import nodemailer from "nodemailer";
import { orderSummaryRows } from "../../shared/order-summary.js";
import { paymentNotice } from "../../shared/booking-copy.js";

export function createEmailService(
    env = process.env,
    makeTransport = nodemailer.createTransport,
) {
    const localHosts = ["127.0.0.1", "localhost", "::1", "mailpit"];
    const host = env.SMTP_HOST || "127.0.0.1";
    const local = localHosts.includes(host);
    if (!local && env.SMTP_ALLOW_EXTERNAL !== "true") {
        throw new Error(
            "Externes SMTP ist gesperrt. Erst nach ausdrücklicher Freigabe SMTP_ALLOW_EXTERNAL=true setzen.",
        );
    }
    const port = Number(env.SMTP_PORT || (local ? 1025 : 587));
    if (!Number.isInteger(port) || port < 1 || port > 65535)
        throw new Error("Ungültiger SMTP_PORT");
    if (Boolean(env.SMTP_USER) !== Boolean(env.SMTP_PASS))
        throw new Error("SMTP_USER und SMTP_PASS gemeinsam setzen");
    const transport = makeTransport({
        host,
        port,
        secure: env.SMTP_SECURE === "true",
        requireTLS: !local,
        auth: env.SMTP_USER
            ? { user: env.SMTP_USER, pass: env.SMTP_PASS }
            : undefined,
        connectionTimeout: 10000,
        greetingTimeout: 10000,
        socketTimeout: 20000,
        disableFileAccess: true,
        disableUrlAccess: true,
    });
    const from = env.SMTP_FROM || "Tri-Hub <buchung@example.test>";
    return async function sendConfirmation(booking) {
        const order = booking.bookedPackage;
        const phone = booking.phone || booking.customer?.phone;
        const lines = [
            `Hallo ${booking.name},`,
            "",
            "vielen Dank für deine Bestellung bei Tri-Hub. Hier findest du die Zusammenfassung deiner Buchung.",
            `Buchungsnummer: ${booking.bookingId}`,
            ...(booking.createdAt
                ? [
                      `Bestelldatum: ${new Intl.DateTimeFormat("de-DE", { dateStyle: "long", timeStyle: "short", timeZone: "Europe/Berlin" }).format(new Date(booking.createdAt))} (Europe/Berlin)`,
                  ]
                : []),
            `Kunde: ${booking.name}`,
            `E-Mail: ${booking.email}`,
            ...(phone ? [`Telefon: ${phone}`] : []),
            ...(booking.customer?.notes
                ? [`Deine Anmerkungen: ${booking.customer.notes}`]
                : []),
            "",
            `Paket: ${order?.title ?? booking.packageName}`,
            ...(order
                ? [
                      order.summaryForBooking,
                      order.subtitle,
                      "",
                      ...orderSummaryRows(order).map(
                          ([label, value]) => `${label}: ${value}`,
                      ),
                      "",
                      "Enthaltene Leistungen:",
                      ...order.includedFeatures.map(
                          (feature) => `• ${feature}`,
                      ),
                      "",
                      "So geht es weiter:",
                      ...(order.processSteps || []).map(
                          ({ step, text }) => `${step}: ${text}`,
                      ),
                  ]
                : []),
            "",
            paymentNotice,
            "",
            "Bitte bewahre diese Bestätigung auf und gib bei Rückfragen deine Buchungsnummer an.",
            "Dein Tri-Hub-Team",
        ];
        const escapeHtml = (value) =>
            String(value).replace(
                /[&<>"']/g,
                (char) =>
                    ({
                        "&": "&amp;",
                        "<": "&lt;",
                        ">": "&gt;",
                        '"': "&quot;",
                        "'": "&#39;",
                    })[char],
            );
        let info;
        try {
            info = await transport.sendMail({
                from,
                to: { address: booking.email, name: booking.name },
                subject: `Bestellbestätigung ${booking.bookingId} – Tri-Hub`,
                text: lines.join("\n"),
                html: `<html lang="de"><body><h1>Deine Bestellbestätigung</h1>${lines.map((line) => (line ? `<p>${escapeHtml(line)}</p>` : "")).join("")}</body></html>`,
            });
        } catch (error) {
            // Bei Verbindungsabbruch kann SMTP die Nachricht schon angenommen
            // haben. Nur ausdrückliche Ablehnungen gelten sicher als Fehler.
            const explicitRejection =
                ["EAUTH", "EENVELOPE", "ECONNECTION", "EDNS"].includes(
                    error.code,
                ) || Number(error.responseCode) >= 400;
            error.deliveryUnknown = !explicitRejection;
            throw error;
        }
        if (
            !info.accepted?.some(
                (address) =>
                    address.toLowerCase() === booking.email.toLowerCase(),
            )
        ) {
            throw new Error("Empfänger vom Mailserver nicht angenommen");
        }
    };
}