import axios from "axios";
import { NextResponse } from "next/server";

async function GET(
  req: Request,
  target: string
) {
  const reqUrl = new URL(req.url);

  const url: string =
    target + reqUrl.pathname + "?" + reqUrl.searchParams.toString();

  const headers: { [key: string]: string } = {
    Authorization: req.headers.get("Authorization") || "",
    Cookie: req.headers.get("Cookie") || "",
  };

  const externalResponse = await axios.get(url, {
    headers: headers,
    responseType: "stream",
  });

  return new NextResponse(nodeReadableToReadableStream(externalResponse.data), {
    status: externalResponse.status,
  });
}

async function POST(req: Request) {
  const reqUrl = new URL(req.url);
  const body = await req.text();

  const url: string =
    process.env.EDITOR_SERVICE_URL +
    reqUrl.pathname +
    "?" +
    reqUrl.searchParams.toString();

  const headers: { [key: string]: string } = {
    "Content-Type": req.headers.get("Content-Type") || "",
    Authorization: req.headers.get("Authorization") || "",
    Cookie: req.headers.get("Cookie") || "",
  };

  const externalResponse = await axios.post(url, body, {
    headers: headers,
    responseType: "stream",
  });

  const responseHeaders = getResponseHeaders(externalResponse);

  return new NextResponse(nodeReadableToReadableStream(externalResponse.data), {
    status: externalResponse.status,
    headers: responseHeaders,
  });
}

const getResponseHeaders = (externalResponse: any) => {
  const responseHeaders = new Headers();
  responseHeaders.set(
    "Content-Type",
    externalResponse.headers["content-type"] || ""
  );
  responseHeaders.set(
    "Set-Cookie",
    externalResponse.headers["set-cookie"] || ""
  );
  return responseHeaders;
};

function nodeReadableToReadableStream(
  nodeStream: NodeJS.ReadableStream
): ReadableStream<Uint8Array> {
  return new ReadableStream<Uint8Array>({
    start(controller) {
      nodeStream.on("data", (chunk: Buffer) => {
        controller.enqueue(new Uint8Array(chunk));
      });

      nodeStream.on("end", () => {
        controller.close();
      });

      nodeStream.on("error", (err: Error) => {
        controller.error(err);
      });
    },
    pull() {},
    cancel() {},
  });
}

export const proxy = {
  POST,
  GET,
};