import { encodeBase64 } from "https://deno.land/std@0.224.0/encoding/base64.ts"; import { email as stdEmail } from "https://esm.town/v/std/email"; import { requestAsObject } from "https://esm.town/v/wilt/serializeRequest"; import { imageSize } from "npm:image-size"; export interface IEmailHandlerProps { /** * If set, sends confirmation messages to whichever email address sent the email. * This will only work for pro accounts! */ replyToSender: boolean; /** Optionally customize the name displayed on email confirmation messages */ emailAlias?: string; /** * List of email addresses which are allowed to use the service * Pass ["*"] to allow any address */ senderAllowlist: string[]; /** * URL of your discord webhook. * Treat this like a secret, or trolls will use it to send you spam! */ webhookUrl: string; } interface IImage { url: string; height?: number; width?: number; } interface IEmbed { title?: string; description?: string; url?: string; footer?: { text: string }; image?: IImage; video?: IImage; provider?: { name?: string; url?: string }; } interface IAttachment { id: number; description?: string; filename: string; } interface IHook { username: string; embeds: IEmbed[]; attachments?: IAttachment[]; } // https://discord.com/developers/docs/reference#editing-message-attachments-using-attachments-within-embeds const VALID_UPLOAD_FILETYPES = [".jpg", ".jpeg", ".png", ".webp", ".gif"]; export function getEmailHandler( { emailAlias, replyToSender, senderAllowlist, webhookUrl, }: IEmailHandlerProps, ): (email: Email) => Promise { const isAuthorized = senderAllowlist.includes("*") ? () => true : (from: string): boolean => senderAllowlist.some(x => from.includes(x)); return async function(incomingEmail: Email) { console.log({ incomingEmail }); if (!incomingEmail.from) { throw new Error("No sender found"); } const sendEmail = async (message: string): Promise => replyToSender && stdEmail({ to: incomingEmail.from, replyTo: incomingEmail.from, from: { name: emailAlias || "Discord Forwarder", email: incomingEmail.to }, subject: "RE: " + incomingEmail.subject, ...(!!incomingEmail.html ? { html: `

${message}

${incomingEmail.html}

` } : { text: message + incomingEmail.text }), }); if (!isAuthorized(incomingEmail.from)) { console.log("Unauthorized sender:", incomingEmail.from); await sendEmail("You aren't on the list!"); throw new Error("Unauthorized sender"); } /* const mainHook = new Webhook(webhookUrl); const hooks = [mainHook]; let lastHook = mainHook; const addEmbed = (newEmbed: InstanceType) => { if (lastHook.embeds.length >= 10) { lastHook = new Webhook(webhookUrl); hooks.push(lastHook); } lastHook.addEmbed(newEmbed); }; */ const contentEmbed: IEmbed = { title: incomingEmail.subject, description: incomingEmail.text, }; const baseHook: IHook = { username: incomingEmail.from, embeds: [contentEmbed], }; const attachmentErrorMsgs = []; const sizedAttachments = incomingEmail.attachments.filter(file => file.size < 1048576); if (sizedAttachments.length < incomingEmail.attachments.length) { attachmentErrorMsgs.push("Some attachments were too large to include"); } const fileTypedAttachments = sizedAttachments.filter(file => VALID_UPLOAD_FILETYPES.some(type => file.name.endsWith(type)) ); if (fileTypedAttachments.length < sizedAttachments.length) { attachmentErrorMsgs.push( "Some attachments could not be uploaded because their filetype is not supported by Discord", ); } if (attachmentErrorMsgs.length > 0) { contentEmbed.footer = { text: attachmentErrorMsgs.join("; ") }; } const fileHooks: RequestInit[] = await Promise.all(sizedAttachments.map(async (file) => { const embed: IEmbed = { image: { url: "attachment://" + file.name } }; const boundary = "--boundary"; const buf = await file.arrayBuffer(); const fileData = encodeBase64(buf); const body = [ boundary, "Content-Disposition: form-data; name=\"payload_json\"", "Content-Type: application/json", "", JSON.stringify({ embeds: [embed], attachments: [{ id: 0, filename: file.name }] }), boundary, `Content-Disposition: form-data; name="files[0]";filename="${file.name}"`, `Content-Type: ${file.type}`, "Content-transfer-encoding: base64", "", fileData, boundary + "--", ].join("\r\n"); return { method: "POST", headers: { "Content-Type": "multipart/form-data" }, body, }; })); const hooks: RequestInit[] = [{ method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify(baseHook), }, ...fileHooks]; let someError = false; for (const hook of hooks) { try { const resp = await sendWithRateLimit(webhookUrl, hook); console.log(resp); if (!resp.ok) { someError = true; } } catch (e) { console.log("Error sending hook", hook, (e as Error)?.message); someError = true; } } if (someError) { await sendEmail("Something went wrong! See log for more information."); throw new Error(); } await sendEmail("Your email has been successfully posted to Discord!"); }; } // https://discord.com/developers/docs/resources/webhook#execute-webhook // https://discord.com/developers/docs/topics/rate-limits async function sendWithRateLimit(url: string, init: RequestInit): Promise { const resp = await fetch(url + "?wait=true", init); if (resp.status === 429) { const retryAfter = resp.headers.get("Retry-After"); if (!retryAfter) { throw new Error("Rate limited with no Retry-After header"); } const timeout = parseInt(retryAfter, 10) * 1000; if (Number.isNaN(timeout)) { throw new Error("Rate limited with invalid Retry-After header"); } return new Promise((resolve, reject) => setTimeout(() => resolve(sendWithRateLimit(url, body)), timeout)); } return resp; }

emailToDiscordWebhook

Version 2