comply with libphonenumber's mainCountryForCode attribute when format…

…ting numbers (#75)

* comply with libphonenumber's mainCountryForCode attribute when formatting numbers

see:
https://github.com/google/libphonenumber/blob/55716be400990f6542112323134cc1abc58abc2e/making-metadata-changes.md?plain=1#L34

Fixes: #74

* add a canadian phone number test

lib/src/metadata/metadata_finder.dart

@@ -49,14 +49,24 @@ abstract class MetadataFinder {
   }
 
   static PhoneMetadataFormats findMetadataFormatsForIsoCode(IsoCode isoCode) {
-    final metadata = metadataFormatsByIsoCode[isoCode];
+    var metadata = metadataFormatsByIsoCode[isoCode];
+    if (metadata is PhoneMetadataFormatReferenceDefinition) {
+      metadata = metadataFormatsByIsoCode[metadata.referenceIsoCode];
+    }
     if (metadata == null) {
       throw PhoneNumberException(
         code: Code.invalidIsoCode,
         description: 'isoCode "$isoCode" not found',
       );
     }
-    return metadata;
+    if (metadata is! PhoneMetadataFormatListDefinition) {
+      throw PhoneNumberException(
+        code: Code.invalidIsoCode,
+        description:
+            'isoCode "$isoCode" reference not a format list: $metadata',
+      );
+    }
+    return metadata.formats;
   }
 
   /// expects normalized countryCode

lib/src/metadata/models/phone_metadata_formats.dart

@@ -1,7 +1,36 @@
 import 'dart:convert';
 
+import '../../iso_codes/iso_code.dart';
+
 typedef PhoneMetadataFormats = List<PhoneMetadataFormat>;
 
+abstract class PhoneMetadataFormatDefinition {}
+
+class PhoneMetadataFormatReferenceDefinition
+    implements PhoneMetadataFormatDefinition {
+  final IsoCode referenceIsoCode;
+
+  const PhoneMetadataFormatReferenceDefinition({
+    required this.referenceIsoCode,
+  });
+}
+
+class PhoneMetadataFormatListDefinition
+    implements PhoneMetadataFormatDefinition {
+  final PhoneMetadataFormats formats;
+
+  const PhoneMetadataFormatListDefinition({
+    required this.formats,
+  });
+
+  factory PhoneMetadataFormatListDefinition.fromMap(Map<String, dynamic> map) {
+    return PhoneMetadataFormatListDefinition(
+      formats: List<PhoneMetadataFormat>.from(
+          map['formats']?.map((x) => PhoneMetadataFormat.fromMap(x))),
+    );
+  }
+}
+
 class PhoneMetadataFormat {
   final String pattern;
   final String? nationalPrefixFormattingRule;

resources/data_sources/read_metadata.dart

@@ -28,15 +28,28 @@ Future<Map<IsoCode, PhoneMetadataLengths>> getMetadataLengths() async {
       PhoneMetadataLengths.fromMap(value['lengths'])));
 }
 
-Future<Map<IsoCode, PhoneMetadataFormats>> getMetadataFormats() async {
+Future<Map<IsoCode, PhoneMetadataFormatDefinition>> getMetadataFormats() async {
   final info = await readMetadataJson();
+  final referencesByCountryCode = <String, IsoCode>{};
+  info.forEach((key, value) {
+    if (value['isMainCountryForDialCode']) {
+      referencesByCountryCode[value['countryCode']] =
+          IsoCode.values.byName(key.toUpperCase());
+    }
+  });
   return info.map((key, value) {
-    PhoneMetadataFormats converted;
-    converted = (value['formats'] as List)
-        .map((v) => PhoneMetadataFormat.fromMap(v))
-        .toList();
+    PhoneMetadataFormatDefinition formatDefinition;
+    String countryCode = value['countryCode'];
+    bool isMainCountryForDialCode = value['isMainCountryForDialCode'];
+    if (!isMainCountryForDialCode &&
+        referencesByCountryCode.containsKey(countryCode)) {
+      formatDefinition = PhoneMetadataFormatReferenceDefinition(
+          referenceIsoCode: referencesByCountryCode[countryCode]!);
+    } else {
+      formatDefinition = PhoneMetadataFormatListDefinition.fromMap(value);
+    }
 
-    return MapEntry(IsoCode.values.byName(key.toUpperCase()), converted);
+    return MapEntry(IsoCode.values.byName(key.toUpperCase()), formatDefinition);
   });
 }
 

resources/generate_files.dart

@@ -91,13 +91,14 @@ Future writeLenghtsMapFile(Map<IsoCode, PhoneMetadataLengths> metadata) async {
   await file.writeAsString(content);
 }
 
-Future writeFormatsMapFile(Map<IsoCode, PhoneMetadataFormats> metadata) async {
+Future writeFormatsMapFile(
+    Map<IsoCode, PhoneMetadataFormatDefinition> metadata) async {
   var content = '$isoCodeImport'
       'import "../models/phone_metadata_formats.dart";'
-      'const metadataFormatsByIsoCode = <IsoCode, PhoneMetadataFormats>{%%};';
+      'const metadataFormatsByIsoCode = <IsoCode, PhoneMetadataFormatDefinition>{%%};';
   var body = '';
   metadata.forEach((key, value) {
-    body += '$key: [${(value).map((f) => encodeFormats(f)).join(',')}],';
+    body += '$key: ${encodeFormatDefinition(value)},';
   });
   content = content.replaceFirst('%%', body);
   final file = await File('$baseFolder/metadata_formats_by_iso_code.dart')

resources/utils/phone_metadata_encoder.dart

@@ -51,6 +51,19 @@ String encodeLengths(PhoneMetadataLengths lengths) {
     )''';
 }
 
+String encodeFormatDefinition(PhoneMetadataFormatDefinition definition) {
+  if (definition is PhoneMetadataFormatReferenceDefinition) {
+    return '''PhoneMetadataFormatReferenceDefinition(
+      referenceIsoCode: ${definition.referenceIsoCode},
+    )''';
+  } else if (definition is PhoneMetadataFormatListDefinition) {
+    return '''PhoneMetadataFormatListDefinition(
+      formats: [${definition.formats.map(encodeFormats).join(', ')}],
+    )''';
+  }
+  throw ArgumentError('Unknown definition type: $definition');
+}
+
 String encodeFormats(PhoneMetadataFormat formats) {
   return '''PhoneMetadataFormat(
       pattern: ${_enc(formats.pattern)},

test/internal/_metadata_finder_test.dart

@@ -35,6 +35,12 @@ void main() {
       }
     });
 
+    test('should get formats metadata for iso code going through references',
+        () {
+      expect(MetadataFinder.findMetadataFormatsForIsoCode(IsoCode.CA),
+          equals(MetadataFinder.findMetadataFormatsForIsoCode(IsoCode.US)));
+    });
+
     test('should get metadata for country calling code', () {
       expect(MetadataFinder.findMetadataForCountryCode('33', '123456')?.isoCode,
           equals(IsoCode.FR));

test/phone_number_test.dart

@@ -325,6 +325,15 @@ void main() {
       expect(format(testNumber), equals('6 89 55 55 5'));
       testNumber = '689555555';
     });
+
+    test('should format through a format reference', () {
+      String format(String phoneNumber) =>
+          PhoneNumber.parse(phoneNumber, destinationCountry: IsoCode.CA)
+              .formatNsn(isoCode: IsoCode.CA);
+
+      var testNumber = '4185551212';
+      expect(format(testNumber), equals('(418) 555-1212'));
+    });
   });
 
   group('range', () {