generator/lib/src/package_configuration.dart - third_party/googleapis.dart.git - Git at Google

 // Copyright (c) 2026, the Dart project authors.  Please see the AUTHORS file
 // for details. 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 'package:discoveryapis_generator/discoveryapis_generator.dart';
 // ignore: implementation_imports
 import 'package:discoveryapis_generator/src/namer.dart';
 import 'package:yaml/yaml.dart';
 import 'package:yaml_edit/yaml_edit.dart';

 import '../googleapis_generator.dart';
 import 'fetch_core.dart';

 class Package {
   final String name;
   final List<String> apis;
   final Pubspec pubspec;
   final String readme;
   final String license;
   final String changelog;
   final String? example;
   final String? monoPkg;

   Package(
     this.name,
     this.apis,
     this.pubspec,
     this.readme,
     this.license,
     this.changelog,
     this.example,
     this.monoPkg,
   );
 }

 /// Configuration of a set of packages generated from a set of APIs exposed by
 /// a Discovery Service.
 class DiscoveryPackagesConfiguration {
   String configFile;
   late Map yaml;
   late Map<String, Package> packages;

   late final Set<String> excessApis;
   late final List<String> missingApis;
   late final Set<String> skipTests;
   final existingApiRevisions = <String, String>{};
   Map<String?, String>? newRevisions;
   Map<String?, String>? oldRevisions;

   /// Create a new discovery packages configuration.
   ///
   /// The format of a YAML document describing a number of packages looks
   /// like this:
   ///
   ///     packages:
   ///       googleapis:
   ///         version: 0.1.0
   ///         repository: https://github.com/dart-lang/googleapis
   ///         readme: resources/README.md
   ///         license: resources/LICENSE
   ///         apis:
   ///         -  analytics:v3
   ///         -  bigquery:v2
   ///       googleapis_beta:
   ///         version: 0.1.0
   ///         repository: https://github.com/dart-lang/googleapis
   ///         readme: resources/README.md
   ///         license: resources/LICENSE
   ///         apis:
   ///         -  datastore:v1beta2
   ///         -  dns:v1beta1
   ///     skipped_apis:
   ///     - adexchangebuyer:v1
   ///
   /// Each package to build is listed under the key `packages:`.
   ///
   /// The key `skipped_apis` is used to list APIs returned buy the Discovery
   /// Service but is not part of any generated packages.
   ///
   /// The file names for the content of readme and license files are resolved
   /// relative to the configuration file.
   DiscoveryPackagesConfiguration(this.configFile) {
     yaml = loadYaml(File(configFile).readAsStringSync()) as Map;
   }

   /// Downloads discovery documents from the configuration.
   ///
   /// [discoveryDocsDir] is the directory where all the downloaded discovery
   /// documents are stored.
   Future<void> download(String discoveryDocsDir) async {
     // Delete all downloaded discovery documents.
     final dir = Directory(discoveryDocsDir);
     if (dir.existsSync()) {
       print('*** Cataloging and deleting existing discovery JSON files');
       for (var file in dir.listSync(recursive: true).whereType<File>()) {
         final json =
             jsonDecode(file.readAsStringSync()) as Map<String, dynamic>;
         final id = json['id'] as String;
         final revision = json['revision'] as String;
         assert(!existingApiRevisions.containsKey(id));
         existingApiRevisions[id] = revision;
       }

       print('Existing API count: ${existingApiRevisions.length}');

       dir.deleteSync(recursive: true);
     }

     // Get all rest discovery documents & initialize this object.
     final allApis = await const FetchCore.github().fetchDiscoveryDocuments(
       existingRevisions: existingApiRevisions,
     );
     _initialize(allApis);

     if (updateConfigurationFile()) {
       _initialize(allApis);
     }

     var count = 0;
     for (var entry in packages.entries) {
       print(' ${++count} of ${packages.length} - ${entry.key}');

       writeDiscoveryDocuments(
         '$discoveryDocsDir/${entry.key}',
         entry.value.apis
             .map((e) {
               final allMatches = allApis
                   .where((element) => element.id == e)
                   .toList();

               if (allMatches.length == 1) {
                 return allMatches.single;
               }

