reflector/www/app/(app)/transcripts/useMp3.ts

import { useContext, useEffect, useState } from "react";
import { DomainContext } from "../../domainContext";
import { useTranscriptGet } from "../../lib/apiHooks";
import { useSession } from "next-auth/react";
import { assertExtendedToken } from "../../lib/types";

export type Mp3Response = {
  media: HTMLMediaElement | null;
  loading: boolean;
  error: string | null;
  getNow: () => void;
  audioDeleted: boolean | null;
};

const useMp3 = (transcriptId: string, waiting?: boolean): Mp3Response => {
  const [media, setMedia] = useState<HTMLMediaElement | null>(null);
  const [later, setLater] = useState(waiting);
  const [audioLoading, setAudioLoading] = useState<boolean>(true);
  const [audioLoadingError, setAudioLoadingError] = useState<null | string>(
    null,
  );
  const [audioDeleted, setAudioDeleted] = useState<boolean | null>(null);
  const { api_url } = useContext(DomainContext);
  const { data: session } = useSession();
  const sessionExtended =
    session === null ? null : assertExtendedToken(session);
  const accessTokenInfo =
    sessionExtended === null ? null : sessionExtended.accessToken;

  const {
    data: transcript,
    isLoading: transcriptMetadataLoading,
    error: transcriptError,
  } = useTranscriptGet(later ? null : transcriptId);

  const [serviceWorker, setServiceWorker] =
    useState<ServiceWorkerRegistration | null>(null);

  useEffect(() => {
    if ("serviceWorker" in navigator) {
      navigator.serviceWorker.register("/service-worker.js").then((worker) => {
        setServiceWorker(worker);
      });
    }
    return () => {
      serviceWorker?.unregister();
    };
  }, []);

  useEffect(() => {
    if (!navigator.serviceWorker) return;
    if (!navigator.serviceWorker.controller) return;
    if (!serviceWorker) return;
    // Send the token to the service worker
    navigator.serviceWorker.controller.postMessage({
      type: "SET_AUTH_TOKEN",
      token: accessTokenInfo,
    });
  }, [navigator.serviceWorker, !serviceWorker, accessTokenInfo]);

  useEffect(() => {
    if (!transcriptId || later || !transcript) return;

    let stopped = false;
    let audioElement: HTMLAudioElement | null = null;
    let handleCanPlay: (() => void) | null = null;
    let handleError: (() => void) | null = null;

    setAudioLoading(true);

    const deleted = transcript.audio_deleted || false;
    setAudioDeleted(deleted);

    if (deleted) {
      // Audio is deleted, don't attempt to load it
      setMedia(null);
      setAudioLoadingError(null);
      setAudioLoading(false);
      return;
    }

    // Audio is not deleted, proceed to load it
    audioElement = document.createElement("audio");
    audioElement.src = `${api_url}/v1/transcripts/${transcriptId}/audio/mp3`;
    audioElement.crossOrigin = "anonymous";
    audioElement.preload = "auto";

    handleCanPlay = () => {
      if (stopped) return;
      setAudioLoading(false);
      setAudioLoadingError(null);
    };

    handleError = () => {
      if (stopped) return;
      setAudioLoading(false);
      setAudioLoadingError("Failed to load audio");
    };

    audioElement.addEventListener("canplay", handleCanPlay);
    audioElement.addEventListener("error", handleError);

    if (!stopped) {
      setMedia(audioElement);
    }

    return () => {
      stopped = true;
      if (audioElement) {
        audioElement.src = "";
        if (handleCanPlay)
          audioElement.removeEventListener("canplay", handleCanPlay);
        if (handleError) audioElement.removeEventListener("error", handleError);
      }
    };
  }, [transcriptId, transcript, later, api_url]);

  const getNow = () => {
    setLater(false);
  };

  const loading = audioLoading || transcriptMetadataLoading;
  const error =
    audioLoadingError ||
    (transcriptError
      ? (transcriptError as any).message || String(transcriptError)
      : null);

  return { media, loading, error, getNow, audioDeleted };
};

export default useMp3;