From 5be204dc19ae7ea2db74eeb18ec5194e4dadf834 Mon Sep 17 00:00:00 2001
From: Cubicroot <github@cubicroot.xyz>
Date: Wed, 2 Jun 2021 17:46:04 +0200
Subject: [PATCH 01/13] proof of concept

---
 internal/api/notification.go        |  9 ++++++
 internal/dispatcher/notification.go | 43 +++++++++++++++++++++++++++++
 internal/model/notification.go      | 11 ++++++++
 internal/router/router.go           |  2 ++
 4 files changed, 65 insertions(+)

diff --git a/internal/api/notification.go b/internal/api/notification.go
index bfb8af0..b4a2100 100644
--- a/internal/api/notification.go
+++ b/internal/api/notification.go
@@ -19,6 +19,7 @@ type NotificationDatabase interface {
 // The NotificationDispatcher interface for relaying notifications.
 type NotificationDispatcher interface {
 	SendNotification(a *model.Application, n *model.Notification) error
+	SendDeleteNotification(a *model.Application, n *model.DeleteNotification) error
 }
 
 // NotificationHandler holds information for processing requests about notifications.
@@ -51,3 +52,11 @@ func (h *NotificationHandler) CreateNotification(ctx *gin.Context) {
 
 	ctx.JSON(http.StatusOK, &notification)
 }
+
+func (h *NotificationHandler) DeleteNotification(ctx *gin.Context) {
+	application := authentication.GetApplication(ctx)
+
+	n := model.DeleteNotification{}
+
+	h.DP.SendDeleteNotification(application, &n)
+}
diff --git a/internal/dispatcher/notification.go b/internal/dispatcher/notification.go
index 2a59a6a..0eb15c3 100644
--- a/internal/dispatcher/notification.go
+++ b/internal/dispatcher/notification.go
@@ -1,6 +1,7 @@
 package dispatcher
 
 import (
+	"encoding/json"
 	"fmt"
 	"html"
 	"log"
@@ -10,6 +11,16 @@ import (
 	"github.com/pushbits/server/internal/model"
 )
 
+type ExampleEvent struct {
+	Body      string    `json:"body"`
+	Msgtype   string    `json:"msgtype"`
+	RelatesTo RelatesTo `json:"m.relates_to,omitempty"`
+}
+
+type RelatesTo struct {
+	InReplyTo map[string]string `json:"m.in_reply_to"`
+}
+
 // SendNotification sends a notification to the specified user.
 func (d *Dispatcher) SendNotification(a *model.Application, n *model.Notification) error {
 	log.Printf("Sending notification to room %s.", a.MatrixID)
@@ -27,6 +38,38 @@ func (d *Dispatcher) SendNotification(a *model.Application, n *model.Notificatio
 	return err
 }
 
+func (d *Dispatcher) SendDeleteNotification(a *model.Application, n *model.DeleteNotification) error {
+	log.Printf("Sending delete notification to room %s", a.MatrixID)
+	event := ExampleEvent{
+		Body:    "Testmessage",
+		Msgtype: "m.text",
+	}
+
+	irt := make(map[string]string)
+
+	irt["event_id"] = "$uf5OLKPaefHTZhc2lxSIY7If7pLFcNHcMZLbMfS-7qw"
+
+	rt := RelatesTo{
+		InReplyTo: irt,
+	}
+
+	event.RelatesTo = rt
+
+	_, err := d.client.SendMessageEvent(a.MatrixID, "m.room.message", event)
+
+	if err != nil {
+		log.Println(err)
+	}
+
+	messages, _ := d.client.Messages(a.MatrixID, "", "", 'b', 10)
+
+	js, _ := json.Marshal(messages)
+
+	log.Println(string(js))
+
+	return nil
+}
+
 // HTML-formats the title
 func (d *Dispatcher) getFormattedTitle(n *model.Notification) string {
 	trimmedTitle := strings.TrimSpace(n.Title)
diff --git a/internal/model/notification.go b/internal/model/notification.go
index ef8d6ed..0b229cf 100644
--- a/internal/model/notification.go
+++ b/internal/model/notification.go
@@ -14,3 +14,14 @@ type Notification struct {
 	Extras        map[string]interface{} `json:"extras,omitempty" form:"-" query:"-"`
 	Date          time.Time              `json:"date"`
 }
+
+// DeleteNotification holds information like the message, the reply to message id and the priority of a deletion notification.
+type DeleteNotification struct {
+	ID            uint                   `json:"id"`
+	DeleteID      uint                   `json:"deleteid"`
+	ApplicationID uint                   `json:"appid"`
+	Message       string                 `json:"message" form:"message" query:"message" binding:"required"`
+	Priority      int                    `json:"priority" form:"priority" query:"priority"`
+	Extras        map[string]interface{} `json:"extras,omitempty" form:"-" query:"-"`
+	Date          time.Time              `json:"date"`
+}
diff --git a/internal/router/router.go b/internal/router/router.go
index 587c256..9dd5e87 100644
--- a/internal/router/router.go
+++ b/internal/router/router.go
@@ -47,6 +47,8 @@ func Create(debug bool, cm *credentials.Manager, db *database.Database, dp *disp
 
 	r.POST("/message", auth.RequireApplicationToken(), notificationHandler.CreateNotification)
 
+	r.GET("/test", auth.RequireApplicationToken(), notificationHandler.DeleteNotification)
+
 	userGroup := r.Group("/user")
 	userGroup.Use(auth.RequireAdmin())
 	{

From b392ea1b44fa25f86e6070aeb028866f28cee57d Mon Sep 17 00:00:00 2001
From: Cubicroot <github@cubicroot.xyz>
Date: Sun, 6 Jun 2021 19:30:25 +0200
Subject: [PATCH 02/13] add endpoint for delete

---
 internal/api/context.go             | 11 +++++++++
 internal/api/middleware.go          | 17 ++++++++++++++
 internal/api/notification.go        | 24 +++++++++++++++-----
 internal/dispatcher/notification.go | 35 +++++++++++++----------------
 internal/model/notification.go      | 11 +++------
 internal/router/router.go           |  1 +
 6 files changed, 65 insertions(+), 34 deletions(-)

diff --git a/internal/api/context.go b/internal/api/context.go
index c408515..90a5ec8 100644
--- a/internal/api/context.go
+++ b/internal/api/context.go
@@ -20,6 +20,17 @@ func getID(ctx *gin.Context) (uint, error) {
 	return id, nil
 }
 
