const MAILPIT = process.env.MAILPIT_URL ?? "http://localhost:8025";

export async function clearMailpit(): Promise<void> {
  const res = await fetch(`${MAILPIT}/api/v1/messages`, { method: "DELETE" });
  if (!res.ok) throw new Error(`Mailpit clear failed: ${res.status}`);
}

type MessageSummary = { ID: string; To: { Address: string }[]; Created: string };

async function listMessagesTo(email: string): Promise<MessageSummary[]> {
  const url = `${MAILPIT}/api/v1/search?query=${encodeURIComponent(`to:${email}`)}`;
  const res = await fetch(url);
  if (!res.ok) throw new Error(`Mailpit search failed: ${res.status}`);
  const data = (await res.json()) as { messages: MessageSummary[] };
  return data.messages ?? [];
}

async function getMessageBody(id: string): Promise<{ text: string; html: string }> {
  const res = await fetch(`${MAILPIT}/api/v1/message/${id}`);
  if (!res.ok) throw new Error(`Mailpit fetch failed: ${res.status}`);
  const data = (await res.json()) as { Text?: string; HTML?: string };
  return { text: data.Text ?? "", html: data.HTML ?? "" };
}

export async function waitForMagicLink(email: string, opts: { timeoutMs?: number } = {}): Promise<string> {
  const timeoutMs = opts.timeoutMs ?? 10_000;
  const deadline = Date.now() + timeoutMs;
  const linkRe = /https?:\/\/[^\s<>"]*\/api\/auth\/callback\/nodemailer[^\s<>"]*/i;

  while (Date.now() < deadline) {
    const messages = await listMessagesTo(email);
    if (messages.length > 0) {
      const newest = messages.sort((a, b) => b.Created.localeCompare(a.Created))[0];
      const { text, html } = await getMessageBody(newest.ID);
      const m = (text.match(linkRe) ?? html.match(linkRe))?.[0];
      if (m) return m.replace(/&amp;/g, "&");
    }
    await new Promise((r) => setTimeout(r, 250));
  }
  throw new Error(`No magic link for ${email} within ${timeoutMs}ms`);
}