Add a generate script to generate the googleapis libraries.

lib/src/package_configuration.dart

Index: lib/src/package_configuration.dart
diff --git a/lib/src/package_configuration.dart b/lib/src/package_configuration.dart
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+// Copyright (c) 2014, 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.
+
+library googleapis_generator.package_configuration;
+
+import 'dart:async';
+import 'dart:io';
+
+import 'package:discoveryapis_generator/discoveryapis_generator.dart';
+import 'package:yaml/yaml.dart';
+
+import '../googleapis_generator.dart';
+
+class Package {
+  final String name;
+  final List<String> apis;
+  final Pubspec pubspec;
+  final String readme;
+  final String license;
+  final String changelog;
+
+  Package(this.name, this.apis, this.pubspec, this.readme, this.license,
+          this.changelog);
+}
+
+/**
+ * Configuration of a set of packages generated from a set of APIs exposed by
+ * a Discovery Service.
+ */
+class DiscoveryPackagesConfiguration {
+  Map<String, Package> packages = {};
+  Iterable<String> excessApis;
+  Iterable<String> missingApis;
+
+  /**
+   * Create a new discovery packages configuration.
+   *
+   * [config] is the path to the YAML configuration file.
+   *
+   * [allApis] is the list of all supported APIs returned by the Discovery
+   * Service.
+   *
+   * The format of a YAML document describing a number of packages looks
+   * like this:
+   *
+   *     packages:
+   *     - googleapis:
+   *         version: 0.1.0
+   *         author: Dart Team <misc@dartlang.org>
+   *         homepage: http://www.dartlang.org
+   *         readme: resources/README.md
+   *         license: resources/LICENSE
+   *         apis:
+   *         -  analytics:v3
+   *         -  bigquery:v2
+   *     - googleapis_beta:
+   *         version: 0.1.0
+   *         author: Dart Team <misc@dartlang.org>
+   *         homepage: http://www.dartlang.org
+   *         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(
+      String configFile, List<DirectoryListItems> allApis) {
+    var configYaml = new File(configFile).readAsStringSync();
+    var yaml = loadYaml(configYaml);
+    packages = _packagesFromYaml(yaml['packages'], configFile, allApis);
+    var knownApis = _calculateKnownApis(packages,
+                                        _listFromYaml(yaml['skipped_apis']));
+    missingApis = _calculateMissingApis(knownApis, allApis);
+    excessApis = _calculateExcessApis(knownApis, allApis);
+  }
+
+  /**
+   * 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.
+   */
+  Future generate(String discoveryDocsDir, String generatedApisDir) {
+    // Delete all downloaded discovery documents.
+    var dir = new Directory(discoveryDocsDir);
+    if (dir.existsSync()) dir.deleteSync(recursive: true);
+
+    // Download the discovery documents for the packages to build.
+    var futures = [];
+    packages.forEach((name, package) {
+      futures.add(downloadDiscoveryDocuments('$discoveryDocsDir/$name',
+                                             ids: package.apis));
+    });
+
+    return Future.wait(futures).then((_) {
+      packages.forEach((name, package) {
+        generateAllLibraries('$discoveryDocsDir/$name',
+                             '$generatedApisDir/$name',
+                             package.pubspec);
+        new File('$generatedApisDir/$name/README.md')
+            .writeAsStringSync(package.readme);
+        if (package.license != null) {
+          new File('$generatedApisDir/$name/LICENSE')
+              .writeAsStringSync(package.license);
+        }
+        if (package.changelog != null) {
+          new File('$generatedApisDir/$name/CHANGELOG.md')
+              .writeAsStringSync(package.changelog);
+        }
+      });
+    });
+  }
+
+  // Return empty list for YAML null value.
+  static List _listFromYaml(value) => value != null ? value : [];
+
+  static String _generateReadme(
+      String readmeFile, List<DirectoryListItems> items) {
+    var sb = new StringBuffer();
+    if (readmeFile != null) {
+      sb.write(new File(readmeFile).readAsStringSync());
+    }
+    sb.writeln('''
+
+## Available Google APIs
+
+The following is a list of APIs that are currently available inside this
+package.