+func getMessageID(ctx *gin.Context) (string, error) {
+	id, ok := ctx.MustGet("messageid").(string)
+	if !ok {
+		err := errors.New("an error occured while retrieving messageID from context")
+		ctx.AbortWithError(http.StatusInternalServerError, err)
+		return "", err
+	}
+
+	return id, nil
+}
+
 func getApplication(ctx *gin.Context, db Database) (*model.Application, error) {
 	id, err := getID(ctx)
 	if err != nil {
diff --git a/internal/api/middleware.go b/internal/api/middleware.go
index a6507e1..3d84840 100644
--- a/internal/api/middleware.go
+++ b/internal/api/middleware.go
@@ -8,6 +8,10 @@ type idInURI struct {
 	ID uint `uri:"id" binding:"required"`
 }
 
+type messageIdInURI struct {
+	MessageID string `uri:"messageid" binding:"required"`
+}
+
 // RequireIDInURI returns a Gin middleware which requires an ID to be supplied in the URI of the request.
 func RequireIDInURI() gin.HandlerFunc {
 	return func(ctx *gin.Context) {
@@ -20,3 +24,16 @@ func RequireIDInURI() gin.HandlerFunc {
 		ctx.Set("id", requestModel.ID)
 	}
 }
+
+// RequireMessageIDInURI returns a Gin middleware which requires an messageID to be supplied in the URI of the request.
+func RequireMessageIDInURI() gin.HandlerFunc {
+	return func(ctx *gin.Context) {
+		var requestModel messageIdInURI
+
+		if err := ctx.BindUri(&requestModel); err != nil {
+			return
+		}
+
+		ctx.Set("messageid", requestModel.MessageID)
+	}
+}
diff --git a/internal/api/notification.go b/internal/api/notification.go
index b4a2100..9cd51d0 100644
--- a/internal/api/notification.go
+++ b/internal/api/notification.go
@@ -18,8 +18,8 @@ type NotificationDatabase interface {
 
 // The NotificationDispatcher interface for relaying notifications.
 type NotificationDispatcher interface {
-	SendNotification(a *model.Application, n *model.Notification) error
-	SendDeleteNotification(a *model.Application, n *model.DeleteNotification) error
+	SendNotification(a *model.Application, n *model.Notification) (id string, err error)
+	DeleteNotification(a *model.Application, n *model.DeleteNotification) error
 }
 
 // NotificationHandler holds information for processing requests about notifications.
@@ -39,24 +39,36 @@ func (h *NotificationHandler) CreateNotification(ctx *gin.Context) {
 	application := authentication.GetApplication(ctx)
 	log.Printf("Sending notification for application %s.", application.Name)
 
-	notification.ID = 0
 	notification.ApplicationID = application.ID
 	if strings.TrimSpace(notification.Title) == "" {
 		notification.Title = application.Name
 	}
 	notification.Date = time.Now()
 
-	if success := successOrAbort(ctx, http.StatusInternalServerError, h.DP.SendNotification(application, &notification)); !success {
+	messageID, err := h.DP.SendNotification(application, &notification)
+
+	if success := successOrAbort(ctx, http.StatusInternalServerError, err); !success {
 		return
 	}
 
+	notification.ID = messageID
+
 	ctx.JSON(http.StatusOK, &notification)
 }
 
+// DeleteNotification is used to delete (or mark as deleted) a notification for a user
 func (h *NotificationHandler) DeleteNotification(ctx *gin.Context) {
 	application := authentication.GetApplication(ctx)
+	id, err := getMessageID(ctx)
 
-	n := model.DeleteNotification{}
+	if success := successOrAbort(ctx, http.StatusUnprocessableEntity, err); !success {
+		return
+	}
 
-	h.DP.SendDeleteNotification(application, &n)
+	n := model.DeleteNotification{
+		ID:   id,
+		Date: time.Now(),
+	}
+
+	h.DP.DeleteNotification(application, &n)
 }
diff --git a/internal/dispatcher/notification.go b/internal/dispatcher/notification.go
index 0eb15c3..edc9c97 100644
--- a/internal/dispatcher/notification.go
+++ b/internal/dispatcher/notification.go
@@ -1,7 +1,6 @@
 package dispatcher
 
 import (
-	"encoding/json"
 	"fmt"
 	"html"
 	"log"
@@ -11,7 +10,7 @@ import (
 	"github.com/pushbits/server/internal/model"
 )
 
-type ExampleEvent struct {
+type ReplyEvent struct {
 	Body      string    `json:"body"`
 	Msgtype   string    `json:"msgtype"`
 	RelatesTo RelatesTo `json:"m.relates_to,omitempty"`
@@ -22,7 +21,7 @@ type RelatesTo struct {
 }
 
 // SendNotification sends a notification to the specified user.
-func (d *Dispatcher) SendNotification(a *model.Application, n *model.Notification) error {
+func (d *Dispatcher) SendNotification(a *model.Application, n *model.Notification) (id string, err error) {
 	log.Printf("Sending notification to room %s.", a.MatrixID)
 
 	plainMessage := strings.TrimSpace(n.Message)
@@ -33,41 +32,37 @@ func (d *Dispatcher) SendNotification(a *model.Application, n *model.Notificatio
 	text := fmt.Sprintf("%s\n\n%s", plainTitle, plainMessage)
 	formattedText := fmt.Sprintf("%s %s", title, message)
 
-	_, err := d.client.SendFormattedText(a.MatrixID, text, formattedText)
+	respSendEvent, err := d.client.SendFormattedText(a.MatrixID, text, formattedText)
 
-	return err
+	return respSendEvent.EventID, err
 }
 
-func (d *Dispatcher) SendDeleteNotification(a *model.Application, n *model.DeleteNotification) error {
+// DeleteNotification sends a notification to the specified user that another notificaion is deleted
+func (d *Dispatcher) DeleteNotification(a *model.Application, n *model.DeleteNotification) error {
 	log.Printf("Sending delete notification to room %s", a.MatrixID)
-	event := ExampleEvent{
-		Body:    "Testmessage",
+	event := ReplyEvent{
+		Body:    "<i>This message got deleted.</i>",
 		Msgtype: "m.text",
 	}
 
 	irt := make(map[string]string)
-
-	irt["event_id"] = "$uf5OLKPaefHTZhc2lxSIY7If7pLFcNHcMZLbMfS-7qw"
-
+	irt["event_id"] = n.ID
 	rt := RelatesTo{
 		InReplyTo: irt,
 	}
-
 	event.RelatesTo = rt
 