               print(
                 'Looking 1 match for "$e" - instead found ${allMatches.length}',
               );
               return null;
             })
             .whereType<RestDescription>()
             .toList(growable: false),
       );
     }
   }

   bool updateConfigurationFile() {
     final editor = YamlEditor(File(configFile).readAsStringSync());

     var changed = false;

     if (missingApis.isNotEmpty) {
       for (var apiId in missingApis) {
         final version = apiId.split(':').last;
         final isStable =
             !version.contains('alpha') && !version.contains('beta');

         final path = isStable
             ? ['packages', 'googleapis', 'apis']
             : ['skipped_apis'];

         final list = (editor.parseAt(path) as YamlList).cast<String>().toList();
         list.add(apiId);
         list.sort();
         editor.update(path, list);
         changed = true;
       }
     }

     if (excessApis.isNotEmpty) {
       for (var apiId in excessApis) {
         // Find which list it's in.
         final googleApisPath = ['packages', 'googleapis', 'apis'];
         final googleApisBetaPath = ['packages', 'googleapis_beta', 'apis'];
         final skippedApisPath = ['skipped_apis'];

         for (final path in [
           googleApisPath,
           googleApisBetaPath,
           skippedApisPath,
         ]) {
           try {
             final node = editor.parseAt(path);
             if (node is YamlList) {
               final list = node.cast<String>().toList();
               if (list.remove(apiId)) {
                 editor.update(path, list);
                 changed = true;
               }
             }
           } catch (_) {
             // Path might not exist in this config, which is fine.
           }
         }
       }
     }

     if (changed) {
       final newContent = editor.toString();
       File(configFile).writeAsStringSync(newContent);
       yaml = loadYaml(newContent) as Map;
       print('Updated $configFile');
     }

     return changed;
   }

   /// Generate packages from the configuration.
   ///
   /// [discoveryDocsDir] is the directory where all the downloaded discovery
   /// documents are stored.
   ///
   /// [generatedApisDir] is the directory where the packages are generated.
   /// Each package is generated in a sub-directory.
   void generate(
     String discoveryDocsDir,
     String generatedApisDir,
     bool deleteExisting,
   ) {
     // Delete all downloaded discovery documents.
     final dir = Directory(discoveryDocsDir);
     if (!dir.existsSync()) {
       throw Exception(
         'Error: The given `$discoveryDocsDir` directory does not exist.',
       );
     }

     // Load discovery documents from disc & initialize this object.
     final allApis = <RestDescription>[];
     for (var name in (yaml['packages'] as Map).keys) {
       allApis.addAll(loadDiscoveryDocuments('$discoveryDocsDir/$name'));
     }
     _initialize(allApis);

     // Generate packages.
     for (var entry in packages.entries) {
       final name = entry.key;
       final package = entry.value;
       final results = generateAllLibraries(
         '$discoveryDocsDir/$name',
         '$generatedApisDir/$name',
         package.pubspec,
         deleteExisting: deleteExisting,
         skipTests: skipTests,
       );
       for (final result in results) {
         if (!result.success) {
           print(result.toString());
         }
       }

       File(
         '$generatedApisDir/$name/README.md',
       ).writeAsStringSync(package.readme);
       File(
         '$generatedApisDir/$name/LICENSE',
       ).writeAsStringSync(package.license);
       File(
         '$generatedApisDir/$name/CHANGELOG.md',
       ).writeAsStringSync(package.changelog);
       if (package.monoPkg != null) {
         File(
           '$generatedApisDir/$name/mono_pkg.yaml',
         ).writeAsStringSync(package.monoPkg!);
       }
       if (package.example != null) {
         Directory('$generatedApisDir/$name/example').createSync();
         File(
           '$generatedApisDir/$name/example/main.dart',
         ).writeAsStringSync(package.example!);
       }
     }
   }

