yaak-mountain-loop/src-web/hooks/useRequestEditor.tsx

import EventEmitter from "eventemitter3";
import { atom, useAtom } from "jotai";
import type { DependencyList } from "react";
import { useCallback, useEffect } from "react";

type EventDataMap = {
  "request_params.focus_value": string;
  "request_pane.focus_tab": undefined;
};

export function useRequestEditorEvent<
  Event extends keyof EventDataMap,
  Data extends EventDataMap[Event],
>(event: Event, fn: (data: Data) => void, deps?: DependencyList) {
  useEffect(() => {
    emitter.on(event, fn);
    return () => {
      emitter.off(event, fn);
    };
    // oxlint-disable-next-line react-hooks/exhaustive-deps -- We're handing deps manually
  }, deps);
}

export const urlKeyAtom = atom<string>(Math.random().toString());
export const urlParamsKeyAtom = atom<string>(Math.random().toString());

export function useRequestEditor() {
  const [urlParametersKey, setUrlParametersKey] = useAtom(urlParamsKeyAtom);
  const [urlKey, setUrlKey] = useAtom(urlKeyAtom);
  const focusParamsTab = useCallback(() => {
    emitter.emit("request_pane.focus_tab", undefined);
  }, []);

  const focusParamValue = useCallback(
    (name: string) => {
      focusParamsTab();
      requestAnimationFrame(() => emitter.emit("request_params.focus_value", name));
    },
    [focusParamsTab],
  );

  const forceUrlRefresh = useCallback(() => setUrlKey(Math.random().toString()), [setUrlKey]);
  const forceParamsRefresh = useCallback(
    () => setUrlParametersKey(Math.random().toString()),
    [setUrlParametersKey],
  );

  return [
    {
      urlParametersKey,
      urlKey,
    },
    {
      focusParamValue,
      focusParamsTab,
      forceParamsRefresh,
      forceUrlRefresh,
    },
  ] as const;
}

const emitter = new (class RequestEditorEventEmitter {
  #emitter: EventEmitter = new EventEmitter();

  emit<Event extends keyof EventDataMap, Data extends EventDataMap[Event]>(
    event: Event,
    data: Data,
  ) {
    this.#emitter.emit(event, data);
  }

  on<Event extends keyof EventDataMap, Data extends EventDataMap[Event]>(
    event: Event,
    fn: (data: Data) => void,
  ) {
    this.#emitter.on(event, fn);
  }

  off<Event extends keyof EventDataMap, Data extends EventDataMap[Event]>(
    event: Event,
    fn: (data: Data) => void,
  ) {
    this.#emitter.off(event, fn);
  }
})();