Refactor peer connection state machine into separate files

Split the monolithic peer.ts file into a modular state-based architecture:
- Created separate files for each state class (idle, creating-offer, waiting-for-answer, answering, exchanging-ice, connected, failed, closed)
- Extracted shared types into types.ts
- Extracted base PeerState class into state.ts
- Updated peer/index.ts to import state classes instead of defining them inline
- Made close() method async to support dynamic imports and avoid circular dependencies
- Used dynamic imports in state transitions to prevent circular dependency issues

This improves code organization, maintainability, and makes each state's logic easier to understand and test.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/peer/answering-state.ts

@@ -0,0 +1,56 @@
+import { PeerState } from './state.js';
+import type { PeerOptions } from './types.js';
+import type RondevuPeer from './index.js';
+
+/**
+ * Answering an offer and sending to server
+ */
+export class AnsweringState extends PeerState {
+  constructor(peer: RondevuPeer) {
+    super(peer);
+  }
+
+  get name() { return 'answering'; }
+
+  async answer(offerId: string, offerSdp: string, options: PeerOptions): Promise<void> {
+    try {
+      this.peer.role = 'answerer';
+      this.peer.offerId = offerId;
+
+      // Set remote description
+      await this.peer.pc.setRemoteDescription({
+        type: 'offer',
+        sdp: offerSdp
+      });
+
+      // Create answer
+      const answer = await this.peer.pc.createAnswer();
+      await this.peer.pc.setLocalDescription(answer);
+
+      // Send answer to server immediately (don't wait for ICE)
+      await this.peer.offersApi.answer(offerId, answer.sdp!);
+
+      // Enable trickle ICE - send candidates as they arrive
+      this.peer.pc.onicecandidate = async (event: RTCPeerConnectionIceEvent) => {
+        if (event.candidate && offerId) {
+          const candidateData = event.candidate.toJSON();
+          if (candidateData.candidate && candidateData.candidate !== '') {
+            try {
+              await this.peer.offersApi.addIceCandidates(offerId, [candidateData]);
+            } catch (err) {
+              console.error('Error sending ICE candidate:', err);
+            }
+          }
+        }
+      };
+
+      // Transition to exchanging ICE
+      const { ExchangingIceState } = await import('./exchanging-ice-state.js');
+      this.peer.setState(new ExchangingIceState(this.peer, offerId, options));
+    } catch (error) {
+      const { FailedState } = await import('./failed-state.js');
+      this.peer.setState(new FailedState(this.peer, error as Error));
+      throw error;
+    }
+  }
+}

src/peer/closed-state.ts

@@ -0,0 +1,12 @@
+import { PeerState } from './state.js';
+
+/**
+ * Closed state - connection has been terminated
+ */
+export class ClosedState extends PeerState {
+  get name() { return 'closed'; }
+
+  cleanup(): void {
+    this.peer.pc.close();
+  }
+}

src/peer/connected-state.ts

@@ -0,0 +1,13 @@
+import { PeerState } from './state.js';
+
+/**
+ * Connected state - peer connection is established
+ */
+export class ConnectedState extends PeerState {
+  get name() { return 'connected'; }
+
+  cleanup(): void {
+    // Keep connection alive, but stop any polling
+    // The peer connection will handle disconnects via onconnectionstatechange
+  }
+}

