import { randomUUID } from "crypto";
import { NextResponse } from "next/server";
import { prisma } from "../../../../lib/prisma";
import { sendMail } from "../../../../lib/mailer";
import { checkRateLimit, getRateLimitConfig } from "../../../../lib/rate-limit";
import { getClientIp } from "../../../../lib/request";

export async function POST(request: Request) {
  const body = await request.json();
  const { email } = body || {};

  if (!email) {
    return NextResponse.json({ error: "E-Mail erforderlich." }, { status: 400 });
  }

  const normalizedEmail = String(email).trim().toLowerCase();
  const ip = getClientIp(request);
  const rateKey = `verify:${normalizedEmail}:${ip}`;
  const rateConfig = getRateLimitConfig("RATE_LIMIT_VERIFY_EMAIL", 3);
  const rate = await checkRateLimit({
    key: rateKey,
    limit: rateConfig.limit,
    windowMs: rateConfig.windowMs
  });
  if (!rate.ok) {
    return NextResponse.json(
      { error: "Zu viele Anfragen. Bitte später erneut versuchen." },
      { status: 429 }
    );
  }

  const user = await prisma.user.findUnique({ where: { email: normalizedEmail } });
  if (!user) {
    return NextResponse.json({ ok: true });
  }

  if (user.emailVerified) {
    return NextResponse.json({ ok: true });
  }

  const existingToken = await prisma.verificationToken.findFirst({
    where: { identifier: normalizedEmail, expires: { gt: new Date() } }
  });

  if (existingToken) {
    return NextResponse.json({ ok: true });
  }

  await prisma.verificationToken.deleteMany({ where: { identifier: normalizedEmail } });

  const token = randomUUID();
  const expires = new Date(Date.now() + 24 * 60 * 60 * 1000);
  await prisma.verificationToken.create({
    data: {
      identifier: normalizedEmail,
      token,
      expires
    }
  });

  const baseUrl = process.env.NEXTAUTH_URL || "http://localhost:3000";
  const verifyUrl = `${baseUrl}/verify/confirm?token=${token}`;
  await sendMail({
    to: normalizedEmail,
    subject: "E-Mail verifizieren",
    text: `Bitte verifiziere deine E-Mail: ${verifyUrl}`
  });

  return NextResponse.json({ ok: true });
}