import nodemailer from "nodemailer";
import type { ContactData } from "./validation";
import { getEnv } from "./env";

export interface Mailer {
  send(data: ContactData, meta: { ipHash: string }): Promise<{ delivered: boolean; id?: string }>;
}

function escapeHtml(s: string) {
  return s
    .replace(/&/g, "&amp;")
    .replace(/</g, "&lt;")
    .replace(/>/g, "&gt;")
    .replace(/"/g, "&quot;");
}

export function renderContactEmail(data: ContactData) {
  const text = [
    `Nouveau message depuis le site PHI Conseil`,
    ``,
    `Nom : ${data.name}`,
    `Courriel : ${data.email}`,
    `Organisation : ${data.organization || "—"}`,
    `Sujet : ${data.subject}`,
    ``,
    data.message,
  ].join("\n");
  const html = `<!doctype html><html lang="fr"><body style="font-family:system-ui,sans-serif;color:#1f2a33">
<h2 style="font-weight:600">Nouveau message depuis le site PHI Conseil</h2>
<table cellpadding="4">
<tr><td><strong>Nom</strong></td><td>${escapeHtml(data.name)}</td></tr>
<tr><td><strong>Courriel</strong></td><td>${escapeHtml(data.email)}</td></tr>
<tr><td><strong>Organisation</strong></td><td>${escapeHtml(data.organization || "—")}</td></tr>
<tr><td><strong>Sujet</strong></td><td>${escapeHtml(data.subject)}</td></tr>
</table>
<p style="white-space:pre-wrap">${escapeHtml(data.message)}</p>
</body></html>`;
  return { subject: `[Site PHI Conseil] ${data.subject}`, text, html };
}

/** Transport « log » : n'envoie rien, journalise une empreinte. Jamais présenté comme une livraison. */
export const logMailer: Mailer = {
  async send(data, meta) {
    console.info(
      `[contact] CONTACT_TRANSPORT=log — courriel NON envoyé (sujet="${data.subject}", ip=${meta.ipHash})`,
    );
    return { delivered: false };
  },
};

export function createSmtpMailer(): Mailer {
  const env = getEnv();
  const transporter = nodemailer.createTransport({
    host: env.SMTP_HOST,
    port: env.SMTP_PORT,
    secure: env.SMTP_SECURE,
    auth: env.SMTP_USER ? { user: env.SMTP_USER, pass: env.SMTP_PASS } : undefined,
  });
  return {
    async send(data) {
      const { subject, text, html } = renderContactEmail(data);
      const info = await transporter.sendMail({
        from: env.CONTACT_FROM,
        to: env.CONTACT_TO,
        replyTo: data.email,
        subject,
        text,
        html,
      });
      return { delivered: true, id: info.messageId };
    },
  };
}

let instance: Mailer | null = null;
export function getMailer(): Mailer {
  if (instance) return instance;
  instance = getEnv().CONTACT_TRANSPORT === "smtp" ? createSmtpMailer() : logMailer;
  return instance;
}

/** Pour les tests. */
export function setMailerForTests(m: Mailer | null) {
  instance = m;
}