   /// Initializes the missingApis/excessApis/packages properties from a list
   /// of [RestDescription]s.
   void _initialize(List<RestDescription> allApis) {
     packages = _packagesFromYaml(
       yaml['packages'] as YamlMap,
       configFile,
       allApis,
     );
     skipTests = _listFromYaml(yaml['skip_tests'] as YamlList?).toSet();
     final knownApis = _calculateKnownApis(
       packages,
       _listFromYaml(yaml['skipped_apis'] as YamlList?),
     );
     missingApis = _calculateMissingApis(knownApis, allApis);
     excessApis = _calculateExcessApis(knownApis, allApis);

     if (existingApiRevisions.isNotEmpty) {
       for (var api in allApis) {
         final existingRevision = existingApiRevisions[api.id!];
         if (existingRevision != null) {
           final compare = api.revision!.compareTo(existingRevision);
           if (compare == 0) {
             continue;
           }
           final value = 'previous: $existingRevision; current: ${api.revision}';
           if (compare.isNegative) {
             (oldRevisions ??= {})[api.id] = value;
           }
           if (compare > 0) {
             (newRevisions ??= {})[api.id] = value;
           }
         }
       }
     }
   }

   // Return empty list for YAML null value.
   static List<String> _listFromYaml(YamlList? value) =>
       value?.cast<String>() ?? [];

   static String _generateReadme(
     String? readmeFile,
     String packageName,
     List<RestDescription?> items, {
     String? packageVersion,
   }) {
     final sb = StringBuffer();
     if (readmeFile != null) {
       sb.write(File(readmeFile).readAsStringSync());
     }
     sb.writeln('''

 ## Available Google APIs

 The following is a list of APIs that are currently available inside this
 package.
 ''');

     for (var item in items) {
       sb.write('#### ');
       if (item!.icons != null &&
           item.icons!.x16 != null &&
           item.icons!.x16!.startsWith('https://')) {
         sb.write('![Logo](${item.icons!.x16}) ');
       }
       final libraryName = ApiLibraryNamer.libraryName(item.name, item.version);
       sb
         ..writeln('${item.title} - `$libraryName`')
         ..writeln();

       if (item.description != null && item.description!.isNotEmpty) {
         sb
           ..writeln(item.description)
           ..writeln();
       }

       if (item.documentationLink != null) {
         sb.writeln('- [Original documentation](${item.documentationLink})');
       }

       if (packageVersion != null) {
         final libraryPathSection = libraryName.replaceAll('/', '_');
         final basePubUri =
             'https://pub.dev/documentation/$packageName/$packageVersion/';
         final pubUri =
             '$basePubUri$libraryPathSection/$libraryPathSection-library.html';
         sb.writeln('- [Dart package details]($pubUri)');
       }
       sb.writeln();
     }
     return sb.toString();
   }

   static Map<String, Package> _packagesFromYaml(
     YamlMap configPackages,
     String configFile,
     List<RestDescription?> allApis,
   ) {
     final packages = <String, Package>{};
     configPackages.forEach((name, values) {
       packages[name as String] = _packageFromYaml(
         name,
         values as YamlMap,
         configFile,
         allApis,
       );
     });

     return packages;
   }

   static Package _packageFromYaml(
     String name,
     YamlMap values,
     String configFile,
     List<RestDescription?> allApis,
   ) {
     final apis = _listFromYaml(values['apis'] as YamlList).cast<String>();
     final version = values['version'] as String?;
     final author = values['author'] as String?;
     final repository = values['repository'] as String?;
     final resolution = values['resolution'] as String?;

     Map<String, String>? extraDevDependencies;
     if (values.containsKey('extraDevDependencies')) {
       extraDevDependencies = (values['extraDevDependencies'] as YamlMap)
           .cast<String, String>();
     }

     final configUri = Uri.file(configFile);

     allApis.sort((RestDescription? a, RestDescription? b) {
       final result = a!.name!.compareTo(b!.name!);
       if (result != 0) return result;
       return a.version!.compareTo(b.version!);
     });

     String? readmeFile;
     if (values['readme'] != null) {
       readmeFile = configUri.resolve(values['readme'] as String).path;
     }
     late String licenseFile;
     if (values['license'] != null) {
       licenseFile = configUri.resolve(values['license'] as String).path;
     }
     late String changelogFile;
     if (values['changelog'] != null) {
       changelogFile = configUri.resolve(values['changelog'] as String).path;
     }
     String? example;
     if (values['example'] != null) {
       final exampleFile = configUri.resolve(values['example'] as String).path;
       example = File(exampleFile).readAsStringSync();
     }

