import { EventEmitter } from "node:events";
import type { IncomingMessage, ServerResponse } from "node:http";

export function makeReq(method: string, body: string): IncomingMessage {
  const req = new EventEmitter() as IncomingMessage & { destroyed: boolean };
  req.method = method;
  req.headers = {};
  req.socket = { remoteAddress: "127.0.0.1" } as unknown as IncomingMessage["socket"];
  req.destroyed = false;
  req.destroy = ((_: Error | undefined) => {
    if (req.destroyed) {
      return req;
    }
    req.destroyed = true;
    return req;
  }) as IncomingMessage["destroy"];
  process.nextTick(() => {
    if (req.destroyed) {
      return;
    }
    req.emit("data", Buffer.from(body));
    req.emit("end");
  });
  return req;
}

export function makeRes(): ServerResponse & { _status: number; _body: string } {
  const res = {
    _status: 0,
    _body: "",
    writeHead(statusCode: number, _headers: Record<string, string>) {
      res._status = statusCode;
    },
    end(body?: string) {
      res._body = body ?? "";
    },
  } as unknown as ServerResponse & { _status: number; _body: string };
  return res;
}

export function makeFormBody(fields: Record<string, string>): string {
  return Object.entries(fields)
    .map(([k, v]) => `${encodeURIComponent(k)}=${encodeURIComponent(v)}`)
    .join("&");
}