Refactor VPN proxy client implementation

src/server/sharedProxy.ts

@@ -0,0 +1,50 @@
+function proxyHostFromHeader(hostHeader: unknown) {
+  const raw = String(hostHeader || "").trim();
+  if (!raw) return "";
+  if (raw.startsWith("[")) {
+    const end = raw.indexOf("]");
+    return end > 0 ? raw.slice(1, end) : "";
+  }
+  return raw.split(":")[0];
+}
+
+export function buildSharedProxyInfo({
+  appMode,
+  proxyPort,
+  running,
+  hostHeader,
+  sharedProxyHost,
+}: {
+  appMode: unknown;
+  proxyPort: unknown;
+  running: unknown;
+  hostHeader: unknown;
+  sharedProxyHost: unknown;
+}) {
+  const host = String(sharedProxyHost || "").trim() || proxyHostFromHeader(hostHeader);
+  const port = Number.parseInt(String(proxyPort), 10);
+  const available =
+    appMode === "gateway" &&
+    Boolean(running) &&
+    host &&
+    Number.isInteger(port) &&
+    port > 0 &&
+    port <= 65535;
+
+  const proxy = available
+    ? {
+        host,
+        port,
+        protocol: "socks5",
+        httpUrl: `http://${host}:${port}`,
+        socksUrl: `socks5://${host}:${port}`,
+      }
+    : null;
+
+  return {
+    success: true,
+    available,
+    mode: appMode,
+    proxy,
+  };
+}