// 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 'package:meta/meta.dart';
import 'package:process/process.dart';

import 'android/android_studio_validator.dart';
import 'android/android_workflow.dart';
import 'artifacts.dart';
import 'base/async_guard.dart';
import 'base/context.dart';
import 'base/file_system.dart';
import 'base/io.dart';
import 'base/logger.dart';
import 'base/os.dart';
import 'base/platform.dart';
import 'base/terminal.dart';
import 'base/user_messages.dart';
import 'base/utils.dart';
import 'cache.dart';
import 'device.dart';
import 'doctor_validator.dart';
import 'features.dart';
import 'fuchsia/fuchsia_workflow.dart';
import 'globals.dart' as globals;
import 'http_host_validator.dart';
import 'intellij/intellij_validator.dart';
import 'linux/linux_doctor.dart';
import 'linux/linux_workflow.dart';
import 'macos/macos_workflow.dart';
import 'macos/xcode_validator.dart';
import 'proxy_validator.dart';
import 'reporting/reporting.dart';
import 'tester/flutter_tester.dart';
import 'version.dart';
import 'vscode/vscode_validator.dart';
import 'web/chrome.dart';
import 'web/web_validator.dart';
import 'web/workflow.dart';
import 'windows/visual_studio_validator.dart';
import 'windows/windows_workflow.dart';

abstract class DoctorValidatorsProvider {
  /// The singleton instance, pulled from the [AppContext].
  static DoctorValidatorsProvider get _instance => context.get<DoctorValidatorsProvider>()!;

  static final DoctorValidatorsProvider defaultInstance = _DefaultDoctorValidatorsProvider();

  List<DoctorValidator> get validators;
  List<Workflow> get workflows;
}

class _DefaultDoctorValidatorsProvider implements DoctorValidatorsProvider {
  List<DoctorValidator>? _validators;
  List<Workflow>? _workflows;

  final LinuxWorkflow linuxWorkflow = LinuxWorkflow(
    platform: globals.platform,
    featureFlags: featureFlags,
  );

  final WebWorkflow webWorkflow = WebWorkflow(
    platform: globals.platform,
    featureFlags: featureFlags,
  );

  final MacOSWorkflow macOSWorkflow = MacOSWorkflow(
    platform: globals.platform,
    featureFlags: featureFlags,
  );

  @override
  List<DoctorValidator> get validators {
    if (_validators != null) {
      return _validators!;
    }

    final List<DoctorValidator> ideValidators = <DoctorValidator>[
      if (androidWorkflow!.appliesToHostPlatform)
        ...AndroidStudioValidator.allValidators(globals.config, globals.platform, globals.fs, globals.userMessages),
      ...IntelliJValidator.installedValidators(
        fileSystem: globals.fs,
        platform: globals.platform,
        userMessages: userMessages,
        plistParser: globals.plistParser,
        processManager: globals.processManager,
      ),
      ...VsCodeValidator.installedValidators(globals.fs, globals.platform, globals.processManager),
    ];
    final ProxyValidator proxyValidator = ProxyValidator(platform: globals.platform);
    _validators = <DoctorValidator>[
      FlutterValidator(
        fileSystem: globals.fs,
        platform: globals.platform,
        flutterVersion: () => globals.flutterVersion,
        devToolsVersion: () => globals.cache.devToolsVersion,
        processManager: globals.processManager,
        userMessages: userMessages,
        artifacts: globals.artifacts!,
        flutterRoot: () => Cache.flutterRoot!,
        operatingSystemUtils: globals.os,
      ),
      if (androidWorkflow!.appliesToHostPlatform)
        GroupedValidator(<DoctorValidator>[androidValidator!, androidLicenseValidator!]),
      if (globals.iosWorkflow!.appliesToHostPlatform || macOSWorkflow.appliesToHostPlatform)
        GroupedValidator(<DoctorValidator>[XcodeValidator(xcode: globals.xcode!, userMessages: userMessages), globals.cocoapodsValidator!]),
      if (webWorkflow.appliesToHostPlatform)
        ChromeValidator(
          chromiumLauncher: ChromiumLauncher(
            browserFinder: findChromeExecutable,
            fileSystem: globals.fs,
            operatingSystemUtils: globals.os,
            platform:  globals.platform,
            processManager: globals.processManager,
            logger: globals.logger,
          ),
          platform: globals.platform,
        ),
      if (linuxWorkflow.appliesToHostPlatform)
        LinuxDoctorValidator(
          processManager: globals.processManager,
          userMessages: userMessages,
        ),
      if (windowsWorkflow!.appliesToHostPlatform)
        visualStudioValidator!,
      if (ideValidators.isNotEmpty)
        ...ideValidators
      else
        NoIdeValidator(),
      if (proxyValidator.shouldShow)
        proxyValidator,
      if (globals.deviceManager?.canListAnything ?? false)
        DeviceValidator(
          deviceManager: globals.deviceManager,
          userMessages: globals.userMessages,
        ),
      HttpHostValidator(
        platform: globals.platform,
        featureFlags: featureFlags,
        httpClient: globals.httpClientFactory?.call() ?? HttpClient(),
      ),
    ];
    return _validators!;
  }

