import 'package:build/build.dart';
import 'package:code_builder/code_builder.dart';
import 'package:swagger_dart_code_generator/src/extensions/file_name_extensions.dart';
import 'package:swagger_dart_code_generator/src/models/generator_options.dart';
import 'package:swagger_dart_code_generator/src/swagger_code_generator.dart';
import 'package:swagger_dart_code_generator/src/swagger_models/responses/swagger_schema.dart';
import 'package:universal_io/io.dart';
import 'package:dart_style/dart_style.dart';

///Returns instance of SwaggerDartCodeGenerator
SwaggerDartCodeGenerator swaggerCodeBuilder(BuilderOptions options) => SwaggerDartCodeGenerator(options);

const _inputFileExtensions = ['.swagger', '.json'];

const String _outputFileExtension = '.dart';
const String _outputEnumsFileExtension = '_enums.dart';
const String _outputModelsFileExtension = '_models.dart';
const String _indexFileName = 'client_index.dart';
// const String _mappingFileName = 'client_mapping.dart';

Map<String, List<String>> _generateExtensions(GeneratorOptions options) {
  final filesList = Directory(options.inputFolder)
      .listSync()
      .where((FileSystemEntity file) => _inputFileExtensions.any((ending) => file.path.endsWith(ending)));

  final result = <String, List<String>>{};

  filesList.forEach((FileSystemEntity element) {
    final name = getFileNameBase(element.path);
    result[element.path] = <String>[
      '${options.outputFolder}$name$_outputFileExtension',
      '${options.outputFolder}$name$_outputEnumsFileExtension',
      '${options.outputFolder}$name$_outputModelsFileExtension',
    ];
  });

  ///Register additional outputs in first input
  result[filesList.first.path]!.add('${options.outputFolder}$_indexFileName');
  // result[filesList.first.path]!.add('${options.outputFolder}$_mappingFileName');

  return result;
}

///Root library entry
class SwaggerDartCodeGenerator implements Builder {
  SwaggerDartCodeGenerator(BuilderOptions builderOptions) {
    options = GeneratorOptions.fromJson(builderOptions.config);
  }

  @override
  Map<String, List<String>> get buildExtensions => _buildExtensionsCopy ??= _generateExtensions(options);

  Map<String, List<String>>? _buildExtensionsCopy;

  late GeneratorOptions options;

  final DartFormatter _formatter = DartFormatter();

  @override
  Future<void> build(BuildStep buildStep) async {
    final fileNameWithExtension = buildStep.inputId.pathSegments.last.replaceAll('-', '_');
    final fileNameWithoutExtension = getFileNameBase(fileNameWithExtension);

    final contents = await buildStep.readAsString(buildStep.inputId);

    final codeGenerator = SwaggerCodeGenerator();

    final responses =
        codeGenerator.generateResponses(contents, getFileNameWithoutExtension(fileNameWithExtension), options);

    final requestBodies =
        codeGenerator.generateRequestBodies(contents, getFileNameWithoutExtension(fileNameWithExtension), options);

    final enums = codeGenerator.generateEnums(contents, getFileNameWithoutExtension(fileNameWithExtension));

    final converter =
        codeGenerator.generateConverter(contents, getFileNameWithoutExtension(fileNameWithExtension), options);

    var requestClass = <String, dynamic>{};

    final requests = codeGenerator.generateRequests(contents, getClassNameFromFileName(fileNameWithExtension),
        getFileNameWithoutExtension(fileNameWithExtension), options, requestClass);

    // print('---------');
    // print(requestClass);

    final models = codeGenerator.generateModels(
        contents, getFileNameWithoutExtension(fileNameWithExtension), options, requestClass);
    final imports = codeGenerator.generateImportsContent(contents, fileNameWithoutExtension, models.isNotEmpty,
        options.buildOnlyModels, enums.isNotEmpty, options.separateModels, options);

    // final customDecoder = codeGenerator.generateCustomJsonConverter(
    //     contents, getFileNameWithoutExtension(fileNameWithExtension), options);

