// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:async';
import 'dart:convert';
import 'dart:io';
import 'dart:typed_data';

import 'package:flutter/services.dart';
import 'package:flutter/widgets.dart';
import 'package:meta/meta.dart';
import 'package:path/path.dart' as path;
// ignore: deprecated_member_use
import 'package:test_api/test_api.dart' as test_package;


import 'binding.dart';

/// Ensure the [WidgetsBinding] is initialized.
WidgetsBinding ensureInitialized([@visibleForTesting Map<String, String> environment]) {
  environment ??= Platform.environment;
  if (WidgetsBinding.instance == null) {
    if (environment.containsKey('FLUTTER_TEST') && environment['FLUTTER_TEST'] != 'false') {
      AutomatedTestWidgetsFlutterBinding();
    } else {
      LiveTestWidgetsFlutterBinding();
    }
  }
  assert(WidgetsBinding.instance is TestWidgetsFlutterBinding);
  return WidgetsBinding.instance;
}

/// Setup mocking of the global [HttpClient].
void setupHttpOverrides() {
  HttpOverrides.global = _MockHttpOverrides();
}

/// Setup mocking of platform assets if `UNIT_TEST_ASSETS` is defined.
void mockFlutterAssets() {
  if (!Platform.environment.containsKey('UNIT_TEST_ASSETS')) {
    return;
  }
  final String assetFolderPath = Platform.environment['UNIT_TEST_ASSETS'];
  final String prefix =  'packages/${Platform.environment['APP_NAME']}/';

  /// Navigation related actions (pop, push, replace) broadcasts these actions via
  /// platform messages.
  SystemChannels.navigation.setMockMethodCallHandler((MethodCall methodCall) async {});

  ServicesBinding.instance.defaultBinaryMessenger.setMockMessageHandler('flutter/assets', (ByteData message) {
    String key = utf8.decode(message.buffer.asUint8List());
    File asset = File(path.join(assetFolderPath, key));

    if (!asset.existsSync()) {
      // For tests in package, it will load assets with its own package prefix.
      // In this case, we do a best-effort look up.
      if (!key.startsWith(prefix)) {
        return null;
      }

      key = key.replaceFirst(prefix, '');
      asset = File(path.join(assetFolderPath, key));
      if (!asset.existsSync()) {
        return null;
      }
    }

    final Uint8List encoded = Uint8List.fromList(asset.readAsBytesSync());
    return Future<ByteData>.value(encoded.buffer.asByteData());
  });
}

/// Provides a default [HttpClient] which always returns empty 400 responses.
///
/// If another [HttpClient] is provided using [HttpOverrides.runZoned], that will
/// take precedence over this provider.
class _MockHttpOverrides extends HttpOverrides {
  bool warningPrinted = false;
  @override
  HttpClient createHttpClient(SecurityContext _) {
    if (!warningPrinted) {
      test_package.printOnFailure(
        'Warning: At least one test in this suite creates an HttpClient. When\n'
        'running a test suite that uses TestWidgetsFlutterBinding, all HTTP\n'
        'requests will return status code 400, and no network request will\n'
        'actually be made. Any test expecting a real network connection and\n'
        'status code will fail.\n'
        'To test code that needs an HttpClient, provide your own HttpClient\n'
        'implementation to the code under test, so that your test can\n'
        'consistently provide a testable response to the code under test.');
      warningPrinted = true;
    }
    return _MockHttpClient();
  }
}

/// A mocked [HttpClient] which always returns a [_MockHttpRequest].
class _MockHttpClient implements HttpClient {
  @override
  bool autoUncompress;

  @override
  Duration connectionTimeout;

  @override
  Duration idleTimeout;

  @override
  int maxConnectionsPerHost;

  @override
  String userAgent;

  @override
  void addCredentials(Uri url, String realm, HttpClientCredentials credentials) { }

  @override
  void addProxyCredentials(String host, int port, String realm, HttpClientCredentials credentials) { }

  @override
  set authenticate(Future<bool> Function(Uri url, String scheme, String realm) f) { }

  @override
  set authenticateProxy(Future<bool> Function(String host, int port, String scheme, String realm) f) { }

  @override
  set badCertificateCallback(bool Function(X509Certificate cert, String host, int port) callback) { }

  @override
  void close({ bool force = false }) { }

  @override
  Future<HttpClientRequest> delete(String host, int port, String path) {
    return Future<HttpClientRequest>.value(_MockHttpRequest());
  }

  @override
  Future<HttpClientRequest> deleteUrl(Uri url) {
    return Future<HttpClientRequest>.value(_MockHttpRequest());
  }

  @override
  set findProxy(String Function(Uri url) f) { }

  @override
  Future<HttpClientRequest> get(String host, int port, String path) {
    return Future<HttpClientRequest>.value(_MockHttpRequest());
  }

  @override
  Future<HttpClientRequest> getUrl(Uri url) {
    return Future<HttpClientRequest>.value(_MockHttpRequest());
  }

