dart_tdlib_gen/bin/tl_scheme.dart

import 'tl_token.dart';

class TlSchema {
  final List<TlSchemeAbstractClass> abstractClasses;
  final List<TlSchemeObject> objects;
  final List<TlSchemeFunction> functions;

  TlSchema({
    required this.abstractClasses,
    required this.objects,
    required this.functions,
  });

  TlSchemeItem? findType(String type) {
    TlSchemeItem? find(List<TlSchemeItem> list) {
      for (final item in list) {
        if (item.name == type) {
          return item;
        }
      }
    }

    return find(abstractClasses) ?? find(objects) ?? find(functions);
  }

  factory TlSchema.parse(String file) {
    var abstractClasses = <String, TlSchemeAbstractClass>{};
    var objects = <String, TlSchemeObject>{};
    var functions = <String, TlSchemeFunction>{};

    var comments = <TlTokenCommentTag>[];

    void finishBuilder(_TlSchemeItemBuilder builder) {
      comments.clear();
      if (builder is _TlSchemeAbstractClassBuilder) {
        final ac = builder.build();
        abstractClasses[ac.name] = ac;
      }
      else if (builder is _TlSchemeObjectBuilder) {
        final obj = builder.build();
        objects[obj.name] = obj;
        if (!abstractClasses.containsKey(obj.baseType)) {
          abstractClasses[obj.baseType] = TlSchemeAbstractClass(
            name: obj.baseType, 
            doc: ''
          );
        }
      }
      else if (builder is _TlSchemeFunctionBuilder) {
        final fn = builder.build();
        functions[fn.name] = fn;
      }
      else {
        throw Exception('Unknown builder: $builder');
      }
    }
    
    var buildingFunctions = false;
    _TlSchemeItemBuilder? builder;

    for (final token in TlToken.tokenize(file)) {
      if (token is TlTokenNone) {
        if (builder != null) {
          finishBuilder(builder);
        }
        builder = null;
      }
      else if (token is TlTokenFunctionsDelimiter) {
        buildingFunctions = true;
      }
      else if (token is TlTokenCommentTag) {
        if (token.name == 'class' && comments.isEmpty && builder == null) {
          builder = _TlSchemeAbstractClassBuilder(
            name: token.value,
          );
        }
        else if (builder is _TlSchemeAbstractClassBuilder && token.name == 'description') {
          builder.doc = token.value;
        }
        else {
          comments.add(token);
        }
      }
      else if (token is TlTokenClassTag) {
        // Check for skippable
        final skippable = [
          'double', 
          'string', 
          'int32',
          'int53',
          'int64',
          'bytes',
          'boolFalse',
          'boolTrue',
          'vector',
        ];
        if (skippable.contains(token.name)) {
          comments.clear();
          builder = null;
          continue;
        }

        var typeDoc = '';
        var paramDoc = <String, String>{};

        for (final comment in comments) {
          if (comment.name == 'description') {
            typeDoc = comment.value;
          }
          else if (comment.name == 'param_description') {
            paramDoc['description'] = comment.value;
          }
          else {
            paramDoc[comment.name] = comment.value;
          }
        }

        if (buildingFunctions) {
          builder = _TlSchemeFunctionBuilder(
            returnType: token.baseType,
            name: token.name,
            doc: typeDoc,
            parameters: token.parameters.map((t) => _TlSchemeParamBuilder(
              name: t.name,
              type: t.type,
              doc: paramDoc[t.name]!,
            )).toList(growable: false),
          );
        }
        else {
          builder = _TlSchemeObjectBuilder(
            baseType: token.baseType,
            name: token.name,
            doc: typeDoc,
            parameters: token.parameters.map((t) => _TlSchemeParamBuilder(
              name: t.name,
              type: t.type,
              doc: paramDoc[t.name]!,
            )).toList(growable: false),
          );
        }
        finishBuilder(builder);
        builder = null;
      }
    }

    return TlSchema(
      abstractClasses: abstractClasses.values.toList(growable: false), 
      objects: objects.values.toList(growable: false),
      functions: functions.values.toList(growable: false),
    );
  }
}

abstract class TlSchemeItem {
  final String name;
  final String doc;
  TlSchemeItem({required this.name, required this.doc});
}
abstract class _TlSchemeItemBuilder<T extends TlSchemeItem> {
  T build();
}

class TlSchemeAbstractClass extends TlSchemeItem {
  TlSchemeAbstractClass({required String name, required String doc}) 
  : super(name: name, doc: doc);

  @override
  String toString() {
    return 'abstract $name';
  }
}
class _TlSchemeAbstractClassBuilder extends _TlSchemeItemBuilder<TlSchemeAbstractClass> {
  String name;
  String doc;
  _TlSchemeAbstractClassBuilder({this.name = '', this.doc = ''});
  @override
  TlSchemeAbstractClass build() => TlSchemeAbstractClass(name: name, doc: doc);
}

class TlSchemeObject extends TlSchemeItem {
  final String baseType;
  final List<TlSchemeParam> parameters;
  TlSchemeObject({
    required this.baseType,
    required String name,
    required String doc,
    required this.parameters,
  }) : super(name: name, doc: doc);

  @override
  String toString() {
    return 'class $name(${parameters.join(', ')}) : $baseType';
  }
}
class _TlSchemeObjectBuilder extends _TlSchemeItemBuilder<TlSchemeObject> {
  String baseType;
  String name;
  String doc;
  List<_TlSchemeParamBuilder> parameters;
  _TlSchemeObjectBuilder({
    this.baseType = '', 
    this.name = '', 
    this.doc = '', 
    this.parameters = const <_TlSchemeParamBuilder>[]
  });
  @override
  TlSchemeObject build() => TlSchemeObject(
    baseType: baseType, 
    name: name, 
    doc: doc, 
    parameters: parameters.map((b) => b.build()).toList(growable: false),
  );
}

class TlSchemeFunction extends TlSchemeItem {
  final String returnType;
  final List<TlSchemeParam> parameters;
  TlSchemeFunction({
    required this.returnType,
    required String name,
    required String doc,
    required this.parameters,
  }) : super(name: name, doc: doc);
  @override
  String toString() {
    return 'fn $name(${parameters.join(', ')}) -> $returnType';
  }
}
class _TlSchemeFunctionBuilder extends _TlSchemeItemBuilder<TlSchemeFunction> {
  String returnType;
  String name;
  String doc;
  List<_TlSchemeParamBuilder> parameters;
  _TlSchemeFunctionBuilder({
    this.returnType = '',
    this.name = '',
    this.doc = '',
    this.parameters = const <_TlSchemeParamBuilder>[]
  });
  @override
  TlSchemeFunction build() => TlSchemeFunction(
    returnType: returnType, 
    name: name, 
    doc: doc, 
    parameters: parameters.map((b) => b.build()).toList(growable: false),
  );
}

class TlSchemeParam {
  final String name;
  final String type;
  final String doc;
  TlSchemeParam({required this.name, required this.type, required this.doc});
  @override
  String toString() {
    return '$name: $type';
  }
}
class _TlSchemeParamBuilder {
  String name;
  String type;
  String doc;
  _TlSchemeParamBuilder({this.name = '', this.type = '', this.doc = ''});
  TlSchemeParam build() => TlSchemeParam(name: name, type: type, doc: doc);
}