out-of-your-element/m2d/converters/event-to-message.js
Cadence Ember 6738290d99 m->d: Reliably put < > around matrix.to links
This replaces the turndown brackets system with a regexp over body
and formatted_body.
2024-02-21 00:00:11 +13:00

832 lines
35 KiB
JavaScript

// @ts-check
const Ty = require("../../types")
const DiscordTypes = require("discord-api-types/v10")
const {Readable} = require("stream")
const chunk = require("chunk-text")
const TurndownService = require("turndown")
const domino = require("domino")
const assert = require("assert").strict
const entities = require("entities")
const passthrough = require("../../passthrough")
const {sync, db, discord, select, from} = passthrough
/** @type {import("../converters/utils")} */
const mxUtils = sync.require("../converters/utils")
/** @type {import("../../discord/utils")} */
const dUtils = sync.require("../../discord/utils")
/** @type {import("./emoji-sheet")} */
const emojiSheet = sync.require("./emoji-sheet")
/** @type {[RegExp, string][]} */
const markdownEscapes = [
[/\\/g, '\\\\'],
[/\*/g, '\\*'],
[/^-/g, '\\-'],
[/^\+ /g, '\\+ '],
[/^(=+)/g, '\\$1'],
[/^(#{1,6}) /g, '\\$1 '],
[/`/g, '\\`'],
[/^~~~/g, '\\~~~'],
[/\[/g, '\\['],
[/\]/g, '\\]'],
[/^>/g, '\\>'],
[/_/g, '\\_'],
[/^(\d+)\. /g, '$1\\. ']
/*
Strikethrough is deliberately not escaped. Usually when Matrix users type ~~ it's not because they wanted to send ~~,
it's because they wanted strikethrough and it didn't work because their client doesn't support it.
As bridge developers, we can choose between "messages should look as similar as possible" vs "it was most likely intended to be strikethrough".
I went with the latter. Even though the appearance doesn't match, I'd rather it displayed as originally intended for 80% of the readers than for 0%.
*/
]
const turndownService = new TurndownService({
hr: "----",
headingStyle: "atx",
preformattedCode: true,
codeBlockStyle: "fenced"
})
/**
* Markdown characters in the HTML content need to be escaped, though take care not to escape the middle of bare links
* @param {string} string
*/
// @ts-ignore bad type from turndown
turndownService.escape = function (string) {
const escapedWords = string.split(" ").map(word => {
if (word.match(/^https?:\/\//)) {
return word
} else {
return markdownEscapes.reduce(function (accumulator, escape) {
return accumulator.replace(escape[0], escape[1])
}, word)
}
})
return escapedWords.join(" ")
}
turndownService.remove("mx-reply")
turndownService.addRule("strikethrough", {
filter: ["del", "s"],
replacement: function (content) {
return "~~" + content + "~~"
}
})
turndownService.addRule("underline", {
filter: ["u"],
replacement: function (content) {
return "__" + content + "__"
}
})
turndownService.addRule("blockquote", {
filter: "blockquote",
replacement: function (content) {
content = content.replace(/^\n+|\n+$/g, "")
content = content.replace(/^/gm, "> ")
return content
}
})
turndownService.addRule("spoiler", {
filter: function (node, options) {
return node.tagName === "SPAN" && node.hasAttribute("data-mx-spoiler")
},
replacement: function (content, node) {
if (node.getAttribute("data-mx-spoiler")) {
// escape parentheses so it can't become a link
return `\\(${node.getAttribute("data-mx-spoiler")}\\) ||${content}||`
}
return `||${content}||`
}
})
turndownService.addRule("inlineLink", {
filter: function (node, options) {
return (
node.nodeName === "A" &&
node.getAttribute("href")
)
},
replacement: function (content, node) {
if (node.getAttribute("data-user-id")) {
const user_id = node.getAttribute("data-user-id")
const row = select("sim_proxy", ["displayname", "proxy_owner_id"], {user_id}).get()
if (row) {
return `**@${row.displayname}** (<@${row.proxy_owner_id}>)`
} else {
return `<@${user_id}>`
}
}
if (node.getAttribute("data-message-id")) return `https://discord.com/channels/${node.getAttribute("data-guild-id")}/${node.getAttribute("data-channel-id")}/${node.getAttribute("data-message-id")}`
if (node.getAttribute("data-channel-id")) return `<#${node.getAttribute("data-channel-id")}>`
const href = node.getAttribute("href")
content = content.replace(/ @.*/, "")
if (href === content) return href
if (href.startsWith("https://matrix.to/#/@") && content[0] !== "@") content = "@" + content
return "[" + content + "](" + href + ")"
}
})
turndownService.addRule("listItem", {
filter: "li",
replacement: function (content, node, options) {
content = content
.replace(/^\n+/, "") // remove leading newlines
