web/composer: send thread message when replying in thread

pkg/hicli/json-commands.go

@@ -41,7 +41,7 @@ func (h *HiClient) handleJSONCommand(ctx context.Context, req *JSONCommand) (any
 		})
 	case "send_message":
 		return unmarshalAndCall(req.Data, func(params *sendMessageParams) (*database.Event, error) {
-			return h.SendMessage(ctx, params.RoomID, params.BaseContent, params.Text, params.ReplyTo, params.Mentions)
+			return h.SendMessage(ctx, params.RoomID, params.BaseContent, params.Text, params.RelatesTo, params.Mentions)
 		})
 	case "send_event":
 		return unmarshalAndCall(req.Data, func(params *sendEventParams) (*database.Event, error) {
@@ -122,7 +122,7 @@ type sendMessageParams struct {
 	RoomID      id.RoomID                  `json:"room_id"`
 	BaseContent *event.MessageEventContent `json:"base_content"`
 	Text        string                     `json:"text"`
-	ReplyTo     id.EventID                 `json:"reply_to"`
+	RelatesTo   *event.RelatesTo           `json:"relates_to"`
 	Mentions    *event.Mentions            `json:"mentions"`
 }
 

pkg/hicli/send.go

@@ -32,7 +32,14 @@ var (
 	rainbowWithHTML = goldmark.New(format.Extensions, format.HTMLOptions, goldmark.WithExtensions(rainbow.Extension))
 )
 
-func (h *HiClient) SendMessage(ctx context.Context, roomID id.RoomID, base *event.MessageEventContent, text string, replyTo id.EventID, mentions *event.Mentions) (*database.Event, error) {
+func (h *HiClient) SendMessage(
+	ctx context.Context,
+	roomID id.RoomID,
+	base *event.MessageEventContent,
+	text string,
+	relatesTo *event.RelatesTo,
+	mentions *event.Mentions,
+) (*database.Event, error) {
 	var content event.MessageEventContent
 	if strings.HasPrefix(text, "/rainbow ") {
 		text = strings.TrimPrefix(text, "/rainbow ")
@@ -66,8 +73,16 @@ func (h *HiClient) SendMessage(ctx context.Context, roomID id.RoomID, base *even
 			}
 		}
 	}
-	if replyTo != "" {
-		content.RelatesTo = (&event.RelatesTo{}).SetReplyTo(replyTo)
+	if relatesTo != nil {
+		if relatesTo.Type == event.RelReplace {
+			contentCopy := content
+			content = event.MessageEventContent{
+				NewContent: &contentCopy,
+				RelatesTo:  relatesTo,
+			}
+		} else {
+			content.RelatesTo = relatesTo
+		}
 	}
 	return h.Send(ctx, roomID, event.EventMessage, &content)
 }

web/src/api/rpc.ts

@@ -27,6 +27,7 @@ import type {
 	RPCEvent,
 	RawDBEvent,
 	ReceiptType,
+	RelatesTo,
 	ResolveAliasResponse,
 	RoomAlias,
 	RoomID,
@@ -50,7 +51,7 @@ export interface SendMessageParams {
 	base_content?: MessageEventContent
 	text: string
 	media_path?: string
-	reply_to?: EventID
+	relates_to?: RelatesTo
 	mentions?: Mentions
 }
 

web/src/api/types/mxtypes.ts

@@ -74,12 +74,24 @@ export interface Mentions {
 	room: boolean
 }
 
+export interface RelatesTo {
+	rel_type?: RelationType
+	event_id?: EventID
+	key?: string
+
+	is_falling_back?: boolean
+	"m.in_reply_to"?: {
+		event_id?: EventID
+	}
+}
+
 export interface BaseMessageEventContent {
 	msgtype: string
 	body: string
 	formatted_body?: string
 	format?: "org.matrix.custom.html"
 	"m.mentions"?: Mentions
+	"m.relates_to"?: RelatesTo
 }
 
 export interface TextMessageEventContent extends BaseMessageEventContent {

web/src/ui/composer/MessageComposer.tsx

@@ -16,7 +16,7 @@
 import React, { use, useCallback, useEffect, useLayoutEffect, useReducer, useRef, useState } from "react"
 import { ScaleLoader } from "react-spinners"
 import { RoomStateStore, useRoomEvent } from "@/api/statestore"
-import type { EventID, MediaMessageEventContent, Mentions, RoomID } from "@/api/types"
+import type { EventID, MediaMessageEventContent, Mentions, RelatesTo, RoomID } from "@/api/types"
 import useEvent from "@/util/useEvent.ts"
 import { ClientContext } from "../ClientContext.ts"
 import { ReplyBody } from "../timeline/ReplyBody.tsx"
@@ -90,14 +90,27 @@ const MessageComposer = ({ room, scrollToBottomRef, setReplyToRef }: MessageComp
 			user_ids: [],
 			room: false,
 		}
+		let relates_to: RelatesTo | undefined = undefined
 		if (replyToEvt) {
 			mentions.user_ids.push(replyToEvt.sender)
+			relates_to = {
+				"m.in_reply_to": {
+					event_id: replyToEvt.event_id,
+				},
+			}
+			if (replyToEvt.content["m.relates_to"]?.rel_type === "m.thread"
+				&& typeof replyToEvt.content["m.relates_to"]?.event_id === "string") {
+				relates_to.rel_type = "m.thread"
+				relates_to.event_id = replyToEvt.content["m.relates_to"].event_id
+				// TODO set this to true if replying to the last event in a thread?
+				relates_to.is_falling_back = false
+			}
 		}
 		client.sendMessage({
 			room_id: room.roomID,
 			base_content: state.media ?? undefined,
 			text: state.text,
-			reply_to: replyToEvt?.event_id,
+			relates_to,
 			mentions,
 		}).catch(err => window.alert("Failed to send message: " + err))
 	})