src/peer/creating-offer-state.ts

@@ -0,0 +1,66 @@
+import { PeerState } from './state.js';
+import type { PeerOptions } from './types.js';
+import type RondevuPeer from './index.js';
+
+/**
+ * Creating offer and sending to server
+ */
+export class CreatingOfferState extends PeerState {
+  constructor(peer: RondevuPeer, private options: PeerOptions) {
+    super(peer);
+  }
+
+  get name() { return 'creating-offer'; }
+
+  async createOffer(options: PeerOptions): Promise<string> {
+    try {
+      this.peer.role = 'offerer';
+
+      // Create data channel if requested
+      if (options.createDataChannel !== false) {
+        const channel = this.peer.pc.createDataChannel(
+          options.dataChannelLabel || 'data'
+        );
+        this.peer.emitEvent('datachannel', channel);
+      }
+
+      // Create WebRTC offer
+      const offer = await this.peer.pc.createOffer();
+      await this.peer.pc.setLocalDescription(offer);
+
+      // Send offer to server immediately (don't wait for ICE)
+      const offers = await this.peer.offersApi.create([{
+        sdp: offer.sdp!,
+        topics: options.topics,
+        ttl: options.ttl || 300000
+      }]);
+
+      const offerId = offers[0].id;
+      this.peer.offerId = offerId;
+
+      // Enable trickle ICE - send candidates as they arrive
+      this.peer.pc.onicecandidate = async (event: RTCPeerConnectionIceEvent) => {
+        if (event.candidate && offerId) {
+          const candidateData = event.candidate.toJSON();
+          if (candidateData.candidate && candidateData.candidate !== '') {
+            try {
+              await this.peer.offersApi.addIceCandidates(offerId, [candidateData]);
+            } catch (err) {
+              console.error('Error sending ICE candidate:', err);
+            }
+          }
+        }
+      };
+
+      // Transition to waiting for answer
+      const { WaitingForAnswerState } = await import('./waiting-for-answer-state.js');
+      this.peer.setState(new WaitingForAnswerState(this.peer, offerId, options));
+
+      return offerId;
+    } catch (error) {
+      const { FailedState } = await import('./failed-state.js');
+      this.peer.setState(new FailedState(this.peer, error as Error));
+      throw error;
+    }
+  }
+}

src/peer/exchanging-ice-state.ts

@@ -0,0 +1,74 @@
+import { PeerState } from './state.js';
+import type { PeerOptions } from './types.js';
+import type RondevuPeer from './index.js';
+
+/**
+ * Exchanging ICE candidates and waiting for connection
+ */
+export class ExchangingIceState extends PeerState {
+  private pollingInterval?: ReturnType<typeof setInterval>;
+  private timeout?: ReturnType<typeof setTimeout>;
+  private lastIceTimestamp = 0;
+
+  constructor(
+    peer: RondevuPeer,
+    private offerId: string,
+    private options: PeerOptions
+  ) {
+    super(peer);
+    this.startPolling();
+  }
+
+  get name() { return 'exchanging-ice'; }
+
+  private startPolling(): void {
+    const connectionTimeout = this.options.timeouts?.iceConnection || 30000;
+
+    this.timeout = setTimeout(async () => {
+      this.cleanup();
+      const { FailedState } = await import('./failed-state.js');
+      this.peer.setState(new FailedState(
+        this.peer,
+        new Error('ICE connection timeout')
+      ));
+    }, connectionTimeout);
+
+    this.pollingInterval = setInterval(async () => {
+      try {
+        const candidates = await this.peer.offersApi.getIceCandidates(
+          this.offerId,
+          this.lastIceTimestamp
+        );
+
+        for (const cand of candidates) {
+          if (cand.candidate && cand.candidate.candidate && cand.candidate.candidate !== '') {
+            try {
+              await this.peer.pc.addIceCandidate(new RTCIceCandidate(cand.candidate));
+              this.lastIceTimestamp = cand.createdAt;
+            } catch (err) {
+              console.warn('Failed to add ICE candidate:', err);
+              this.lastIceTimestamp = cand.createdAt;
+            }
+          } else {
+            this.lastIceTimestamp = cand.createdAt;
+          }
+        }
+      } catch (err) {
+        console.error('Error polling for ICE candidates:', err);
+        if (err instanceof Error && err.message.includes('not found')) {
+          this.cleanup();
+          const { FailedState } = await import('./failed-state.js');
+          this.peer.setState(new FailedState(
+            this.peer,
+            new Error('Offer expired or not found')
+          ));
+        }
+      }
+    }, 1000);
+  }
+
+  cleanup(): void {
+    if (this.pollingInterval) clearInterval(this.pollingInterval);
+    if (this.timeout) clearTimeout(this.timeout);
+  }
+}

