import 'package:swagger_generator_flutter/commands/services/service_typedefs.dart';
import 'package:swagger_generator_flutter/core/models.dart';
import 'package:swagger_generator_flutter/pipeline/parse/impl/swagger_data_parser.dart';

class DocumentMergeService {
  DocumentMergeService({SwaggerDataParser? parser})
      : _parser = parser ?? SwaggerDataParser();

  final SwaggerDataParser _parser;

  Future<SwaggerDocument?> fetchAndMerge(
    List<String> urls, {
    LogCallback? progress,
  }) async {
    SwaggerDocument? mergedDocument;

    for (var i = 0; i < urls.length; i++) {
      final url = urls[i];
      progress?.call('  [${i + 1}/${urls.length}] 正在解析: $url');

      final doc = await _parser.fetchAndParseSwaggerDocument(url);
      progress?.call(
        '    解析完成: ${doc.models.length} 个模型, ${doc.paths.length} 个路径',
      );

      if (mergedDocument == null) {
        mergedDocument = doc;
        progress?.call('    初始文档: ${doc.models.length} 个模型');
        continue;
      }

      final beforeModelCount = mergedDocument.models.length;
      final currentModelCount = doc.models.length;

      final overlappingModels = <String>[];
      for (final key in doc.models.keys) {
        if (mergedDocument.models.containsKey(key)) {
          overlappingModels.add(key);
        }
      }

      if (overlappingModels.isNotEmpty) {
        progress?.call(
          '    发现 ${overlappingModels.length} 个同名模型将被覆盖: '
          '${overlappingModels.take(5).join(", ")}'
          '${overlappingModels.length > 5 ? "..." : ""}',
        );
      }

      mergedDocument = SwaggerDocument(
        title: mergedDocument.title,
        description: mergedDocument.description,
        version: '${mergedDocument.version} + ${doc.version}',
        paths: {...mergedDocument.paths, ...doc.paths},
        models: {...mergedDocument.models, ...doc.models},
        controllers: {...mergedDocument.controllers, ...doc.controllers},
      );

      final afterModelCount = mergedDocument.models.length;
      progress?.call(
        '    合并后: $beforeModelCount + $currentModelCount '
        '-> $afterModelCount 个模型',
      );

      if (overlappingModels.isNotEmpty) {
        progress?.call(
          '    同名模型列表: '
          '${overlappingModels.take(10).join(", ")}'
          '${overlappingModels.length > 10 ? "..." : ""}',
        );
      }
    }

    return mergedDocument;
  }
}