+''');
+    for (DirectoryListItems item in items) {
+      sb.write("#### ");
+      if (item.icons != null && item.icons.x16 != null) {
+        sb.write("![Logo](${item.icons.x16}) ");
+      }
+      sb..writeln('${item.title} - ${item.name} ${item.version}')
+          ..writeln()
+          ..writeln('${item.description}')
+          ..writeln();
+      if (item.documentationLink != null) {
+        sb.writeln(
+            'Official API documentation: ${item.documentationLink}');
+        sb.writeln();
+      }
+    }
+    return sb.toString();
+  }
+
+  static Map<String, Package> _packagesFromYaml(
+      YamlList configPackages,
+      String configFile,
+      List<DirectoryListItems>  allApis) {
+    var packages = {};
+    configPackages.forEach((package) {
+      package.forEach((name, values) {
+        packages[name] = _packageFromYaml(name, values, configFile, allApis);
+      });
+    });
+
+    return packages;
+  }
+
+  static Package _packageFromYaml(String name,
+                                  YamlMap values,
+                                  String configFile,
+                                  List<DirectoryListItems> allApis) {
+    var apis = _listFromYaml(values['apis']);
+    var version =
+        values['version'] != null ? values['version'] : '0.1.0-dev';
+    var author = values['author'];
+    var homepage = values['homepage'];
+
+    var configUri = new Uri.file(configFile);
+
+    var readmeFile;
+    if (values['readme'] != null) {
+      readmeFile = configUri.resolve(values['readme']).path;
+    }
+    var licenseFile;
+    if (values['license'] != null) {
+      licenseFile = configUri.resolve(values['license']).path;
+    }
+    var changelogFile;
+    if (values['changelog'] != null) {
+      changelogFile = configUri.resolve(values['changelog']).path;
+    }
+
+    // Generate package description.
+    var apiDescriptions = [];
+    var sb = new StringBuffer()
+        ..write('"Auto-generated client libraries for accessing '
+                'the following APIs:');
+    bool first = true;
+    allApis.forEach((DirectoryListItems apiDescription) {
+      if (apis.contains(apiDescription.id)) {
+        if (!first) sb.write(', ');
+        sb.write(apiDescription.id);
+        apiDescriptions.add(apiDescription);
+        first = false;
+      }
+    });
+    sb.write('"');
+
+    // Generate the README.md file content.
+    var readme = _generateReadme(readmeFile, apiDescriptions);
+
+    // Read the LICENSE
+    var license = new File(licenseFile).readAsStringSync();
+
+    // Read CHANGELOG.md
+    var changelog = new File(changelogFile).readAsStringSync();
+
+    // Create package description with pubspec.yaml information.
+    var pubspec = new Pubspec(
+        name, version, sb.toString(), author: author, homepage: homepage);
+    return new Package(name, apis, pubspec, readme, license, changelog);
+  }
+
+  /// The known APIs are the APis mentioned in each package together with
+  /// the APIs explicitly skipped.
+  static Set<String> _calculateKnownApis(Map<String, Package> packages,
+                                         YamlList skippedApis) {
+    var knownApis = new Set();
+    knownApis.addAll(skippedApis);
+    packages.forEach((_, package) => knownApis.addAll(package.apis));
+    return knownApis;
+  }
+
+  /// The missing APIs are the APIs returned from the Discovery Service
+  /// but not mentioned in the configuration.
+  static Iterable<String> _calculateMissingApis(
+      Iterable<String> knownApis, List<DirectoryListItems> allApis) {
+    return allApis
+        .where((item) => !knownApis.contains(item.id))
+        .map((item) => item.id);
+  }
+
+  /// The excess APIs are the APIs mentioned in the configuration but not
+  /// returned from the Discovery Service.
+  static Iterable<String> _calculateExcessApis(
+      Iterable<String> knownApis, List<DirectoryListItems> allApis) {
+    var excessApis = new Set.from(knownApis);
+    allApis.forEach((item) => excessApis.remove(item.id));
+    return excessApis;
+  }
+}
+