  @override
  List<Workflow> get workflows {
    if (_workflows == null) {
      _workflows = <Workflow>[];

      if (globals.iosWorkflow!.appliesToHostPlatform) {
        _workflows!.add(globals.iosWorkflow!);
      }

      if (androidWorkflow?.appliesToHostPlatform ?? false) {
        _workflows!.add(androidWorkflow!);
      }

      if (fuchsiaWorkflow?.appliesToHostPlatform ?? false) {
        _workflows!.add(fuchsiaWorkflow!);
      }

      if (linuxWorkflow.appliesToHostPlatform) {
        _workflows!.add(linuxWorkflow);
      }

      if (macOSWorkflow.appliesToHostPlatform) {
        _workflows!.add(macOSWorkflow);
      }

      if (windowsWorkflow?.appliesToHostPlatform ?? false) {
        _workflows!.add(windowsWorkflow!);
      }

      if (webWorkflow.appliesToHostPlatform) {
        _workflows!.add(webWorkflow);
      }

    }
    return _workflows!;
  }
}

class Doctor {
  Doctor({
    required Logger logger,
  }) : _logger = logger;

  final Logger _logger;

  List<DoctorValidator> get validators {
    return DoctorValidatorsProvider._instance.validators;
  }

  /// Return a list of [ValidatorTask] objects and starts validation on all
  /// objects in [validators].
  List<ValidatorTask> startValidatorTasks() => <ValidatorTask>[
    for (final DoctorValidator validator in validators)
      ValidatorTask(
        validator,
        // We use an asyncGuard() here to be absolutely certain that
        // DoctorValidators do not result in an uncaught exception. Since the
        // Future returned by the asyncGuard() is not awaited, we pass an
        // onError callback to it and translate errors into ValidationResults.
        asyncGuard<ValidationResult>(
          () {
            final Completer<ValidationResult> timeoutCompleter = Completer<ValidationResult>();
            final Timer timer = Timer(doctorDuration, () {
              timeoutCompleter.completeError(
                Exception('${validator.title} exceeded maximum allowed duration of $doctorDuration'),
              );
            });
            final Future<ValidationResult> validatorFuture = validator.validate();
            return Future.any<ValidationResult>(<Future<ValidationResult>>[
              validatorFuture,
              // This future can only complete with an error
              timeoutCompleter.future,
            ]).then((ValidationResult result) async {
              timer.cancel();
              return result;
            });
          },
          onError: (Object exception, StackTrace stackTrace) {
            return ValidationResult.crash(exception, stackTrace);
          },
        ),
      ),
    ];

  List<Workflow> get workflows {
    return DoctorValidatorsProvider._instance.workflows;
  }