src/peer/failed-state.ts

@@ -0,0 +1,18 @@
+import { PeerState } from './state.js';
+
+/**
+ * Failed state - connection attempt failed
+ */
+export class FailedState extends PeerState {
+  constructor(peer: any, private error: Error) {
+    super(peer);
+    peer.emitEvent('failed', error);
+  }
+
+  get name() { return 'failed'; }
+
+  cleanup(): void {
+    // Connection is failed, clean up resources
+    this.peer.pc.close();
+  }
+}

src/peer/idle-state.ts

@@ -0,0 +1,18 @@
+import { PeerState } from './state.js';
+import type { PeerOptions } from './types.js';
+
+export class IdleState extends PeerState {
+  get name() { return 'idle'; }
+
+  async createOffer(options: PeerOptions): Promise<string> {
+    const { CreatingOfferState } = await import('./creating-offer-state.js');
+    this.peer.setState(new CreatingOfferState(this.peer, options));
+    return this.peer.state.createOffer(options);
+  }
+
+  async answer(offerId: string, offerSdp: string, options: PeerOptions): Promise<void> {
+    const { AnsweringState } = await import('./answering-state.js');
+    this.peer.setState(new AnsweringState(this.peer));
+    return this.peer.state.answer(offerId, offerSdp, options);
+  }
+}

src/peer/index.ts

@@ -1,395 +1,18 @@
 import { RondevuOffers } from '../offers.js';
 import { EventEmitter } from '../event-emitter.js';
+import type { PeerOptions, PeerEvents } from './types.js';
+import { PeerState } from './state.js';
+import { IdleState } from './idle-state.js';
+import { CreatingOfferState } from './creating-offer-state.js';
+import { WaitingForAnswerState } from './waiting-for-answer-state.js';
+import { AnsweringState } from './answering-state.js';
+import { ExchangingIceState } from './exchanging-ice-state.js';
+import { ConnectedState } from './connected-state.js';
+import { FailedState } from './failed-state.js';
+import { ClosedState } from './closed-state.js';
 