 	_, err := d.client.SendMessageEvent(a.MatrixID, "m.room.message", event)
 
-	if err != nil {
-		log.Println(err)
-	}
+	return err
 
-	messages, _ := d.client.Messages(a.MatrixID, "", "", 'b', 10)
+	/*
+		messages, _ := d.client.Messages(a.MatrixID, "", "", 'b', 10)
 
-	js, _ := json.Marshal(messages)
+		js, _ := json.Marshal(messages)
 
-	log.Println(string(js))
-
-	return nil
+		log.Println(string(js))
+	*/
 }
 
 // HTML-formats the title
diff --git a/internal/model/notification.go b/internal/model/notification.go
index 0b229cf..7bb64b7 100644
--- a/internal/model/notification.go
+++ b/internal/model/notification.go
@@ -6,7 +6,7 @@ import (
 
 // Notification holds information like the message, the title, and the priority of a notification.
 type Notification struct {
-	ID            uint                   `json:"id"`
+	ID            string                 `json:"id"`
 	ApplicationID uint                   `json:"appid"`
 	Message       string                 `json:"message" form:"message" query:"message" binding:"required"`
 	Title         string                 `json:"title" form:"title" query:"title"`
@@ -17,11 +17,6 @@ type Notification struct {
 
 // DeleteNotification holds information like the message, the reply to message id and the priority of a deletion notification.
 type DeleteNotification struct {
-	ID            uint                   `json:"id"`
-	DeleteID      uint                   `json:"deleteid"`
-	ApplicationID uint                   `json:"appid"`
-	Message       string                 `json:"message" form:"message" query:"message" binding:"required"`
-	Priority      int                    `json:"priority" form:"priority" query:"priority"`
-	Extras        map[string]interface{} `json:"extras,omitempty" form:"-" query:"-"`
-	Date          time.Time              `json:"date"`
+	ID   string    `json:"id" form:"id"`
+	Date time.Time `json:"date"`
 }
diff --git a/internal/router/router.go b/internal/router/router.go
index 9dd5e87..1debc4a 100644
--- a/internal/router/router.go
+++ b/internal/router/router.go
@@ -46,6 +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.GET("/test", auth.RequireApplicationToken(), notificationHandler.DeleteNotification)
 

From eebc7f7e316d3fd8a2bd696879f3d116039e2526 Mon Sep 17 00:00:00 2001
From: Cubicroot <github@cubicroot.xyz>
Date: Sun, 6 Jun 2021 21:13:07 +0200
Subject: [PATCH 03/13] get delete messages to work

---
 README.md                           | 12 ++++
 internal/api/errors.go              |  5 ++
 internal/api/notification.go        |  8 ++-
 internal/api/util.go                |  8 ++-
 internal/dispatcher/notification.go | 85 ++++++++++++++++++++++++-----
 internal/model/notification.go      |  1 +
 internal/router/router.go           |  2 +-
 7 files changed, 103 insertions(+), 18 deletions(-)
 create mode 100644 internal/api/errors.go

diff --git a/README.md b/README.md
index 8bb3256..48b7570 100644
--- a/README.md
+++ b/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"
+```
+
 ## 👮&nbsp;Acknowledgments
 
 The idea for this software and most parts of the initial source are heavily inspired by [Gotify](https://gotify.net/).
diff --git a/internal/api/errors.go b/internal/api/errors.go
new file mode 100644
index 0000000..db296e3
--- /dev/null
+++ b/internal/api/errors.go
@@ -0,0 +1,5 @@
+package api
+
+import "errors"
+
+var ErrorMessageNotFound = errors.New("Message not found")
diff --git a/internal/api/notification.go b/internal/api/notification.go
index 9cd51d0..064c716 100644
--- a/internal/api/notification.go
+++ b/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)
 }
diff --git a/internal/api/util.go b/internal/api/util.go
index 177f537..d045139 100644
--- a/internal/api/util.go
+++ b/internal/api/util.go
@@ -11,7 +11,13 @@ import (
 
 func successOrAbort(ctx *gin.Context, code int, err error) bool {
 	if err != nil {
-		ctx.AbortWithError(code, err)
+		// 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
diff --git a/internal/dispatcher/notification.go b/internal/dispatcher/notification.go
index edc9c97..c17c634 100644
--- a/internal/dispatcher/notification.go
+++ b/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"`
-	Msgtype   string    `json:"msgtype"`
-	RelatesTo RelatesTo `json:"m.relates_to,omitempty"`
+	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>",
-		Msgtype: "m.text",
+		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")
+}
diff --git a/internal/model/notification.go b/internal/model/notification.go
index 7bb64b7..569e8ee 100644
--- a/internal/model/notification.go
+++ b/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"`
diff --git a/internal/router/router.go b/internal/router/router.go
index 1debc4a..6392973 100644
--- a/internal/router/router.go
+++ b/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)
 

From 60277386d942e684cf3157b4444cef3204fd6d41 Mon Sep 17 00:00:00 2001
From: Cubicroot <github@cubicroot.xyz>
Date: Tue, 8 Jun 2021 13:00:31 +0200
Subject: [PATCH 04/13] polish implementation

---
 internal/dispatcher/notification.go | 105 +++++++++++++++++++++-------
 1 file changed, 79 insertions(+), 26 deletions(-)

diff --git a/internal/dispatcher/notification.go b/internal/dispatcher/notification.go
index c17c634..9b974d0 100644
--- a/internal/dispatcher/notification.go
+++ b/internal/dispatcher/notification.go
@@ -1,7 +1,6 @@
 package dispatcher
 
 import (
-	"errors"
 	"fmt"
 	"html"
 	"log"
@@ -13,22 +12,41 @@ import (
 	"github.com/pushbits/server/internal/model"
 )
 
+// MessageFormat is a matrix message format
 type MessageFormat string
 
+// MsgType is a matrix msgtype
+type MsgType string
+
+// Define matrix constants
 const (
-	FormatHTML = MessageFormat("org.matrix.custom.html")
+	MessageFormatHTML = MessageFormat("org.matrix.custom.html")
+	MsgTypeText       = MsgType("m.text")
 )
 
