// Copyright 2013 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:io' as io;

import 'package:file/file.dart';
import 'package:http/http.dart' as http;
import 'package:pub_semver/pub_semver.dart';
import 'package:pubspec_parse/pubspec_parse.dart';
import 'package:yaml_edit/yaml_edit.dart';

import 'common/core.dart';
import 'common/output_utils.dart';
import 'common/package_looping_command.dart';
import 'common/pub_utils.dart';
import 'common/pub_version_finder.dart';
import 'common/repository_package.dart';

const int _exitIncorrectTargetDependency = 3;
const int _exitNoTargetVersion = 4;
const int _exitInvalidTargetVersion = 5;

/// A command to update a dependency in packages.
///
/// This is intended to expand over time to support any sort of dependency that
/// packages use, including pub packages and native dependencies, and should
/// include any tasks related to the dependency (e.g., regenerating files when
/// updating a dependency that is responsible for code generation).
class UpdateDependencyCommand extends PackageLoopingCommand {
  /// Creates an instance of the version check command.
  UpdateDependencyCommand(
    super.packagesDir, {
    super.processRunner,
    http.Client? httpClient,
  }) : _pubVersionFinder =
            PubVersionFinder(httpClient: httpClient ?? http.Client()) {
    argParser.addOption(
      _pubPackageFlag,
      help: 'A pub package to update.',
    );
    argParser.addOption(_androidDependency,
        help: 'An Android dependency to update.',
        allowed: <String>[
          _AndroidDepdencyType.gradle,
          _AndroidDepdencyType.compileSdk,
          _AndroidDepdencyType.compileSdkForExamples,
        ],
        allowedHelp: <String, String>{
          _AndroidDepdencyType.gradle:
              'Updates Gradle version used in plugin example apps.',
          _AndroidDepdencyType.compileSdk:
              'Updates compileSdk version used to compile plugins.',
          _AndroidDepdencyType.compileSdkForExamples:
              'Updates compileSdk version used to compile plugin examples.',
        });
    argParser.addOption(
      _versionFlag,
      help: 'The version to update to.\n\n'
          '- For pub, defaults to the latest published version if not '
          'provided. This can be any constraint that pubspec.yaml allows; a '
          'specific version will be treated as the exact version for '
          'dependencies that are alread pinned, or a ^ range for those that '
          'are unpinned.\n'
          '- For Android dependencies, a version must be provided.',
    );
  }

  static const String _pubPackageFlag = 'pub-package';
  static const String _androidDependency = 'android-dependency';
  static const String _versionFlag = 'version';

  final PubVersionFinder _pubVersionFinder;

  late final String? _targetPubPackage;
  late final String? _targetAndroidDependency;
  late final String _targetVersion;

  @override
  final String name = 'update-dependency';

  @override
  final String description = 'Updates a dependency in a package.';

  @override
  bool get hasLongOutput => false;

  @override
  PackageLoopingType get packageLoopingType =>
      PackageLoopingType.includeAllSubpackages;

  @override
  Future<void> initializeRun() async {
    const Set<String> targetFlags = <String>{
      _pubPackageFlag,
      _androidDependency
    };
    final Set<String> passedTargetFlags =
        targetFlags.where((String flag) => argResults![flag] != null).toSet();
    if (passedTargetFlags.length != 1) {
      printError(
          'Exactly one of the target flags must be provided: (${targetFlags.join(', ')})');
      throw ToolExit(_exitIncorrectTargetDependency);
    }

    // Setup for updating pub dependency.
    _targetPubPackage = getNullableStringArg(_pubPackageFlag);
    if (_targetPubPackage != null) {
      final String? version = getNullableStringArg(_versionFlag);
      if (version == null) {
        final PubVersionFinderResponse response = await _pubVersionFinder
            .getPackageVersion(packageName: _targetPubPackage!);
        switch (response.result) {
          case PubVersionFinderResult.success:
            _targetVersion = response.versions.first.toString();
          case PubVersionFinderResult.fail:
            printError('''
Error fetching $_targetPubPackage version from pub: ${response.httpResponse.statusCode}:
${response.httpResponse.body}
''');
            throw ToolExit(_exitNoTargetVersion);
          case PubVersionFinderResult.noPackageFound:
            printError('$_targetPubPackage does not exist on pub');
            throw ToolExit(_exitNoTargetVersion);
        }
      } else {
        _targetVersion = version;
        return;
      }
    }