  @override
  Future<HttpClientRequest> head(String host, int port, String path) {
    return Future<HttpClientRequest>.value(_MockHttpRequest());
  }

  @override
  Future<HttpClientRequest> headUrl(Uri url) {
    return Future<HttpClientRequest>.value(_MockHttpRequest());
  }

  @override
  Future<HttpClientRequest> open(String method, String host, int port, String path) {
    return Future<HttpClientRequest>.value(_MockHttpRequest());
  }

  @override
  Future<HttpClientRequest> openUrl(String method, Uri url) {
    return Future<HttpClientRequest>.value(_MockHttpRequest());
  }

  @override
  Future<HttpClientRequest> patch(String host, int port, String path) {
    return Future<HttpClientRequest>.value(_MockHttpRequest());
  }

  @override
  Future<HttpClientRequest> patchUrl(Uri url) {
    return Future<HttpClientRequest>.value(_MockHttpRequest());
  }

  @override
  Future<HttpClientRequest> post(String host, int port, String path) {
    return Future<HttpClientRequest>.value(_MockHttpRequest());
  }

  @override
  Future<HttpClientRequest> postUrl(Uri url) {
    return Future<HttpClientRequest>.value(_MockHttpRequest());
  }

  @override
  Future<HttpClientRequest> put(String host, int port, String path) {
    return Future<HttpClientRequest>.value(_MockHttpRequest());
  }

  @override
  Future<HttpClientRequest> putUrl(Uri url) {
    return Future<HttpClientRequest>.value(_MockHttpRequest());
  }
}

/// A mocked [HttpClientRequest] which always returns a [_MockHttpClientResponse].
class _MockHttpRequest extends HttpClientRequest {
  @override
  Encoding encoding;

  @override
  final HttpHeaders headers = _MockHttpHeaders();

  @override
  void add(List<int> data) { }

  @override
  void addError(Object error, [ StackTrace stackTrace ]) { }

  @override
  Future<void> addStream(Stream<List<int>> stream) {
    return Future<void>.value();
  }

  @override
  Future<HttpClientResponse> close() {
    return Future<HttpClientResponse>.value(_MockHttpResponse());
  }

  @override
  HttpConnectionInfo get connectionInfo => null;

  @override
  List<Cookie> get cookies => null;

  @override
  Future<HttpClientResponse> get done async => null;

  @override
  Future<void> flush() {
    return Future<void>.value();
  }

  @override
  String get method => null;

  @override
  Uri get uri => null;

  @override
  void write(Object obj) { }

  @override
  void writeAll(Iterable<Object> objects, [ String separator = '' ]) { }

  @override
  void writeCharCode(int charCode) { }

  @override
  void writeln([ Object obj = '' ]) { }
}

/// A mocked [HttpClientResponse] which is empty and has a [statusCode] of 400.
// TODO(tvolkert): Change to `extends Stream<Uint8List>` once
// https://dart-review.googlesource.com/c/sdk/+/104525 is rolled into the framework.
class _MockHttpResponse implements HttpClientResponse {
  final Stream<Uint8List> _delegate = Stream<Uint8List>.fromIterable(const Iterable<Uint8List>.empty());

  @override
  final HttpHeaders headers = _MockHttpHeaders();

  @override
  X509Certificate get certificate => null;

  @override
  HttpConnectionInfo get connectionInfo => null;

  @override
  int get contentLength => -1;

  @override
  HttpClientResponseCompressionState get compressionState {
    return HttpClientResponseCompressionState.decompressed;
  }

  @override
  List<Cookie> get cookies => null;

  @override
  Future<Socket> detachSocket() {
    return Future<Socket>.error(UnsupportedError('Mocked response'));
  }

  @override
  bool get isRedirect => false;

  @override
  StreamSubscription<Uint8List> listen(void Function(Uint8List event) onData, { Function onError, void Function() onDone, bool cancelOnError }) {
    return const Stream<Uint8List>.empty().listen(onData, onError: onError, onDone: onDone, cancelOnError: cancelOnError);
  }

  @override
  bool get persistentConnection => null;

  @override
  String get reasonPhrase => null;

  @override
  Future<HttpClientResponse> redirect([ String method, Uri url, bool followLoops ]) {
    return Future<HttpClientResponse>.error(UnsupportedError('Mocked response'));
  }

  @override
  List<RedirectInfo> get redirects => <RedirectInfo>[];

  @override
  int get statusCode => 400;

  @override
  Future<bool> any(bool Function(Uint8List element) test) {
    return _delegate.any(test);
  }

  @override
  Stream<Uint8List> asBroadcastStream({
    void Function(StreamSubscription<Uint8List> subscription) onListen,
    void Function(StreamSubscription<Uint8List> subscription) onCancel,
  }) {
    return _delegate.asBroadcastStream(onListen: onListen, onCancel: onCancel);
  }

  @override
  Stream<E> asyncExpand<E>(Stream<E> Function(Uint8List event) convert) {
    return _delegate.asyncExpand<E>(convert);
  }