.replace(/\n+$/, "\n") // replace trailing newlines with just a single one
.replace(/\n/gm, "\n ") // indent
var prefix = options.bulletListMarker + " "
var parent = node.parentNode
if (parent.nodeName === "OL") {
var start = parent.getAttribute("start")
var index = Array.prototype.indexOf.call(parent.children, node)
prefix = (start ? Number(start) + index : index + 1) + ". "
}
return prefix + content + (node.nextSibling && !/\n$/.test(content) ? "\n" : "")
}
})
/** @type {string[]} SPRITE SHEET EMOJIS FEATURE: mxc urls for the currently processing message */
let endOfMessageEmojis = []
turndownService.addRule("emoji", {
filter: function (node, options) {
if (node.nodeName !== "IMG" || !node.hasAttribute("data-mx-emoticon") || !node.getAttribute("src") || !node.getAttribute("title")) return false
return true
},
replacement: function (content, node) {
const mxcUrl = node.getAttribute("src")
const guessedName = node.getAttribute("title").replace(/^:|:$/g, "")
return convertEmoji(mxcUrl, guessedName, true, true)
}
})
turndownService.addRule("fencedCodeBlock", {
filter: function (node, options) {
return (
options.codeBlockStyle === "fenced" &&
node.nodeName === "PRE" &&
node.firstChild &&
node.firstChild.nodeName === "CODE"
)
},
replacement: function (content, node, options) {
const className = node.firstChild.getAttribute("class") || ""
const language = (className.match(/language-(\S+)/) || [null, ""])[1]
const code = node.firstChild
const visibleCode = getCodeContent(code)
var fence = "```"
return (
fence + language + "\n" +
visibleCode +
"\n" + fence
)
}
})
/** @param {{ childNodes: Node[]; }} preCode the <code> directly inside the <pre> */
function getCodeContent(preCode) {
return preCode.childNodes.map(c => c.nodeName === "BR" ? "\n" : c.textContent).join("").replace(/\n*$/g, "")
}
/**
* @param {string | null} mxcUrl
* @param {string | null} nameForGuess without colons
* @param {boolean} allowSpriteSheetIndicator
* @param {boolean} allowLink
* @returns {string} discord markdown that represents the custom emoji in some form
*/
function convertEmoji(mxcUrl, nameForGuess, allowSpriteSheetIndicator, allowLink) {
// Get the known emoji from the database.
let row
if (mxcUrl) row = select("emoji", ["emoji_id", "name", "animated"], {mxc_url: mxcUrl}).get()
// Now we have to search all servers to see if we're able to send this emoji.
if (row) {
const found = [...discord.guilds.values()].find(g => g.emojis.find(e => e.id === row.id))
if (!found) row = null
}
// Or, if we don't have an emoji right now, we search for the name instead.
if (!row && nameForGuess) {
const nameForGuessLower = nameForGuess.toLowerCase()
for (const guild of discord.guilds.values()) {
/** @type {{name: string, id: string, animated: number}[]} */
// @ts-ignore
const emojis = guild.emojis
const found = emojis.find(e => e.id === row?.id || e.name?.toLowerCase() === nameForGuessLower)
if (found) {
row = {
animated: found.animated,
emoji_id: found.id,
name: found.name
}
break
}
}
}
if (row) {
// We know an emoji, and we can use it
const animatedChar = row.animated ? "a" : ""
return `<${animatedChar}:${row.name}:${row.emoji_id}>`
} else if (allowSpriteSheetIndicator && mxcUrl && endOfMessageEmojis.includes(mxcUrl)) {
// We can't locate or use a suitable emoji. After control returns, it will rewind over this, delete this section, and upload the emojis as a sprite sheet.
return `<::>`
} else if (allowLink && mxcUrl && nameForGuess) {
// We prefer not to upload this as a sprite sheet because the emoji is not at the end of the message, it is in the middle.
return `[:${nameForGuess}:](${mxUtils.getPublicUrlForMxc(mxcUrl)})`
} else if (nameForGuess) {
return `:${nameForGuess}:`
} else {
return ""
}
}
/**
* @param {string} roomID
* @param {string} mxid
* @returns {Promise<{displayname?: string?, avatar_url?: string?}>}
*/
async function getMemberFromCacheOrHomeserver(roomID, mxid, api) {
const row = select("member_cache", ["displayname", "avatar_url"], {room_id: roomID, mxid}).get()
if (row) return row
return api.getStateEvent(roomID, "m.room.member", mxid).then(event => {
db.prepare("REPLACE INTO member_cache (room_id, mxid, displayname, avatar_url) VALUES (?, ?, ?, ?)").run(roomID, mxid, event?.displayname || null, event?.avatar_url || null)
return event
}).catch(() => {
return {displayname: null, avatar_url: null}
})
}
/**
* Splits a display name into one chunk containing <=80 characters, and another chunk containing the rest of the characters. Splits on
* whitespace if possible.