    // Setup for updating Android dependency.
    _targetAndroidDependency = getNullableStringArg(_androidDependency);
    if (_targetAndroidDependency != null) {
      final String? version = getNullableStringArg(_versionFlag);
      if (version == null) {
        printError('A version must be provided to update this dependency.');
        throw ToolExit(_exitNoTargetVersion);
      } else if (_targetAndroidDependency == _AndroidDepdencyType.gradle) {
        final RegExp validGradleVersionPattern = RegExp(r'^\d+(?:\.\d+){1,2}$');
        final bool isValidGradleVersion =
            validGradleVersionPattern.stringMatch(version) == version;
        if (!isValidGradleVersion) {
          printError(
              'A version with a valid format (maximum 2-3 numbers separated by period) must be provided.');
          throw ToolExit(_exitInvalidTargetVersion);
        }
      } else if (_targetAndroidDependency == _AndroidDepdencyType.compileSdk ||
          _targetAndroidDependency ==
              _AndroidDepdencyType.compileSdkForExamples) {
        final RegExp validSdkVersion = RegExp(r'^\d{1,2}$');
        final bool isValidSdkVersion =
            validSdkVersion.stringMatch(version) == version;
        if (!isValidSdkVersion) {
          printError(
              'A valid Android SDK version number (1-2 digit numbers) must be provided.');
          throw ToolExit(_exitInvalidTargetVersion);
        }
      } else {
        // TODO(camsim99): Add other supported Android dependencies like the min/target Android SDK and AGP.
        printError(
            'Target Android dependency $_targetAndroidDependency is unrecognized.');
        throw ToolExit(_exitIncorrectTargetDependency);
      }
      _targetVersion = version;
    }
  }

  @override
  Future<void> completeRun() async {
    _pubVersionFinder.httpClient.close();
  }

  @override
  Future<PackageResult> runForPackage(RepositoryPackage package) async {
    if (_targetPubPackage != null) {
      return _runForPubDependency(package, _targetPubPackage!);
    }
    if (_targetAndroidDependency != null) {
      return _runForAndroidDependency(package);
    }

    // TODO(stuartmorgan): Add other dependency types here (e.g., maven).

    return PackageResult.fail();
  }

  /// Handles all of the updates for [package] when the target dependency is
  /// a pub dependency.
  Future<PackageResult> _runForPubDependency(
      RepositoryPackage package, String dependency) async {
    final _PubDependencyInfo? dependencyInfo =
        _getPubDependencyInfo(package, dependency);
    if (dependencyInfo == null) {
      return PackageResult.skip('Does not depend on $dependency');
    } else if (!dependencyInfo.hosted) {
      return PackageResult.skip('$dependency in not a hosted dependency');
    }

    // Determine the target version constraint.
    final String sectionKey = dependencyInfo.type == _PubDependencyType.dev
        ? 'dev_dependencies'
        : 'dependencies';
    final String versionString;
    final VersionConstraint parsedConstraint =
        VersionConstraint.parse(_targetVersion);
    // If the provided string was a constraint, or if it's a specific
    // version but the package has a pinned dependency, use it as-is.
    if (dependencyInfo.pinned ||
        parsedConstraint is! VersionRange ||
        parsedConstraint.min != parsedConstraint.max) {
      versionString = _targetVersion;
    } else {
      // Otherwise, it's a specific version; treat it as '^version'.
      final Version minVersion = parsedConstraint.min!;
      versionString = '^$minVersion';
    }

    // Update pubspec.yaml with the new version.
    print('${indentation}Updating to "$versionString"');
    if (versionString == dependencyInfo.constraintString) {
      return PackageResult.skip('Already depends on $versionString');
    }
    final YamlEditor editablePubspec =
        YamlEditor(package.pubspecFile.readAsStringSync());
    editablePubspec.update(
      <String>[sectionKey, dependency],
      versionString,
    );
    package.pubspecFile.writeAsStringSync(editablePubspec.toString());

    // Do any dependency-specific extra processing.
    if (dependency == 'pigeon') {
      if (!await _regeneratePigeonFiles(package)) {
        return PackageResult.fail(<String>['Failed to update pigeon files']);
      }
    } else if (dependency == 'mockito') {
      if (!await _regenerateMocks(package)) {
        return PackageResult.fail(<String>['Failed to update mocks']);
      }
    }
    // TODO(stuartmorgan): Add additional handling of known packages that
    // do file generation.

    return PackageResult.success();
  }

  /// Handles all of the updates for [package] when the target dependency is
  /// an Android dependency.
  Future<PackageResult> _runForAndroidDependency(
      RepositoryPackage package) async {
    if (_targetAndroidDependency == _AndroidDepdencyType.compileSdk) {
      return _runForCompileSdkVersion(package);
    } else if (_targetAndroidDependency == _AndroidDepdencyType.gradle ||
        _targetAndroidDependency ==
            _AndroidDepdencyType.compileSdkForExamples) {
      return _runForAndroidDependencyOnExamples(package);
    }

    return PackageResult.fail(<String>[
      'Target Android dependency $_androidDependency is unrecognized.'
    ]);
  }

