+		if !app.SessionHasPermissionToTeam(c.Session, teamId, model.PERMISSION_MANAGE_WEBHOOKS) {
+			c.SetPermissionError(model.PERMISSION_MANAGE_WEBHOOKS)
+			return
+		}
+
+		hooks, err = app.GetIncomingWebhooksForTeamPage(teamId, c.Params.Page, c.Params.PerPage)
+	} else {
+		if !app.SessionHasPermissionTo(c.Session, model.PERMISSION_MANAGE_WEBHOOKS) {
+			c.SetPermissionError(model.PERMISSION_MANAGE_WEBHOOKS)
+			return
+		}
+
+		hooks, err = app.GetIncomingWebhooksPage(c.Params.Page, c.Params.PerPage)
+	}
+
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	w.Write([]byte(model.IncomingWebhookListToJson(hooks)))
+}