add models to get study as JSON and PGN

lib/src/model/study/study.dart

@@ -1,11 +1,115 @@
+import 'package:collection/collection.dart';
+import 'package:dartchess/dartchess.dart';
 import 'package:fast_immutable_collections/fast_immutable_collections.dart';
 import 'package:freezed_annotation/freezed_annotation.dart';
+import 'package:lichess_mobile/src/model/common/chess.dart';
 import 'package:lichess_mobile/src/model/common/id.dart';
 import 'package:lichess_mobile/src/model/user/user.dart';
 
 part 'study.freezed.dart';
 part 'study.g.dart';
 
+@Freezed(fromJson: true)
+class Study with _$Study {
+  const Study._();
+
+  const factory Study({
+    required StudyId id,
+    required String name,
+    required ({StudyChapterId chapterId, String path}) position,
+    required bool liked,
+    required int likes,
+    required UserId? ownerId,
+    required IList<String> topics,
+    required IList<StudyChapterMeta> chapters,
+    required StudyChapter chapter,
+  }) = _Study;
+
+  StudyChapterMeta get currentChapterMeta =>
+      chapters.firstWhere((c) => c.id == chapter.id);
+
+  factory Study.fromJson(Map<String, Object?> json) => _$StudyFromJson(json);
+}
+
+@Freezed(fromJson: true)
+class StudyFeatures with _$StudyFeatures {
+  const StudyFeatures._();
+
+  const factory StudyFeatures({
+    @JsonKey(defaultValue: false) required bool cloneable,
+    @JsonKey(defaultValue: false) required bool chat,
+    @JsonKey(defaultValue: false) required bool sticky,
+  }) = _StudyFeatures;
+
+  factory StudyFeatures.fromJson(Map<String, Object?> json) =>
+      _$StudyFeaturesFromJson(json);
+}
+
+@Freezed(fromJson: true)
+class StudyChapter with _$StudyChapter {
+  const StudyChapter._();
+
+  const factory StudyChapter({
+    required StudyChapterId id,
+    required StudyChapterSetup setup,
+    @JsonKey(defaultValue: false) required bool practise,
+    required int? conceal,
+    @JsonKey(defaultValue: false) required bool gamebook,
+    required StudyChapterFeatures features,
+  }) = _StudyChapter;
+
+  factory StudyChapter.fromJson(Map<String, Object?> json) =>
+      _$StudyChapterFromJson(json);
+}
+
+@Freezed(fromJson: true)
+class StudyChapterFeatures with _$StudyChapterFeatures {
+  const StudyChapterFeatures._();
+
+  const factory StudyChapterFeatures({
+    @JsonKey(defaultValue: false) required bool computer,
+    @JsonKey(defaultValue: false) required bool explorer,
+  }) = _StudyChapterFeatures;
+
+  factory StudyChapterFeatures.fromJson(Map<String, Object?> json) =>
+      _$StudyChapterFeaturesFromJson(json);
+}
+
+@Freezed(fromJson: true)
+class StudyChapterSetup with _$StudyChapterSetup {
+  const StudyChapterSetup._();
+
+  const factory StudyChapterSetup({
+    required GameId? id,
+    required Side orientation,
+    @JsonKey(fromJson: _variantFromJson) required Variant variant,
+    required bool? fromFen,
+  }) = _StudyChapterSetup;
+
+  factory StudyChapterSetup.fromJson(Map<String, Object?> json) =>
+      _$StudyChapterSetupFromJson(json);
+}
+
+Variant _variantFromJson(Map<String, Object?> json) {
+  return Variant.values.firstWhereOrNull(
+    (v) => v.name == json['key'],
+  )!;
+}
+
+@Freezed(fromJson: true)
+class StudyChapterMeta with _$StudyChapterMeta {
+  const StudyChapterMeta._();
+
+  const factory StudyChapterMeta({
+    required StudyChapterId id,
+    required String name,
+    required String? fen,
+  }) = _StudyChapterMeta;
+
+  factory StudyChapterMeta.fromJson(Map<String, Object?> json) =>
+      _$StudyChapterMetaFromJson(json);
+}
+
 @Freezed(fromJson: true)
 class StudyPageData with _$StudyPageData {
   const StudyPageData._();

lib/src/model/study/study_repository.dart

@@ -1,6 +1,9 @@
+import 'dart:convert';
+
 import 'package:deep_pick/deep_pick.dart';
 import 'package:fast_immutable_collections/fast_immutable_collections.dart';
 import 'package:http/http.dart';
+import 'package:lichess_mobile/src/model/common/id.dart';
 import 'package:lichess_mobile/src/model/study/study.dart';
 import 'package:lichess_mobile/src/model/study/study_filter.dart';
 import 'package:lichess_mobile/src/network/http.dart';
@@ -53,4 +56,31 @@ class StudyRepository {
       },
     );
   }
+
+  Future<(Study study, String pgn)> getStudy({
+    required StudyId id,
+    StudyChapterId? chapterId,
+  }) async {
+    final study = await client.readJson(
+      Uri(
+        path: (chapterId != null) ? '/study/$id/$chapterId' : '/study/$id',
+        queryParameters: {
+          'chapters': '1',
+        },
+      ),
+      headers: {'Accept': 'application/json'},
+      mapper: (Map<String, dynamic> json) {
+        return Study.fromJson(
+          pick(json, 'study').asMapOrThrow(),
+        );
+      },
+    );
+
+    final pgnBytes = await client.readBytes(
+      Uri(path: '/api/study/$id/${chapterId ?? study.chapter.id}.pgn'),
+      headers: {'Accept': 'application/x-chess-pgn'},
+    );
+
+    return (study, utf8.decode(pgnBytes));
+  }
 }