-/**
- * Timeout configurations for different connection phases
- */
-export interface PeerTimeouts {
-  /** Timeout for ICE gathering (default: 10000ms) */
-  iceGathering?: number;
-  /** Timeout for waiting for answer (default: 30000ms) */
-  waitingForAnswer?: number;
-  /** Timeout for creating answer (default: 10000ms) */
-  creatingAnswer?: number;
-  /** Timeout for ICE connection (default: 30000ms) */
-  iceConnection?: number;
-}
-
-/**
- * Options for creating a peer connection
- */
-export interface PeerOptions {
-  /** RTCConfiguration for the peer connection */
-  rtcConfig?: RTCConfiguration;
-  /** Topics to advertise this connection under */
-  topics: string[];
-  /** How long the offer should live (milliseconds) */
-  ttl?: number;
-  /** Whether to create a data channel automatically (for offerer) */
-  createDataChannel?: boolean;
-  /** Label for the automatically created data channel */
-  dataChannelLabel?: string;
-  /** Timeout configurations */
-  timeouts?: PeerTimeouts;
-}
-
-/**
- * Events emitted by RondevuPeer
- */
-export interface PeerEvents extends Record<string, (...args: any[]) => void> {
-  'state': (state: string) => void;
-  'connected': () => void;
-  'disconnected': () => void;
-  'failed': (error: Error) => void;
-  'datachannel': (channel: RTCDataChannel) => void;
-  'track': (event: RTCTrackEvent) => void;
-}
-
-/**
- * Base class for peer connection states
- */
-abstract class PeerState {
-  constructor(protected peer: RondevuPeer) {}
-
-  abstract get name(): string;
-
-  async createOffer(options: PeerOptions): Promise<string> {
-    throw new Error(`Cannot create offer in ${this.name} state`);
-  }
-
-  async answer(offerId: string, offerSdp: string, options: PeerOptions): Promise<void> {
-    throw new Error(`Cannot answer in ${this.name} state`);
-  }
-
-  async handleAnswer(sdp: string): Promise<void> {
-    throw new Error(`Cannot handle answer in ${this.name} state`);
-  }
-
-  async handleIceCandidate(candidate: any): Promise<void> {
-    // ICE candidates can arrive in multiple states, so default is to add them
-    if (this.peer.pc.remoteDescription) {
-      await this.peer.pc.addIceCandidate(new RTCIceCandidate(candidate));
-    }
-  }
-
-  cleanup(): void {
-    // Override in states that need cleanup
-  }
-
-  close(): void {
-    this.cleanup();
-    this.peer.setState(new ClosedState(this.peer));
-  }
-}
-
-/**
- * Initial idle state
- */
-class IdleState extends PeerState {
-  get name() { return 'idle'; }
-
-  async createOffer(options: PeerOptions): Promise<string> {
-    this.peer.setState(new CreatingOfferState(this.peer, options));
-    return this.peer.state.createOffer(options);
-  }
-
-  async answer(offerId: string, offerSdp: string, options: PeerOptions): Promise<void> {
-    this.peer.setState(new AnsweringState(this.peer));
-    return this.peer.state.answer(offerId, offerSdp, options);
-  }
-}
-
-/**
- * Creating offer and sending to server
- */
-class CreatingOfferState extends PeerState {
-  constructor(peer: RondevuPeer, private options: PeerOptions) {
-    super(peer);
-  }
-
-  get name() { return 'creating-offer'; }
-
-  async createOffer(options: PeerOptions): Promise<string> {
-    try {
-      this.peer.role = 'offerer';
-
-      // Create data channel if requested
-      if (options.createDataChannel !== false) {
-        const channel = this.peer.pc.createDataChannel(
-          options.dataChannelLabel || 'data'
-        );
-        this.peer.emitEvent('datachannel', channel);
-      }
-
-      // Create WebRTC offer
-      const offer = await this.peer.pc.createOffer();
-      await this.peer.pc.setLocalDescription(offer);
-
-      // Send offer to server immediately (don't wait for ICE)
-      const offers = await this.peer.offersApi.create([{
-        sdp: offer.sdp!,
-        topics: options.topics,
-        ttl: options.ttl || 300000
-      }]);
-
-      const offerId = offers[0].id;
-      this.peer.offerId = offerId;
-
-      // Enable trickle ICE - send candidates as they arrive
-      this.peer.pc.onicecandidate = async (event) => {
-        if (event.candidate && offerId) {
-          const candidateData = event.candidate.toJSON();
-          if (candidateData.candidate && candidateData.candidate !== '') {
-            try {
-              await this.peer.offersApi.addIceCandidates(offerId, [candidateData]);
-            } catch (err) {
-              console.error('Error sending ICE candidate:', err);
-            }
-          }
-        }
-      };
-
-      // Transition to waiting for answer
-      this.peer.setState(new WaitingForAnswerState(this.peer, offerId, options));
-
-      return offerId;
-    } catch (error) {
-      this.peer.setState(new FailedState(this.peer, error as Error));
-      throw error;
-    }
-  }
-}
-
-/**
- * Waiting for answer from another peer
- */
-class WaitingForAnswerState extends PeerState {
-  private pollingInterval?: ReturnType<typeof setInterval>;
-  private timeout?: ReturnType<typeof setTimeout>;
-
-  constructor(
-    peer: RondevuPeer,
-    private offerId: string,
-    private options: PeerOptions
-  ) {
-    super(peer);
-    this.startPolling();
-  }
-
-  get name() { return 'waiting-for-answer'; }
-
-  private startPolling(): void {
-    const answerTimeout = this.options.timeouts?.waitingForAnswer || 30000;
-
-    this.timeout = setTimeout(() => {
-      this.cleanup();
-      this.peer.setState(new FailedState(
-        this.peer,
-        new Error('Timeout waiting for answer')
-      ));
-    }, answerTimeout);
-
-    this.pollingInterval = setInterval(async () => {
-      try {
-        const answers = await this.peer.offersApi.getAnswers();
