import type { Plugin, PluginAPI } from "@lumeweb/interface-relay";
import fetch, { Request, RequestInit } from "node-fetch";

import { URL } from "url";

const EXECUTION_RPC_URL =
  "https://g.w.lavanet.xyz:443/gateway/eth/rpc-http/f195d68175eb091ec1f71d00f8952b85";

const CONSENSUS_RPC_URL = "https://www.lightclientdata.org";

async function doFetch(url: string, request: RequestInit) {
  sanitizeRequestArgs(url, request);

  let req = new Request(url, {
    ...request,
    headers: {
      "Content-Type": "application/json",
    },
  });

  const resp = await fetch(req);

  return (await resp.json()) as any;
}

function sanitizeRequestArgs(url: string, request: RequestInit) {
  if (!request || typeof request !== "object") {
    throw Error("invalid request");
  }

  [
    "agent",
    "hostname",
    "referrer",
    "referrerPolicy",
    "compress",
    "port",
    "protocol",
    "hostname",
    "insecureHTTPParser",
    "highWaterMark",
    "size",
  ].forEach((element) => {
    if (element in request) {
      delete request[element];
    }
  });
}

interface ConsensusRequest extends RequestInit {
  path: string;
}
interface ExecutionRequest {
  method: string;
  params: string;
}

const plugin: Plugin = {
  name: "eth",
  async plugin(api: PluginAPI): Promise<void> {
    api.registerMethod("consensus_request", {
      cacheable: false,
      async handler(request: ConsensusRequest): Promise<object> {
        const consensusUrl = new URL(CONSENSUS_RPC_URL);

        let dummyUrl = new URL(
          `http://dummy/${request.path.replace(/^\/+/, "")}`
        );
        consensusUrl.pathname = dummyUrl.pathname;
        consensusUrl.search = dummyUrl.search;

        return doFetch(consensusUrl.toString(), request);
      },
    });
    api.registerMethod("execution_request", {
      cacheable: false,
      async handler(request: ExecutionRequest): Promise<object> {
        return doFetch(EXECUTION_RPC_URL, {
          method: "POST",
          body: JSON.stringify(request),
        });
      },
    });
  },
};

export default plugin;