* These chunks, respectively, go in the display name, and at the top of the message.
* If the second part isn't empty, it'll also contain boldening markdown and a line break at the end, so that regardless of its value it
* can be prepended to the message content as-is.
* @summary Splits too-long Matrix names into a display name chunk and a message content chunk.
* @param {string} displayName - The Matrix side display name to chop up.
* @returns {[string, string]} [shortened display name, display name runoff]
*/
function splitDisplayName(displayName) {
/** @type {string[]} */
let displayNameChunks = chunk(displayName, 80)
if (displayNameChunks.length === 1) {
return [displayName, ""]
} else {
const displayNamePreRunoff = displayNameChunks[0]
// displayNameRunoff is a slice of the original rather than a concatenation of the rest of the chunks in order to preserve whatever whitespace it was broken on.
const displayNameRunoff = `**${displayName.slice(displayNamePreRunoff.length + 1)}**\n`
return [displayNamePreRunoff, displayNameRunoff]
}
}
/**
* Convert a Matrix user ID into a Discord user ID for mentioning, where if the user is a PK proxy, it will mention the proxy owner.
* @param {string} mxid
*/
function getUserOrProxyOwnerID(mxid) {
const row = from("sim").join("sim_proxy", "user_id", "left").select("user_id", "proxy_owner_id").where({mxid}).get()
if (!row) return null
return row.proxy_owner_id || row.user_id
}
/**
* At the time of this executing, we know what the end of message emojis are, and we know that at least one of them is unknown.
* This function will strip them from the content and generate the correct pending file of the sprite sheet.
* @param {string} content
* @param {{id: string, name: string}[]} attachments
* @param {({name: string, url: string} | {name: string, url: string, key: string, iv: string} | {name: string, buffer: Buffer})[]} pendingFiles
*/
async function uploadEndOfMessageSpriteSheet(content, attachments, pendingFiles) {
if (!content.includes("<::>")) return content // No unknown emojis, nothing to do
// Remove known and unknown emojis from the end of the message
const r = /<a?:[a-zA-Z0-9_]*:[0-9]*>\s*$/
while (content.match(r)) {
content = content.replace(r, "")
}
// Create a sprite sheet of known and unknown emojis from the end of the message
const buffer = await emojiSheet.compositeMatrixEmojis(endOfMessageEmojis)
// Attach it
const name = "emojis.png"
attachments.push({id: String(attachments.length), name})
pendingFiles.push({name, buffer})
return content
}
/**
* @param {string} input
* @param {{api: import("../../matrix/api")}} di simple-as-nails dependency injection for the matrix API
*/
async function handleRoomOrMessageLinks(input, di) {
let offset = 0
for (const match of [...input.matchAll(/("?https:\/\/matrix.to\/#\/(![^"/, ?)]+)(?:\/(\$[^"/ ?)]+))?(?:\?[^",:!? )]*)?)(">|[, )]|$)/g)]) {
assert(typeof match.index === "number")
const [_, attributeValue, roomID, eventID, endMarker] = match
let result
const resultType = endMarker === '">' ? "html" : "plain"
const MAKE_RESULT = {
ROOM_LINK: {
html: channelID => `${attributeValue}" data-channel-id="${channelID}">`,
plain: channelID => `<#${channelID}>${endMarker}`
},
MESSAGE_LINK: {
html: (guildID, channelID, messageID) => `${attributeValue}" data-channel-id="${channelID}" data-guild-id="${guildID}" data-message-id="${messageID}">`,
plain: (guildID, channelID, messageID) => `https://discord.com/channels/${guildID}/${channelID}/${messageID}${endMarker}`
}
}
// Don't process links that are part of the reply fallback, they'll be removed entirely by turndown
if (input.slice(match.index + match[0].length + offset).startsWith("In reply to")) continue
const channelID = select("channel_room", "channel_id", {room_id: roomID}).pluck().get()
if (!channelID) continue
if (!eventID) {
// 1: It's a room link, so <#link> to the channel
result = MAKE_RESULT.ROOM_LINK[resultType](channelID)
} else {
// Linking to a particular event with a discord.com/channels/guildID/channelID/messageID link
// Need to know the guildID and messageID
const guildID = discord.channels.get(channelID)?.["guild_id"]
if (!guildID) continue
const messageID = select("event_message", "message_id", {event_id: eventID}).pluck().get()
if (messageID) {
