import 'package:analyzer/dart/element/element.dart';
import 'package:angel_serialize/angel_serialize.dart';
import 'package:code_builder/code_builder.dart';
import 'package:recase/recase.dart';
import 'package:source_gen/source_gen.dart';

/// A base context for building serializable classes.
class BuildContext {
  ReCase _modelClassNameRecase;
  TypeReference _modelClassType;

  /// A map of fields that are absolutely required, and error messages for when they are absent.
  final Map<String, String> requiredFields = {};

  /// A map of field names to resolved names from `@Alias()` declarations.
  final Map<String, String> aliases = {};

  /// A map of fields that have been marked as to be excluded from serialization.
  final Map<String, Exclude> excluded = {};

  /// A map of "synthetic" fields, i.e. `id` and `created_at` injected automatically.
  final Map<String, bool> shimmed = {};

  final bool autoIdAndDateFields, autoSnakeCaseNames;

  final String originalClassName, sourceFilename;

  /// The fields declared on the original class.
  final List<FieldElement> fields = [];

  final List<ParameterElement> constructorParameters = [];

  final ConstantReader annotation;

  /// The name of the field that identifies data of this model type.
  String primaryKeyName = 'id';

  BuildContext(this.annotation,
      {this.originalClassName,
      this.sourceFilename,
      this.autoSnakeCaseNames,
      this.autoIdAndDateFields});

  /// The name of the generated class.
  String get modelClassName => originalClassName.startsWith('_')
      ? originalClassName.substring(1)
      : originalClassName;

  /// A [ReCase] instance reflecting on the [modelClassName].
  ReCase get modelClassNameRecase =>
      _modelClassNameRecase ??= new ReCase(modelClassName);

  TypeReference get modelClassType =>
      _modelClassType ??= new TypeReference((b) => b.symbol = modelClassName);

  /// The [FieldElement] pointing to the primary key.
  FieldElement get primaryKeyField =>
      fields.firstWhere((f) => f.name == primaryKeyName);

  /// Get the aliased name (if one is defined) for a field.
  String resolveFieldName(String name) =>
      aliases.containsKey(name) ? aliases[name] : name;
}