-type ReplyEvent struct {
+// MessageEvent is the content of a matrix message event
+type MessageEvent struct {
 	Body          string        `json:"body"`
 	FormattedBody string        `json:"formatted_body"`
-	Msgtype       string        `json:"msgtype"`
+	MsgType       MsgType       `json:"msgtype"`
 	RelatesTo     RelatesTo     `json:"m.relates_to,omitempty"`
 	Format        MessageFormat `json:"format"`
+	NewContent    NewContent    `json:"m.new_content,omitempty"`
 }
 
+// RelatesTo holds information about relations to other message events
 type RelatesTo struct {
-	InReplyTo map[string]string `json:"m.in_reply_to"`
+	InReplyTo map[string]string `json:"m.in_reply_to,omitempty"`
+	RelType   string            `json:"rel_type,omitempty"`
+	EventID   string            `json:"event_id,omitempty"`
+}
+
+// NewContent holds information about an updated message event
+type NewContent struct {
+	Body          string        `json:"body"`
+	FormattedBody string        `json:"formatted_body"`
+	MsgType       MsgType       `json:"msgtype"`
+	Format        MessageFormat `json:"format"`
 }
 
 // SendNotification sends a notification to the specified user.
@@ -50,10 +68,11 @@ 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)
+	var oldFormattedBody string
+	var oldBody string
 
+	// get the message we want to delete
 	deleteMessage, err := d.getMessage(a, n.ID)
 
 	if err != nil {
@@ -64,8 +83,8 @@ func (d *Dispatcher) DeleteNotification(a *model.Application, n *model.DeleteNot
 	if val, ok := deleteMessage.Content["body"]; ok {
 		body, ok := val.(string)
 		if ok {
-			deleteMessageBody = body
-			deleteMessageFormattedBody = body
+			oldBody = body
+			oldFormattedBody = body
 		}
 	} else {
 		log.Println("Message to delete has wrong format")
@@ -75,29 +94,63 @@ func (d *Dispatcher) DeleteNotification(a *model.Application, n *model.DeleteNot
 	if val, ok := deleteMessage.Content["formatted_body"]; ok {
 		body, ok := val.(string)
 		if ok {
-			deleteMessageFormattedBody = body
+			oldFormattedBody = body
 		}
 	}
 
+	// update the message with strikethrough
+	newBody := fmt.Sprintf("<del>%s</del>\n- deleted", oldBody)
+	newFormattedBody := fmt.Sprintf("<del>%s</del><br>- deleted", oldFormattedBody)
+
+	newMessage := NewContent{
+		Body:          newBody,
+		FormattedBody: newFormattedBody,
+		MsgType:       MsgTypeText,
+		Format:        MessageFormatHTML,
+	}
+
+	replaceRelation := RelatesTo{
+		RelType: "m.replace",
+		EventID: deleteMessage.ID,
+	}
+
+	replaceEvent := MessageEvent{
+		Body:          oldBody,
+		FormattedBody: oldFormattedBody,
+		MsgType:       MsgTypeText,
+		NewContent:    newMessage,
+		RelatesTo:     replaceRelation,
+		Format:        MessageFormatHTML,
+	}
+
+	_, err = d.client.SendMessageEvent(a.MatrixID, "m.room.message", replaceEvent)
+
+	if err != nil {
+		log.Println(err)
+		return err
+	}
+
+	// send a notification about the deletion
 	// 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)
+	notificationFormattedBody := 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, oldFormattedBody)
+	notificationBody := fmt.Sprintf("> <%s>%s\n\nThis message got deleted", deleteMessage.Sender, oldBody)
 
-	event := ReplyEvent{
-		FormattedBody: formattedBody,
-		Body:          body,
-		Msgtype:       "m.text",
-		Format:        FormatHTML,
+	notificationEvent := MessageEvent{
+		FormattedBody: notificationFormattedBody,
+		Body:          notificationBody,
+		MsgType:       MsgTypeText,
+		Format:        MessageFormatHTML,
 	}
 
-	irt := make(map[string]string)
-	rt := RelatesTo{
-		InReplyTo: irt,
-	}
-	event.RelatesTo = rt
-	irt["event_id"] = deleteMessage.ID
+	notificationReply := make(map[string]string)
+	notificationReply["event_id"] = deleteMessage.ID
 
-	_, err = d.client.SendMessageEvent(a.MatrixID, "m.room.message", event)
+	notificationRelation := RelatesTo{
+		InReplyTo: notificationReply,
+	}
+	notificationEvent.RelatesTo = notificationRelation
+
+	_, err = d.client.SendMessageEvent(a.MatrixID, "m.room.message", notificationEvent)
 
 	return err
 }
@@ -168,7 +221,7 @@ 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
+// Searches in the messages list for the given id
 func (d *Dispatcher) getMessage(a *model.Application, id string) (gomatrix.Event, error) {
 	start := ""
 	end := ""
@@ -183,5 +236,5 @@ func (d *Dispatcher) getMessage(a *model.Application, id string) (gomatrix.Event
 		}
 		start = messages.End
 	}
-	return gomatrix.Event{}, errors.New("Message not found")
+	return gomatrix.Event{}, api.ErrorMessageNotFound
 }

From 975c0a246b9c808df7a45422b64b27940783830f Mon Sep 17 00:00:00 2001
From: Cubicroot <github@cubicroot.xyz>
Date: Tue, 8 Jun 2021 13:10:59 +0200
Subject: [PATCH 05/13] remove debug

---
 internal/router/router.go | 2 --
 1 file changed, 2 deletions(-)

diff --git a/internal/router/router.go b/internal/router/router.go
index 6392973..68f61ca 100644
--- a/internal/router/router.go
+++ b/internal/router/router.go
@@ -48,8 +48,6 @@ func Create(debug bool, cm *credentials.Manager, db *database.Database, dp *disp
 	r.POST("/message", auth.RequireApplicationToken(), notificationHandler.CreateNotification)
 	r.DELETE("/message/:messageid", api.RequireMessageIDInURI(), auth.RequireApplicationToken(), notificationHandler.DeleteNotification)
 
-	r.GET("/test", auth.RequireApplicationToken(), notificationHandler.DeleteNotification)
-
 	userGroup := r.Group("/user")
 	userGroup.Use(auth.RequireAdmin())
 	{