// 2: Linking to a known event
result = MAKE_RESULT.MESSAGE_LINK[resultType](guildID, channelID, messageID)
} else {
// 3: Linking to an unknown event that OOYE didn't originally bridge - we can guess messageID from the timestamp
let originalEvent
try {
originalEvent = await di.api.getEvent(roomID, eventID)
} catch (e) {
continue // Our homeserver doesn't know about the event, so can't resolve it to a Discord link
}
const guessedMessageID = dUtils.timestampToSnowflakeInexact(originalEvent.origin_server_ts)
result = MAKE_RESULT.MESSAGE_LINK[resultType](guildID, channelID, guessedMessageID)
}
}
input = input.slice(0, match.index + offset) + result + input.slice(match.index + match[0].length + offset)
offset += result.length - match[0].length
}
return input
}
/**
* @param {string} content
* @param {DiscordTypes.APIGuild} guild
* @param {{api: import("../../matrix/api"), snow: import("snowtransfer").SnowTransfer, fetch: import("node-fetch")["default"]}} di
*/
async function checkWrittenMentions(content, guild, di) {
let writtenMentionMatch = content.match(/(?:^|[^"[<>/A-Za-z0-9])@([A-Za-z][A-Za-z0-9._\[\]\(\)-]+):?/d) // /d flag for indices requires node.js 16+
if (writtenMentionMatch) {
const results = await di.snow.guild.searchGuildMembers(guild.id, {query: writtenMentionMatch[1]})
if (results[0]) {
assert(results[0].user)
return {
// @ts-ignore - typescript doesn't know about indices yet
content: content.slice(0, writtenMentionMatch.indices[1][0]-1) + `<@${results[0].user.id}>` + content.slice(writtenMentionMatch.indices[1][1]),
ensureJoined: results[0].user
}
}
}
}
/**
* @param {Element} node
* @param {string[]} tagNames allcaps tag names
* @returns {any | undefined} the node you were checking for, or undefined
*/
function nodeIsChildOf(node, tagNames) {
// @ts-ignore
for (; node; node = node.parentNode) if (tagNames.includes(node.tagName)) return node
}
const attachmentEmojis = new Map([
["m.image", "🖼️"],
["m.video", "🎞️"],
["m.audio", "🎶"],
["m.file", "📄"]
])
/**
* @param {Ty.Event.Outer_M_Room_Message | Ty.Event.Outer_M_Room_Message_File | Ty.Event.Outer_M_Sticker | Ty.Event.Outer_M_Room_Message_Encrypted_File} event
* @param {import("discord-api-types/v10").APIGuild} guild
* @param {{api: import("../../matrix/api"), snow: import("snowtransfer").SnowTransfer, fetch: import("node-fetch")["default"]}} di simple-as-nails dependency injection for the matrix API
*/
async function eventToMessage(event, guild, di) {
/** @type {(DiscordTypes.RESTPostAPIWebhookWithTokenJSONBody & {files?: {name: string, file: Buffer | Readable}[]})[]} */
let messages = []
let displayName = event.sender
let avatarURL = undefined
/** @type {string[]} */
let messageIDsToEdit = []
let replyLine = ""
// Extract a basic display name from the sender
const match = event.sender.match(/^@(.*?):/)
if (match) displayName = match[1]
// Try to extract an accurate display name and avatar URL from the member event
const member = await getMemberFromCacheOrHomeserver(event.room_id, event.sender, di?.api)
if (member.displayname) displayName = member.displayname
if (member.avatar_url) avatarURL = mxUtils.getPublicUrlForMxc(member.avatar_url) || undefined
// If the display name is too long to be put into the webhook (80 characters is the maximum),
// put the excess characters into displayNameRunoff, later to be put at the top of the message
let [displayNameShortened, displayNameRunoff] = splitDisplayName(displayName)
// If the message type is m.emote, the full name is already included at the start of the message, so remove any runoff
if (event.type === "m.room.message" && event.content.msgtype === "m.emote") {
displayNameRunoff = ""
}
let content = event.content.body // ultimate fallback
const attachments = []
/** @type {({name: string, url: string} | {name: string, url: string, key: string, iv: string} | {name: string, buffer: Buffer})[]} */
const pendingFiles = []
/** @type {DiscordTypes.APIUser[]} */
const ensureJoined = []
// Convert content depending on what the message is
if (event.type === "m.room.message" && (event.content.msgtype === "m.text" || event.content.msgtype === "m.emote")) {
// Handling edits. If the edit was an edit of a reply, edits do not include the reply reference, so we need to fetch up to 2 more events.
