out-of-your-element/m2d/converters/event-to-message.js

446 lines
18 KiB
JavaScript

// @ts-check
const Ty = require("../../types")
const DiscordTypes = require("discord-api-types/v10")
const chunk = require("chunk-text")
const TurndownService = require("turndown")
const assert = require("assert").strict
const passthrough = require("../../passthrough")
const { sync, db, discord } = passthrough
/** @type {import("../../matrix/file")} */
const file = sync.require("../../matrix/file")
/** @type {import("../converters/utils")} */
const utils = sync.require("../converters/utils")
const BLOCK_ELEMENTS = [
"ADDRESS", "ARTICLE", "ASIDE", "AUDIO", "BLOCKQUOTE", "BODY", "CANVAS",
"CENTER", "DD", "DETAILS", "DIR", "DIV", "DL", "DT", "FIELDSET", "FIGCAPTION", "FIGURE",
"FOOTER", "FORM", "FRAMESET", "H1", "H2", "H3", "H4", "H5", "H6", "HEADER",
"HGROUP", "HR", "HTML", "ISINDEX", "LI", "MAIN", "MENU", "NAV", "NOFRAMES",
"NOSCRIPT", "OL", "OUTPUT", "P", "PRE", "SECTION", "SUMMARY", "TABLE", "TBODY", "TD",
"TFOOT", "TH", "THEAD", "TR", "UL"
]
/** @type {[RegExp, string][]} */
const markdownEscapes = [
[/\\/g, '\\\\'],
[/\*/g, '\\*'],
[/^-/g, '\\-'],
[/^\+ /g, '\\+ '],
[/^(=+)/g, '\\$1'],
[/^(#{1,6}) /g, '\\$1 '],
[/`/g, '\\`'],
[/^~~~/g, '\\~~~'],
[/\[/g, '\\['],
[/\]/g, '\\]'],
[/^>/g, '\\>'],
[/_/g, '\\_'],
[/^(\d+)\. /g, '$1\\. ']
]
const turndownService = new TurndownService({
hr: "----",
headingStyle: "atx",
preformattedCode: true,
codeBlockStyle: "fenced",
})
/**
* Markdown characters in the HTML content need to be escaped, though take care not to escape the middle of bare links
* @param {string} string
*/
// @ts-ignore bad type from turndown
turndownService.escape = function (string) {
const escapedWords = string.split(" ").map(word => {
if (word.match(/^https?:\/\//)) {
return word
} else {
return markdownEscapes.reduce(function (accumulator, escape) {
return accumulator.replace(escape[0], escape[1])
}, word)
}
})
return escapedWords.join(" ")
}
turndownService.remove("mx-reply")
turndownService.addRule("strikethrough", {
filter: ["del", "s"],
replacement: function (content) {
return "~~" + content + "~~"
}
})
turndownService.addRule("underline", {
filter: ["u"],
replacement: function (content) {
return "__" + content + "__"
}
})
turndownService.addRule("blockquote", {
filter: "blockquote",
replacement: function (content) {
content = content.replace(/^\n+|\n+$/g, "")
content = content.replace(/^/gm, "> ")
return content
}
})
turndownService.addRule("spoiler", {
filter: function (node, options) {
return node.hasAttribute("data-mx-spoiler")
},
replacement: function (content, node) {
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")) return `<@${node.getAttribute("data-user-id")}>`
if (node.getAttribute("data-channel-id")) return `<#${node.getAttribute("data-channel-id")}>`
const href = node.getAttribute("href")
let brackets = ["", ""]
if (href.startsWith("https://matrix.to")) brackets = ["<", ">"]
return "[" + content + "](" + brackets[0] + href + brackets[1] + ")"
}
})
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 = code.childNodes.map(c => c.nodeName === "BR" ? "\n" : c.textContent).join("").replace(/\n*$/g, "")
var fence = "```"
return (
fence + language + "\n" +
visibleCode +
"\n" + fence
)
}
})
/**
* @param {string} roomID
* @param {string} mxid
* @returns {Promise<{displayname?: string?, avatar_url?: string?}>}
*/
async function getMemberFromCacheOrHomeserver(roomID, mxid, api) {
const row = db.prepare("SELECT displayname, avatar_url FROM member_cache WHERE room_id = ? AND mxid = ?").get(roomID, mxid)
if (row) return row
return api.getStateEvent(roomID, "m.room.member", mxid).then(event => {
db.prepare("REPLACE INTO member_cache (room_id, mxid, displayname, avatar_url) VALUES (?, ?, ?, ?)").run(roomID, mxid, event?.displayname || null, event?.avatar_url || null)
return event
}).catch(() => {
return {displayname: null, avatar_url: null}
})
}
/**
* Splits a display name into one chunk containing <=80 characters, and another chunk containing the rest of the characters. Splits on
* whitespace if possible.
* These chunks, respectively, go in the display name, and at the top of the message.
* If the second part isn't empty, it'll also contain boldening markdown and a line break at the end, so that regardless of its value it
* can be prepended to the message content as-is.
* @summary Splits too-long Matrix names into a display name chunk and a message content chunk.
* @param {string} displayName - The Matrix side display name to chop up.
