middleware.ts

import { NextRequest, NextResponse } from "next/server";
import { createWallet, getAddress } from "./auth";
import { Sequencer } from "./sequencer";

export async function middleware(request: NextRequest) {
  const readRequest = request.method === "GET" || request.method === "HEAD";

  let session = request.cookies.get("session")?.value;
  let address: string | null = null;
  if (session) {
    address = await getAddress(session);
  } else {
    const wallet = await createWallet();
    address = wallet.walletAddress;
    session = wallet.id;
  }

  if (readRequest) {
    let response = NextResponse.next();

    if (!request.cookies.get("session")?.value) {
      request.cookies.set({
        name: "session",
        value: session,
      });

      response = NextResponse.next({
        request,
      });
      response.cookies.set({
        name: "session",
        value: session,
        httpOnly: true,
        sameSite: "lax",
        secure: process.env.NODE_ENV === "production",
      });
    }

    return response;
  }

  if (process.env.MODE === "replay") {
    if (request.headers.get("x-sequencer") !== process.env.SEQUENCER_SECRET) {
      return Response.json(
        {
          success: false,
          message: "Only sequencer can perform action in replay mode.",
        },
        { status: 401 }
      );
    }
    return NextResponse.next({
      request,
    });
  }

  const body = await request.text();

  await Sequencer.enqueue({
    method: request.method,
    path: request.nextUrl.pathname,
    headers: {
      accept: request.headers.get("accept") || "*/*",
      "content-type": request.headers.get("content-type"),
      "next-action": request.headers.get("next-action"),
      "next-router-state-tree": request.headers.get("next-router-state-tree"),
    },
    body,
    address,
  });

  const response = await fetch(request.url, {
    method: request.method,
    headers: {
      cookie: `session=${session};`,
      accept: request.headers.get("accept") || "*/*",
      "content-type": request.headers.get("content-type"),
      "next-action": request.headers.get("next-action"),
      "next-router-state-tree": request.headers.get("next-router-state-tree"),
    } as any,
    body,
  });

  await Sequencer.next();
  return response;
}