     String? monoPkg;
     if (values['mono_pkg'] != null) {
       final monoPkgFile = configUri.resolve(values['mono_pkg'] as String).path;
       monoPkg = File(monoPkgFile).readAsStringSync();
     }

     // Generate package description.
     final apiDescriptions = <RestDescription?>[];
     const description =
         'Auto-generated client libraries for accessing Google '
         'APIs described through the API discovery service.';
     for (var apiDescription in allApis) {
       if (apis.contains(apiDescription!.id)) {
         apiDescriptions.add(apiDescription);
       }
     }

     // Generate the README.md file content.
     final readme = _generateReadme(
       readmeFile,
       name,
       apiDescriptions,
       packageVersion: version,
     );

     // Read the LICENSE
     final license = File(licenseFile).readAsStringSync();

     // Read CHANGELOG.md
     final changelog = File(changelogFile).readAsStringSync();

     // Create package description with pubspec.yaml information.
     final pubspec = Pubspec(
       name,
       version,
       description,
       author: author,
       repository: repository,
       extraDevDependencies: extraDevDependencies,
       resolution: resolution,
     );
     return Package(
       name,
       apis,
       pubspec,
       readme,
       license,
       changelog,
       example,
       monoPkg,
     );
   }

   /// The known APIs are the APis mentioned in each package together with
   /// the APIs explicitly skipped.
   static Set<String> _calculateKnownApis(
     Map<String, Package> packages,
     List<String> skippedApis,
   ) => <String>{...skippedApis, ...packages.values.expand((v) => v.apis)};

   /// The missing APIs are the APIs returned from the Discovery Service
   /// but not mentioned in the configuration.
   static List<String> _calculateMissingApis(
     Iterable<String> knownApis,
     List<RestDescription> allApis,
   ) => allApis
       .where((item) => !knownApis.contains(item.id))
       .map((item) => item.id!)
       .toList();

   /// The excess APIs are the APIs mentioned in the configuration but not
   /// returned from the Discovery Service.
   static Set<String> _calculateExcessApis(
     Iterable<String> knownApis,
     List<RestDescription> allApis,
   ) => Set<String>.from(knownApis)..removeAll(allApis.map((e) => e.id));
 }
	// Copyright (c) 2026, the Dart project authors. Please see the AUTHORS file
	// for details. 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 'package:discoveryapis_generator/discoveryapis_generator.dart';
	// ignore: implementation_imports
	import 'package:discoveryapis_generator/src/namer.dart';
	import 'package:yaml/yaml.dart';
	import 'package:yaml_edit/yaml_edit.dart';

	import '../googleapis_generator.dart';
	import 'fetch_core.dart';

	class Package {
	final String name;
	final List<String> apis;
	final Pubspec pubspec;
	final String readme;
	final String license;
	final String changelog;
	final String? example;
	final String? monoPkg;

	Package(
	this.name,
	this.apis,
	this.pubspec,
	this.readme,
	this.license,
	this.changelog,
	this.example,
	this.monoPkg,
	);
	}

	/// Configuration of a set of packages generated from a set of APIs exposed by
	/// a Discovery Service.
	class DiscoveryPackagesConfiguration {
	String configFile;
	late Map yaml;
	late Map<String, Package> packages;

	late final Set<String> excessApis;
	late final List<String> missingApis;
	late final Set<String> skipTests;
	final existingApiRevisions = <String, String>{};
	Map<String?, String>? newRevisions;
	Map<String?, String>? oldRevisions;

	/// Create a new discovery packages configuration.
	///
	/// The format of a YAML document describing a number of packages looks
	/// like this:
	///
	/// packages:
	/// googleapis:
	/// version: 0.1.0
	/// repository: https://github.com/dart-lang/googleapis
	/// readme: resources/README.md
	/// license: resources/LICENSE
	/// apis:
	/// - analytics:v3
	/// - bigquery:v2
	/// googleapis_beta:
	/// version: 0.1.0
	/// repository: https://github.com/dart-lang/googleapis
	/// readme: resources/README.md
	/// license: resources/LICENSE
	/// apis:
	/// - datastore:v1beta2
	/// - dns:v1beta1
	/// skipped_apis:
	/// - adexchangebuyer:v1
	///
	/// Each package to build is listed under the key `packages:`.
	///
	/// The key `skipped_apis` is used to list APIs returned buy the Discovery
	/// Service but is not part of any generated packages.
	///
	/// The file names for the content of readme and license files are resolved
	/// relative to the configuration file.
	DiscoveryPackagesConfiguration(this.configFile) {
	yaml = loadYaml(File(configFile).readAsStringSync()) as Map;
	}