* @returns {[string, string]} [shortened display name, display name runoff]
*/
function splitDisplayName(displayName) {
/** @type {string[]} */
let displayNameChunks = chunk(displayName, 80)
if (displayNameChunks.length === 1) {
return [displayName, ""]
} else {
const displayNamePreRunoff = displayNameChunks[0]
// displayNameRunoff is a slice of the original rather than a concatenation of the rest of the chunks in order to preserve whatever whitespace it was broken on.
const displayNameRunoff = `**${displayName.slice(displayNamePreRunoff.length + 1)}**\n`
return [displayNamePreRunoff, displayNameRunoff]
}
}
/**
* @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")}} di simple-as-nails dependency injection for the matrix API
*/
async function eventToMessage(event, guild, di) {
/** @type {(DiscordTypes.RESTPostAPIWebhookWithTokenJSONBody & {files?: {name: string, file: Buffer}[]})[]} */
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 = utils.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})[]} */
const pendingFiles = []
// 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 () => {
if (!event.content["m.new_content"]) return
const relatesTo = event.content["m.relates_to"]
if (!relatesTo) return
// Check if we have a pointer to what was edited
const relType = relatesTo.rel_type
if (relType !== "m.replace") return
const originalEventId = relatesTo.event_id
if (!originalEventId) return
messageIDsToEdit = db.prepare("SELECT message_id FROM event_message WHERE event_id = ? ORDER BY part").pluck().all(originalEventId)
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 = await di.api.getEvent(event.room_id, repliedToEventId)
if (!repliedToEvent) return
const row = db.prepare("SELECT channel_id, message_id FROM event_message INNER JOIN message_channel USING (message_id) WHERE event_id = ? ORDER BY part").get(repliedToEventId)
if (row) {
replyLine = `<:L1:1144820033948762203><:L2:1144820084079087647>https://discord.com/channels/${guild.id}/${row.channel_id}/${row.message_id} `
} else {
replyLine = `<:L1:1144820033948762203><:L2:1144820084079087647>`
}
const sender = repliedToEvent.sender
const senderName = sender.match(/@([^:]*)/)?.[1] || sender
const authorID = db.prepare("SELECT discord_id FROM sim WHERE mxid = ?").pluck().get(repliedToEvent.sender)
if (authorID) {
replyLine += `<@${authorID}>`
} else {
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 =
( repliedToEvent.content.msgtype === "m.image" ? "🖼️"
: repliedToEvent.content.msgtype === "m.video" ? "🎞️"
: repliedToEvent.content.msgtype === "m.audio" ? "🎶"
: repliedToEvent.content.msgtype === "m.file" ? "📄"
: null)
if (fileReplyContentAlternative) {
contentPreview = " " + fileReplyContentAlternative
} else {
const repliedToContent = repliedToEvent.content.formatted_body || repliedToEvent.content.body
const contentPreviewChunks = chunk(
repliedToContent.replace(/.*<\/mx-reply>/, "") // Remove everything before replies, so just use the actual message body
.replace(/.*?<\/blockquote>/, "") // 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, ""), 50) // Completely strip all other formatting.
contentPreview = ":\n> "
contentPreview += contentPreviewChunks.length > 1 ? contentPreviewChunks[0] + "..." : contentPreviewChunks[0]
}
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} ${input}`
}
// Handling mentions of Discord users
input = input.replace(/("https:\/\/matrix.to\/#\/(@[^"]+)")>/g, (whole, attributeValue, mxid) => {
if (!utils.eventSenderIsFromDiscord(mxid)) return whole
const userID = db.prepare("SELECT discord_id FROM sim WHERE mxid = ?").pluck().get(mxid)
if (!userID) return whole
return `${attributeValue} data-user-id="${userID}">`
})
// Handling mentions of Discord rooms
input = input.replace(/("https:\/\/matrix.to\/#\/(![^"]+)")>/g, (whole, attributeValue, roomID) => {
const channelID = db.prepare("SELECT channel_id FROM channel_room WHERE room_id = ?").pluck().get(roomID)
if (!channelID) return whole
return `${attributeValue} data-channel-id="${channelID}">`
})
// 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 (!BLOCK_ELEMENTS.includes(beforeTag.toUpperCase()) && !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"
// @ts-ignore bad type from turndown
content = turndownService.turndown(input)
// It's designed for commonmark, we need to replace the space-space-newline with just newline
content = content.replace(/ \n/g, "\n")
} else {
// Looks like we're using the plaintext body!
content = event.content.body
if (event.content.msgtype === "m.emote") {
content = `* ${displayName} ${content}`
}
// 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.body
if ("url" in event.content) {
// Unencrypted
const url = utils.getPublicUrlForMxc(event.content.url)
assert(url)
attachments.push({id: "0", filename})
pendingFiles.push({name: filename, url})
} else {
// Encrypted
const url = utils.getPublicUrlForMxc(event.content.file.url)
assert(url)
assert.equal(event.content.file.key.alg, "A256CTR")
attachments.push({id: "0", filename})
pendingFiles.push({name: filename, url, key: event.content.file.key.k, iv: event.content.file.iv})
}
} else if (event.type === "m.sticker") {
content = ""
let filename = event.content.body
if (event.type === "m.sticker" && event.content.info.mimetype.includes("/")) {
filename += "." + event.content.info.mimetype.split("/")[1]
}
const url = utils.getPublicUrlForMxc(event.content.url)
assert(url)
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
}
}
module.exports.eventToMessage = eventToMessage