Adding QR code login

Added the ability to login to the TV via the mobile app
Fixed some other login issues with back button presses not working

Signed-off-by: Lance Chant <13349722+lancechant@users.noreply.github.com>

utils/pairingService.ts

@@ -0,0 +1,142 @@
+import dgram from "react-native-udp";
+
+const PAIRING_PORT = 54322;
+const PAIRING_MESSAGE_TYPE = "streamyfin-pair-response";
+
+export interface PairingCredentials {
+  serverUrl: string;
+  username: string;
+  password: string;
+}
+
+export function generatePairingCode(): string {
+  return String(Math.floor(100000 + Math.random() * 900000));
+}
+
+export function startPairingListener(
+  code: string,
+  onCredentialsReceived: (credentials: PairingCredentials) => void,
+  onError?: (error: string) => void,
+): () => void {
+  let active = true;
+
+  const socket = dgram.createSocket({
+    type: "udp4",
+    reusePort: true,
+    debug: __DEV__,
+  });
+
+  socket.on("error", (err) => {
+    console.error("[PairingService] Socket error:", err);
+    onError?.(err.message);
+    cleanup();
+  });
+
+  socket.bind(PAIRING_PORT, () => {
+    console.log("[PairingService] Listening on port", PAIRING_PORT);
+  });
+
+  socket.on("message", (msg) => {
+    if (!active) return;
+
+    try {
+      const data = JSON.parse(new TextDecoder().decode(msg));
+
+      if (data.type !== PAIRING_MESSAGE_TYPE) return;
+      if (data.code !== code) return;
+
+      if (!data.server_url || !data.username || !data.password) {
+        console.error("[PairingService] Missing fields in pairing response");
+        return;
+      }
+
+      console.log("[PairingService] Credentials received");
+      active = false;
+      onCredentialsReceived({
+        serverUrl: data.server_url,
+        username: data.username,
+        password: data.password,
+      });
+      cleanup();
+    } catch (error) {
+      console.error("[PairingService] Error parsing message:", error);
+    }
+  });
+
+  function cleanup() {
+    active = false;
+    try {
+      socket.close();
+    } catch {
+      // Socket may already be closed
+    }
+  }
+
+  return cleanup;
+}
+
+export function sendCredentialsToTV(
+  code: string,
+  serverUrl: string,
+  username: string,
+  password: string,
+): Promise<void> {
+  return new Promise((resolve, reject) => {
+    const socket = dgram.createSocket({
+      type: "udp4",
+      reusePort: true,
+      debug: __DEV__,
+    });
+
+    const message = JSON.stringify({
+      type: PAIRING_MESSAGE_TYPE,
+      code,
+      server_url: serverUrl,
+      username,
+      password,
+    });
+
+    const messageBuffer = new TextEncoder().encode(message);
+
+    socket.on("error", (err) => {
+      reject(err);
+      try {
+        socket.close();
+      } catch {
+        // Ignore
+      }
+    });
+
+    socket.bind(0, () => {
+      try {
+        socket.setBroadcast(true);
+        socket.send(
+          messageBuffer,
+          0,
+          messageBuffer.length,
+          PAIRING_PORT,
+          "255.255.255.255",
+          (err) => {
+            try {
+              socket.close();
+            } catch {
+              // Ignore
+            }
+            if (err) {
+              reject(err);
+            } else {
+              resolve();
+            }
+          },
+        );
+      } catch (error) {
+        try {
+          socket.close();
+        } catch {
+          // Ignore
+        }
+        reject(error);
+      }
+    });
+  });
+}