// this event ---is an edit of--> original event ---is a reply to--> past event
await (async () => {
// Check if there is an edit
const relatesTo = event.content["m.relates_to"]
if (!event.content["m.new_content"] || !relatesTo || relatesTo.rel_type !== "m.replace") return
// Check if we have a pointer to what was edited
const originalEventId = relatesTo.event_id
if (!originalEventId) return
messageIDsToEdit = select("event_message", "message_id", {event_id: originalEventId}, "ORDER BY part").pluck().all()
if (!messageIDsToEdit.length) return
// Ok, it's an edit.
event.content = event.content["m.new_content"]
// Is it editing a reply? We need special handling if it is.
// Get the original event, then check if it was a reply
const originalEvent = await di.api.getEvent(event.room_id, originalEventId)
if (!originalEvent) return
const repliedToEventId = originalEvent.content["m.relates_to"]?.["m.in_reply_to"]?.event_id
if (!repliedToEventId) return
// After all that, it's an edit of a reply.
// We'll be sneaky and prepare the message data so that the next steps can handle it just like original messages.
Object.assign(event.content, {
"m.relates_to": {
"m.in_reply_to": {
event_id: repliedToEventId
}
}
})
})()
// Handling replies. We'll look up the data of the replied-to event from the Matrix homeserver.
// Note that an <mx-reply> element is not guaranteed because this might be m.new_content.
await (async () => {
const repliedToEventId = event.content["m.relates_to"]?.["m.in_reply_to"]?.event_id
if (!repliedToEventId) return
let repliedToEvent
try {
repliedToEvent = await di.api.getEvent(event.room_id, repliedToEventId)
} catch (e) {
// Original event isn't on our homeserver, so we'll *partially* trust the client's reply fallback.
// We'll trust the fallback's quoted content and put it in the reply preview, but we won't trust the authorship info on it.
// (But if the fallback's quoted content doesn't exist, we give up. There's nothing for us to quote.)
if (event.content["format"] !== "org.matrix.custom.html" || typeof event.content["formatted_body"] !== "string") {
const lines = event.content.body.split("\n")
let stage = 0
for (let i = 0; i < lines.length; i++) {
if (stage >= 0 && lines[i][0] === ">") stage = 1
if (stage >= 1 && lines[i].trim() === "") stage = 2
if (stage === 2 && lines[i].trim() !== "") {
event.content.body = lines.slice(i).join("\n")
break
}
}
return
}
const mxReply = event.content["formatted_body"]
const quoted = mxReply.match(/^<mx-reply><blockquote>.*?In reply to.*?<br>(.*)<\/blockquote><\/mx-reply>/)?.[1]
if (!quoted) return
const contentPreviewChunks = chunk(
entities.decodeHTML5Strict( // Remove entities like &amp; &quot;
quoted.replace(/^\s*<blockquote>.*?<\/blockquote>(.....)/s, "$1") // If the message starts with a blockquote, don't count it and use the message body afterwards
.replace(/(?:\n|<br>)+/g, " ") // Should all be on one line
.replace(/<span [^>]*data-mx-spoiler\b[^>]*>.*?<\/span>/g, "[spoiler]") // Good enough method of removing spoiler content. (I don't want to break out the HTML parser unless I have to.)
.replace(/<[^>]+>/g, "") // Completely strip all HTML tags and formatting.
), 50)
replyLine = "> " + contentPreviewChunks[0]
if (contentPreviewChunks.length > 1) replyLine = replyLine.replace(/[,.']$/, "") + "..."