From 27c65921d960644aa27ed8c25d1f50777e655d20 Mon Sep 17 00:00:00 2001
From: eikendev <raphael@eiken.dev>
Date: Fri, 11 Jun 2021 00:00:50 +0200
Subject: [PATCH 06/13] Replace golint with staticcheck

---
 .github/workflows/main.yml |  3 ++-
 Makefile                   |  7 ++-----
 go.mod                     |  5 ++++-
 go.sum                     | 37 +++++++++++++++++++++++++++++++++++++
 4 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 93e6fc3..d185008 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -5,7 +5,8 @@ jobs:
     name: Test and publish
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - name: Checkout code
+        uses: actions/checkout@v2
       - name: Install dependencies
         run: make setup
       - name: Run tests
diff --git a/Makefile b/Makefile
index 56aeeed..b540007 100644
--- a/Makefile
+++ b/Makefile
@@ -12,16 +12,13 @@ test:
 	fi
 	go vet ./...
 	gocyclo -over 10 $(shell find . -iname '*.go' -type f)
+	staticcheck ./...
 	go test -v -cover ./...
-	stdout=$$(golint ./... 2>&1); \
-	if [ "$$stdout" ]; then \
-		exit 1; \
-	fi
 
 .PHONY: setup
 setup:
 	go get -u github.com/fzipp/gocyclo/cmd/gocyclo
-	go get -u golang.org/x/lint/golint
+	go get -u honnef.co/go/tools/cmd/staticcheck
 
 .PHONY: build_image
 build_image:
diff --git a/go.mod b/go.mod
index e5c9e72..28b463c 100644
--- a/go.mod
+++ b/go.mod
@@ -4,6 +4,7 @@ go 1.14
 
 require (
 	github.com/alexedwards/argon2id v0.0.0-20201228115903-cf543ebc1f7b
+	github.com/fzipp/gocyclo v0.3.1 // indirect
 	github.com/gin-contrib/location v0.0.2
 	github.com/gin-gonic/gin v1.6.3
 	github.com/go-playground/validator/v10 v10.3.0 // indirect
@@ -18,9 +19,11 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.1 // indirect
 	github.com/ugorji/go v1.2.4 // indirect
-	golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c // indirect
+	golang.org/x/sys v0.0.0-20210608053332-aa57babbf139 // indirect
+	golang.org/x/tools v0.1.3 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gorm.io/driver/mysql v1.0.4
 	gorm.io/driver/sqlite v1.1.4
 	gorm.io/gorm v1.20.12
+	honnef.co/go/tools v0.2.0 // indirect
 )
diff --git a/go.sum b/go.sum
index c30c298..35c2598 100644
--- a/go.sum
+++ b/go.sum
@@ -5,6 +5,8 @@ github.com/alexedwards/argon2id v0.0.0-20201228115903-cf543ebc1f7b/go.mod h1:Kmn
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/fzipp/gocyclo v0.3.1 h1:A9UeX3HJSXTBzvHzhqoYVuE0eAhe+aM8XBCCwsPMZOc=
+github.com/fzipp/gocyclo v0.3.1/go.mod h1:DJHO6AUmbdqj2ET4Z9iArSuwWgYDRryYt2wASxc7x3E=
 github.com/gin-contrib/location v0.0.2 h1:QZKh1+K/LLR4KG/61eIO3b7MLuKi8tytQhV6texLgP4=
 github.com/gin-contrib/location v0.0.2/go.mod h1:NGoidiRlf0BlA/VKSVp+g3cuSMeTmip/63PhEjRhUAc=
 github.com/gin-contrib/sse v0.1.0 h1:Y/yl/+YNO8GZSjAhjMsSuLt29uWRFHdHYUb5lYOV9qE=
@@ -85,22 +87,55 @@ github.com/ugorji/go/codec v1.1.7 h1:2SvQaVZ1ouYrrKKwoSk2pzd4A9evlKJb9oTL+OaLUSs
 github.com/ugorji/go/codec v1.1.7/go.mod h1:Ax+UKWsSmolVDwsd+7N3ZtXu+yMGCf907BLYF3GoBXY=
 github.com/ugorji/go/codec v1.2.4 h1:C5VurWRRCKjuENsbM6GYVw8W++WVW9rSxoACKIvxzz8=
 github.com/ugorji/go/codec v1.2.4/go.mod h1:bWBu1+kIRWcF8uMklKaJrR6fTWQOwAlrIzX22pHwryA=
+github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 golang.org/dl v0.0.0-20190829154251-82a15e2f2ead/go.mod h1:IUMfjQLJQd4UTqG1Z90tenwKoCX93Gn3MAQJMOSBsDQ=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20201221181555-eec23a3978ad h1:DN0cp81fZ3njFcrLCytUHRSUkqBjfTo4Tx9RJTWs0EY=
 golang.org/x/crypto v0.0.0-20201221181555-eec23a3978ad/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
+golang.org/x/mod v0.3.0 h1:RM4zey1++hCTbCVQfnWeKs9/IEsaBLA8vTkd0WVtmH4=
+golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/mod v0.4.2 h1:Gz96sIWK3OalVv/I/qNygP42zyoKp3xptRVCWRFEBvo=
+golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
+golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c h1:VwygUrnw9jn88c4u8GD3rZQbqrP/tgas88tPUbBxQrk=
 golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20210608053332-aa57babbf139 h1:C+AwYEtBp/VQwoLntUmQ/yx3MS9vmZaKNdw5eOpoQe8=
+golang.org/x/sys v0.0.0-20210608053332-aa57babbf139/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.1.0 h1:po9/4sTYwZU9lPhi1tOrb4hCv3qrhiQ77LZfGa2OjwY=
+golang.org/x/tools v0.1.0/go.mod h1:xkSsbof2nBLbhDlRMhhhyNLN/zl3eTqcnHD5viDpcZ0=
+golang.org/x/tools v0.1.3 h1:L69ShwSZEyCsLKoAxDKeMvLDZkumEe8gXUZAjab0tX8=
+golang.org/x/tools v0.1.3/go.mod h1:o0xws9oXOQQZyjljx8fwUC0k7L1pTE6eaCbjGeHmOkk=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/protobuf v0.0.0-20200109180630-ec00e32a8dfd/go.mod h1:DFci5gLYBciE7Vtevhsrf46CRTquxDuWsQurQQe4oz8=
 google.golang.org/protobuf v0.0.0-20200221191635-4d8936d0db64/go.mod h1:kwYJMbMJ01Woi6D6+Kah6886xMZcty6N08ah7+eCXa0=
 google.golang.org/protobuf v0.0.0-20200228230310-ab0ca4ff8a60/go.mod h1:cfTl7dwQJ+fmap5saPgwCLgHXTUD7jkjRqWcaiX5VyM=
@@ -124,3 +159,5 @@ gorm.io/driver/sqlite v1.1.4/go.mod h1:mJCeTFr7+crvS+TRnWc5Z3UvwxUN1BGBLMrf5LA9D
 gorm.io/gorm v1.20.7/go.mod h1:0HFTzE/SqkGTzK6TlDPPQbAYCluiVvhzoA1+aVyzenw=
 gorm.io/gorm v1.20.12 h1:ebZ5KrSHzet+sqOCVdH9mTjW91L298nX3v5lVxAzSUY=
 gorm.io/gorm v1.20.12/go.mod h1:0HFTzE/SqkGTzK6TlDPPQbAYCluiVvhzoA1+aVyzenw=
+honnef.co/go/tools v0.2.0 h1:ws8AfbgTX3oIczLPNPCu5166oBg9ST2vNs0rcht+mDE=
+honnef.co/go/tools v0.2.0/go.mod h1:lPVVZ2BS5TfnjLyizF7o7hv7j9/L+8cZY2hLyjP9cGY=