  Future<PackageResult> _runForAndroidDependencyOnExamples(
      RepositoryPackage package) async {
    final Iterable<RepositoryPackage> packageExamples = package.getExamples();
    bool updateRanForExamples = false;
    for (final RepositoryPackage example in packageExamples) {
      if (!example.platformDirectory(FlutterPlatform.android).existsSync()) {
        continue;
      }

      updateRanForExamples = true;
      final Directory androidDirectory =
          example.platformDirectory(FlutterPlatform.android);
      final List<File> filesToUpdate = <File>[];
      final RegExp dependencyVersionPattern;
      final String newDependencyVersionEntry;

      if (_targetAndroidDependency == _AndroidDepdencyType.gradle) {
        if (androidDirectory
            .childDirectory('gradle')
            .childDirectory('wrapper')
            .existsSync()) {
          filesToUpdate.add(androidDirectory
              .childDirectory('gradle')
              .childDirectory('wrapper')
              .childFile('gradle-wrapper.properties'));
        }
        if (androidDirectory
            .childDirectory('app')
            .childDirectory('gradle')
            .childDirectory('wrapper')
            .existsSync()) {
          filesToUpdate.add(androidDirectory
              .childDirectory('app')
              .childDirectory('gradle')
              .childDirectory('wrapper')
              .childFile('gradle-wrapper.properties'));
        }
        dependencyVersionPattern =
            RegExp(r'^\s*distributionUrl\s*=\s*.*\.zip', multiLine: true);
        // TODO(camsim99): Validate current AGP version against target Gradle
        // version: https://github.com/flutter/flutter/issues/133887.
        newDependencyVersionEntry =
            'distributionUrl=https\\://services.gradle.org/distributions/gradle-$_targetVersion-all.zip';
      } else if (_targetAndroidDependency ==
          _AndroidDepdencyType.compileSdkForExamples) {
        filesToUpdate.add(
            androidDirectory.childDirectory('app').childFile('build.gradle'));
        dependencyVersionPattern = RegExp(
            r'(compileSdk|compileSdkVersion) (\d{1,2}|flutter.compileSdkVersion)');
        newDependencyVersionEntry = 'compileSdk $_targetVersion';
      } else {
        printError(
            'Target Android dependency $_targetAndroidDependency is unrecognized.');
        throw ToolExit(_exitIncorrectTargetDependency);
      }

      for (final File fileToUpdate in filesToUpdate) {
        final String oldFileToUpdateContents = fileToUpdate.readAsStringSync();

        if (!dependencyVersionPattern.hasMatch(oldFileToUpdateContents)) {
          return PackageResult.fail(<String>[
            'Unable to find a $_targetAndroidDependency version entry to update for ${example.displayName}.'
          ]);
        }

        print(
            '${indentation}Updating ${getRelativePosixPath(example.directory, from: package.directory)} to "$_targetVersion"');
        final String newGradleWrapperPropertiesContents =
            oldFileToUpdateContents.replaceFirst(
                dependencyVersionPattern, newDependencyVersionEntry);

        fileToUpdate.writeAsStringSync(newGradleWrapperPropertiesContents);
      }
    }
    return updateRanForExamples
        ? PackageResult.success()
        : PackageResult.skip('No example apps run on Android.');
  }

  Future<PackageResult> _runForCompileSdkVersion(
      RepositoryPackage package) async {
    if (!package.platformDirectory(FlutterPlatform.android).existsSync()) {
      return PackageResult.skip(
          'Package ${package.displayName} does not run on Android.');
    } else if (package.isExample) {
      // We skip examples for this command.
      return PackageResult.skip(
          'Package ${package.displayName} is not a top-level package; run with "compileSdkForExamples" to update.');
    }
    final File buildConfigurationFile = package
        .platformDirectory(FlutterPlatform.android)
        .childFile('build.gradle');
    final String buildConfigurationContents =
        buildConfigurationFile.readAsStringSync();
    final RegExp validCompileSdkVersion =
        RegExp(r'(compileSdk|compileSdkVersion) \d{1,2}');

    if (!validCompileSdkVersion.hasMatch(buildConfigurationContents)) {
      return PackageResult.fail(<String>[
        'Unable to find a compileSdk version entry to update for ${package.displayName}.'
      ]);
    }
    print('${indentation}Updating ${package.directory} to "$_targetVersion"');
    final String newBuildConfigurationContents = buildConfigurationContents
        .replaceFirst(validCompileSdkVersion, 'compileSdk $_targetVersion');
    buildConfigurationFile.writeAsStringSync(newBuildConfigurationContents);

    return PackageResult.success();
  }

  /// Returns information about the current dependency of [package] on
  /// the package named [dependencyName], or null if there is no dependency.
  _PubDependencyInfo? _getPubDependencyInfo(
      RepositoryPackage package, String dependencyName) {
    final Pubspec pubspec = package.parsePubspec();

