From 7e793ec0ba6835f40ef038a6d8c1b643f27db71e Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Mon, 28 Oct 2024 00:28:59 +0200
Subject: [PATCH] web/composer: surround selection with markdown when pasting
 link

---
 web/src/ui/composer/Autocompleter.tsx   |  7 ++-----
 web/src/ui/composer/MessageComposer.tsx | 27 ++++++++++++++++++++-----
 web/src/util/markdown.ts                | 21 +++++++++++++++++++
 3 files changed, 45 insertions(+), 10 deletions(-)
 create mode 100644 web/src/util/markdown.ts

diff --git a/web/src/ui/composer/Autocompleter.tsx b/web/src/ui/composer/Autocompleter.tsx
index 7bc31ee..fdd49cc 100644
--- a/web/src/ui/composer/Autocompleter.tsx
+++ b/web/src/ui/composer/Autocompleter.tsx
@@ -17,6 +17,7 @@ import { JSX, use, useEffect } from "react"
 import { getAvatarURL, getMediaURL } from "@/api/media.ts"
 import { RoomStateStore, useCustomEmojis } from "@/api/statestore"
 import { Emoji, emojiToMarkdown, useSortedAndFilteredEmojis } from "@/util/emoji"
+import { escapeMarkdown } from "@/util/markdown.ts"
 import useEvent from "@/util/useEvent.ts"
 import ClientContext from "../ClientContext.ts"
 import type { ComposerState } from "./MessageComposer.tsx"
@@ -111,11 +112,7 @@ export const EmojiAutocompleter = ({ params, room, ...rest }: AutocompleterProps
 	return useAutocompleter({ params, room, ...rest, items, ...emojiFuncs })
 }
 
-const escapeDisplayname = (input: string) => input
-	.replace("\n", " ")
-	.replace(/([\\`*_[\]])/g, "\\$1")
-	.replace("<", "&lt;")
-	.replace(">", "&gt;")
+const escapeDisplayname = (input: string) => escapeMarkdown(input).replace("\n", " ")
 
 const userFuncs = {
 	getText: (user: AutocompleteUser) =>
diff --git a/web/src/ui/composer/MessageComposer.tsx b/web/src/ui/composer/MessageComposer.tsx
index e3f28d8..ec37310 100644
--- a/web/src/ui/composer/MessageComposer.tsx
+++ b/web/src/ui/composer/MessageComposer.tsx
@@ -26,6 +26,7 @@ import type {
 	RoomID,
 } from "@/api/types"
 import { PartialEmoji, emojiToMarkdown } from "@/util/emoji"
+import { escapeMarkdown } from "@/util/markdown.ts"
 import useEvent from "@/util/useEvent.ts"
 import ClientContext from "../ClientContext.ts"
 import EmojiPicker from "../emojipicker/EmojiPicker.tsx"
@@ -266,11 +267,26 @@ const MessageComposer = () => {
 	const onAttachFile = useEvent(
 		(evt: React.ChangeEvent<HTMLInputElement>) => doUploadFile(evt.target.files?.[0]),
 	)
-	useEffect(() => {
-		const listener = (evt: ClipboardEvent) => doUploadFile(evt.clipboardData?.files?.[0])
-		document.addEventListener("paste", listener)
-		return () => document.removeEventListener("paste", listener)
-	}, [doUploadFile])
+	const onPaste = useEvent((evt: React.ClipboardEvent<HTMLTextAreaElement>) => {
+		const file = evt.clipboardData?.files?.[0]
+		const text = evt.clipboardData.getData("text/plain")
+		const input = evt.currentTarget
+		if (file) {
+			doUploadFile(file)
+		} else if (
+			input.selectionStart !== input.selectionEnd
+			&& (text.startsWith("http://") || text.startsWith("https://") || text.startsWith("matrix:"))
+		) {
+			setState({
+				text: `${state.text.slice(0, input.selectionStart)}[${
+					escapeMarkdown(state.text.slice(input.selectionStart, input.selectionEnd))
+				}](${escapeMarkdown(text)})${state.text.slice(input.selectionEnd)}`,
+			})
+		} else {
+			return
+		}
+		evt.preventDefault()
+	})
 	// To ensure the cursor jumps to the end, do this in an effect rather than as the initial value of useState
 	// To try to avoid the input bar flashing, use useLayoutEffect instead of useEffect
 	useLayoutEffect(() => {
@@ -370,6 +386,7 @@ const MessageComposer = () => {
 				onKeyDown={onComposerKeyDown}
 				onKeyUp={onComposerCaretChange}
 				onClick={onComposerCaretChange}
+				onPaste={onPaste}
 				onChange={onChange}
 				placeholder="Send a message"
 				id="message-composer"
diff --git a/web/src/util/markdown.ts b/web/src/util/markdown.ts
new file mode 100644
index 0000000..e2db3bb
--- /dev/null
+++ b/web/src/util/markdown.ts
@@ -0,0 +1,21 @@
+// gomuks - A Matrix client written in Go.
+// Copyright (C) 2024 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/>.
+
+
+export const escapeMarkdown = (input: string) => input
+	.replace(/([\\`*_[\]])/g, "\\$1")
+	.replace("<", "&lt;")
+	.replace(">", "&gt;")