From 628d96bdb76144566627af54509e3301378da786 Mon Sep 17 00:00:00 2001
From: eikendev <raphael@eiken.dev>
Date: Fri, 11 Jun 2021 00:11:30 +0200
Subject: [PATCH 07/13] Fix linting errors

---
 .gitignore                                      | 2 +-
 Makefile                                        | 3 ++-
 cmd/pushbits/main.go                            | 2 +-
 internal/authentication/credentials/password.go | 2 +-
 internal/dispatcher/dispatcher.go               | 7 +------
 5 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/.gitignore b/.gitignore
index 4471252..f5f8b98 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,4 @@
-app
+out/
 *.db
 config.yml
 
diff --git a/Makefile b/Makefile
index b540007..a45cbe8 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,8 @@ IMAGE := eikendev/pushbits
 
 .PHONY: build
 build:
-	go build -ldflags="-w -s" -o app ./cmd/pushbits
+	mkdir -p ./out
+	go build -ldflags="-w -s" -o ./out/pushbits ./cmd/pushbits
 
 .PHONY: test
 test:
diff --git a/cmd/pushbits/main.go b/cmd/pushbits/main.go
index 424816a..f2965e6 100644
--- a/cmd/pushbits/main.go
+++ b/cmd/pushbits/main.go
@@ -47,7 +47,7 @@ func main() {
 		log.Fatal(err)
 	}
 
-	dp, err := dispatcher.Create(db, c.Matrix.Homeserver, c.Matrix.Username, c.Matrix.Password, c.Formatting)
+	dp, err := dispatcher.Create(c.Matrix.Homeserver, c.Matrix.Username, c.Matrix.Password, c.Formatting)
 	if err != nil {
 		log.Fatal(err)
 	}
diff --git a/internal/authentication/credentials/password.go b/internal/authentication/credentials/password.go
index 729838a..f5ab29c 100644
--- a/internal/authentication/credentials/password.go
+++ b/internal/authentication/credentials/password.go
@@ -14,7 +14,7 @@ func (m *Manager) CreatePasswordHash(password string) ([]byte, error) {
 		if err != nil {
 			return []byte{}, errors.New("HIBP is not available, please wait until service is available again")
 		} else if pwned {
-			return []byte{}, errors.New("Password is pwned, please choose another one")
+			return []byte{}, errors.New("password is pwned, please choose another one")
 		}
 	}
 
diff --git a/internal/dispatcher/dispatcher.go b/internal/dispatcher/dispatcher.go
index a9128ff..735c072 100644
--- a/internal/dispatcher/dispatcher.go
+++ b/internal/dispatcher/dispatcher.go
@@ -11,19 +11,14 @@ var (
 	loginType = "m.login.password"
 )
 
-// The Database interface for encapsulating database access.
-type Database interface {
-}
-
 // Dispatcher holds information for sending notifications to clients.
 type Dispatcher struct {
-	db         Database
 	client     *gomatrix.Client
 	formatting configuration.Formatting
 }
 
 // Create instanciates a dispatcher connection.
-func Create(db Database, homeserver, username, password string, formatting configuration.Formatting) (*Dispatcher, error) {
+func Create(homeserver, username, password string, formatting configuration.Formatting) (*Dispatcher, error) {
 	log.Println("Setting up dispatcher.")
 
 	client, err := gomatrix.NewClient(homeserver, "", "")

From 28e3927290dce32efdf79654fd3a05e2c8ef5c15 Mon Sep 17 00:00:00 2001
From: eikendev <raphael@eiken.dev>
Date: Fri, 11 Jun 2021 00:16:01 +0200
Subject: [PATCH 08/13] Update Dockerfile to reflect filename changes

---
 Dockerfile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 3f22476..4dfd8dc 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -9,7 +9,7 @@ RUN set -ex \
 	&& go mod download \
 	&& go mod verify \
 	&& make build \
-	&& chmod +x /build/app
+	&& chmod +x /build/out/pushbits
 
 FROM alpine
 
@@ -22,7 +22,7 @@ EXPOSE 8080
 WORKDIR /app
 
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
-COPY --from=builder /build/app ./run
+COPY --from=builder /build/out/pushbits ./run
 
 RUN set -ex \
 	&& apk add --no-cache ca-certificates curl \

From 8e5a43e5a4524751849dbbd693f7b2214e485284 Mon Sep 17 00:00:00 2001
From: eikendev <raphael@eiken.dev>
Date: Fri, 11 Jun 2021 00:50:06 +0200
Subject: [PATCH 09/13] Run code linters for pull requests