  /// Print a summary of the state of the tooling, as well as how to get more info.
  Future<void> summary() async {
    _logger.printStatus(await _summaryText());
  }

  Future<String> _summaryText() async {
    final StringBuffer buffer = StringBuffer();

    bool missingComponent = false;
    bool sawACrash = false;

    for (final DoctorValidator validator in validators) {
      final StringBuffer lineBuffer = StringBuffer();
      ValidationResult result;
      try {
        result = await asyncGuard<ValidationResult>(() => validator.validate());
      } on Exception catch (exception) {
        // We're generating a summary, so drop the stack trace.
        result = ValidationResult.crash(exception);
      }
      lineBuffer.write('${result.coloredLeadingBox} ${validator.title}: ');
      switch (result.type) {
        case ValidationType.crash:
          lineBuffer.write('the doctor check crashed without a result.');
          sawACrash = true;
          break;
        case ValidationType.missing:
          lineBuffer.write('is not installed.');
          break;
        case ValidationType.partial:
          lineBuffer.write('is partially installed; more components are available.');
          break;
        case ValidationType.notAvailable:
          lineBuffer.write('is not available.');
          break;
        case ValidationType.installed:
          lineBuffer.write('is fully installed.');
          break;
      }

      if (result.statusInfo != null) {
        lineBuffer.write(' (${result.statusInfo})');
      }

      buffer.write(wrapText(
        lineBuffer.toString(),
        hangingIndent: result.leadingBox.length + 1,
        columnWidth: globals.outputPreferences.wrapColumn,
        shouldWrap: globals.outputPreferences.wrapText,
      ));
      buffer.writeln();

      if (result.type != ValidationType.installed) {
        missingComponent = true;
      }
    }

    if (sawACrash) {
      buffer.writeln();
      buffer.writeln('Run "flutter doctor" for information about why a doctor check crashed.');
    }

    if (missingComponent) {
      buffer.writeln();
      buffer.writeln('Run "flutter doctor" for information about installing additional components.');
    }

    return buffer.toString();
  }

  Future<bool> checkRemoteArtifacts(String engineRevision) async {
    return globals.cache.areRemoteArtifactsAvailable(engineVersion: engineRevision);
  }

  /// Maximum allowed duration for an entire validator to take.
  ///
  /// This should only ever be reached if a process is stuck.
  static const Duration doctorDuration = Duration(minutes: 10);

  /// Print information about the state of installed tooling.
  ///
  /// To exclude personally identifiable information like device names and
  /// paths, set [showPii] to false.
  Future<bool> diagnose({
    bool androidLicenses = false,
    bool verbose = true,
    bool showColor = true,
    AndroidLicenseValidator? androidLicenseValidator,
    bool showPii = true,
    List<ValidatorTask>? startedValidatorTasks,
    bool sendEvent = true,
  }) async {
    if (androidLicenses && androidLicenseValidator != null) {
      return androidLicenseValidator.runLicenseManager();
    }

    if (!verbose) {
      _logger.printStatus('Doctor summary (to see all details, run flutter doctor -v):');
    }
    bool doctorResult = true;
    int issues = 0;

    for (final ValidatorTask validatorTask in startedValidatorTasks ?? startValidatorTasks()) {
      final DoctorValidator validator = validatorTask.validator;
      final Status status = _logger.startSpinner(
        timeout: validator.slowWarningDuration,
        slowWarningCallback: () => validator.slowWarning,
      );
      ValidationResult result;
      try {
        result = await validatorTask.result;
        status.stop();
      } on Exception catch (exception, stackTrace) {
        result = ValidationResult.crash(exception, stackTrace);
        status.cancel();
      }

      switch (result.type) {
        case ValidationType.crash:
          doctorResult = false;
          issues += 1;
          break;
        case ValidationType.missing:
          doctorResult = false;
          issues += 1;
          break;
        case ValidationType.partial:
        case ValidationType.notAvailable:
          issues += 1;
          break;
        case ValidationType.installed:
          break;
      }
      if (sendEvent) {
        DoctorResultEvent(validator: validator, result: result).send();
      }

