first commit

src/hooks/useWhepPlayer.ts

@@ -0,0 +1,177 @@
+import { useCallback, useEffect, useMemo, useRef, useState } from "react";
+
+type PlayerStatus = "idle" | "connecting" | "playing" | "error";
+
+function withNoTrailingSlash(url: string) {
+  return url.endsWith("/") ? url.slice(0, -1) : url;
+}
+
+async function waitForIceGatheringComplete(pc: RTCPeerConnection) {
+  if (pc.iceGatheringState === "complete") return;
+  await new Promise<void>((resolve) => {
+    const onState = () => {
+      if (pc.iceGatheringState === "complete") {
+        pc.removeEventListener("icegatheringstatechange", onState);
+        resolve();
+      }
+    };
+    pc.addEventListener("icegatheringstatechange", onState);
+  });
+}
+
+export function useWhepPlayer({
+  enabled,
+  webrtcBaseUrl,
+  streamName,
+}: {
+  enabled: boolean;
+  webrtcBaseUrl: string;
+  streamName: string;
+}) {
+  const videoRef = useRef<HTMLVideoElement | null>(null);
+  const pcRef = useRef<RTCPeerConnection | null>(null);
+  const sessionUrlRef = useRef<string | null>(null);
+  const abortRef = useRef<AbortController | null>(null);
+  const [status, setStatus] = useState<PlayerStatus>("idle");
+  const [error, setError] = useState<string | null>(null);
+  const [restartNonce, setRestartNonce] = useState(0);
+
+  const whepUrl = useMemo(() => {
+    return `${withNoTrailingSlash(webrtcBaseUrl)}/${encodeURIComponent(streamName)}/whep`;
+  }, [webrtcBaseUrl, streamName]);
+
+  const stop = useCallback(async () => {
+    abortRef.current?.abort();
+    abortRef.current = null;
+
+    const sessionUrl = sessionUrlRef.current;
+    sessionUrlRef.current = null;
+
+    const pc = pcRef.current;
+    pcRef.current = null;
+
+    if (pc) {
+      try {
+        pc.ontrack = null;
+        pc.onconnectionstatechange = null;
+        pc.oniceconnectionstatechange = null;
+        pc.close();
+      } catch {
+      }
+    }
+
+    const v = videoRef.current;
+    if (v) {
+      try {
+        v.srcObject = null;
+        v.removeAttribute("src");
+      } catch {
+      }
+    }
+
+    if (sessionUrl) {
+      try {
+        await fetch(sessionUrl, { method: "DELETE" });
+      } catch {
+      }
+    }
+  }, []);
+
+  const restart = useCallback(() => {
+    setRestartNonce((n) => n + 1);
+  }, []);
+
+  useEffect(() => {
+    let disposed = false;
+
+    const run = async () => {
+      await stop();
+      if (!enabled) {
+        setStatus("idle");
+        setError(null);
+        return;
+      }
+
+      setStatus("connecting");
+      setError(null);
+
+      const abort = new AbortController();
+      abortRef.current = abort;
+
+      try {
+        const videoEl = videoRef.current;
+        if (!videoEl) throw new Error("no_video");
+
+        const pc = new RTCPeerConnection();
+        pcRef.current = pc;
+
+        pc.addTransceiver("video", { direction: "recvonly" });
+        pc.addTransceiver("audio", { direction: "recvonly" });
+
+        pc.ontrack = (ev) => {
+          const stream = ev.streams?.[0];
+          if (!stream) return;
+          if (videoEl.srcObject !== stream) {
+            videoEl.srcObject = stream;
+            void videoEl.play().catch(() => undefined);
+          }
+        };
+
+        pc.onconnectionstatechange = () => {
+          if (pc.connectionState === "failed") {
+            restart();
+          }
+        };
+
+        const offer = await pc.createOffer();
+        await pc.setLocalDescription(offer);
+        await waitForIceGatheringComplete(pc);
+
+        const sdpOffer = pc.localDescription?.sdp;
+        if (!sdpOffer) throw new Error("no_offer");
+
+        const res = await fetch(whepUrl, {
+          method: "POST",
+          headers: {
+            "Content-Type": "application/sdp",
+            Accept: "application/sdp",
+          },
+          body: sdpOffer,
+          signal: abort.signal,
+        });
+
+        if (!res.ok) {
+          const t = await res.text().catch(() => "");
+          throw new Error(`whep_http_${res.status}${t ? `: ${t}` : ""}`);
+        }
+
+        const answerSdp = await res.text();
+        const location = res.headers.get("location") || res.headers.get("Location");
+        if (location) sessionUrlRef.current = location;
+
+        await pc.setRemoteDescription({ type: "answer", sdp: answerSdp });
+        if (!disposed) setStatus("playing");
+      } catch (e) {
+        if (!disposed) {
+          setStatus("error");
+          setError(e instanceof Error ? e.message : "unknown_error");
+        }
+      }
+    };
+
+    run();
+    return () => {
+      disposed = true;
+      void stop();
+    };
+  }, [enabled, restartNonce, stop, whepUrl, restart]);
+
+  return {
+    videoRef,
+    status,
+    error,
+    restart,
+    stop,
+  };
+}
+