    // final dateToJson = codeGenerator.generateDateToJson(contents);

    final copyAssetId =
        AssetId(buildStep.inputId.package, '${options.outputFolder}$fileNameWithoutExtension$_outputFileExtension');

    if (!options.separateModels || !options.buildOnlyModels) {
      await buildStep.writeAsString(
          copyAssetId,
          _generateFileContent(
            imports, requests, converter, options.separateModels ? '' : models,
            options.separateModels ? '' : responses, options.separateModels ? '' : requestBodies, '', '',
            // customDecoder,
            // dateToJson,
          ));
    }

    if (enums.isNotEmpty) {
      ///Write enums
      final formatterEnums = _tryFormatCode(enums);

      final enumsAssetId = AssetId(
          buildStep.inputId.package, '${options.outputFolder}$fileNameWithoutExtension$_outputEnumsFileExtension');

      await buildStep.writeAsString(enumsAssetId, formatterEnums);
    }

    if (options.separateModels) {
      ///Write models to separate file
      final formattedModels = _tryFormatCode(_generateSeparateModelsFileContent(
        models,
        responses,
        requestBodies,
        fileNameWithoutExtension,
        enums.isNotEmpty,
      ));

      final enumsAssetId = AssetId(
          buildStep.inputId.package, '${options.outputFolder}$fileNameWithoutExtension$_outputModelsFileExtension');

      await buildStep.writeAsString(enumsAssetId, formattedModels);
    }

    ///Write additional files on first input
    // if (buildExtensions.keys.first == buildStep.inputId.path) {
    //   await _generateAdditionalFiles(contents, buildStep.inputId, buildStep, models.isNotEmpty);
    // }
  }

  String _generateFileContent(String imports, String requests, String converter, String models, String responses,
      String requestBodies, String customDecoder, String dateToJson) {
    final result = """
$imports

${options.buildOnlyModels ? '' : requests}

${options.withConverter && !options.buildOnlyModels ? converter : ''}

$models

$responses

$requestBodies

${options.buildOnlyModels ? '' : customDecoder}

$dateToJson
""";

    return _tryFormatCode(result);
  }

  String _tryFormatCode(String code) {
    try {
      final formattedResult = _formatter.format(code);
      return formattedResult;
    } catch (e) {
      print('''[WARNING] Code formatting failed.
          Please raise an issue on https://github.com/epam-cross-platform-lab/swagger-dart-code-generator/issues/
          Reason: $e''');
      return code;
    }
  }

  // Future<void> _generateAdditionalFiles(
  //     String swaggerCode, AssetId inputId, BuildStep buildStep, bool hasModels) async {
  //   final codeGenerator = SwaggerCodeGenerator();

  //   final indexAssetId = AssetId(inputId.package, '${options.outputFolder}$_indexFileName');

  //   final imports = codeGenerator.generateIndexes(swaggerCode, buildExtensions);

  //   if (!options.buildOnlyModels) {
  //     await buildStep.writeAsString(indexAssetId, _formatter.format(imports));
  //   }

  //   if (options.withConverter && !options.buildOnlyModels) {
  //     final mappingAssetId = AssetId(inputId.package, '${options.outputFolder}$_mappingFileName');

  //     final mapping = codeGenerator.generateConverterMappings(swaggerCode, buildExtensions, hasModels);

  //     await buildStep.writeAsString(mappingAssetId, _formatter.format(mapping));
  //   }
  // }

  String _generateSeparateModelsFileContent(
    String models,
    String responses,
    String requestBodies,
    String fileNameWithoutExtension,
    bool hasEnums,
  ) {
    final enumsImport = hasEnums ? "import '${fileNameWithoutExtension}_enums.dart' as enums;" : '';

    return '''
import 'package:json_annotation/json_annotation.dart';
import 'package:collection/collection.dart';
$enumsImport

    part '${fileNameWithoutExtension}_models.g.dart';

    $models

    $responses

    $requestBodies
    ''';
  }
}