	/// Downloads discovery documents from the configuration.
	///
	/// [discoveryDocsDir] is the directory where all the downloaded discovery
	/// documents are stored.
	Future<void> download(String discoveryDocsDir) async {
	// Delete all downloaded discovery documents.
	final dir = Directory(discoveryDocsDir);
	if (dir.existsSync()) {
	print('*** Cataloging and deleting existing discovery JSON files');
	for (var file in dir.listSync(recursive: true).whereType<File>()) {
	final json =
	jsonDecode(file.readAsStringSync()) as Map<String, dynamic>;
	final id = json['id'] as String;
	final revision = json['revision'] as String;
	assert(!existingApiRevisions.containsKey(id));
	existingApiRevisions[id] = revision;
	}

	print('Existing API count: ${existingApiRevisions.length}');

	dir.deleteSync(recursive: true);
	}

	// Get all rest discovery documents & initialize this object.
	final allApis = await const FetchCore.github().fetchDiscoveryDocuments(
	existingRevisions: existingApiRevisions,
	);
	_initialize(allApis);

	if (updateConfigurationFile()) {
	_initialize(allApis);
	}

	var count = 0;
	for (var entry in packages.entries) {
	print(' ${++count} of ${packages.length} - ${entry.key}');

	writeDiscoveryDocuments(
	'$discoveryDocsDir/${entry.key}',
	entry.value.apis
	.map((e) {
	final allMatches = allApis
	.where((element) => element.id == e)
	.toList();

	if (allMatches.length == 1) {
	return allMatches.single;
	}

	print(
	'Looking 1 match for "$e" - instead found ${allMatches.length}',
	);
	return null;
	})
	.whereType<RestDescription>()
	.toList(growable: false),
	);
	}
	}

	bool updateConfigurationFile() {
	final editor = YamlEditor(File(configFile).readAsStringSync());

	var changed = false;

	if (missingApis.isNotEmpty) {
	for (var apiId in missingApis) {
	final version = apiId.split(':').last;
	final isStable =
	!version.contains('alpha') && !version.contains('beta');

	final path = isStable
	? ['packages', 'googleapis', 'apis']
	: ['skipped_apis'];

	final list = (editor.parseAt(path) as YamlList).cast<String>().toList();
	list.add(apiId);
	list.sort();
	editor.update(path, list);
	changed = true;
	}
	}

	if (excessApis.isNotEmpty) {
	for (var apiId in excessApis) {
	// Find which list it's in.
	final googleApisPath = ['packages', 'googleapis', 'apis'];
	final googleApisBetaPath = ['packages', 'googleapis_beta', 'apis'];
	final skippedApisPath = ['skipped_apis'];

	for (final path in [
	googleApisPath,
	googleApisBetaPath,
	skippedApisPath,
	]) {
	try {
	final node = editor.parseAt(path);
	if (node is YamlList) {
	final list = node.cast<String>().toList();
	if (list.remove(apiId)) {
	editor.update(path, list);
	changed = true;
	}
	}
	} catch (_) {
	// Path might not exist in this config, which is fine.
	}
	}
	}
	}

	if (changed) {
	final newContent = editor.toString();
	File(configFile).writeAsStringSync(newContent);
	yaml = loadYaml(newContent) as Map;
	print('Updated $configFile');
	}

	return changed;
	}

	/// Generate packages from the configuration.
	///
	/// [discoveryDocsDir] is the directory where all the downloaded discovery
	/// documents are stored.
	///
	/// [generatedApisDir] is the directory where the packages are generated.
	/// Each package is generated in a sub-directory.
	void generate(
	String discoveryDocsDir,
	String generatedApisDir,
	bool deleteExisting,
	) {
	// Delete all downloaded discovery documents.
	final dir = Directory(discoveryDocsDir);
	if (!dir.existsSync()) {
	throw Exception(
	'Error: The given `$discoveryDocsDir` directory does not exist.',
	);
	}