replyLine += "\n"
return
}
// @ts-ignore
const autoEmoji = new Map(select("auto_emoji", ["name", "emoji_id"], {}, "WHERE name = 'L1' OR name = 'L2'").raw().all())
replyLine = `<:L1:${autoEmoji.get("L1")}><:L2:${autoEmoji.get("L2")}>`
const row = from("event_message").join("message_channel", "message_id").select("channel_id", "message_id").where({event_id: repliedToEventId}).and("ORDER BY part").get()
if (row) {
replyLine += `https://discord.com/channels/${guild.id}/${row.channel_id}/${row.message_id} `
}
const sender = repliedToEvent.sender
const authorID = getUserOrProxyOwnerID(sender)
if (authorID) {
replyLine += `<@${authorID}>`
} else {
let senderName = select("member_cache", "displayname", {mxid: sender}).pluck().get()
if (!senderName) {
const match = sender.match(/@([^:]*)/)
assert(match)
senderName = match[1]
}
replyLine += `Ⓜ️**${senderName}**`
}
// If the event has been edited, the homeserver will include the relation in `unsigned`.
if (repliedToEvent.unsigned?.["m.relations"]?.["m.replace"]?.content?.["m.new_content"]) {
repliedToEvent = repliedToEvent.unsigned["m.relations"]["m.replace"] // Note: this changes which event_id is in repliedToEvent.
repliedToEvent.content = repliedToEvent.content["m.new_content"]
}
let contentPreview
const fileReplyContentAlternative = attachmentEmojis.get(repliedToEvent.content.msgtype)
if (fileReplyContentAlternative) {
contentPreview = " " + fileReplyContentAlternative
} else if (repliedToEvent.unsigned?.redacted_because) {
contentPreview = " (in reply to a deleted message)"
} else {
// Generate a reply preview for a standard message
/** @type {string} */
let repliedToContent = repliedToEvent.content.formatted_body || repliedToEvent.content.body
repliedToContent = repliedToContent.replace(/.*<\/mx-reply>/s, "") // Remove everything before replies, so just use the actual message body
repliedToContent = repliedToContent.replace(/^\s*<blockquote>.*?<\/blockquote>(.....)/s, "$1") // If the message starts with a blockquote, don't count it and use the message body afterwards
repliedToContent = repliedToContent.replace(/(?:\n|<br>)+/g, " ") // Should all be on one line
repliedToContent = repliedToContent.replace(/<span [^>]*data-mx-spoiler\b[^>]*>.*?<\/span>/g, "[spoiler]") // Good enough method of removing spoiler content. (I don't want to break out the HTML parser unless I have to.)
repliedToContent = repliedToContent.replace(/<img([^>]*)>/g, (_, att) => { // Convert Matrix emoji images into Discord emoji markdown
const mxcUrlMatch = att.match(/\bsrc="(mxc:\/\/[^"]+)"/)
const titleTextMatch = att.match(/\btitle=":?([^:"]+)/)
return convertEmoji(mxcUrlMatch?.[1], titleTextMatch?.[1], false, false)
})
repliedToContent = repliedToContent.replace(/<[^:>][^>]*>/g, "") // Completely strip all HTML tags and formatting.
repliedToContent = entities.decodeHTML5Strict(repliedToContent) // Remove entities like &amp; &quot;
const contentPreviewChunks = chunk(repliedToContent, 50)
if (contentPreviewChunks.length) {
contentPreview = ":\n> " + contentPreviewChunks[0]
if (contentPreviewChunks.length > 1) contentPreview = contentPreview.replace(/[,.']$/, "") + "..."
} else {
console.log("Unable to generate reply preview for this replied-to event because we stripped all of it:", repliedToEvent)
contentPreview = ""
}
}
replyLine = `> ${replyLine}${contentPreview}\n`
})()
if (event.content.format === "org.matrix.custom.html" && event.content.formatted_body) {
let input = event.content.formatted_body
if (event.content.msgtype === "m.emote") {
input = `* ${displayName} ${input}`
}
// Handling mentions of Discord users
input = input.replace(/("https:\/\/matrix.to\/#\/((?:@|%40)[^"]+)")>/g, (whole, attributeValue, mxid) => {
mxid = decodeURIComponent(mxid)
if (mxUtils.eventSenderIsFromDiscord(mxid)) {
// Handle mention of an OOYE sim user by their mxid
const id = select("sim", "user_id", {mxid}).pluck().get()
if (!id) return whole
return `${attributeValue} data-user-id="${id}">`
} else {
// Handle mention of a Matrix user by their mxid
// Check if this Matrix user is actually the sim user from another old bridge in the room?
const match = mxid.match(/[^:]*discord[^:]*_([0-9]{6,}):/) // try to match @_discord_123456, @_discordpuppet_123456, etc.
if (match) return `${attributeValue} data-user-id="${match[1]}">`
// Nope, just a real Matrix user.
return whole
}
})
// Handling mentions of rooms and room-messages
input = await handleRoomOrMessageLinks(input, di)
// Stripping colons after mentions
input = input.replace(/( data-user-id.*?<\/a>):?/g, "$1")
input = input.replace(/("https:\/\/matrix.to.*?<\/a>):?/g, "$1")
// Element adds a bunch of <br> before </blockquote> but doesn't render them. I can't figure out how this even works in the browser, so let's just delete those.
input = input.replace(/(?:\n|<br ?\/?>\s*)*<\/blockquote>/g, "</blockquote>")
// The matrix spec hasn't decided whether \n counts as a newline or not, but I'm going to count it, because if it's in the data it's there for a reason.
