MM-12843 Add interactive dialogs (#9816)

* Add interactive dialogs

* Fix unit test

* Updates per feedback

* Fix typo

* Updates per feedback, add icon_url and error returns

* Updates per feedback

* Update per feedback

api4/integration_action.go

@@ -0,0 +1,105 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package api4
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/mattermost/mattermost-server/model"
+)
+
+func (api *API) InitAction() {
+	api.BaseRoutes.Post.Handle("/actions/{action_id:[A-Za-z0-9]+}", api.ApiSessionRequired(doPostAction)).Methods("POST")
+
+	api.BaseRoutes.ApiRoot.Handle("/actions/dialogs/open", api.ApiHandler(openDialog)).Methods("POST")
+	api.BaseRoutes.ApiRoot.Handle("/actions/dialogs/submit", api.ApiSessionRequired(submitDialog)).Methods("POST")
+}
+
+func doPostAction(c *Context, w http.ResponseWriter, r *http.Request) {
+	c.RequirePostId().RequireActionId()
+	if c.Err != nil {
+		return
+	}
+
+	if !c.App.SessionHasPermissionToChannelByPost(c.Session, c.Params.PostId, model.PERMISSION_READ_CHANNEL) {
+		c.SetPermissionError(model.PERMISSION_READ_CHANNEL)
+		return
+	}
+
+	actionRequest := model.DoPostActionRequestFromJson(r.Body)
+	if actionRequest == nil {
+		actionRequest = &model.DoPostActionRequest{}
+	}
+
+	var err *model.AppError
+	resp := &model.PostActionAPIResponse{Status: "OK"}
+
+	if resp.TriggerId, err = c.App.DoPostAction(c.Params.PostId, c.Params.ActionId, c.Session.UserId, actionRequest.SelectedOption); err != nil {
+		c.Err = err
+		return
+	}
+
+	b, _ := json.Marshal(resp)
+
+	w.Write(b)
+}
+
+func openDialog(c *Context, w http.ResponseWriter, r *http.Request) {
+	var dialog model.OpenDialogRequest
+	err := json.NewDecoder(r.Body).Decode(&dialog)
+	if err != nil {
+		c.SetInvalidParam("dialog")
+		return
+	}
+
+	if dialog.URL == "" {
+		c.SetInvalidParam("url")
+		return
+	}
+
+	if err := c.App.OpenInteractiveDialog(dialog); err != nil {
+		c.Err = err
+		return
+	}
+
+	ReturnStatusOK(w)
+}
+
+func submitDialog(c *Context, w http.ResponseWriter, r *http.Request) {
+	var submit model.SubmitDialogRequest
+
+	jsonErr := json.NewDecoder(r.Body).Decode(&submit)
+	if jsonErr != nil {
+		c.SetInvalidParam("dialog")
+		return
+	}
+
+	if submit.URL == "" {
+		c.SetInvalidParam("url")
+		return
+	}
+
+	submit.UserId = c.Session.UserId
+
+	if !c.App.SessionHasPermissionToChannel(c.Session, submit.ChannelId, model.PERMISSION_READ_CHANNEL) {
+		c.SetPermissionError(model.PERMISSION_READ_CHANNEL)
+		return
+	}
+
+	if !c.App.SessionHasPermissionToTeam(c.Session, submit.TeamId, model.PERMISSION_VIEW_TEAM) {
+		c.SetPermissionError(model.PERMISSION_VIEW_TEAM)
+		return
+	}
+
+	resp, err := c.App.SubmitInteractiveDialog(submit)
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	b, _ := json.Marshal(resp)
+
+	w.Write(b)
+}