-        const myAnswer = answers.find(a => a.offerId === this.offerId);
-
-        if (myAnswer) {
-          this.cleanup();
-          await this.handleAnswer(myAnswer.sdp);
-        }
-      } catch (err) {
-        console.error('Error polling for answers:', err);
-        if (err instanceof Error && err.message.includes('not found')) {
-          this.cleanup();
-          this.peer.setState(new FailedState(
-            this.peer,
-            new Error('Offer expired or not found')
-          ));
-        }
-      }
-    }, 2000);
-  }
-
-  async handleAnswer(sdp: string): Promise<void> {
-    try {
-      await this.peer.pc.setRemoteDescription({
-        type: 'answer',
-        sdp
-      });
-
-      // Transition to exchanging ICE
-      this.peer.setState(new ExchangingIceState(this.peer, this.offerId, this.options));
-    } catch (error) {
-      this.peer.setState(new FailedState(this.peer, error as Error));
-    }
-  }
-
-  cleanup(): void {
-    if (this.pollingInterval) clearInterval(this.pollingInterval);
-    if (this.timeout) clearTimeout(this.timeout);
-  }
-}
-
-/**
- * Answering an offer and sending to server
- */
-class AnsweringState extends PeerState {
-  constructor(peer: RondevuPeer) {
-    super(peer);
-  }
-
-  get name() { return 'answering'; }
-
-  async answer(offerId: string, offerSdp: string, options: PeerOptions): Promise<void> {
-    try {
-      this.peer.role = 'answerer';
-      this.peer.offerId = offerId;
-
-      // Set remote description
-      await this.peer.pc.setRemoteDescription({
-        type: 'offer',
-        sdp: offerSdp
-      });
-
-      // Create answer
-      const answer = await this.peer.pc.createAnswer();
-      await this.peer.pc.setLocalDescription(answer);
-
-      // Send answer to server immediately (don't wait for ICE)
-      await this.peer.offersApi.answer(offerId, answer.sdp!);
-
-      // Enable trickle ICE - send candidates as they arrive
-      this.peer.pc.onicecandidate = async (event) => {
-        if (event.candidate && offerId) {
-          const candidateData = event.candidate.toJSON();
-          if (candidateData.candidate && candidateData.candidate !== '') {
-            try {
-              await this.peer.offersApi.addIceCandidates(offerId, [candidateData]);
-            } catch (err) {
-              console.error('Error sending ICE candidate:', err);
-            }
-          }
-        }
-      };
-
-      // Transition to exchanging ICE
-      this.peer.setState(new ExchangingIceState(this.peer, offerId, options));
-    } catch (error) {
-      this.peer.setState(new FailedState(this.peer, error as Error));
-      throw error;
-    }
-  }
-}
-
-/**
- * Exchanging ICE candidates and waiting for connection
- */
-class ExchangingIceState extends PeerState {
-  private pollingInterval?: ReturnType<typeof setInterval>;
-  private timeout?: ReturnType<typeof setTimeout>;
-  private lastIceTimestamp = 0;
-
-  constructor(
-    peer: RondevuPeer,
-    private offerId: string,
-    private options: PeerOptions
-  ) {
-    super(peer);
-    this.startPolling();
-  }
-
-  get name() { return 'exchanging-ice'; }
-
-  private startPolling(): void {
-    const connectionTimeout = this.options.timeouts?.iceConnection || 30000;
-
-    this.timeout = setTimeout(() => {
-      this.cleanup();
-      this.peer.setState(new FailedState(
-        this.peer,
-        new Error('ICE connection timeout')
-      ));
-    }, connectionTimeout);
-
-    this.pollingInterval = setInterval(async () => {
-      try {
-        const candidates = await this.peer.offersApi.getIceCandidates(
-          this.offerId,
-          this.lastIceTimestamp
-        );
-
-        for (const cand of candidates) {
-          if (cand.candidate && cand.candidate.candidate && cand.candidate.candidate !== '') {
-            try {
-              await this.peer.pc.addIceCandidate(new RTCIceCandidate(cand.candidate));
-              this.lastIceTimestamp = cand.createdAt;
-            } catch (err) {
-              console.warn('Failed to add ICE candidate:', err);
-              this.lastIceTimestamp = cand.createdAt;
-            }
-          } else {
-            this.lastIceTimestamp = cand.createdAt;
-          }
-        }
-      } catch (err) {
-        console.error('Error polling for ICE candidates:', err);
-        if (err instanceof Error && err.message.includes('not found')) {
-          this.cleanup();
-          this.peer.setState(new FailedState(
-            this.peer,
-            new Error('Offer expired or not found')
-          ));
-        }
-      }
-    }, 1000);
-  }
-
-  cleanup(): void {
-    if (this.pollingInterval) clearInterval(this.pollingInterval);
-    if (this.timeout) clearTimeout(this.timeout);
-  }
-}
-
-/**
- * Successfully connected state
- */
-class ConnectedState extends PeerState {
-  get name() { return 'connected'; }
-
-  cleanup(): void {
-    // Keep connection alive, but stop any polling
-    // The peer connection will handle disconnects via onconnectionstatechange
-  }
-}
-
-/**
- * Failed state
- */
-class FailedState extends PeerState {
-  constructor(peer: RondevuPeer, private error: Error) {
-    super(peer);
-    peer.emitEvent('failed', error);
-  }
-
-  get name() { return 'failed'; }
-
-  cleanup(): void {
-    // Connection is failed, clean up resources
-    this.peer.pc.close();
-  }
-}
-
-/**
- * Closed state
- */
-class ClosedState extends PeerState {
-  get name() { return 'closed'; }
-
-  cleanup(): void {
-    this.peer.pc.close();
-  }
-}
+// Re-export types for external consumers
+export type { PeerTimeouts, PeerOptions, PeerEvents } from './types.js';
 
