Update pacakge generation from configuration file

main.dart

 import "dart:io";
 import "dart:async";
 
 import '../discovery_api_dart_client_generator/lib/generator.dart';
 import 'package:google_discovery_v1_api/discovery_v1_api_client.dart';
 import 'package:yaml/yaml.dart';
 
+class Package {
+  final String name;
+  final List<String> apis;
+  final Pubspec pubspec;
+  final String readme;
+  final String license;
+
+  Package(this.name, this.apis, this.pubspec, this.readme, this.license);
+}
+
+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();
+}
+
 main() {
+  listFromYaml(value) => value != null ? value : [];
+
+  // Set up paths to directories 'discovery' and 'generated'.
+  var discoveryDocsDir = Platform.script.resolve('discovery').path;
+  var generatedApisDir = Platform.script.resolve('generated').path;
+
   // Read the configuration.
   var configFile = Platform.script.resolve('config.yaml').path;
-  var discoveryDocsDir = Platform.script.resolve('discovery').path;
   var config = loadYaml(new File(configFile).readAsStringSync());
-  var pkgs = config['packages'];
-  var packages = {};
-  var supportedApis = [];
-  var knownApis = [];
-  pkgs.forEach((pkg) {
-    pkg.forEach((name, values) {
-      packages[name] = values != null ? values : [];
+
+  listAllApis().then((List<DirectoryListItems> items) {
+    var pkgs = config['packages'];
+    var packages = {};
+    var supportedApis = [];
+    pkgs.forEach((package) {
+      package.forEach((name, values) {
+        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 readmeFile;
+        if (values['readme'] != null) {
+          readmeFile = Platform.script.resolve(values['readme']).path;
+        }
+        var licenseFile;
+        if (values['license'] != null) {
+          licenseFile = Platform.script.resolve(values['license']).path;
+        }
+
+
+        // Generate package description.
+        var apiDescriptions = [];
+        var sb = new StringBuffer()
+            ..write('Auto-generated client libraries for accessing '
+                    'the following APIs:');
+        items.forEach((DirectoryListItems apiDescription) {
+          if (apis.contains(apiDescription.id)) {
+            sb..writeln('  ')
+                ..write(apiDescription.id)
+                ..write(' - ')
+                ..write(apiDescription.description);
+            apiDescriptions.add(apiDescription);
+          }
+        });
+
+        // Generate the README.md file content.
+        var readme = generateReadme(readmeFile, apiDescriptions);
+
+        // Read the LICENSE
+        var license = new File(licenseFile).readAsStringSync();
+
+        // Create package description with pubspec.yaml information.
+        var pubspec = new Pubspec(
+            name, version, sb.toString(), author: author, homepage: homepage);
+        packages[name] = new Package(name, apis, pubspec, readme, license);
+      });
     });
-  });
-  var skippedApis = config['skipped_apis'];
-  packages.forEach((_, values) => supportedApis.addAll(values));
-  knownApis.addAll(supportedApis);
-  knownApis.addAll(skippedApis);
 
-  // Check that all APIs are mentioned in the configuration.
-  var missingApis = [];
-  listAllApis().then((List<DirectoryListItems> items) {
+    // Check that all APIs are mentioned in the configuration.
+    var skippedApis = listFromYaml(config['skipped_apis']);
+    packages.forEach((_, package) => supportedApis.addAll(package.apis));
+    var knownApis = new Set();
+    knownApis.addAll(supportedApis);
+    knownApis.addAll(skippedApis);
+    var excessApis = new Set.from(knownApis);
+
+    var missingApis = [];
     items.forEach((item) {
       if (!knownApis.contains(item.id)) missingApis.add(item.id);
+      excessApis.remove(item.id);
     });
 
     if (missingApis.isNotEmpty) {
-      print('No configuration for the following APIs;');
-      missingApis.forEach((id) => print('-  $id'));
-      return;
+      print('WARNING: No configuration for the following APIs:');
+      missingApis.forEach((id) => print('- $id'));
+    }
+
+    if (excessApis.isNotEmpty) {
+      print('WARNING: The following APIs does not exist:');
+      excessApis.forEach((id) => print('- $id'));
     }
 
     // Delete 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, values) {
-      futures.add(downloadDiscoveryDocuments('discovery/$name', ids: values));
+    packages.forEach((name, package) {
+      futures.add(downloadDiscoveryDocuments('$discoveryDocsDir/$name',
+                                             ids: package.apis));
     });
 
     Future.wait(futures).then((_) {
-      packages.forEach((name, values) {
+      packages.forEach((name, package) {
         print('Generating library $name');
-        generateAllLibraries('discovery/$name', 'generated/$name');
+        generateAllLibraries('$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);
+        }
       });
       print('DONE');
     });
   });
 }