// But I should not count it if it's between block elements.
input = input.replace(/(<\/?([^ >]+)[^>]*>)?\n(<\/?([^ >]+)[^>]*>)?/g, (whole, beforeContext, beforeTag, afterContext, afterTag) => {
// console.error(beforeContext, beforeTag, afterContext, afterTag)
if (typeof beforeTag !== "string" && typeof afterTag !== "string") {
return "<br>"
}
beforeContext = beforeContext || ""
beforeTag = beforeTag || ""
afterContext = afterContext || ""
afterTag = afterTag || ""
if (!mxUtils.BLOCK_ELEMENTS.includes(beforeTag.toUpperCase()) && !mxUtils.BLOCK_ELEMENTS.includes(afterTag.toUpperCase())) {
return beforeContext + "<br>" + afterContext
} else {
return whole
}
})
// Note: Element's renderers on Web and Android currently collapse whitespace, like the browser does. Turndown also collapses whitespace which is good for me.
// If later I'm using a client that doesn't collapse whitespace and I want turndown to follow suit, uncomment the following line of code, and it Just Works:
// input = input.replace(/ /g, "&nbsp;")
// There is also a corresponding test to uncomment, named "event2message: whitespace is retained"
// Handling written @mentions: we need to look for candidate Discord members to join to the room
// This shouldn't apply to code blocks, links, or inside attributes. So editing the HTML tree instead of regular expressions is a sensible choice here.
// We're using the domino parser because Turndown uses the same and can reuse this tree.
const doc = domino.createDocument(
// DOM parsers arrange elements in the <head> and <body>. Wrapping in a custom element ensures elements are reliably arranged in a single element.
'<x-turndown id="turndown-root">' + input + '</x-turndown>'
);
const root = doc.getElementById("turndown-root");
async function forEachNode(node) {
for (; node; node = node.nextSibling) {
// Check written mentions
if (node.nodeType === 3 && node.nodeValue.includes("@") && !nodeIsChildOf(node, ["A", "CODE", "PRE"])) {
const result = await checkWrittenMentions(node.nodeValue, guild, di)
if (result) {
node.nodeValue = result.content
ensureJoined.push(result.ensureJoined)
}
}
// Check for incompatible backticks in code blocks
let preNode
if (node.nodeType === 3 && node.nodeValue.includes("```") && (preNode = nodeIsChildOf(node, ["PRE"]))) {
if (preNode.firstChild?.nodeName === "CODE") {
const ext = (preNode.firstChild.className.match(/language-(\S+)/) || [null, "txt"])[1]
const filename = `inline_code.${ext}`
// Build the replacement <code> node
const replacementCode = doc.createElement("code")
replacementCode.textContent = `[${filename}]`
// Build its containing <span> node
const replacement = doc.createElement("span")
replacement.appendChild(doc.createTextNode(" "))
replacement.appendChild(replacementCode)
replacement.appendChild(doc.createTextNode(" "))
// Replace the code block with the <span>
preNode.replaceWith(replacement)
// Upload the code as an attachment
const content = getCodeContent(preNode.firstChild)
attachments.push({id: String(attachments.length), filename})
pendingFiles.push({name: filename, buffer: Buffer.from(content, "utf8")})
}
}
await forEachNode(node.firstChild)
}
}
await forEachNode(root)
// SPRITE SHEET EMOJIS FEATURE: Emojis at the end of the message that we don't know about will be reuploaded as a sprite sheet.