      final String leadingBox = showColor ? result.coloredLeadingBox : result.leadingBox;
      if (result.statusInfo != null) {
        _logger.printStatus('$leadingBox ${validator.title} (${result.statusInfo})',
            hangingIndent: result.leadingBox.length + 1);
      } else {
        _logger.printStatus('$leadingBox ${validator.title}',
            hangingIndent: result.leadingBox.length + 1);
      }

      for (final ValidationMessage message in result.messages) {
        if (!message.isInformation || verbose == true) {
          int hangingIndent = 2;
          int indent = 4;
          final String indicator = showColor ? message.coloredIndicator : message.indicator;
          for (final String line in '$indicator ${showPii ? message.message : message.piiStrippedMessage}'.split('\n')) {
            _logger.printStatus(line, hangingIndent: hangingIndent, indent: indent, emphasis: true);
            // Only do hanging indent for the first line.
            hangingIndent = 0;
            indent = 6;
          }
          if (message.contextUrl != null) {
            _logger.printStatus('🔨 ${message.contextUrl}', hangingIndent: hangingIndent, indent: indent, emphasis: true);
          }
        }
      }
      if (verbose) {
        _logger.printStatus('');
      }
    }

    // Make sure there's always one line before the summary even when not verbose.
    if (!verbose) {
      _logger.printStatus('');
    }

    if (issues > 0) {
      _logger.printStatus('${showColor ? globals.terminal.color('!', TerminalColor.yellow) : '!'}'
        ' Doctor found issues in $issues categor${issues > 1 ? "ies" : "y"}.', hangingIndent: 2);
    } else {
      _logger.printStatus('${showColor ? globals.terminal.color('•', TerminalColor.green) : '•'}'
        ' No issues found!', hangingIndent: 2);
    }

    return doctorResult;
  }

  bool get canListAnything => workflows.any((Workflow workflow) => workflow.canListDevices);

  bool get canLaunchAnything {
    if (FlutterTesterDevices.showFlutterTesterDevice) {
      return true;
    }
    return workflows.any((Workflow workflow) => workflow.canLaunchDevices);
  }
}

/// A validator that checks the version of Flutter, as well as some auxiliary information
/// such as the pub or Flutter cache overrides.
///
/// This is primarily useful for diagnosing issues on Github bug reports by displaying
/// specific commit information.
class FlutterValidator extends DoctorValidator {
  FlutterValidator({
    required Platform platform,
    required FlutterVersion Function() flutterVersion,
    required String Function() devToolsVersion,
    required UserMessages userMessages,
    required FileSystem fileSystem,
    required Artifacts artifacts,
    required ProcessManager processManager,
    required String Function() flutterRoot,
    required OperatingSystemUtils operatingSystemUtils,
  }) : _flutterVersion = flutterVersion,
       _devToolsVersion = devToolsVersion,
       _platform = platform,
       _userMessages = userMessages,
       _fileSystem = fileSystem,
       _artifacts = artifacts,
       _processManager = processManager,
       _flutterRoot = flutterRoot,
       _operatingSystemUtils = operatingSystemUtils,
       super('Flutter');

  final Platform _platform;
  final FlutterVersion Function() _flutterVersion;
  final String Function() _devToolsVersion;
  final String Function() _flutterRoot;
  final UserMessages _userMessages;
  final FileSystem _fileSystem;
  final Artifacts _artifacts;
  final ProcessManager _processManager;
  final OperatingSystemUtils _operatingSystemUtils;

