sdk/pkg/analysis_server/tool/spec/codegen_dart_notification_handler.dart

// Copyright (c) 2018, 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:convert';

import 'package:analyzer/src/codegen/tools.dart';
import 'package:html/dom.dart' as dom;
import 'package:path/path.dart' as path;

import 'api.dart';
import 'codegen_dart.dart';
import 'codegen_protocol_constants.dart' show generateConstName;
import 'from_html.dart';
import 'implied_types.dart';
import 'to_html.dart';

GeneratedFile clientTarget() {
  return new GeneratedFile(
      '../analysis_server_client/lib/notification_handler.dart',
      (String pkgPath) async {
    CodegenNotificationHandlerVisitor visitor =
        new CodegenNotificationHandlerVisitor(readApi(pkgPath));
    return visitor.collectCode(visitor.visitApi);
  });
}

/**
 * Visitor which produces Dart code representing the API.
 */
class CodegenNotificationHandlerVisitor extends DartCodegenVisitor
    with CodeGenerator {
  CodegenNotificationHandlerVisitor(Api api) : super(api) {
    codeGeneratorSettings.commentLineLength = 79;
    codeGeneratorSettings.languageName = 'dart';
  }

  void emitImports() {
    writeln("import 'package:analysis_server_client/protocol.dart';");
  }

  void emitNotificationHandler() {
    _NotificationVisitor visitor = new _NotificationVisitor(api)..visitApi();
    final notifications = visitor.notificationConstants;
    notifications.sort((n1, n2) => n1.constName.compareTo(n2.constName));

    writeln('''
class NotificationHandler {
  /// Dispatch the notification named [event], and containing parameters
  /// [params], to the appropriate stream.
  void handleEvent(String event, params) {
    ResponseDecoder decoder = new ResponseDecoder(null);
    switch (event) {
''');
    for (_Notification notification in notifications) {
      writeln('      case ${notification.constName}:');
      writeln('        ${notification.methodName}(');
      writeln('          new ${notification.paramsTypeName}');
      writeln("            .fromJson(decoder, 'params', params));");
      writeln('        break;');
    }
    writeln('      default:');
    writeln('        onUnknownNotification(event, params);');
    writeln('        break;');
    writeln('    }');
    writeln('  }');
    for (_Notification notification in notifications) {
      writeln();
      writeln('  void ${notification.methodName}(');
      writeln('    ${notification.paramsTypeName} params) {');
      writeln('  }');
    }
    writeln();
    writeln('  void onUnknownNotification(String event, params) {}');
    writeln('}');
  }

  @override
  visitApi() {
    outputHeader(year: '2018');
    writeln();
    emitImports();
    emitNotificationHandler();
  }
}

class _Notification {
  final String constName;
  final String methodName;
  final String paramsTypeName;

  _Notification(this.constName, this.methodName, this.paramsTypeName);
}

class _NotificationVisitor extends HierarchicalApiVisitor {
  final notificationConstants = <_Notification>[];

  _NotificationVisitor(Api api) : super(api);

  @override
  void visitNotification(Notification notification) {
    notificationConstants.add(new _Notification(
        generateConstName(
            notification.domainName, 'notification', notification.event),
        _generateNotificationMethodName(
            notification.domainName, notification.event),
        _generateParamTypeName(notification.domainName, notification.event)));
  }
}

String _generateNotificationMethodName(String domainName, String event) =>
    'on${_capitalize(domainName)}${_capitalize(event)}';

String _generateParamTypeName(String domainName, String event) =>
    '${_capitalize(domainName)}${_capitalize(event)}Params';

_capitalize(String name) =>
    '${name.substring(0, 1).toUpperCase()}${name.substring(1)}';