feat: embed a Flutter G4F client with Cronet, cookie jar, and origin WebView

Port the Oracle off the Python g4f container onto on-device providers: Chromium HTTP via Cronet, a shared cookie session, IterList retry, hosted OpenAI-compat aggregators, and same-origin WebView fallbacks instead of CORS fetch.
2026-09-01 22:05:38 +05:00
parent f3e7412cf9
commit fbf04d90db
49 changed files with 4856 additions and 92 deletions
@@ -0,0 +1,75 @@
+const kBrowserUserAgent =
+    'Mozilla/5.0 (Linux; Android 14; Pixel 8 Pro) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Mobile Safari/537.36';
+
+const kDesktopUserAgent =
+    'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36';
+
+Map<String, String> browserHeaders({
+  String? origin,
+  String? referer,
+  String? accept,
+  String? contentType,
+  bool desktop = false,
+  Map<String, String>? extra,
+}) {
+  return {
+    'User-Agent': desktop ? kDesktopUserAgent : kBrowserUserAgent,
+    'Accept': accept ?? '*/*',
+    'Accept-Language': 'en-US,en;q=0.9',
+    if (origin != null) 'Origin': origin,
+    if (referer != null) 'Referer': referer,
+    if (contentType != null) 'Content-Type': contentType,
+    ...?extra,
+  };
+}
+
+/// True when a provider dumped an error page / WAF / paywall instead of model text.
+bool looksLikeGarbage(String text) {
+  final t = text.trimLeft();
+  if (t.isEmpty) return true;
+  final lower = t.toLowerCase();
+  if (t.startsWith('<!DOCTYPE') || t.startsWith('<html') || t.startsWith('<HTML')) {
+    return true;
+  }
+  if (lower.contains('just a moment') ||
+      lower.contains('cf-browser-verification') ||
+      lower.contains('attention required') ||
+      lower.contains('payment required') ||
+      lower.contains('frontend_captcha') ||
+      lower.contains('err_challenge') ||
+      lower.contains('error code:') ||
+      lower.contains('missing api key') ||
+      lower.contains('invalid api key') ||
+      lower.contains('you have to be logged in') ||
+      lower.contains('no cake credits') ||
+      lower.contains('insufficient_credits')) {
+    return true;
+  }
+  return false;
+}
+
+bool looksLikeModelOutput(String text) {
+  final trimmed = text.trim();
+  if (trimmed.length < 8) return false;
+  final lower = trimmed.toLowerCase();
+  if (lower == ': ping' || lower == 'ping' || lower == 'pong' || lower == '{}') {
+    return false;
+  }
+  if (RegExp(r'^[\{\}\[\]":\s]+$').hasMatch(trimmed)) return false;
+  return !looksLikeGarbage(trimmed);
+}
+
+String? cookieHeaderFromSetCookie(String? setCookie, {String? name}) {
+  if (setCookie == null || setCookie.isEmpty) return null;
+  // http package may join multiple Set-Cookie values with ", ".
+  final parts = setCookie.split(RegExp(r',(?=\s*[^;=]+=)'));
+  final pairs = <String>[];
+  for (final part in parts) {
+    final nv = part.split(';').first.trim();
+    if (nv.isEmpty || !nv.contains('=')) continue;
+    if (name != null && !nv.startsWith('$name=')) continue;
+    pairs.add(nv);
+  }
+  if (pairs.isEmpty) return null;
+  return pairs.join('; ');
+}