Convert everyone/here into room and block other room mentions

formatter.go

@@ -31,13 +31,9 @@ import (
 	"maunium.net/go/mautrix/util/variationselector"
 )
 
-var discordExtensions = goldmark.WithExtensions(mdext.SimpleSpoiler, mdext.DiscordUnderline)
+var discordExtensions = goldmark.WithExtensions(mdext.SimpleSpoiler, mdext.DiscordUnderline, &DiscordEveryone{})
 var escapeFixer = regexp.MustCompile(`\\(__[^_]|\*\*[^*])`)
 
-func (portal *Portal) renderDiscordMarkdown(text string) event.MessageEventContent {
-	return format.HTMLToContent(portal.renderDiscordMarkdownOnlyHTML(text))
-}
-
 func (portal *Portal) renderDiscordMarkdownOnlyHTML(text string) string {
 	text = escapeFixer.ReplaceAllStringFunc(text, func(s string) string {
 		return s[:2] + `\` + s[2:]

formatter_everyone.go

@@ -0,0 +1,108 @@
+// mautrix-discord - A Matrix-Discord puppeting bridge.
+// Copyright (C) 2023 Tulir Asokan
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"fmt"
+	"regexp"
+
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/renderer"
+	"github.com/yuin/goldmark/text"
+	"github.com/yuin/goldmark/util"
+)
+
+type astDiscordEveryone struct {
+	ast.BaseInline
+	onlyHere bool
+}
+
+var _ ast.Node = (*astDiscordEveryone)(nil)
+var astKindDiscordEveryone = ast.NewNodeKind("DiscordEveryone")
+
+func (n *astDiscordEveryone) Dump(source []byte, level int) {
+	ast.DumpHelper(n, source, level, nil, nil)
+}
+
+func (n *astDiscordEveryone) Kind() ast.NodeKind {
+	return astKindDiscordEveryone
+}
+
+func (n *astDiscordEveryone) String() string {
+	if n.onlyHere {
+		return "@here"
+	}
+	return "@everyone"
+}
+
+type discordEveryoneParser struct{}
+
+var discordEveryoneRegex = regexp.MustCompile(`@(everyone|here)`)
+var defaultDiscordEveryoneParser = &discordEveryoneParser{}
+
+func (s *discordEveryoneParser) Trigger() []byte {
+	return []byte{'@'}
+}
+
+func (s *discordEveryoneParser) Parse(parent ast.Node, block text.Reader, pc parser.Context) ast.Node {
+	line, _ := block.PeekLine()
+	match := discordEveryoneRegex.FindSubmatch(line)
+	if match == nil {
+		return nil
+	}
+	block.Advance(len(match[0]))
+	return &astDiscordEveryone{
+		onlyHere: string(match[1]) == "here",
+	}
+}
+
+func (s *discordEveryoneParser) CloseBlock(parent ast.Node, pc parser.Context) {
+	// nothing to do
+}
+
+type discordEveryoneHTMLRenderer struct{}
+
+func (r *discordEveryoneHTMLRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
+	reg.Register(astKindDiscordEveryone, r.renderDiscordEveryone)
+}
+
+func (r *discordEveryoneHTMLRenderer) renderDiscordEveryone(w util.BufWriter, source []byte, n ast.Node, entering bool) (status ast.WalkStatus, err error) {
+	status = ast.WalkContinue
+	if !entering {
+		return
+	}
+	mention, _ := n.(*astDiscordEveryone)
+	class := "everyone"
+	if mention != nil && mention.onlyHere {
+		class = "here"
+	}
+	_, _ = fmt.Fprintf(w, `<span class="discord-mention-%s">@room</span>`, class)
+	return
+}
+
+type DiscordEveryone struct{}
+
+func (e *DiscordEveryone) Extend(m goldmark.Markdown) {
+	m.Parser().AddOptions(parser.WithInlineParsers(
+		util.Prioritized(defaultDiscordEveryoneParser, 600),
+	))
+	m.Renderer().AddOptions(renderer.WithNodeRenderers(
+		util.Prioritized(&discordEveryoneHTMLRenderer{}, 600),
+	))
+}

portal.go

@@ -951,7 +951,12 @@ func (portal *Portal) convertDiscordTextMessage(intent *appservice.IntentAPI, ms
 		return nil
 	}
 
-	content := format.HTMLToContent(strings.Join(htmlParts, "\n"))
+	fullHTML := strings.Join(htmlParts, "\n")
+	if !msg.MentionEveryone {
+		fullHTML = strings.ReplaceAll(fullHTML, "@room", "@\u2063ro\u2063om")
+	}
+
+	content := format.HTMLToContent(fullHTML)
 	if relation != nil {
 		content.RelatesTo = relation.Copy()
 	}