import nodemailer from "nodemailer";

// E-mail versturen. Voorkeur: SendGrid, met dezelfde instellingen als het Rikx ZRM-platform
// (SENDGRID_API_KEY, SENDGRID_FROM_EMAIL, SENDGRID_FROM_NAME). Anders SMTP (SMTP_*).
// Zonder beide wordt er niets verstuurd; de aanroeper toont dan bijvoorbeeld de uitnodigingslink in beeld.
export function isMailConfigured(): boolean {
  return Boolean(process.env.SENDGRID_API_KEY || process.env.SMTP_HOST);
}

type Message = { to: string; toName?: string; subject: string; text: string; html?: string };

export async function sendMail(message: Message): Promise<void> {
  if (process.env.SENDGRID_API_KEY) return sendViaSendGrid(message, process.env.SENDGRID_API_KEY);
  return sendViaSmtp(message);
}

async function sendViaSendGrid(message: Message, apiKey: string): Promise<void> {
  const res = await fetch("https://api.sendgrid.com/v3/mail/send", {
    method: "POST",
    headers: { Authorization: `Bearer ${apiKey}`, "Content-Type": "application/json" },
    body: JSON.stringify({
      personalizations: [{ to: [{ email: message.to, name: message.toName }], subject: message.subject }],
      from: {
        email: process.env.SENDGRID_FROM_EMAIL || "no-reply@rikxplatform.nl",
        name: process.env.SENDGRID_FROM_NAME || "Rikx",
      },
      content: [
        { type: "text/plain", value: message.text },
        ...(message.html ? [{ type: "text/html", value: message.html }] : []),
      ],
    }),
  });
  if (!res.ok) throw new Error(`SendGrid ${res.status}: ${await res.text()}`);
}

async function sendViaSmtp(message: Message): Promise<void> {
  const port = Number(process.env.SMTP_PORT || 587);
  const transport = nodemailer.createTransport({
    host: process.env.SMTP_HOST,
    port,
    secure: port === 465,
    auth: process.env.SMTP_USER ? { user: process.env.SMTP_USER, pass: process.env.SMTP_PASS } : undefined,
  });
  const { toName: _toName, ...rest } = message;
  await transport.sendMail({ from: process.env.SMTP_FROM || "noreply@rikx.nl", ...rest });
}