  @override
  Future<ValidationResult> validate() async {
    final List<ValidationMessage> messages = <ValidationMessage>[];
    String? versionChannel;
    String? frameworkVersion;

    try {
      final FlutterVersion version = _flutterVersion();
      final String? gitUrl = _platform.environment['FLUTTER_GIT_URL'];
      versionChannel = version.channel;
      frameworkVersion = version.frameworkVersion;

      messages.add(_getFlutterVersionMessage(frameworkVersion, versionChannel));
      messages.add(_getFlutterUpstreamMessage(version));
      if (gitUrl != null) {
        messages.add(ValidationMessage(_userMessages.flutterGitUrl(gitUrl)));
      }
      messages.add(ValidationMessage(_userMessages.flutterRevision(
        version.frameworkRevisionShort,
        version.frameworkAge,
        version.frameworkCommitDate,
      )));
      messages.add(ValidationMessage(_userMessages.engineRevision(version.engineRevisionShort)));
      messages.add(ValidationMessage(_userMessages.dartRevision(version.dartSdkVersion)));
      messages.add(ValidationMessage(_userMessages.devToolsVersion(_devToolsVersion())));
      final String? pubUrl = _platform.environment['PUB_HOSTED_URL'];
      if (pubUrl != null) {
        messages.add(ValidationMessage(_userMessages.pubMirrorURL(pubUrl)));
      }
      final String? storageBaseUrl = _platform.environment['FLUTTER_STORAGE_BASE_URL'];
      if (storageBaseUrl != null) {
        messages.add(ValidationMessage(_userMessages.flutterMirrorURL(storageBaseUrl)));
      }
    } on VersionCheckError catch (e) {
      messages.add(ValidationMessage.error(e.message));
    }

    // Check that the binaries we downloaded for this platform actually run on it.
    // If the binaries are not downloaded (because android is not enabled), then do
    // not run this check.
    final String genSnapshotPath = _artifacts.getArtifactPath(Artifact.genSnapshot);
    if (_fileSystem.file(genSnapshotPath).existsSync() && !_genSnapshotRuns(genSnapshotPath)) {
      final StringBuffer buffer = StringBuffer();
      buffer.writeln(_userMessages.flutterBinariesDoNotRun);
      if (_platform.isLinux) {
        buffer.writeln(_userMessages.flutterBinariesLinuxRepairCommands);
      }
      messages.add(ValidationMessage.error(buffer.toString()));
    }

    final ValidationType valid = messages.every((ValidationMessage message) => message.isInformation)
      ? ValidationType.installed
      : ValidationType.partial;

    return ValidationResult(
      valid,
      messages,
      statusInfo: _userMessages.flutterStatusInfo(
        versionChannel,
        frameworkVersion,
        _operatingSystemUtils.name,
        _platform.localeName,
      ),
    );
  }

  ValidationMessage _getFlutterVersionMessage(String frameworkVersion, String versionChannel) {
    final String flutterVersionMessage = _userMessages.flutterVersion(frameworkVersion, versionChannel, _flutterRoot());

    // The tool sets the channel as "unknown", if the current branch is on a
    // "detached HEAD" state or doesn't have an upstream, and sets the
    // frameworkVersion as "0.0.0-unknown" if  "git describe" on HEAD doesn't
    // produce an expected format to be parsed for the frameworkVersion.
    if (versionChannel == 'unknown' || frameworkVersion == '0.0.0-unknown') {
      return ValidationMessage.hint(flutterVersionMessage);
    }
    return ValidationMessage(flutterVersionMessage);
  }

  ValidationMessage _getFlutterUpstreamMessage(FlutterVersion version) {
    final String? repositoryUrl = version.repositoryUrl;
    final VersionCheckError? upstreamValidationError = VersionUpstreamValidator(version: version, platform: _platform).run();