---
 .github/workflows/main.yml | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index d185008..9700373 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -1,26 +1,33 @@
 name: Main
-on: push
+on: [push, pull_request]
 jobs:
-  test_publish:
-    name: Test and publish
+  test_build_publish:
+    name: Test, build, and publish
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
         uses: actions/checkout@v2
       - name: Install dependencies
         run: make setup
+      - name: Export GOBIN
+        uses: actions/setup-go@v2
+        with:
+          go-version: 1.16
       - name: Run tests
-        run: |
-            export PATH="$PATH:$(go env GOPATH)/bin" # Currently the path needs to be set manually.
-            make test
+        run: make test
       - name: Build image
         run: make build_image
+      - name: Get Branch
+        run: |
+          raw=$(git branch -r --contains ${{ github.ref }})
+          branch=${raw##*/}
+          echo "BRANCH=$branch" >> $GITHUB_ENV
       - name: Login to Docker Hub
+        if: ${{ startsWith(github.ref, 'refs/tags/v') && github.event_name == 'push' && env.BRANCH == 'master' }} # Only publish for tagged commits pushed to master.
         uses: docker/login-action@v1
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
       - name: Publish image
-        if: startsWith(github.ref, 'refs/tags/') # Only publish for tagged commits.
-        run: |
-            make push_image
+        if: ${{ startsWith(github.ref, 'refs/tags/v') && github.event_name == 'push' && env.BRANCH == 'master' }} # Only publish for tagged commits pushed to master.
+        run: make push_image

From c5e4669fdab01f12abd6b220d07acfb347900c8b Mon Sep 17 00:00:00 2001
From: Cubicroot <github@cubicroot.xyz>
Date: Fri, 11 Jun 2021 10:21:48 +0200
Subject: [PATCH 10/13] clean up

---
 internal/dispatcher/notification.go | 11 ++++++++---
 internal/model/notification.go      |  2 +-
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/internal/dispatcher/notification.go b/internal/dispatcher/notification.go
index 9b974d0..6571d8d 100644
--- a/internal/dispatcher/notification.go
+++ b/internal/dispatcher/notification.go
@@ -82,10 +82,15 @@ func (d *Dispatcher) DeleteNotification(a *model.Application, n *model.DeleteNot
 
 	if val, ok := deleteMessage.Content["body"]; ok {
 		body, ok := val.(string)
-		if ok {
-			oldBody = body
-			oldFormattedBody = body
+
+		if !ok {
+			log.Println("Event does not have a body")
+			return api.ErrorMessageNotFound
 		}
+
+		oldBody = body
+		oldFormattedBody = body
+
 	} else {
 		log.Println("Message to delete has wrong format")
 		return api.ErrorMessageNotFound
diff --git a/internal/model/notification.go b/internal/model/notification.go
index 569e8ee..fc46221 100644
--- a/internal/model/notification.go
+++ b/internal/model/notification.go
@@ -16,7 +16,7 @@ type Notification struct {
 	Date          time.Time              `json:"date"`
 }
 
-// DeleteNotification holds information like the message, the reply to message id and the priority of a deletion notification.
+// DeleteNotification holds information like the message ID of a deletion notification.
 type DeleteNotification struct {
 	ID   string    `json:"id" form:"id"`
 	Date time.Time `json:"date"`

From ac5819dfc93a228d57f1d03b95267076ab30f47e Mon Sep 17 00:00:00 2001
From: Cubicroot <github@cubicroot.xyz>
Date: Fri, 11 Jun 2021 10:47:11 +0200
Subject: [PATCH 11/13] move respond/replace logic to separate functions

---
 internal/api/errors.go              |   2 +-
 internal/dispatcher/notification.go | 157 ++++++++++++++++------------
 2 files changed, 94 insertions(+), 65 deletions(-)

diff --git a/internal/api/errors.go b/internal/api/errors.go
index db296e3..64c744a 100644
--- a/internal/api/errors.go
+++ b/internal/api/errors.go
@@ -2,4 +2,4 @@ package api
 
 import "errors"
 
-var ErrorMessageNotFound = errors.New("Message not found")
+var ErrorMessageNotFound = errors.New("message not found")
diff --git a/internal/dispatcher/notification.go b/internal/dispatcher/notification.go
index 6571d8d..16248de 100644
--- a/internal/dispatcher/notification.go
+++ b/internal/dispatcher/notification.go
@@ -80,82 +80,23 @@ func (d *Dispatcher) DeleteNotification(a *model.Application, n *model.DeleteNot
 		return api.ErrorMessageNotFound
 	}
 
-	if val, ok := deleteMessage.Content["body"]; ok {
-		body, ok := val.(string)
+	oldBody, oldFormattedBody, err = bodiesFromMessage(deleteMessage)
 
-		if !ok {
-			log.Println("Event does not have a body")
-			return api.ErrorMessageNotFound
-		}
-
-		oldBody = body
-		oldFormattedBody = 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 {
-			oldFormattedBody = body
-		}
+	if err != nil {
+		return err
 	}
 
 	// update the message with strikethrough
 	newBody := fmt.Sprintf("<del>%s</del>\n- deleted", oldBody)
 	newFormattedBody := fmt.Sprintf("<del>%s</del><br>- deleted", oldFormattedBody)
 
-	newMessage := NewContent{
-		Body:          newBody,
-		FormattedBody: newFormattedBody,
-		MsgType:       MsgTypeText,
-		Format:        MessageFormatHTML,
-	}
-
-	replaceRelation := RelatesTo{
-		RelType: "m.replace",
-		EventID: deleteMessage.ID,
-	}
-
-	replaceEvent := MessageEvent{
-		Body:          oldBody,
-		FormattedBody: oldFormattedBody,
-		MsgType:       MsgTypeText,
-		NewContent:    newMessage,
-		RelatesTo:     replaceRelation,
-		Format:        MessageFormatHTML,
-	}
-
-	_, err = d.client.SendMessageEvent(a.MatrixID, "m.room.message", replaceEvent)
+	_, err = d.replaceMessage(a, newBody, newFormattedBody, deleteMessage.ID, oldBody, oldFormattedBody)
 
