PLT-6403: Interactive messages (#7274)

* wip

* finish first pass

* requested changes

* add DoPostAction to Client4

app/post.go

@@ -4,8 +4,11 @@
 package app
 
 import (
+	"encoding/json"
+	"fmt"
 	"net/http"
 	"regexp"
+	"strings"
 
 	l4g "github.com/alecthomas/log4go"
 	"github.com/dyatlov/go-opengraph/opengraph"
@@ -210,7 +213,7 @@ func parseSlackLinksToMarkdown(text string) string {
 	return linkWithTextRegex.ReplaceAllString(text, "[${2}](${1})")
 }
 
-func SendEphemeralPost(teamId, userId string, post *model.Post) *model.Post {
+func SendEphemeralPost(userId string, post *model.Post) *model.Post {
 	post.Type = model.POST_EPHEMERAL
 
 	// fill in fields which haven't been specified which have sensible defaults
@@ -638,3 +641,65 @@ func GetOpenGraphMetadata(url string) *opengraph.OpenGraph {
 
 	return og
 }
+
+func DoPostAction(postId string, actionId string, userId string) *model.AppError {
+	pchan := Srv.Store.Post().GetSingle(postId)
+
+	var post *model.Post
+	if result := <-pchan; result.Err != nil {
+		return result.Err
+	} else {
+		post = result.Data.(*model.Post)
+	}
+
+	action := post.GetAction(actionId)
+	if action == nil || action.Integration == nil {
+		return model.NewAppError("DoPostAction", "api.post.do_action.action_id.app_error", nil, fmt.Sprintf("action=%v", action), http.StatusNotFound)
+	}
+
+	request := &model.PostActionIntegrationRequest{
+		UserId:  userId,
+		Context: action.Integration.Context,
+	}
+
+	req, _ := http.NewRequest("POST", action.Integration.URL, strings.NewReader(request.ToJson()))
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Accept", "application/json")
+	resp, err := utils.HttpClient(false).Do(req)
+	if err != nil {
+		return model.NewAppError("DoPostAction", "api.post.do_action.action_integration.app_error", nil, "err="+err.Error(), http.StatusBadRequest)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return model.NewAppError("DoPostAction", "api.post.do_action.action_integration.app_error", nil, fmt.Sprintf("status=%v", resp.StatusCode), http.StatusBadRequest)
+	}
+
+	var response model.PostActionIntegrationResponse
+	if err := json.NewDecoder(resp.Body).Decode(&response); err != nil {
+		return model.NewAppError("DoPostAction", "api.post.do_action.action_integration.app_error", nil, "err="+err.Error(), http.StatusBadRequest)
+	}
+
+	if response.Update != nil {
+		response.Update.Id = postId
+		response.Update.AddProp("from_webhook", "true")
+		if _, err := UpdatePost(response.Update, false); err != nil {
+			return err
+		}
+	}
+
+	if response.EphemeralText != "" {
+		ephemeralPost := &model.Post{}
+		ephemeralPost.Message = parseSlackLinksToMarkdown(response.EphemeralText)
+		ephemeralPost.ChannelId = post.ChannelId
+		ephemeralPost.RootId = post.RootId
+		if ephemeralPost.RootId == "" {
+			ephemeralPost.RootId = post.Id
+		}
+		ephemeralPost.UserId = userId
+		ephemeralPost.AddProp("from_webhook", "true")
+		SendEphemeralPost(userId, ephemeralPost)
+	}
+
+	return nil
+}