    // VersionUpstreamValidator can produce an error if repositoryUrl is null
    if (upstreamValidationError != null) {
      final String errorMessage = upstreamValidationError.message;
      if (errorMessage.contains('could not determine the remote upstream which is being tracked')) {
        return ValidationMessage.hint(_userMessages.flutterUpstreamRepositoryUrl('unknown'));
      }
      // At this point, repositoryUrl must not be null
      if (errorMessage.contains('Flutter SDK is tracking a non-standard remote')) {
        return ValidationMessage.hint(_userMessages.flutterUpstreamRepositoryUrlNonStandard(repositoryUrl!));
      }
      if (errorMessage.contains('Either remove "FLUTTER_GIT_URL" from the environment or set it to')){
        return ValidationMessage.hint(_userMessages.flutterUpstreamRepositoryUrlEnvMismatch(repositoryUrl!));
      }
    }
    return ValidationMessage(_userMessages.flutterUpstreamRepositoryUrl(repositoryUrl!));
  }

  bool _genSnapshotRuns(String genSnapshotPath) {
    const int kExpectedExitCode = 255;
    try {
      return _processManager.runSync(<String>[genSnapshotPath]).exitCode == kExpectedExitCode;
    } on Exception {
      return false;
    }
  }
}

class DeviceValidator extends DoctorValidator {
  // TODO(jmagman): Make required once g3 rolls and is updated.
  DeviceValidator({
    DeviceManager? deviceManager,
    UserMessages? userMessages,
  }) : _deviceManager = deviceManager ?? globals.deviceManager!,
       _userMessages = userMessages ?? globals.userMessages,
       super('Connected device');

  final DeviceManager _deviceManager;
  final UserMessages _userMessages;

  @override
  String get slowWarning => 'Scanning for devices is taking a long time...';

  @override
  Future<ValidationResult> validate() async {
    final List<Device> devices = await _deviceManager.getAllConnectedDevices();
    List<ValidationMessage> installedMessages = <ValidationMessage>[];
    if (devices.isNotEmpty) {
      installedMessages = (await Device.descriptions(devices))
          .map<ValidationMessage>((String msg) => ValidationMessage(msg)).toList();
    }

    List<ValidationMessage> diagnosticMessages = <ValidationMessage>[];
    final List<String> diagnostics = await _deviceManager.getDeviceDiagnostics();
    if (diagnostics.isNotEmpty) {
      diagnosticMessages = diagnostics.map<ValidationMessage>((String message) => ValidationMessage.hint(message)).toList();
    } else if (devices.isEmpty) {
      diagnosticMessages = <ValidationMessage>[ValidationMessage.hint(_userMessages.devicesMissing)];
    }

    if (devices.isEmpty) {
      return ValidationResult(ValidationType.notAvailable, diagnosticMessages);
    } else if (diagnostics.isNotEmpty) {
      installedMessages.addAll(diagnosticMessages);
      return ValidationResult(
        ValidationType.installed,
        installedMessages,
        statusInfo: _userMessages.devicesAvailable(devices.length)
      );
    } else {
      return ValidationResult(
        ValidationType.installed,
        installedMessages,
        statusInfo: _userMessages.devicesAvailable(devices.length)
      );
    }
  }
}

/// Wrapper for doctor to run multiple times with PII and without, running the validators only once.
class DoctorText {
  DoctorText(
    BufferLogger logger, {
    @visibleForTesting Doctor? doctor,
  }) : _doctor = doctor ?? Doctor(logger: logger), _logger = logger;

  final BufferLogger _logger;
  final Doctor _doctor;
  bool _sendDoctorEvent = true;

  late final Future<String> text = _runDiagnosis(true);
  late final Future<String> piiStrippedText = _runDiagnosis(false);

  // Start the validator tasks only once.
  late final List<ValidatorTask> _validatorTasks = _doctor.startValidatorTasks();

  Future<String> _runDiagnosis(bool showPii) async {
    try {
      await _doctor.diagnose(showColor: false, startedValidatorTasks: _validatorTasks, showPii: showPii, sendEvent: _sendDoctorEvent);
      // Do not send the doctor event a second time.
      _sendDoctorEvent = false;
      final String text = _logger.statusText;
      _logger.clear();
      return text;
    } on Exception catch (error, trace) {
      return 'encountered exception: $error\n\n${trace.toString().trim()}\n';
    }
  }
}