Aggiunge newsletter custom con D1, double opt-in e invio campagne.

Attiva il form footer, API subscribe/confirm/unsubscribe e endpoint admin protetti, riusando Resend per le email.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/lib/newsletter.ts

@@ -0,0 +1,146 @@
+/**
+ * Shared helpers for newsletter API routes (Cloudflare Worker / Astro).
+ */
+
+export type RuntimeEnv = Record<string, unknown>;
+
+export type SubscriberStatus = 'pending' | 'active' | 'unsubscribed';
+
+export type NewsletterSubscriber = {
+  id: number;
+  email: string;
+  status: SubscriberStatus;
+  locale: string;
+  confirm_token: string | null;
+  unsubscribe_token: string;
+  source: string;
+  created_at: string;
+  confirmed_at: string | null;
+  unsubscribed_at: string | null;
+};
+
+export function getRuntimeEnv(locals: unknown): RuntimeEnv {
+  if (
+    locals &&
+    typeof locals === 'object' &&
+    'runtime' in locals &&
+    locals.runtime &&
+    typeof locals.runtime === 'object' &&
+    'env' in locals.runtime &&
+    locals.runtime.env &&
+    typeof locals.runtime.env === 'object'
+  ) {
+    return locals.runtime.env as RuntimeEnv;
+  }
+  return {};
+}
+
+export function readEnv(name: string, runtimeEnv: RuntimeEnv): string {
+  const runtimeValue = runtimeEnv[name];
+  if (typeof runtimeValue === 'string' && runtimeValue.trim().length > 0) {
+    return runtimeValue.trim();
+  }
+  const staticValue = import.meta.env[name];
+  return typeof staticValue === 'string' ? staticValue.trim() : '';
+}
+
+export function getNewsletterDb(runtimeEnv: RuntimeEnv): D1Database | null {
+  const db = runtimeEnv.NEWSLETTER_DB;
+  if (db && typeof db === 'object' && 'prepare' in db) {
+    return db as D1Database;
+  }
+  return null;
+}
+
+export function sanitizeRedirect(candidate: string, requestUrl: URL): string {
+  if (!candidate) return '';
+  try {
+    const u = new URL(candidate, requestUrl);
+    if (u.origin !== requestUrl.origin) return '';
+    return u.pathname + u.search + u.hash;
+  } catch {
+    return '';
+  }
+}
+
+export function required(value: FormDataEntryValue | null): string {
+  return typeof value === 'string' ? value.trim() : '';
+}
+
+export function isValidEmail(email: string): boolean {
+  return /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email) && email.length <= 254;
+}
+
+export function normalizeEmail(email: string): string {
+  return email.trim().toLowerCase();
+}
+
+export function createToken(): string {
+  const bytes = new Uint8Array(32);
+  crypto.getRandomValues(bytes);
+  return [...bytes].map((b) => b.toString(16).padStart(2, '0')).join('');
+}
+
+export async function verifyTurnstile(
+  token: string,
+  secret: string,
+  ip?: string | null,
+): Promise<boolean> {
+  const body = new URLSearchParams();
+  body.set('secret', secret);
+  body.set('response', token);
+  if (ip) body.set('remoteip', ip);
+
+  const response = await fetch('https://challenges.cloudflare.com/turnstile/v0/siteverify', {
+    method: 'POST',
+    body,
+  });
+  if (!response.ok) return false;
+  const payload = (await response.json()) as { success?: boolean };
+  return payload.success === true;
+}
+
+export async function sendWithResend(options: {
+  apiKey: string;
+  fromEmail: string;
+  toEmail: string;
+  subject: string;
+  text: string;
+  html?: string;
+}): Promise<void> {
+  const response = await fetch('https://api.resend.com/emails', {
+    method: 'POST',
+    headers: {
+      Authorization: `Bearer ${options.apiKey}`,
+      'Content-Type': 'application/json',
+    },
+    body: JSON.stringify({
+      from: options.fromEmail,
+      to: [options.toEmail],
+      subject: options.subject,
+      text: options.text,
+      ...(options.html ? { html: options.html } : {}),
+    }),
+  });
+
+  if (!response.ok) {
+    const detail = await response.text();
+    throw new Error(`Resend error ${response.status}: ${detail}`);
+  }
+}
+
+export function siteOrigin(requestUrl: URL, runtimeEnv: RuntimeEnv): string {
+  const configured = readEnv('PUBLIC_SITE_URL', runtimeEnv) || readEnv('SITE', runtimeEnv);
+  if (configured) {
+    try {
+      return new URL(configured).origin;
+    } catch {
+      /* fall through */
+    }
+  }
+  return requestUrl.origin;
+}
+
+export function absoluteUrl(origin: string, path: string): string {
+  return new URL(path, origin).toString();
+}