// Copyright (c) 2017, 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 'package:analyzer/dart/analysis/results.dart';
import 'package:analyzer/file_system/file_system.dart';
import 'package:analyzer_plugin/protocol/protocol.dart';
import 'package:analyzer_plugin/protocol/protocol_common.dart' show KytheEntry;
import 'package:analyzer_plugin/protocol/protocol_generated.dart';
import 'package:analyzer_plugin/src/utilities/kythe/entries.dart';
import 'package:analyzer_plugin/utilities/generator.dart';

/// The information about a requested set of entries when computing entries in a
/// `.dart` file.
///
/// Clients may not extend, implement or mix-in this class.
abstract class DartEntryRequest implements EntryRequest {
  /// The analysis result for the file in which the entries are being requested.
  ResolvedUnitResult get result;
}

/// An object that [EntryContributor]s use to record entries.
///
/// Clients may not extend, implement or mix-in this class.
abstract class EntryCollector {
  /// Record a new [entry].
  void addEntry(KytheEntry entry);
}

/// An object used to produce entries.
///
/// Clients may implement this class when implementing plugins.
abstract class EntryContributor {
  /// Contribute entries for the file specified by the given [request] into the
  /// given [collector].
  void computeEntries(EntryRequest request, EntryCollector collector);
}

/// A generator that will generate a 'kythe.getEntries' response.
///
/// Clients may not extend, implement or mix-in this class.
class EntryGenerator {
  /// The contributors to be used to generate the entries.
  final List<EntryContributor> contributors;

  /// Initialize a newly created entry generator to use the given
  /// [contributors].
  EntryGenerator(this.contributors);

  /// Create a 'kythe.getEntries' response for the file specified by the given
  /// [request]. If any of the contributors throws an exception, also create a
  /// non-fatal 'plugin.error' notification.
  GeneratorResult<KytheGetKytheEntriesResult> generateGetEntriesResponse(
      EntryRequest request) {
    var notifications = <Notification>[];
    var collector = EntryCollectorImpl();
    for (var contributor in contributors) {
      try {
        contributor.computeEntries(request, collector);
      } catch (exception, stackTrace) {
        notifications.add(PluginErrorParams(
                false, exception.toString(), stackTrace.toString())
            .toNotification());
      }
    }
    var result = KytheGetKytheEntriesResult(collector.entries, collector.files);
    return GeneratorResult(result, notifications);
  }
}

/// The information about a requested set of entries.
///
/// Clients may not extend, implement or mix-in this class.
abstract class EntryRequest {
  /// Return the path of the file in which entries are being requested.
  String get path;

  /// Return the resource provider associated with this request.
  ResourceProvider get resourceProvider;
}