	// Load discovery documents from disc & initialize this object.
	final allApis = <RestDescription>[];
	for (var name in (yaml['packages'] as Map).keys) {
	allApis.addAll(loadDiscoveryDocuments('$discoveryDocsDir/$name'));
	}
	_initialize(allApis);

	// Generate packages.
	for (var entry in packages.entries) {
	final name = entry.key;
	final package = entry.value;
	final results = generateAllLibraries(
	'$discoveryDocsDir/$name',
	'$generatedApisDir/$name',
	package.pubspec,
	deleteExisting: deleteExisting,
	skipTests: skipTests,
	);
	for (final result in results) {
	if (!result.success) {
	print(result.toString());
	}
	}

	File(
	'$generatedApisDir/$name/README.md',
	).writeAsStringSync(package.readme);
	File(
	'$generatedApisDir/$name/LICENSE',
	).writeAsStringSync(package.license);
	File(
	'$generatedApisDir/$name/CHANGELOG.md',
	).writeAsStringSync(package.changelog);
	if (package.monoPkg != null) {
	File(
	'$generatedApisDir/$name/mono_pkg.yaml',
	).writeAsStringSync(package.monoPkg!);
	}
	if (package.example != null) {
	Directory('$generatedApisDir/$name/example').createSync();
	File(
	'$generatedApisDir/$name/example/main.dart',
	).writeAsStringSync(package.example!);
	}
	}
	}

	/// Initializes the missingApis/excessApis/packages properties from a list
	/// of [RestDescription]s.
	void _initialize(List<RestDescription> allApis) {
	packages = _packagesFromYaml(
	yaml['packages'] as YamlMap,
	configFile,
	allApis,
	);
	skipTests = _listFromYaml(yaml['skip_tests'] as YamlList?).toSet();
	final knownApis = _calculateKnownApis(
	packages,
	_listFromYaml(yaml['skipped_apis'] as YamlList?),
	);
	missingApis = _calculateMissingApis(knownApis, allApis);
	excessApis = _calculateExcessApis(knownApis, allApis);

	if (existingApiRevisions.isNotEmpty) {
	for (var api in allApis) {
	final existingRevision = existingApiRevisions[api.id!];
	if (existingRevision != null) {
	final compare = api.revision!.compareTo(existingRevision);
	if (compare == 0) {
	continue;
	}
	final value = 'previous: $existingRevision; current: ${api.revision}';
	if (compare.isNegative) {
	(oldRevisions ??= {})[api.id] = value;
	}
	if (compare > 0) {
	(newRevisions ??= {})[api.id] = value;
	}
	}
	}
	}
	}

	// Return empty list for YAML null value.
	static List<String> _listFromYaml(YamlList? value) =>
	value?.cast<String>() ?? [];

	static String _generateReadme(
	String? readmeFile,
	String packageName,
	List<RestDescription?> items, {
	String? packageVersion,
	}) {
	final sb = StringBuffer();
	if (readmeFile != null) {
	sb.write(File(readmeFile).readAsStringSync());
	}
	sb.writeln('''

	## Available Google APIs

	The following is a list of APIs that are currently available inside this
	package.
	''');

	for (var item in items) {
	sb.write('#### ');
	if (item!.icons != null &&
	item.icons!.x16 != null &&
	item.icons!.x16!.startsWith('https://')) {
	sb.write('![Logo](${item.icons!.x16}) ');
	}
	final libraryName = ApiLibraryNamer.libraryName(item.name, item.version);
	sb
	..writeln('${item.title} - `$libraryName`')
	..writeln();

	if (item.description != null && item.description!.isNotEmpty) {
	sb
	..writeln(item.description)
	..writeln();
	}

	if (item.documentationLink != null) {
	sb.writeln('- [Original documentation](${item.documentationLink})');
	}

	if (packageVersion != null) {
	final libraryPathSection = libraryName.replaceAll('/', '_');
	final basePubUri =
	'https://pub.dev/documentation/$packageName/$packageVersion/';
	final pubUri =
	'$basePubUri$libraryPathSection/$libraryPathSection-library.html';
	sb.writeln('- [Dart package details]($pubUri)');
	}
	sb.writeln();
	}
	return sb.toString();
	}

