pkgs/messages/lib/src/message.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 'plural_selector.dart';

sealed class Message {
  final String? id;

  Message(this.id);

  String generateString(
    List allArgs, {
    required PluralSelector pluralSelector,
    String? locale,
    String Function(String p1)? cleaner,
  });
}

final class CombinedMessage extends Message {
  final List<Message> messages;

  CombinedMessage(super.id, this.messages);

  @override
  String generateString(
    List allArgs, {
    required PluralSelector pluralSelector,
    String Function(String p1)? cleaner,
    String? locale,
  }) =>
      messages
          .map((e) => e.generateString(
                allArgs,
                pluralSelector: pluralSelector,
                cleaner: cleaner,
                locale: locale,
              ))
          .join();
  static const int type = 6;
}

final class StringMessage extends Message {
  final String value;

  /// Maps argument indices to their position in the string, where they are to
  /// be inserted.
  ///
  /// This list is expected to be sorted by `argPositions.stringIndex`
  final List<({int stringIndex, int argIndex})> argPositions;

  StringMessage(this.value, {this.argPositions = const [], String? id})
      : super(id);

  static const int type = 1;

  @override
  String generateString(
    List allArgs, {
    required PluralSelector pluralSelector,
    String Function(String p1)? cleaner,
    String? locale,
  }) {
    final s = cleaner?.call(value) ?? value;
    if (argPositions.isNotEmpty) {
      final sb = StringBuffer(value.substring(0, argPositions[0].stringIndex));
      for (var i = 0; i < argPositions.length; i++) {
        final position = argPositions[i];
        sb.write(allArgs[position.argIndex]);
        sb.write(value.substring(
          position.stringIndex,
          i + 1 < argPositions.length
              ? argPositions[i + 1].stringIndex
              : s.length,
        ));
      }
      return sb.toString();
    } else {
      return s;
    }
  }
}

final class PluralMessage extends Message {
  final Map<int, Message> numberCases;
  final Map<int, Message> wordCases;
  final Message? few;
  final Message? many;
  final Message other;
  final int argIndex;

  PluralMessage({
    this.numberCases = const {},
    this.wordCases = const {},
    this.few,
    this.many,
    required this.other,
    required this.argIndex,
    String? id,
  }) : super(id);

  static const int type = 3;

  @override
  String generateString(
    List allArgs, {
    required PluralSelector pluralSelector,
    String Function(String p1)? cleaner,
    String? locale,
  }) {
    return pluralSelector(
      allArgs[argIndex] as num,
      locale!,
      numberCases: numberCases,
      wordCases: wordCases,
      few: few,
      many: many,
      other: other,
    ).generateString(allArgs,
        pluralSelector: pluralSelector, cleaner: cleaner, locale: locale);
  }
}

final class SelectMessage extends Message {
  final Message other;
  final Map<String, Message> cases;
  final int argIndex;
  SelectMessage(
    this.other,
    this.cases,
    this.argIndex, [
    super.id,
  ]);

  static const int type = 4;

  @override
  String generateString(
    List allArgs, {
    required PluralSelector pluralSelector,
    String Function(String p1)? cleaner,
    String? locale,
  }) {
    final selected = cases[allArgs[argIndex]!] ?? other;
    return selected.generateString(
      pluralSelector: pluralSelector,
      allArgs,
      cleaner: cleaner,
      locale: locale,
    );
  }
}