 /**
  * High-level WebRTC peer connection manager with state-based lifecycle
@@ -521,8 +144,8 @@ export default class RondevuPeer extends EventEmitter<PeerEvents> {
   /**
    * Close the connection and clean up
    */
-  close(): void {
-    this._state.close();
+  async close(): Promise<void> {
+    await this._state.close();
     this.removeAllListeners();
   }
 }

src/peer/state.ts

@@ -0,0 +1,41 @@
+import type { PeerOptions } from './types.js';
+import type RondevuPeer from './index.js';
+
+/**
+ * Base class for peer connection states
+ * Implements the State pattern for managing WebRTC connection lifecycle
+ */
+export abstract class PeerState {
+  constructor(protected peer: RondevuPeer) {}
+
+  abstract get name(): string;
+
+  async createOffer(options: PeerOptions): Promise<string> {
+    throw new Error(`Cannot create offer in ${this.name} state`);
+  }
+
+  async answer(offerId: string, offerSdp: string, options: PeerOptions): Promise<void> {
+    throw new Error(`Cannot answer in ${this.name} state`);
+  }
+
+  async handleAnswer(sdp: string): Promise<void> {
+    throw new Error(`Cannot handle answer in ${this.name} state`);
+  }
+
+  async handleIceCandidate(candidate: any): Promise<void> {
+    // ICE candidates can arrive in multiple states, so default is to add them
+    if (this.peer.pc.remoteDescription) {
+      await this.peer.pc.addIceCandidate(new RTCIceCandidate(candidate));
+    }
+  }
+
+  cleanup(): void {
+    // Override in states that need cleanup
+  }
+
+  async close(): Promise<void> {
+    this.cleanup();
+    const { ClosedState } = await import('./closed-state.js');
+    this.peer.setState(new ClosedState(this.peer));
+  }
+}

