pkgs/messages_builder/lib/generation_options.dart

// Copyright (c) 2023, 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:build/build.dart';
import 'package:glob/glob.dart';
import 'package:yaml/yaml.dart';

/// Options for the message data file and code generation.
class GenerationOptions {
  /// Whether to generate named message calls. Example:
  /// An arb file like this
  /// ```json
  /// {
  ///   "helloName": "Hello {name}"
  /// }
  /// ```
  /// leads to
  /// ```dart
  /// String helloName(String name) {
  /// ```
  /// being generated.
  final bool messageCalls;

  /// Whether to generate a method to fetch a message by its id. Leads to the
  /// ids being stored in the data file.
  final bool findById;

  /// How the messages should be indexed, either through `int`s or an `enum`
  final IndexType indexType;

  /// The data file serialization, either json or (TBD) binary.
  final SerializationType serialization;

  /// The data file deserialization, either through browser functionalities or
  /// dart native code.
  final DeserializationType deserialization;

  /// The header to add to all generated files, for example for licensing.
  final String header;

  /// The origin of the algorithm for determining which plural case to use.
  final PluralSelectorType pluralSelector;

  GenerationOptions({
    required this.serialization,
    required this.deserialization,
    required this.messageCalls,
    required this.findById,
    required this.indexType,
    required this.header,
    required this.pluralSelector,
  });

  static Future<GenerationOptions> fromPubspec(String pubspecData) async {
    final pubspec = loadYaml(pubspecData) as YamlMap;
    final packageOptions = pubspec['package_options'] as YamlMap?;
    final messagesOptions = packageOptions?['messages_builder'] as YamlMap?;
    final generationOptions = GenerationOptions(
      serialization: SerializationType.json,
      deserialization: DeserializationType.web,
      messageCalls: (messagesOptions?['generateMethods'] as bool?) ?? true,
      findById: (messagesOptions?['generateFindById'] as bool?) ?? false,
      indexType: _indexType(messagesOptions),
      header: messagesOptions?['header'] as String? ??
          'Generated by package:messages_builder.',
      pluralSelector: _pluralSelector(messagesOptions),
    );
    return generationOptions;
  }

  static Future<String> getPubspecFrom(BuildStep buildStep) async {
    final pubspecId = await buildStep.findAssets(Glob('pubspec.yaml')).first;
    final pubspecData = await buildStep.readAsString(pubspecId);
    return pubspecData;
  }

  static IndexType _indexType(YamlMap? messagesOptions) {
    final generateFindString = messagesOptions?['generateFindBy'] as String?;
    return generateFindString != null
        ? IndexType.values
            .where((type) => type.name == generateFindString)
            .first
        : IndexType.integer;
  }

  static PluralSelectorType _pluralSelector(YamlMap? messagesOptions) {
    final pluralSelectorString = messagesOptions?['pluralSelector'] as String?;
    return pluralSelectorString != null
        ? PluralSelectorType.values
            .where((type) => type.name == pluralSelectorString)
            .first
        : PluralSelectorType.intl;
  }
}

enum SerializationType {
  json;
}

enum DeserializationType {
  web;
}

/// How the indexing of the messages should be implemented.
enum IndexType {
  /// No indexing.
  none,

  /// Indexing via a collection of `static int`s.
  integer,

  /// Indexing via an enum.
  enumerate;
}

/// The origin of the algorithm for determining which plural case to use.
enum PluralSelectorType {
  /// From `package:intl`.
  intl,

  /// From `package:intl4x`.

  intl4x,

  /// A user-specified algorithm.
  custom;
}