pkgs/messages_builder/lib/arb_parser.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 'dart:convert';

import 'package:crypto/crypto.dart';

import 'message_file.dart';
import 'message_parser/message_parser.dart';
import 'parameterized_message.dart';
import 'placeholder.dart';

class ArbParser {
  ArbParser();

  MessageFile parseMessageFile(Map<String, dynamic> arb) {
    final locale = arb['@@locale'] as String?;
    final context = arb['@@context'] as String?;
    final messages = arb.keys
        .where((key) => !key.startsWith('@'))
        .map(
          (key) => parseMessage(
            arb[key] as String,
            arb['@$key'] as Map<String, dynamic>?,
            key,
            '${context}_$locale',
          ),
        )
        .toList();
    messages.sort((a, b) => a.name.compareTo(b.name));
    return MessageFile(
      messages,
      locale,
      context,
      getHash(arb),
      arb.keys.any((key) => key.startsWith('@') && !key.startsWith('@@')),
    );
  }

  String getHash(Map<String, dynamic> arb) {
    final digest = sha1.convert(arb.toString().codeUnits);
    return base64Encode(digest.bytes).substring(0, 8);
  }

  ParameterizedMessage parseMessage(
    String messageContent,
    Map<String, dynamic>? metadata,
    String name,
    String debugString,
  ) {
    final (message, arguments) = MessageParser.parse(
      debugString,
      messageContent,
      name,
    );
    final meaning = metadata?['meaning'] as String?;
    final description = metadata?['description'] as String?;

    final placeholdersMap = metadata?['placeholders'] as Map<String, dynamic>?;
    final placeholdersWithMetadata = placeholdersMap?.map((name, metadata) {
          final type = (metadata as Map<String, dynamic>)['type'] as String?;
          final example = metadata['example'] as String?;
          return MapEntry(name, Placeholder(name, type ?? 'String', example));
        }) ??
        <String, Placeholder>{};

    return ParameterizedMessage(
      message: message,
      name: name,
      meaning: meaning,
      description: description,
      placeholders: arguments
          .map(
            (name) => placeholdersWithMetadata[name] ?? Placeholder(name),
          )
          .toList(),
    );
  }
}