// Copyright (c) 2017 The Chromium 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:io' as dart_io;

import 'package:file/file.dart';
import 'package:file/local.dart' as io;
import 'package:path/path.dart' as path;

const String _kProvisioningConfigFileEnvironmentVariable = 'FLUTTER_DEVICELAB_XCODE_PROVISIONING_CONFIG';
const String _kTestXcconfigFileName = 'TestConfig.xcconfig';
const FileSystem _fs = const io.LocalFileSystem();

/// Patches the given Xcode project adding provisioning certificates and team
/// information required to build and run the project.
Future<Null> prepareProvisioningCertificates(String flutterProjectPath) async {
  final String certificateConfig = await _readProvisioningConfigFile();
  await _patchFlutterXcconfigIfNotPatched(flutterProjectPath);

  final File testXcconfig = _fs.file(path.join(flutterProjectPath, 'ios/Flutter/$_kTestXcconfigFileName'));
  await testXcconfig.writeAsString(certificateConfig);
}

Future<Null> _patchFlutterXcconfigIfNotPatched(String flutterProjectPath) async {
  final File flutterXcconfig = _fs.file(path.join(flutterProjectPath, 'ios/Flutter/Flutter.xcconfig'));

  if (!(await flutterXcconfig.exists())) {
    throw 'File not found: ${flutterXcconfig.path}';
  }

  const String include = '#include "$_kTestXcconfigFileName"';
  final String contents = await flutterXcconfig.readAsString();
  if (!contents.contains(include)) {
    final IOSink patchOut = flutterXcconfig.openWrite(mode: FileMode.APPEND);
    patchOut.writeln(include);
    await patchOut.close();
  }
}

Future<String> _readProvisioningConfigFile() async {
  void throwUsageError(String specificMessage) {
    throw '''
================================================================================
You are attempting to build an XCode project, which requires a provisioning
certificate and team information. The test framework attempted to locate an
.xcconfig file whose path is defined by the environment variable
$_kProvisioningConfigFileEnvironmentVariable.

$specificMessage
================================================================================
'''.trim();
  }

  if (!dart_io.Platform.environment.containsKey(_kProvisioningConfigFileEnvironmentVariable)) {
    throwUsageError('''
$_kProvisioningConfigFileEnvironmentVariable variable is not defined in your
environment. Please, define it and try again.

Example provisioining xcconfig:

ProvisioningStyle=Manual
CODE_SIGN_IDENTITY=...
PROVISIONING_PROFILE=...
DEVELOPMENT_TEAM=...
PROVISIONING_PROFILE_SPECIFIER=...
'''.trim());
  }

  final String filePath = dart_io.Platform.environment[_kProvisioningConfigFileEnvironmentVariable];
  final File file = _fs.file(filePath);
  if (!(await file.exists())) {
    throwUsageError('''
File not found: $filePath

It is defined by environment variable $_kProvisioningConfigFileEnvironmentVariable
'''.trim());
  }

  return file.readAsString();
}