feat: mailer backend (#310)

Author: aster-void

.env.sample

@@ -9,11 +9,14 @@ COOKIE_SIGN_SECRET=128-digit-long-random-generated-secret
 SQL_LOGS=true
 ARTIFICIAL_NETWORK_LATENCY=1500
 
-#cloudflare
+# cloudflare
 CLOUDFLARE_R2_ACCESS_KEY=xxx
 CLOUDFLARE_R2_SECRET_KEY=xxx
 CLOUDFLARE_R2_TOKEN=xxx
 
+# mailing
+MAILING_BREVO_API_KEY=xkeysib-xxx
+
 # web
 NEXT_PUBLIC_API_ENDPOINT=http://localhost:3000
 ## firebase

server/email/index.ts

@@ -0,0 +1,51 @@
+import type { Context } from "hono";
+import { env } from "../lib/env.ts";
+
+type APIStructure = {
+  subject: string;
+  sender: { name: string; email: string };
+  type?: string;
+  htmlContent: string;
+  to: { email: string }[];
+};
+
+function createBody(to: { name: string; email: string }[], subject: string, body: string): APIStructure {
+  return {
+    subject,
+    sender: { name: "UT-Bridge", email: "[email protected]" },
+    type: "classic",
+    htmlContent: body,
+    to,
+  };
+}
+
+export async function send(
+  to: { name: string; email: string }[],
+  subject: string,
+  body: string,
+  env: {
+    apiKey: string;
+  },
+) {
+  const resp = await fetch("https://api.brevo.com/v3/smtp/email", {
+    method: "POST",
+    headers: {
+      "api-key": env.apiKey,
+      "content-type": "application/json",
+    },
+    body: JSON.stringify(createBody(to, subject, body)),
+  });
+  console.log(await resp.text());
+}
+
+export type MailOptions = {
+  to: { name: string; email: string }[];
+  subject: string;
+  /** HTML */
+  body: string;
+};
+export async function sendEmail(c: Context, options: MailOptions) {
+  return await send(options.to, options.subject, options.body, {
+    apiKey: env(c, "MAILING_BREVO_API_KEY"),
+  });
+}

server/lib/env.ts

@@ -5,6 +5,33 @@ export function env(c: Context, name: string, options?: { fallback?: string }):
   return hono_env(c)[name] ?? options?.fallback ?? panic(`Environment variable not found: ${name}`);
 }
 
+export function env_int(c: Context, name: string, options?: { fallback?: string }): number {
+  const val = env(c, name, options);
+  const parsed = Number.parseInt(val);
+  if (Number.isNaN(parsed)) throw new Error(`[env_int] expected int-parsable value, got ${val}`);
+  return parsed;
+}
+
+export function env_bool(c: Context, name: string, options?: { fallback?: string }): boolean {
+  const val = env(c, name, options);
+  switch (val.toLowerCase()) {
+    case "1":
+    case "true":
+    case "t":
+    case "yes":
+    case "y":
+      return true;
+    case "0":
+    case "false":
+    case "f":
+    case "no":
+    case "n":
+      return false;
+    default:
+      throw new Error(`[env_bool] expected bool-castable value, got "${val}"`);
+  }
+}
+
 export function panic(message: string): never {
   throw new Error(message);
 }