get delete messages to work

README.md

@@ -142,6 +142,18 @@ curl \
 
 HTML-Content might not be fully rendered in your Matrix-Client - see the corresponding [Matrix specs](https://spec.matrix.org/unstable/client-server-api/#mroommessage-msgtypes). This also holds for Markdown, as it is transfered to the corresponding HTML-syntax.
 
+### Deleting a Message
+
+You can delete a message, this will send a notification in response to the original message informing you that the message is "deleted". 
+
+You need the message ID for deleting a message. As it might contain characters not valid in uris we provide an additional `id_url_encoded` field for messages, use that value for deleting a message.
+
+```bash
+curl \
+	--request DELETE \
+	"https://pushbits.example.com/message/${MESSAGE_ID}?token=$PB_TOKEN"
+```
+
 ## 👮 Acknowledgments
 
 The idea for this software and most parts of the initial source are heavily inspired by [Gotify](https://gotify.net/).

internal/api/errors.go

@@ -0,0 +1,5 @@
+package api
+
+import "errors"
+
+var ErrorMessageNotFound = errors.New("Message not found")

internal/api/notification.go

@@ -3,6 +3,7 @@ package api
 import (
 	"log"
 	"net/http"
+	"net/url"
 	"strings"
 	"time"
 
@@ -52,6 +53,7 @@ func (h *NotificationHandler) CreateNotification(ctx *gin.Context) {
 	}
 
 	notification.ID = messageID
+	notification.UrlEncodedID = url.QueryEscape(messageID)
 
 	ctx.JSON(http.StatusOK, &notification)
 }
@@ -70,5 +72,9 @@ func (h *NotificationHandler) DeleteNotification(ctx *gin.Context) {
 		Date: time.Now(),
 	}
 
-	h.DP.DeleteNotification(application, &n)
+	if success := successOrAbort(ctx, http.StatusInternalServerError, h.DP.DeleteNotification(application, &n)); !success {
+		return
+	}
+
+	ctx.Status(http.StatusOK)
 }

internal/api/util.go

@@ -11,8 +11,14 @@ import (
 
 func successOrAbort(ctx *gin.Context, code int, err error) bool {
 	if err != nil {
+		// If we know the error force error code
+		switch err {
+		case ErrorMessageNotFound:
+			ctx.AbortWithError(http.StatusNotFound, err)
+		default:
 			ctx.AbortWithError(code, err)
 		}
+	}
 
 	return err == nil
 }

internal/dispatcher/notification.go

@@ -1,19 +1,30 @@
 package dispatcher
 
 import (
+	"errors"
 	"fmt"
 	"html"
 	"log"
 	"strings"
 
 	"github.com/gomarkdown/markdown"
+	"github.com/matrix-org/gomatrix"
+	"github.com/pushbits/server/internal/api"
 	"github.com/pushbits/server/internal/model"
 )
 
+type MessageFormat string
+
+const (
+	FormatHTML = MessageFormat("org.matrix.custom.html")
+)
+
 type ReplyEvent struct {
 	Body          string        `json:"body"`
+	FormattedBody string        `json:"formatted_body"`
 	Msgtype       string        `json:"msgtype"`
 	RelatesTo     RelatesTo     `json:"m.relates_to,omitempty"`
+	Format        MessageFormat `json:"format"`
 }
 
 type RelatesTo struct {
@@ -39,30 +50,56 @@ func (d *Dispatcher) SendNotification(a *model.Application, n *model.Notificatio
 
