import { sql, transaction } from "@/lib/db";
import { isDevOtpExposed, sendEmail } from "@/lib/mailer";
import {
  CODE_TTL_MINUTES,
  generateCode,
  hashCode,
  resetEmail,
} from "@/lib/otp";

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

  if (!email?.trim()) {
    return Response.json({ error: "Email is required." }, { status: 400 });
  }

  const normalized = email.trim().toLowerCase();

  try {
    const users = await sql<{ id: string }>`
      SELECT id FROM users WHERE email = ${normalized}
    `;

    // Don't reveal whether the address is registered: always answer the same.
    if (!users[0]) {
      return Response.json({ data: { sent: false } });
    }

    const code = await transaction(async (tx) => {
      const generated = generateCode();

      await tx`
        INSERT INTO password_reset_codes (email, code_hash, expires_at)
        VALUES (
          ${normalized},
          ${hashCode(normalized, generated)},
          CURRENT_TIMESTAMP + make_interval(mins => ${CODE_TTL_MINUTES})
        )
        ON CONFLICT (email) DO UPDATE SET
          code_hash = EXCLUDED.code_hash,
          expires_at = EXCLUDED.expires_at,
          attempts = 0
      `;

      return generated;
    });

    const mail = resetEmail(code);
    const delivered = await sendEmail(normalized, mail.subject, mail.text);

    return Response.json({
      data: {
        sent: delivered,
        // Without SMTP configured there is nothing to receive, so surface the
        // code to keep the reset flow usable on a self-hosted box. Never
        // expose the code in production, even on delivery failure.
        ...(delivered || !isDevOtpExposed() ? {} : { devCode: code }),
      },
    });
  } catch (error) {
    console.error("[FORGOT_PASSWORD]: ", error);
    return Response.json({ error: "Internal Server Error" }, { status: 500 });
  }
}