src/peer/types.ts

@@ -0,0 +1,43 @@
+/**
+ * Timeout configurations for different connection phases
+ */
+export interface PeerTimeouts {
+  /** Timeout for ICE gathering (default: 10000ms) */
+  iceGathering?: number;
+  /** Timeout for waiting for answer (default: 30000ms) */
+  waitingForAnswer?: number;
+  /** Timeout for creating answer (default: 10000ms) */
+  creatingAnswer?: number;
+  /** Timeout for ICE connection (default: 30000ms) */
+  iceConnection?: number;
+}
+
+/**
+ * Options for creating a peer connection
+ */
+export interface PeerOptions {
+  /** RTCConfiguration for the peer connection */
+  rtcConfig?: RTCConfiguration;
+  /** Topics to advertise this connection under */
+  topics: string[];
+  /** How long the offer should live (milliseconds) */
+  ttl?: number;
+  /** Whether to create a data channel automatically (for offerer) */
+  createDataChannel?: boolean;
+  /** Label for the automatically created data channel */
+  dataChannelLabel?: string;
+  /** Timeout configurations */
+  timeouts?: PeerTimeouts;
+}
+
+/**
+ * Events emitted by RondevuPeer
+ */
+export interface PeerEvents extends Record<string, (...args: any[]) => void> {
+  'state': (state: string) => void;
+  'connected': () => void;
+  'disconnected': () => void;
+  'failed': (error: Error) => void;
+  'datachannel': (channel: RTCDataChannel) => void;
+  'track': (event: RTCTrackEvent) => void;
+}

src/peer/waiting-for-answer-state.ts

@@ -0,0 +1,78 @@
+import { PeerState } from './state.js';
+import type { PeerOptions } from './types.js';
+import type RondevuPeer from './index.js';
+
+/**
+ * Waiting for answer from another peer
+ */
+export class WaitingForAnswerState extends PeerState {
+  private pollingInterval?: ReturnType<typeof setInterval>;
+  private timeout?: ReturnType<typeof setTimeout>;
+
+  constructor(
+    peer: RondevuPeer,
+    private offerId: string,
+    private options: PeerOptions
+  ) {
+    super(peer);
+    this.startPolling();
+  }
+
+  get name() { return 'waiting-for-answer'; }
+
+  private startPolling(): void {
+    const answerTimeout = this.options.timeouts?.waitingForAnswer || 30000;
+
+    this.timeout = setTimeout(async () => {
+      this.cleanup();
+      const { FailedState } = await import('./failed-state.js');
+      this.peer.setState(new FailedState(
+        this.peer,
+        new Error('Timeout waiting for answer')
+      ));
+    }, answerTimeout);
+
+    this.pollingInterval = setInterval(async () => {
+      try {
+        const answers = await this.peer.offersApi.getAnswers();
+        const myAnswer = answers.find((a: any) => a.offerId === this.offerId);
+
+        if (myAnswer) {
+          this.cleanup();
+          await this.handleAnswer(myAnswer.sdp);
+        }
+      } catch (err) {
+        console.error('Error polling for answers:', err);
+        if (err instanceof Error && err.message.includes('not found')) {
+          this.cleanup();
+          const { FailedState } = await import('./failed-state.js');
+          this.peer.setState(new FailedState(
+            this.peer,
+            new Error('Offer expired or not found')
+          ));
+        }
+      }
+    }, 2000);
+  }
+
+  async handleAnswer(sdp: string): Promise<void> {
+    try {
+      await this.peer.pc.setRemoteDescription({
+        type: 'answer',
+        sdp
+      });
+
+      // Transition to exchanging ICE
+      const { ExchangingIceState } = await import('./exchanging-ice-state.js');
+      this.peer.setState(new ExchangingIceState(this.peer, this.offerId, this.options));
+    } catch (error) {
+      const { FailedState } = await import('./failed-state.js');
+      this.peer.setState(new FailedState(this.peer, error as Error));
+    }
+  }
+
+  cleanup(): void {
+    if (this.pollingInterval) clearInterval(this.pollingInterval);
+    if (this.timeout) clearTimeout(this.timeout);
+  }
+}