 // DeleteNotification sends a notification to the specified user that another notificaion is deleted
 func (d *Dispatcher) DeleteNotification(a *model.Application, n *model.DeleteNotification) error {
+	var deleteMessageFormattedBody string
+	var deleteMessageBody string
 	log.Printf("Sending delete notification to room %s", a.MatrixID)
+
+	deleteMessage, err := d.getMessage(a, n.ID)
+
+	if err != nil {
+		log.Println(err)
+		return api.ErrorMessageNotFound
+	}
+
+	if val, ok := deleteMessage.Content["body"]; ok {
+		body, ok := val.(string)
+		if ok {
+			deleteMessageBody = body
+			deleteMessageFormattedBody = body
+		}
+	} else {
+		log.Println("Message to delete has wrong format")
+		return api.ErrorMessageNotFound
+	}
+
+	if val, ok := deleteMessage.Content["formatted_body"]; ok {
+		body, ok := val.(string)
+		if ok {
+			deleteMessageFormattedBody = body
+		}
+	}
+
+	// formatting according to https://matrix.org/docs/spec/client_server/latest#fallbacks-and-event-representation
+	formattedBody := fmt.Sprintf("<mx-reply><blockquote><a href='https://matrix.to/#/%s/%s'>In reply to</a> <a href='https://matrix.to/#/%s'>%s</a><br />%s</blockquote>\n</mx-reply><i>This message got deleted.</i>", deleteMessage.RoomID, deleteMessage.ID, deleteMessage.Sender, deleteMessage.Sender, deleteMessageFormattedBody)
+	body := fmt.Sprintf("> <%s>%s\n\nThis message got deleted", deleteMessage.Sender, deleteMessageBody)
+
 	event := ReplyEvent{
-		Body:    "<i>This message got deleted.</i>",
+		FormattedBody: formattedBody,
+		Body:          body,
 		Msgtype:       "m.text",
+		Format:        FormatHTML,
 	}
 
 	irt := make(map[string]string)
-	irt["event_id"] = n.ID
 	rt := RelatesTo{
 		InReplyTo: irt,
 	}
 	event.RelatesTo = rt
+	irt["event_id"] = deleteMessage.ID
 
-	_, err := d.client.SendMessageEvent(a.MatrixID, "m.room.message", event)
+	_, err = d.client.SendMessageEvent(a.MatrixID, "m.room.message", event)
 
 	return err
-
-	/*
-		messages, _ := d.client.Messages(a.MatrixID, "", "", 'b', 10)
-
-		js, _ := json.Marshal(messages)
-
-		log.Println(string(js))
-	*/
 }
 
 // HTML-formats the title
@@ -130,3 +167,21 @@ func (d *Dispatcher) coloredText(color string, text string) string {
 
 	return "<font data-mx-color='" + color + "'>" + text + "</font>"
 }
+
+// TODO cubicroot: find a way to only request on specific event
+func (d *Dispatcher) getMessage(a *model.Application, id string) (gomatrix.Event, error) {
+	start := ""
+	end := ""
+	maxPages := 10 // maximum pages to request (10 messages per page)
+
+	for i := 0; i < maxPages; i++ {
+		messages, _ := d.client.Messages(a.MatrixID, start, end, 'b', 10)
+		for _, event := range messages.Chunk {
+			if event.ID == id {
+				return event, nil
+			}
+		}
+		start = messages.End
+	}
+	return gomatrix.Event{}, errors.New("Message not found")
+}

internal/model/notification.go

@@ -7,6 +7,7 @@ import (
 // Notification holds information like the message, the title, and the priority of a notification.
 type Notification struct {
 	ID            string                 `json:"id"`
+	UrlEncodedID  string                 `json:"id_url_encoded"`
 	ApplicationID uint                   `json:"appid"`
 	Message       string                 `json:"message" form:"message" query:"message" binding:"required"`
 	Title         string                 `json:"title" form:"title" query:"title"`

internal/router/router.go

@@ -46,7 +46,7 @@ func Create(debug bool, cm *credentials.Manager, db *database.Database, dp *disp
 	r.GET("/health", healthHandler.Health)
 
 	r.POST("/message", auth.RequireApplicationToken(), notificationHandler.CreateNotification)
-	r.DELETE("/message/:messageid", api.RequireIDInURI(), auth.RequireApplicationToken(), notificationHandler.DeleteNotification)
+	r.DELETE("/message/:messageid", api.RequireMessageIDInURI(), auth.RequireApplicationToken(), notificationHandler.DeleteNotification)
 
 	r.GET("/test", auth.RequireApplicationToken(), notificationHandler.DeleteNotification)