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

241 lines
9.2 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 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"
]
function cleanAttribute (attribute) {
return attribute ? attribute.replace(/(\n+\s*)+/g, "\n") : ""
}
const turndownService = new TurndownService({
hr: "----",
headingStyle: "atx",
preformattedCode: true,
codeBlockStyle: "fenced"
})
turndownService.remove("mx-reply")
turndownService.addRule("strikethrough", {
filter: ["del", "s", "strike"],
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+$/g, "")
content = content.replace(/^/gm, "> ")
return content
}
})
turndownService.addRule("inlineLink", {
filter: function (node, options) {
return (
options.linkStyle === "inlined" &&
node.nodeName === "A" &&
node.getAttribute("href")
)
},
replacement: function (content, node) {
if (node.getAttribute("data-user-id")) return `<@${node.getAttribute("data-user-id")}>`
if (node.getAttribute("data-channel-id")) return `<#${node.getAttribute("data-channel-id")}>`
const href = node.getAttribute("href")
let title = cleanAttribute(node.getAttribute("title"))
if (title) title = ` "` + title + `"`
let brackets = ["", ""]
if (href.startsWith("https://matrix.to")) brackets = ["<", ">"]
return "[" + content + "](" + brackets[0] + href + title + brackets[1] + ")"
}
})
turndownService.addRule("fencedCodeBlock", {
filter: function (node, options) {
return (
options.codeBlockStyle === "fenced" &&
node.nodeName === "PRE" &&
node.firstChild &&
node.firstChild.nodeName === "CODE"
)
},
replacement: function (content, node, options) {
const className = node.firstChild.getAttribute("class") || ""
const language = (className.match(/language-(\S+)/) || [null, ""])[1]
const code = node.firstChild
const visibleCode = code.childNodes.map(c => c.nodeName === "BR" ? "\n" : c.textContent).join("").replace(/\n*$/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}
})
}
/**
* @param {Ty.Event.Outer<Ty.Event.M_Room_Message>} 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
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)
// Convert content depending on what the message is
let content = event.content.body // ultimate fallback
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} ${input}`
}
// Note: Element's renderers on Web and Android currently collapse whitespace, like the browser does. Turndown also collapses whitespace which is good for me.
// If later I'm using a client that doesn't collapse whitespace and I want turndown to follow suit, uncomment the following line of code, and it Just Works:
// input = input.replace(/ /g, "&nbsp;")
// There is also a corresponding test to uncomment, named "event2message: whitespace is retained"
// Handling replies. We'll look up the data of the replied-to event from the Matrix homeserver.
await (async () => {
const repliedToEventId = event.content["m.relates_to"]?.["m.in_reply_to"].event_id
if (!repliedToEventId) return
const repliedToEvent = await di.api.getEvent(event.room_id, repliedToEventId)
if (!repliedToEvent) return
const row = db.prepare("SELECT channel_id, message_id FROM event_message WHERE event_id = ? ORDER BY part").get(repliedToEventId)
if (row) {
replyLine = `<:L1:1144820033948762203><:L2:1144820084079087647>https://discord.com/channels/${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}**: `
}
const repliedToContent = repliedToEvent.content.formatted_body || repliedToEvent.content.body
const contentPreviewChunks = chunk(repliedToContent.replace(/.*<\/mx-reply>/, "").replace(/(?:\n|<br>)+/g, " ").replace(/<[^>]+>/g, ""), 24)
const contentPreview = contentPreviewChunks.length > 1 ? contentPreviewChunks[0] + "..." : contentPreviewChunks[0]
replyLine += contentPreview + "\n"
})()
// 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
}
})
// @ts-ignore bad type from turndown
content = turndownService.turndown(input)
// It's optimised 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!
// Markdown needs to be escaped
content = content.replace(/([*_~`#])/g, `\\$1`)
}
content = replyLine + content
// Split into 2000 character chunks
const chunks = chunk(content, 2000)
messages = messages.concat(chunks.map(content => ({
content,
username: displayName,
avatar_url: avatarURL
})))
return messages
}
module.exports.eventToMessage = eventToMessage