 	if err != nil {
-		log.Println(err)
 		return err
 	}
 
-	// send a notification about the deletion
-	// formatting according to https://matrix.org/docs/spec/client_server/latest#fallbacks-and-event-representation
-	notificationFormattedBody := 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, oldFormattedBody)
-	notificationBody := fmt.Sprintf("> <%s>%s\n\nThis message got deleted", deleteMessage.Sender, oldBody)
-
-	notificationEvent := MessageEvent{
-		FormattedBody: notificationFormattedBody,
-		Body:          notificationBody,
-		MsgType:       MsgTypeText,
-		Format:        MessageFormatHTML,
-	}
-
-	notificationReply := make(map[string]string)
-	notificationReply["event_id"] = deleteMessage.ID
-
-	notificationRelation := RelatesTo{
-		InReplyTo: notificationReply,
-	}
-	notificationEvent.RelatesTo = notificationRelation
-
-	_, err = d.client.SendMessageEvent(a.MatrixID, "m.room.message", notificationEvent)
+	_, err = d.respondToMessage(a, "This message got deleted", "<i>This message got deleted.</i>", deleteMessage)
 
 	return err
 }
@@ -243,3 +184,91 @@ func (d *Dispatcher) getMessage(a *model.Application, id string) (gomatrix.Event
 	}
 	return gomatrix.Event{}, api.ErrorMessageNotFound
 }
+
+// Replaces the content of a matrix message
+func (d *Dispatcher) replaceMessage(a *model.Application, newBody, newFormattedBody string, messageID string, oldBody, oldFormattedBody string) (*gomatrix.RespSendEvent, error) {
+	newMessage := NewContent{
+		Body:          newBody,
+		FormattedBody: newFormattedBody,
+		MsgType:       MsgTypeText,
+		Format:        MessageFormatHTML,
+	}
+
+	replaceRelation := RelatesTo{
+		RelType: "m.replace",
+		EventID: messageID,
+	}
+
+	replaceEvent := MessageEvent{
+		Body:          oldBody,
+		FormattedBody: oldFormattedBody,
+		MsgType:       MsgTypeText,
+		NewContent:    newMessage,
+		RelatesTo:     replaceRelation,
+		Format:        MessageFormatHTML,
+	}
+
+	sendEvent, err := d.client.SendMessageEvent(a.MatrixID, "m.room.message", replaceEvent)
+
+	if err != nil {
+		log.Println(err)
+		return nil, err
+	}
+
+	return sendEvent, nil
+}
+
+// Sends a notification in response to another matrix message event
+func (d *Dispatcher) respondToMessage(a *model.Application, body, formattedBody string, respondMessage gomatrix.Event) (*gomatrix.RespSendEvent, error) {
+	oldBody, oldFormattedBody, err := bodiesFromMessage(respondMessage)
+
+	if err != nil {
+		return nil, err
+	}
+
+	// formatting according to https://matrix.org/docs/spec/client_server/latest#fallbacks-and-event-representation
+	newFormattedBody := 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>%s", respondMessage.RoomID, respondMessage.ID, respondMessage.Sender, respondMessage.Sender, oldFormattedBody, formattedBody)
+	newBody := fmt.Sprintf("> <%s>%s\n\n%s", respondMessage.Sender, oldBody, body)
+
+	notificationEvent := MessageEvent{
+		FormattedBody: newFormattedBody,
+		Body:          newBody,
+		MsgType:       MsgTypeText,
+		Format:        MessageFormatHTML,
+	}
+
+	notificationReply := make(map[string]string)
+	notificationReply["event_id"] = respondMessage.ID
+
+	notificationRelation := RelatesTo{
+		InReplyTo: notificationReply,
+	}
+	notificationEvent.RelatesTo = notificationRelation
+
+	return d.client.SendMessageEvent(a.MatrixID, "m.room.message", notificationEvent)
+}
+
+// Extracts body and formatted body from a matrix message event
+func bodiesFromMessage(message gomatrix.Event) (body, formattedBody string, err error) {
+	if val, ok := message.Content["body"]; ok {
+		body, ok := val.(string)
+
+		if !ok {
+			return "", "", api.ErrorMessageNotFound
+		}
+
+		formattedBody = body
+
+	} else {
+		return "", "", api.ErrorMessageNotFound
+	}
+
+	if val, ok := message.Content["formatted_body"]; ok {
+		body, ok := val.(string)
+		if ok {
+			formattedBody = body
+		}
+	}
+
+	return body, formattedBody, nil
+}

From 5450d44f53b97544aa4b68b5ad7594aa053a879a Mon Sep 17 00:00:00 2001
From: eikendev <raphael@eiken.dev>
Date: Fri, 11 Jun 2021 23:18:29 +0200
Subject: [PATCH 12/13] Fix CI for pull requests

---
 .github/workflows/main.yml | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 9700373..f46a74b 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -17,15 +17,16 @@ jobs:
         run: make test
       - name: Build image
         run: make build_image
-      - name: Get Branch
+      - name: Get Branch # Needed to evaluate env.BRANCH.
+        if: ${{ startsWith(github.ref, 'refs/tags/v') && github.event_name == 'push' }} # Otherwise will fail on pull requests.
         run: |
           raw=$(git branch -r --contains ${{ github.ref }})
           branch=${raw##*/}
           echo "BRANCH=$branch" >> $GITHUB_ENV
       - name: Login to Docker Hub
-        if: ${{ startsWith(github.ref, 'refs/tags/v') && github.event_name == 'push' && env.BRANCH == 'master' }} # Only publish for tagged commits pushed to master.
+        if: ${{ startsWith(github.ref, 'refs/tags/v') && github.event_name == 'push' && env.BRANCH == 'master' }} # Only login for tagged commits pushed to master.
         uses: docker/login-action@v1
-        with:
+        with: # Secrets are not exposed to pull request contexts.
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
       - name: Publish image

From c1cc369d1e741195320137253c190d60dad1343e Mon Sep 17 00:00:00 2001
From: Cubicroot <github@cubicroot.xyz>
Date: Thu, 17 Jun 2021 17:37:24 +0200
Subject: [PATCH 13/13] more strict type handling

---
 internal/dispatcher/notification.go | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/internal/dispatcher/notification.go b/internal/dispatcher/notification.go
index 16248de..9fce7a0 100644
--- a/internal/dispatcher/notification.go
+++ b/internal/dispatcher/notification.go
@@ -265,9 +265,11 @@ func bodiesFromMessage(message gomatrix.Event) (body, formattedBody string, err
 
 	if val, ok := message.Content["formatted_body"]; ok {
 		body, ok := val.(string)
-		if ok {
-			formattedBody = body
+		if !ok {
+			return "", "", api.ErrorMessageNotFound
 		}
+
+		formattedBody = body
 	}
 
 	return body, formattedBody, nil