client: add wrapper for /relations endpoints

client.go

@@ -2088,6 +2088,12 @@ func (cli *Client) GetUnredactedEventContent(ctx context.Context, roomID id.Room
 	return
 }
 
+func (cli *Client) GetRelations(ctx context.Context, roomID id.RoomID, eventID id.EventID, req *ReqGetRelations) (resp *RespGetRelations, err error) {
+	urlPath := cli.BuildURLWithQuery(append(ClientURLPath{"v1", "rooms", roomID, "relations", eventID}, req.PathSuffix()...), req.Query())
+	_, err = cli.MakeRequest(ctx, http.MethodGet, urlPath, nil, &resp)
+	return
+}
+
 func (cli *Client) MarkRead(ctx context.Context, roomID id.RoomID, eventID id.EventID) (err error) {
 	return cli.SendReceipt(ctx, roomID, eventID, event.ReceiptTypeRead, nil)
 }

requests.go

@@ -543,3 +543,44 @@ type ReqReport struct {
 	Reason string `json:"reason,omitempty"`
 	Score  int    `json:"score,omitempty"`
 }
+
+type ReqGetRelations struct {
+	RelationType event.RelationType
+	EventType    event.Type
+
+	Dir     Direction
+	From    string
+	To      string
+	Limit   int
+	Recurse bool
+}
+
+func (rgr *ReqGetRelations) PathSuffix() ClientURLPath {
+	if rgr.RelationType != "" {
+		if rgr.EventType.Type != "" {
+			return ClientURLPath{rgr.RelationType, rgr.EventType.Type}
+		}
+		return ClientURLPath{rgr.RelationType}
+	}
+	return ClientURLPath{}
+}
+
+func (rgr *ReqGetRelations) Query() map[string]string {
+	query := map[string]string{}
+	if rgr.Dir != 0 {
+		query["dir"] = string(rgr.Dir)
+	}
+	if rgr.From != "" {
+		query["from"] = rgr.From
+	}
+	if rgr.To != "" {
+		query["to"] = rgr.To
+	}
+	if rgr.Limit > 0 {
+		query["limit"] = strconv.Itoa(rgr.Limit)
+	}
+	if rgr.Recurse {
+		query["recurse"] = "true"
+	}
+	return query
+}

responses.go

@@ -709,3 +709,10 @@ type RespOpenIDToken struct {
 	MatrixServerName string `json:"matrix_server_name"`
 	TokenType        string `json:"token_type"` // Always "Bearer"
 }
+
+type RespGetRelations struct {
+	Chunk          []*event.Event `json:"chunk"`
+	NextBatch      string         `json:"next_batch,omitempty"`
+	PrevBatch      string         `json:"prev_batch,omitempty"`
+	RecursionDepth int            `json:"recursion_depth,omitempty"`
+}