  @override
  Stream<E> asyncMap<E>(FutureOr<E> Function(Uint8List event) convert) {
    return _delegate.asyncMap<E>(convert);
  }

  @override
  Stream<R> cast<R>() {
    return _delegate.cast<R>();
  }

  @override
  Future<bool> contains(Object needle) {
    return _delegate.contains(needle);
  }

  @override
  Stream<Uint8List> distinct([bool Function(Uint8List previous, Uint8List next) equals]) {
    return _delegate.distinct(equals);
  }

  @override
  Future<E> drain<E>([E futureValue]) {
    return _delegate.drain<E>(futureValue);
  }

  @override
  Future<Uint8List> elementAt(int index) {
    return _delegate.elementAt(index);
  }

  @override
  Future<bool> every(bool Function(Uint8List element) test) {
    return _delegate.every(test);
  }

  @override
  Stream<S> expand<S>(Iterable<S> Function(Uint8List element) convert) {
    return _delegate.expand(convert);
  }

  @override
  Future<Uint8List> get first => _delegate.first;

  @override
  Future<Uint8List> firstWhere(
      bool Function(Uint8List element) test, {
        List<int> Function() orElse,
      }) {
    return _delegate.firstWhere(test, orElse: () {
      return Uint8List.fromList(orElse());
    });
  }

  @override
  Future<S> fold<S>(S initialValue, S Function(S previous, Uint8List element) combine) {
    return _delegate.fold<S>(initialValue, combine);
  }

  @override
  Future<dynamic> forEach(void Function(Uint8List element) action) {
    return _delegate.forEach(action);
  }

  @override
  Stream<Uint8List> handleError(
      Function onError, {
        bool Function(dynamic error) test,
      }) {
    return _delegate.handleError(onError, test: test);
  }

  @override
  bool get isBroadcast => _delegate.isBroadcast;

  @override
  Future<bool> get isEmpty => _delegate.isEmpty;

  @override
  Future<String> join([String separator = '']) {
    return _delegate.join(separator);
  }

  @override
  Future<Uint8List> get last => _delegate.last;

  @override
  Future<Uint8List> lastWhere(
      bool Function(Uint8List element) test, {
        List<int> Function() orElse,
      }) {
    return _delegate.lastWhere(test, orElse: () {
      return Uint8List.fromList(orElse());
    });
  }

  @override
  Future<int> get length => _delegate.length;

  @override
  Stream<S> map<S>(S Function(Uint8List event) convert) {
    return _delegate.map<S>(convert);
  }

  @override
  Future<dynamic> pipe(StreamConsumer<List<int>> streamConsumer) {
    return _delegate.cast<List<int>>().pipe(streamConsumer);
  }

  @override
  Future<Uint8List> reduce(List<int> Function(Uint8List previous, Uint8List element) combine) {
    return _delegate.reduce((Uint8List previous, Uint8List element) {
      return Uint8List.fromList(combine(previous, element));
    });
  }

  @override
  Future<Uint8List> get single => _delegate.single;

  @override
  Future<Uint8List> singleWhere(bool Function(Uint8List element) test, {List<int> Function() orElse}) {
    return _delegate.singleWhere(test, orElse: () {
      return Uint8List.fromList(orElse());
    });
  }

  @override
  Stream<Uint8List> skip(int count) {
    return _delegate.skip(count);
  }

  @override
  Stream<Uint8List> skipWhile(bool Function(Uint8List element) test) {
    return _delegate.skipWhile(test);
  }

  @override
  Stream<Uint8List> take(int count) {
    return _delegate.take(count);
  }

  @override
  Stream<Uint8List> takeWhile(bool Function(Uint8List element) test) {
    return _delegate.takeWhile(test);
  }

  @override
  Stream<Uint8List> timeout(
      Duration timeLimit, {
        void Function(EventSink<Uint8List> sink) onTimeout,
      }) {
    return _delegate.timeout(timeLimit, onTimeout: onTimeout);
  }

  @override
  Future<List<Uint8List>> toList() {
    return _delegate.toList();
  }

  @override
  Future<Set<Uint8List>> toSet() {
    return _delegate.toSet();
  }

  @override
  Stream<S> transform<S>(StreamTransformer<List<int>, S> streamTransformer) {
    return _delegate.cast<List<int>>().transform<S>(streamTransformer);
  }

  @override
  Stream<Uint8List> where(bool Function(Uint8List event) test) {
    return _delegate.where(test);
  }
}

/// A mocked [HttpHeaders] that ignores all writes.
class _MockHttpHeaders extends HttpHeaders {
  @override
  List<String> operator [](String name) => <String>[];

  @override
  void add(String name, Object value, {bool preserveHeaderCase = false}) { }

  @override
  void clear() { }

  @override
  void forEach(void Function(String name, List<String> values) f) { }

  @override
  void noFolding(String name) { }

  @override
  void remove(String name, Object value) { }

  @override
  void removeAll(String name) { }

  @override
  void set(String name, Object value, {bool preserveHeaderCase = false}) { }

  @override
  String value(String name) => null;
}