    Dependency? dependency;
    final _PubDependencyType type;
    if (pubspec.dependencies.containsKey(dependencyName)) {
      dependency = pubspec.dependencies[dependencyName];
      type = _PubDependencyType.normal;
    } else if (pubspec.devDependencies.containsKey(dependencyName)) {
      dependency = pubspec.devDependencies[dependencyName];
      type = _PubDependencyType.dev;
    } else {
      return null;
    }
    if (dependency != null && dependency is HostedDependency) {
      final VersionConstraint version = dependency.version;
      return _PubDependencyInfo(
        type,
        pinned: version is VersionRange && version.min == version.max,
        hosted: true,
        constraintString: version.toString(),
      );
    }
    return _PubDependencyInfo(type, pinned: false, hosted: false);
  }

  /// Returns all of the files in [package] that are, according to repository
  /// convention, Pigeon input files.
  Iterable<File> _getPigeonInputFiles(RepositoryPackage package) {
    // Repo convention is that the Pigeon input files are the Dart files in a
    // top-level "pigeons" directory.
    final Directory pigeonsDir = package.directory.childDirectory('pigeons');
    if (!pigeonsDir.existsSync()) {
      return <File>[];
    }
    return pigeonsDir
        .listSync()
        .whereType<File>()
        .where((File file) => file.basename.endsWith('.dart'));
  }

  /// Re-runs Pigeon generation for [package].
  ///
  /// This assumes that all output configuration is set in the input files, so
  /// no additional arguments are needed. If that assumption stops holding true,
  /// the tooling will need a way for packages to control the generation (e.g.,
  /// with a script file with a known name in the pigeons/ directory.)
  Future<bool> _regeneratePigeonFiles(RepositoryPackage package) async {
    final Iterable<File> inputs = _getPigeonInputFiles(package);
    if (inputs.isEmpty) {
      logWarning('No pigeon input files found.');
      return true;
    }

    print('${indentation}Running pub get...');
    if (!await runPubGet(package, processRunner, platform,
        streamOutput: false)) {
      printError('${indentation}Fetching dependencies failed');
      return false;
    }

    print('${indentation}Updating Pigeon files...');
    for (final File input in inputs) {
      final String relativePath =
          getRelativePosixPath(input, from: package.directory);
      final io.ProcessResult pigeonResult = await processRunner.run(
          'dart', <String>['run', 'pigeon', '--input', relativePath],
          workingDir: package.directory);
      if (pigeonResult.exitCode != 0) {
        printError('dart run pigeon failed (${pigeonResult.exitCode}):\n'
            '${pigeonResult.stdout}\n${pigeonResult.stderr}\n');
        return false;
      }
    }
    return true;
  }

  /// Re-runs Mockito mock generation for [package] if necessary.
  Future<bool> _regenerateMocks(RepositoryPackage package) async {
    final Pubspec pubspec = package.parsePubspec();
    if (!pubspec.devDependencies.keys.contains('build_runner')) {
      print(
          '${indentation}No build_runner dependency; skipping mock regeneration.');
      return true;
    }

    print('${indentation}Running pub get...');
    if (!await runPubGet(package, processRunner, platform,
        streamOutput: false)) {
      printError('${indentation}Fetching dependencies failed');
      return false;
    }

    print('${indentation}Updating mocks...');
    final io.ProcessResult buildRunnerResult = await processRunner.run(
        'dart',
        <String>[
          'run',
          'build_runner',
          'build',
          '--delete-conflicting-outputs'
        ],
        workingDir: package.directory);
    if (buildRunnerResult.exitCode != 0) {
      printError(
          '"dart run build_runner build" failed (${buildRunnerResult.exitCode}):\n'
          '${buildRunnerResult.stdout}\n${buildRunnerResult.stderr}\n');
      return false;
    }
    return true;
  }
}

class _PubDependencyInfo {
  const _PubDependencyInfo(this.type,
      {required this.pinned, required this.hosted, this.constraintString});
  final _PubDependencyType type;
  final bool pinned;
  final bool hosted;
  final String? constraintString;
}

enum _PubDependencyType { normal, dev }

class _AndroidDepdencyType {
  static const String gradle = 'gradle';
  static const String compileSdk = 'compileSdk';
  static const String compileSdkForExamples = 'compileSdkForExamples';
}