	static Map<String, Package> _packagesFromYaml(
	YamlMap configPackages,
	String configFile,
	List<RestDescription?> allApis,
	) {
	final packages = <String, Package>{};
	configPackages.forEach((name, values) {
	packages[name as String] = _packageFromYaml(
	name,
	values as YamlMap,
	configFile,
	allApis,
	);
	});

	return packages;
	}

	static Package _packageFromYaml(
	String name,
	YamlMap values,
	String configFile,
	List<RestDescription?> allApis,
	) {
	final apis = _listFromYaml(values['apis'] as YamlList).cast<String>();
	final version = values['version'] as String?;
	final author = values['author'] as String?;
	final repository = values['repository'] as String?;
	final resolution = values['resolution'] as String?;

	Map<String, String>? extraDevDependencies;
	if (values.containsKey('extraDevDependencies')) {
	extraDevDependencies = (values['extraDevDependencies'] as YamlMap)
	.cast<String, String>();
	}

	final configUri = Uri.file(configFile);

	allApis.sort((RestDescription? a, RestDescription? b) {
	final result = a!.name!.compareTo(b!.name!);
	if (result != 0) return result;
	return a.version!.compareTo(b.version!);
	});

	String? readmeFile;
	if (values['readme'] != null) {
	readmeFile = configUri.resolve(values['readme'] as String).path;
	}
	late String licenseFile;
	if (values['license'] != null) {
	licenseFile = configUri.resolve(values['license'] as String).path;
	}
	late String changelogFile;
	if (values['changelog'] != null) {
	changelogFile = configUri.resolve(values['changelog'] as String).path;
	}
	String? example;
	if (values['example'] != null) {
	final exampleFile = configUri.resolve(values['example'] as String).path;
	example = File(exampleFile).readAsStringSync();
	}

	String? monoPkg;
	if (values['mono_pkg'] != null) {
	final monoPkgFile = configUri.resolve(values['mono_pkg'] as String).path;
	monoPkg = File(monoPkgFile).readAsStringSync();
	}

	// Generate package description.
	final apiDescriptions = <RestDescription?>[];
	const description =
	'Auto-generated client libraries for accessing Google '
	'APIs described through the API discovery service.';
	for (var apiDescription in allApis) {
	if (apis.contains(apiDescription!.id)) {
	apiDescriptions.add(apiDescription);
	}
	}

	// Generate the README.md file content.
	final readme = _generateReadme(
	readmeFile,
	name,
	apiDescriptions,
	packageVersion: version,
	);

	// Read the LICENSE
	final license = File(licenseFile).readAsStringSync();

	// Read CHANGELOG.md
	final changelog = File(changelogFile).readAsStringSync();

	// Create package description with pubspec.yaml information.
	final pubspec = Pubspec(
	name,
	version,
	description,
	author: author,
	repository: repository,
	extraDevDependencies: extraDevDependencies,
	resolution: resolution,
	);
	return Package(
	name,
	apis,
	pubspec,
	readme,
	license,
	changelog,
	example,
	monoPkg,
	);
	}

	/// The known APIs are the APis mentioned in each package together with
	/// the APIs explicitly skipped.
	static Set<String> _calculateKnownApis(
	Map<String, Package> packages,
	List<String> skippedApis,
	) => <String>{...skippedApis, ...packages.values.expand((v) => v.apis)};

	/// The missing APIs are the APIs returned from the Discovery Service
	/// but not mentioned in the configuration.
	static List<String> _calculateMissingApis(
	Iterable<String> knownApis,
	List<RestDescription> allApis,
	) => allApis
	.where((item) => !knownApis.contains(item.id))
	.map((item) => item.id!)
	.toList();

	/// The excess APIs are the APIs mentioned in the configuration but not
	/// returned from the Discovery Service.
	static Set<String> _calculateExcessApis(
	Iterable<String> knownApis,
	List<RestDescription> allApis,
	) => Set<String>.from(knownApis)..removeAll(allApis.map((e) => e.id));
	}