// First we need to determine which emojis are at the end.
endOfMessageEmojis = []
let match
let last = input.length
while ((match = input.slice(0, last).match(/<img [^>]*>\s*$/))) {
if (!match[0].includes("data-mx-emoticon")) break
const mxcUrl = match[0].match(/\bsrc="(mxc:\/\/[^"]+)"/)
if (mxcUrl) endOfMessageEmojis.unshift(mxcUrl[1])
assert(typeof match.index === "number", "Your JavaScript implementation does not comply with TC39: https://tc39.es/ecma262/multipage/text-processing.html#sec-regexpbuiltinexec")
last = match.index
}
// @ts-ignore bad type from turndown
content = turndownService.turndown(root)
// Put < > around any surviving matrix.to links to hide the URL previews
content = content.replace(/\bhttps?:\/\/matrix\.to\/[^ )]*/, "<$&>")
// It's designed for commonmark, we need to replace the space-space-newline with just newline
content = content.replace(/ \n/g, "\n")
// If there's a blockquote at the start of the message body and this message is a reply, they should be visually separated
if (replyLine && content.startsWith("> ")) content = "\n" + content
// SPRITE SHEET EMOJIS FEATURE:
content = await uploadEndOfMessageSpriteSheet(content, attachments, pendingFiles)
} else {
// Looks like we're using the plaintext body!
content = event.content.body
if (event.content.msgtype === "m.emote") {
content = `* ${displayName} ${content}`
}
content = await handleRoomOrMessageLinks(content, di) // Replace matrix.to links with discord.com equivalents where possible
content = content.replace(/\bhttps?:\/\/matrix\.to\/[^ )]*/, "<$&>") // Put < > around any surviving matrix.to links to hide the URL previews
const result = await checkWrittenMentions(content, guild, di)
if (result) {
content = result.content
ensureJoined.push(result.ensureJoined)
}
// Markdown needs to be escaped, though take care not to escape the middle of links
// @ts-ignore bad type from turndown
content = turndownService.escape(content)
}
} else if (event.type === "m.room.message" && (event.content.msgtype === "m.file" || event.content.msgtype === "m.video" || event.content.msgtype === "m.audio" || event.content.msgtype === "m.image")) {
content = ""
const filename = event.content.filename || event.content.body
// A written `event.content.body` will be bridged to Discord's image `description` which is like alt text.
// Bridging as description rather than message content in order to match Matrix clients (Element, Neochat) which treat this as alt text or title text.
const description = (event.content.body !== event.content.filename && event.content.filename && event.content.body) || undefined
if ("url" in event.content) {
// Unencrypted
const url = mxUtils.getPublicUrlForMxc(event.content.url)
assert(url)
attachments.push({id: "0", description, filename})
pendingFiles.push({name: filename, url})
} else {
// Encrypted
const url = mxUtils.getPublicUrlForMxc(event.content.file.url)
assert(url)
assert.equal(event.content.file.key.alg, "A256CTR")
attachments.push({id: "0", description, filename})
pendingFiles.push({name: filename, url, key: event.content.file.key.k, iv: event.content.file.iv})
}
} else if (event.type === "m.sticker") {
content = ""
const url = mxUtils.getPublicUrlForMxc(event.content.url)
assert(url)
let filename = event.content.body
if (event.type === "m.sticker") {
let mimetype
if (event.content.info?.mimetype?.includes("/")) {
mimetype = event.content.info.mimetype
} else {
const res = await di.fetch(url, {method: "HEAD"})
if (res.status === 200) {
mimetype = res.headers.get("content-type")
}
if (!mimetype) throw new Error(`Server error ${res.status} or missing content-type while detecting sticker mimetype`)
}
filename += "." + mimetype.split("/")[1]
}
attachments.push({id: "0", filename})
pendingFiles.push({name: filename, url})
}
content = displayNameRunoff + replyLine + content
// Split into 2000 character chunks
const chunks = chunk(content, 2000)
messages = messages.concat(chunks.map(content => ({
content,
username: displayNameShortened,
avatar_url: avatarURL
})))
if (attachments.length) {
// If content is empty (should be the case when uploading a file) then chunk-text will create 0 messages.
// There needs to be a message to add attachments to.
if (!messages.length) messages.push({
content,
username: displayNameShortened,
avatar_url: avatarURL
})
messages[0].attachments = attachments
// @ts-ignore these will be converted to real files when the message is about to be sent
messages[0].pendingFiles = pendingFiles
}
const messagesToEdit = []
const messagesToSend = []
for (let i = 0; i < messages.length; i++) {
const next = messageIDsToEdit[0]
if (next) {
messagesToEdit.push({id: next, message: messages[i]})
messageIDsToEdit.shift()
} else {
messagesToSend.push(messages[i])
}
}
// Ensure there is code coverage for adding, editing, and deleting
if (messagesToSend.length) void 0
if (messagesToEdit.length) void 0
if (messageIDsToEdit.length) void 0
return {
messagesToEdit,
messagesToSend,
messagesToDelete: messageIDsToEdit,
ensureJoined
}
}
module.exports.eventToMessage = eventToMessage