Split `run_config` into `run_config download` and `run_config generate`.

lib/src/package_configuration.dart

 // 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';
@@ skipping 11 matching lines @@
 
   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 {
+  String configFile;
+  Map yaml;
   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
@@ skipping 25 matching lines @@
    *     - 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);
+  DiscoveryPackagesConfiguration(this.configFile) {
+    yaml = loadYaml(new File(configFile).readAsStringSync());
+  }
+
+  /**
+   * Downloads discovery documents from the configuration.
+   *
+   * [discoveryDocsDir] is the directory where all the downloaded discovery
+   * documents are stored.
+   */
+  Future download(String discoveryDocsDir,
+                  List<DirectoryListItems> items) async {
+    // Delete all downloaded discovery documents.
+    var dir = new Directory(discoveryDocsDir);
+    if (dir.existsSync()) dir.deleteSync(recursive: true);
+
+    // Get all rest discovery documents & initialize this object.
+    List<RestDescription> allApis = await fetchDiscoveryDocuments();
+    _initialize(allApis);
+
+    // Download the discovery documents for the packages to build
+    // (only the APIs we're interested in).
+    var futures = [];
+    packages.forEach((name, package) {
+      futures.add(downloadDiscoveryDocuments('$discoveryDocsDir/$name',
+                                             ids: package.apis));
+    });
+
+    return Future.wait(futures).then((List<List<RestDescription>> results) {
+      _initialize(results.expand((result) => result).toList());
+    });
   }
 
   /**
    * 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) {
+  void generate(String discoveryDocsDir, String generatedApisDir) {
     // Delete all downloaded discovery documents.
     var dir = new Directory(discoveryDocsDir);
-    if (dir.existsSync()) dir.deleteSync(recursive: true);
+    if (!dir.existsSync()) {
+      throw new Exception(
+          'Error: The given `$discoveryDocsDir` directory does not exist.');
+    }
 
-    // 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);
-        }
+    // Load discovery documents from disc & initialize this object.
+    List<RestDescription> allApis = [];
+    yaml['packages'].forEach((Map package) {
+      package.forEach((String name, _) {
+        allApis.addAll(loadDiscoveryDocuments('$discoveryDocsDir/$name'));
       });
     });
+    _initialize(allApis);
+
+    // Generate packages.
+    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);
+      }
+    });
+  }
+
+  /**
+   * Initializes the missingApis/excessApis/packages properties from a list
+   * of [RestDescription]s.
+   */
+  void _initialize(List<RestDescription> allApis) {
+    packages = _packagesFromYaml(yaml['packages'], configFile, allApis);
+    var knownApis = _calculateKnownApis(packages,
+                                        _listFromYaml(yaml['skipped_apis']));
+    missingApis = _calculateMissingApis(knownApis, allApis);
+    excessApis = _calculateExcessApis(knownApis, allApis);
   }
 
   // Return empty list for YAML null value.
   static List _listFromYaml(value) => value != null ? value : [];
 
   static String _generateReadme(
-      String readmeFile, List<DirectoryListItems> items) {
+      String readmeFile, List<RestDescription> 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) {
+    for (RestDescription 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) {
+      List<RestDescription>  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) {
+                                  List<RestDescription> 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);
 
+    allApis.sort((RestDescription a, RestDescription b) {
+      int result = a.name.compareTo(b.name);
+      if (result != 0) return result;
+      return a.version.compareTo(b.version);
+    });
+
     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) {
+    allApis.forEach((RestDescription 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.
@@ skipping 17 matching lines @@
                                          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) {
+      Iterable<String> knownApis, List<RestDescription> 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) {
+      Iterable<String> knownApis, List<RestDescription> allApis) {
     var excessApis = new Set.from(knownApis);
     allApis.forEach((item) => excessApis.remove(item.id));
     return excessApis;
   }
 }