// Drive a self-managed Telecom call session alongside the active DM call
// (docs/plans/telecom_migration.md, Phase B). Mirror of
// useAndroidCallForegroundSync: keyed to the widget's JoinCall signal (via
// useCallJoined), not the mere presence of callEmbedAtom.
//
// What this gives us once TELECOM_ENABLED is flipped on:
//   - the Vojo call is registered with the OS as a real call → cellular-call
//     interop (an incoming GSM call holds/arbitrates against it), audio-focus
//     arbitration, and a system "ongoing call" presence;
//   - a remote/system Telecom disconnect (the user takes a GSM call, or a
//     Bluetooth/Android-Auto "end call") tears the Vojo call down too;
//   - Telecom owns the audio route, so its active endpoint is mirrored into the
//     speaker-toggle atom (earpiece / speaker / Bluetooth all reflected).
//
// §4 (validated on Samsung One UI: the call gets system call-audio focus and
// the route endpoint flow emits cleanly): Telecom owns routing. The speaker
// toggle now drives Telecom endpoints (see useCallSpeaker) and AudioRoutePlugin
// is kept off the audio session while a Telecom call is live.
//
// Android-only, and additionally gated on TELECOM_ENABLED + API>=26 inside
// telecomCall — on web / iOS / old Android every call here is a no-op.

import { useEffect } from 'react';
import { useAtomValue, useSetAtom, useStore } from 'jotai';
import { callEmbedAtom, callSpeakerAtom } from '../state/callEmbed';
import { telecomCall, type TelecomRoute } from '../plugins/call/telecomCall';
import { useCallJoined } from './useCallEmbed';

export const useTelecomConnectionSync = (): void => {
  const callEmbed = useAtomValue(callEmbedAtom);
  const joined = useCallJoined(callEmbed);
  const store = useStore();
  const setSpeaker = useSetAtom(callSpeakerAtom);

  useEffect(() => {
    if (!telecomCall.enabled()) return undefined;
    if (!callEmbed || !joined) return undefined;

    let cancelled = false;
    const removers: Array<() => void> = [];
    const track = (p: ReturnType<typeof telecomCall.addListener>) => {
      p.then((handle) => {
        if (cancelled) handle.remove();
        else removers.push(() => handle.remove());
      }).catch(() => {
        /* listener registration best-effort */
      });
    };

    telecomCall
      .startCall({
        roomId: callEmbed.roomId,
        // For a DM the room name resolves to the peer's display name; good
        // enough for the system call label. Refined per-direction later.
        displayName: callEmbed.room.name || 'Vojo',
        video: !callEmbed.voiceOnly,
        incoming: false,
      })
      .catch((err: unknown) => {
        // eslint-disable-next-line no-console
        console.warn('[telecom] startCall failed', err);
      });

    // A Telecom-side disconnect we did NOT initiate (interrupting cellular
    // call, BT/Auto "end", system) ends the Vojo call too. hangup() lets
    // Element Call tear LiveKit down; the resulting Hangup event clears the
    // atom, which unmounts this effect and fires endCall() below. Idempotent:
    // our own hangup re-entering here is a no-op via the current-embed guard.
    track(
      telecomCall.addListener('telecomDisconnect', () => {
        if (store.get(callEmbedAtom) !== callEmbed) return;
        callEmbed.hangup().catch(() => {
          /* widget already gone */
        });
      })
    );

    // Telecom owns the route; reflect the active endpoint in the speaker-toggle
    // atom so the UI tracks reality (speaker vs earpiece/Bluetooth/wired).
    track(
      telecomCall.addListener('telecomEndpoint', (data: { route: TelecomRoute }) => {
        setSpeaker(data.route === 'SPEAKER');
      })
    );

    return () => {
      cancelled = true;
      removers.forEach((remove) => remove());
      telecomCall.endCall().catch(() => {
        /* best-effort teardown */
      });
    };
  }, [callEmbed, joined, store, setSpeaker]);
};