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 +1,191 @@
+/// In-process cookie jar. Python g4f keeps a curl_cffi session; Dart/Cronet
+/// does not, so every provider must share cookies across GET-then-POST.
+class G4fCookieJar {
+  final Map<String, _StoredCookie> _cookies = {};
+
+  int get length => _cookies.length;
+
+  void clear() => _cookies.clear();
+
+  void set({
+    required String name,
+    required String value,
+    required String domain,
+    String path = '/',
+    DateTime? expires,
+    bool secure = false,
+    bool hostOnly = true,
+  }) {
+    if (name.isEmpty) return;
+    final canon = _canonDomain(domain);
+    if (canon.isEmpty) return;
+    final key = _key(canon, path, name);
+    if (value.isEmpty && expires != null) {
+      _cookies.remove(key);
+      return;
+    }
+    _cookies[key] = _StoredCookie(
+      name: name,
+      value: value,
+      domain: canon,
+      path: path.isEmpty ? '/' : path,
+      expires: expires,
+      secure: secure,
+      hostOnly: hostOnly,
+    );
+  }
+
+  /// Parse `Set-Cookie` from an HTTP response for [uri].
+  void absorb(Uri uri, Map<String, String> headers) {
+    final raw = headers['set-cookie'];
+    if (raw == null || raw.isEmpty) return;
+    for (final part in splitSetCookieHeader(raw)) {
+      final parsed = _parseSetCookie(part, uri);
+      if (parsed == null) continue;
+      if (parsed.expired) {
+        _cookies.remove(_key(parsed.domain, parsed.path, parsed.name));
+        continue;
+      }
+      _cookies[_key(parsed.domain, parsed.path, parsed.name)] = parsed;
+    }
+  }
+
+  String headerFor(Uri uri) {
+    final now = DateTime.now().toUtc();
+    final matching = <_StoredCookie>[];
+    final stale = <String>[];
+    _cookies.forEach((key, cookie) {
+      if (cookie.expires != null && !cookie.expires!.isAfter(now)) {
+        stale.add(key);
+        return;
+      }
+      if (cookie.matches(uri)) matching.add(cookie);
+    });
+    for (final key in stale) {
+      _cookies.remove(key);
+    }
+    matching.sort((a, b) => b.path.length.compareTo(a.path.length));
+    return matching.map((c) => '${c.name}=${c.value}').join('; ');
+  }
+
+  /// Test helper.
+  Map<String, String> asMapFor(Uri uri) {
+    final header = headerFor(uri);
+    if (header.isEmpty) return {};
+    final out = <String, String>{};
+    for (final part in header.split('; ')) {
+      final eq = part.indexOf('=');
+      if (eq <= 0) continue;
+      out[part.substring(0, eq)] = part.substring(eq + 1);
+    }
+    return out;
+  }
+}
+
+class _StoredCookie {
+  _StoredCookie({
+    required this.name,
+    required this.value,
+    required this.domain,
+    required this.path,
+    required this.secure,
+    required this.hostOnly,
+    this.expires,
+  });
+
+  final String name;
+  final String value;
+  final String domain;
+  final String path;
+  final DateTime? expires;
+  final bool secure;
+  final bool hostOnly;
+
+  bool get expired {
+    if (expires == null) return false;
+    return !expires!.isAfter(DateTime.now().toUtc());
+  }
+
+  bool matches(Uri uri) {
+    if (secure && uri.scheme != 'https') return false;
+    final host = uri.host.toLowerCase();
+    if (hostOnly) {
+      if (host != domain) return false;
+    } else {
+      if (host != domain && !host.endsWith('.$domain')) return false;
+    }
+    final reqPath = uri.path.isEmpty ? '/' : uri.path;
+    if (path == '/') return true;
+    if (reqPath == path) return true;
+    if (reqPath.startsWith(path.endsWith('/') ? path : '$path/')) return true;
+    return false;
+  }
+}
+
+String _canonDomain(String domain) {
+  var d = domain.trim().toLowerCase();
+  if (d.startsWith('.')) d = d.substring(1);
+  return d;
+}
+
+String _key(String domain, String path, String name) =>
+    '${_canonDomain(domain)}|$path|$name';
+
+/// Split a folded Set-Cookie header (commas inside Expires dates).
+List<String> splitSetCookieHeader(String header) {
+  return header
+      .split(RegExp(r',(?=\s*[^;=]+=)'))
+      .map((s) => s.trim())
+      .where((s) => s.isNotEmpty)
+      .toList();
+}
+
+_StoredCookie? _parseSetCookie(String raw, Uri uri) {
+  final parts = raw.split(';');
+  if (parts.isEmpty) return null;
+  final nv = parts.first.trim();
+  final eq = nv.indexOf('=');
+  if (eq <= 0) return null;
+  final name = nv.substring(0, eq).trim();
+  final value = nv.substring(eq + 1).trim();
+  if (name.isEmpty) return null;
+
+  String? domain;
+  var path = '/';
+  DateTime? expires;
+  var secure = false;
+  var hostOnly = true;
+
+  for (var i = 1; i < parts.length; i++) {
+    final attr = parts[i].trim();
+    if (attr.isEmpty) continue;
+    final aEq = attr.indexOf('=');
+    final key = (aEq < 0 ? attr : attr.substring(0, aEq)).trim().toLowerCase();
+    final val = aEq < 0 ? '' : attr.substring(aEq + 1).trim();
+    if (key == 'domain' && val.isNotEmpty) {
+      domain = _canonDomain(val);
+      hostOnly = false;
+    } else if (key == 'path' && val.isNotEmpty) {
+      path = val;
+    } else if (key == 'expires') {
+      expires ??= DateTime.tryParse(val)?.toUtc();
+    } else if (key == 'max-age') {
+      final secs = int.tryParse(val);
+      if (secs != null) {
+        expires = DateTime.now().toUtc().add(Duration(seconds: secs));
+      }
+    } else if (key == 'secure') {
+      secure = true;
+    }
+  }
+
+  return _StoredCookie(
+    name: name,
+    value: value,
+    domain: domain ?? uri.host.toLowerCase(),
+    path: path,
+    expires: expires,
+    secure: secure,
+    hostOnly: domain == null ? true : hostOnly,
+  );
+}