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import type { Answer } from '@/shared/contracts/signaling.ts';
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export async function gatheredAnswer(peer: RTCPeerConnection): Promise<Answer> {
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  await peer.setLocalDescription(await peer.createAnswer());
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  if (peer.iceGatheringState !== 'complete')
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    await new Promise<void>((resolve, reject) => {
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      const timer = setTimeout(() => {
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        cleanup();
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        reject(new Error('Connection setup timed out. Try again.'));
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      }, 10000);
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      const changed = () => {
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        if (peer.iceGatheringState === 'complete') {
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          cleanup();
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          resolve();
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        }
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      };
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      const closed = () => {
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        if (peer.connectionState === 'closed') {
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          cleanup();
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          reject(new Error('Connection cancelled.'));
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        }
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      };
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      function cleanup() {
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        clearTimeout(timer);
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        peer.removeEventListener('icegatheringstatechange', changed);
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        peer.removeEventListener('connectionstatechange', closed);
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      }
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      peer.addEventListener('icegatheringstatechange', changed);
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      peer.addEventListener('connectionstatechange', closed);
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      changed();
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      closed();
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    });
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  if (!peer.localDescription?.sdp) throw new Error('Could not set up the connection. Try again.');
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  return { type: 'answer', sdp: peer.localDescription.sdp };
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}
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export async function acknowledge(channel: RTCDataChannel): Promise<void> {
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  if (channel.readyState !== 'open')
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    await new Promise<void>((resolve, reject) => {
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      const timer = setTimeout(() => {
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        cleanup();
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        reject(new Error(`The ${channel.label} channel did not open. Try again.`));
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      }, 15000);
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      const opened = () => {
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        cleanup();
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        resolve();
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      };
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      const failed = () => {
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        cleanup();
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        reject(new Error('Data channel closed during setup. Try again.'));
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      };
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      function cleanup() {
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        clearTimeout(timer);
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        channel.removeEventListener('open', opened);
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        channel.removeEventListener('close', failed);
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        channel.removeEventListener('error', failed);
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      }
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      channel.addEventListener('open', opened);
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      channel.addEventListener('close', failed);
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      channel.addEventListener('error', failed);
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      if (channel.readyState === 'closed' || channel.readyState === 'closing') failed();
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    });
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  channel.send('ack');
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}