import { prisma } from "./prisma";

interface EmailPayload {
  to: string;
  subject: string;
  html: string;
  text?: string;
}

async function getConfig(key: string): Promise<string> {
  const row = await prisma.systemConfig.findUnique({ where: { key } });
  return row?.value ?? process.env[key.toUpperCase()] ?? "";
}

async function sendMailgun(payload: EmailPayload): Promise<void> {
  const apiKey = await getConfig("mailgun_api_key");
  const domain = await getConfig("mailgun_domain");
  const from = await getConfig("mailgun_from");
  if (!apiKey || !domain) throw new Error("Mailgun non configuré");

  const formData = new FormData();
  formData.append("from", from || `Grow <noreply@${domain}>`);
  formData.append("to", payload.to);
  formData.append("subject", payload.subject);
  formData.append("html", payload.html);
  if (payload.text) formData.append("text", payload.text);

  const res = await fetch(`https://api.mailgun.net/v3/${domain}/messages`, {
    method: "POST",
    headers: { Authorization: `Basic ${Buffer.from(`api:${apiKey}`).toString("base64")}` },
    body: formData,
  });
  if (!res.ok) {
    const err = await res.text();
    throw new Error(`Mailgun error: ${err}`);
  }
}

async function sendSmtp(payload: EmailPayload): Promise<void> {
  const host = await getConfig("smtp_host");
  const port = parseInt(await getConfig("smtp_port") || "587");
  const user = await getConfig("smtp_user");
  const pass = await getConfig("smtp_pass");
  const from = await getConfig("smtp_from");
  if (!host) throw new Error("SMTP non configuré");

  const nodemailer = await import("nodemailer");
  const transport = nodemailer.default.createTransport({ host, port, auth: { user, pass } });
  await transport.sendMail({ from, to: payload.to, subject: payload.subject, html: payload.html, text: payload.text });
}

export async function sendEmail(payload: EmailPayload): Promise<void> {
  const provider = await getConfig("email_provider");
  if (provider === "smtp") return sendSmtp(payload);
  if (provider === "mailgun") return sendMailgun(payload);
  // Fallback: check env vars directly
  if (process.env.MAILGUN_API_KEY) return sendMailgun(payload);
  if (process.env.SMTP_HOST) return sendSmtp(payload);
  throw new Error("Aucun service email configuré");
}

export function resetPasswordEmail(name: string, resetUrl: string): { html: string; text: string } {
  return {
    text: `Bonjour ${name},\n\nCliquez sur ce lien pour réinitialiser votre mot de passe :\n${resetUrl}\n\nLien valide 1 heure.\n\nGrow`,
    html: `
      <div style="font-family:sans-serif;max-width:480px;margin:0 auto">
        <h2 style="color:#4f46e5">Grow — Réinitialisation du mot de passe</h2>
        <p>Bonjour ${name},</p>
        <p>Cliquez sur le bouton ci-dessous pour réinitialiser votre mot de passe. Le lien est valide pendant <strong>1 heure</strong>.</p>
        <a href="${resetUrl}" style="display:inline-block;margin:16px 0;padding:12px 24px;background:#4f46e5;color:#fff;border-radius:8px;text-decoration:none;font-weight:600">
          Réinitialiser mon mot de passe
        </a>
        <p style="color:#64748b;font-size:13px">Si vous n'avez pas demandé cette réinitialisation, ignorez cet email.</p>
        <p style="color:#64748b;font-size:13px">Ou copiez ce lien : ${resetUrl}</p>
      </div>
    `,
  };
}