Add support for message deletion (nctalk) (#1492)

* nctalk: add message deletion support

Signed-off-by: Gary Kim <gary@garykim.dev>

* nctalk: seperate out deletion and sending logic

Signed-off-by: Gary Kim <gary@garykim.dev>

* nctalk: update library to v0.2.0

Signed-off-by: Gary Kim <gary@garykim.dev>

* Rename functions to be clearer

Signed-off-by: Gary Kim <gary@garykim.dev>

* Update to go-nc-talk v0.2.1

Signed-off-by: Gary Kim <gary@garykim.dev>

* Update to go-nc-talk v0.2.2

Signed-off-by: Gary Kim <gary@garykim.dev>

* Make deletions easier to debug

Signed-off-by: Gary Kim <gary@garykim.dev>

vendor/gomod.garykim.dev/nc-talk/room/room.go

@@ -18,6 +18,7 @@ import (
 	"context"
 	"errors"
 	"io/ioutil"
+	"net/http"
 	"strconv"
 	"time"
 
@@ -41,6 +42,12 @@ var (
 	ErrUnexpectedReturnCode = errors.New("unexpected return code")
 	// ErrTooManyRequests is returned if the server returns a 429
 	ErrTooManyRequests = errors.New("too many requests")
+	// ErrLackingCapabilities is returned if the server lacks the required capability for the given function
+	ErrLackingCapabilities = errors.New("lacking required capabilities")
+	// ErrForbidden is returned if the user is forbidden from accessing the requested resource
+	ErrForbidden = errors.New("request forbidden")
+	// ErrUnexpectedResponse is returned if the response from the Nextcloud Talk server is not formatted as expected
+	ErrUnexpectedResponse = errors.New("unexpected response")
 )
 
 // TalkRoom represents a room in Nextcloud Talk
@@ -90,6 +97,39 @@ func (t *TalkRoom) SendMessage(msg string) (*ocs.TalkRoomMessageData, error) {
 	return &msgInfo.OCS.TalkRoomMessage, err
 }
 
+// DeleteMessage deletes the message with the given messageID on the server.
+//
+// Requires "delete-messages" capability on the Nextcloud Talk server
+func (t *TalkRoom) DeleteMessage(messageID int) (*ocs.TalkRoomMessageData, error) {
+	// Check for required capability
+	capable, err := t.User.Capabilities()
+	if err != nil {
+		return nil, err
+	}
+	if !capable.DeleteMessages {
+		return nil, ErrLackingCapabilities
+	}
+
+	url := t.User.NextcloudURL + constants.BaseEndpoint + "/chat/" + t.Token + "/" + strconv.Itoa(messageID)
+
+	client := t.User.RequestClient(request.Client{
+		URL:    url,
+		Method: "DELETE",
+	})
+	res, err := client.Do()
+	if err != nil {
+		return nil, err
+	}
+	if res.StatusCode() != http.StatusOK && res.StatusCode() != http.StatusAccepted {
+		return nil, ErrUnexpectedReturnCode
+	}
+	msgInfo, err := ocs.TalkRoomSentResponseUnmarshal(&res.Data)
+	if err != nil {
+		return nil, err
+	}
+	return &msgInfo.OCS.TalkRoomMessage, nil
+}
+
 // ReceiveMessages starts watching for new messages
 func (t *TalkRoom) ReceiveMessages(ctx context.Context) (chan ocs.TalkRoomMessageData, error) {
 	c := make(chan ocs.TalkRoomMessageData)
@@ -133,23 +173,28 @@ func (t *TalkRoom) ReceiveMessages(ctx context.Context) (chan ocs.TalkRoomMessag
 			}
 
 			// If it seems that we no longer have access to the chat for one reason or another, stop the goroutine and set error in the next return.
-			if res.StatusCode == 404 {
+			if res.StatusCode == http.StatusNotFound {
 				_ = res.Body.Close()
 				c <- ocs.TalkRoomMessageData{Error: ErrRoomNotFound}
 				return
 			}
-			if res.StatusCode == 401 {
+			if res.StatusCode == http.StatusUnauthorized {
 				_ = res.Body.Close()
 				c <- ocs.TalkRoomMessageData{Error: ErrUnauthorized}
 				return
 			}
-			if res.StatusCode == 429 {
+			if res.StatusCode == http.StatusTooManyRequests {
 				_ = res.Body.Close()
 				c <- ocs.TalkRoomMessageData{Error: ErrTooManyRequests}
 				return
 			}
+			if res.StatusCode == http.StatusForbidden {
+				_ = res.Body.Close()
+				c <- ocs.TalkRoomMessageData{Error: ErrForbidden}
+				return
+			}
 
-			if res.StatusCode == 200 {
+			if res.StatusCode == http.StatusOK {
 				lastKnown = res.Header.Get("X-Chat-Last-Given")
 				data, err := ioutil.ReadAll(res.Body)
 				_ = res.Body.Close()
@@ -192,13 +237,13 @@ func (t *TalkRoom) TestConnection() error {
 		return err
 	}
 	switch res.StatusCode() {
-	case 200:
+	case http.StatusOK:
 		return nil
-	case 304:
+	case http.StatusNotModified:
 		return nil
-	case 404:
+	case http.StatusNotFound:
 		return ErrRoomNotFound
-	case 412:
+	case http.StatusPreconditionFailed:
 		return ErrNotModeratorInLobby
 	}
 	return ErrUnexpectedReturnCode