// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0

import 'package:collection/collection.dart';
import 'package:smithy/ast.dart' hide Matcher;
import 'package:test/test.dart';

/// Creates an AST from [shapes].
SmithyAst createAst(List<Shape> shapes) {
  return SmithyAst(
    (b) =>
        b..shapes = ShapeMap({for (var shape in shapes) shape.shapeId: shape}),
  );
}

/// Performs deep equality on two objects.
const deepEquals = _DeepEqualityMatcher.new;

class _DeepEqualityMatcher extends Matcher {
  _DeepEqualityMatcher(this.o);

  final Object? o;

  @override
  Description describe(Description description) {
    return description..add(o.toString());
  }

  @override
  Description describeMismatch(
    Object? item,
    Description mismatchDescription,
    Map<Object?, Object?> matchState,
    bool verbose,
  ) {
    return StringDescription()
      ..add('Expected: $o\n')
      ..add('Got: $item');
  }

  @override
  bool matches(Object? item, Map<Object?, Object?> matchState) {
    return const DeepCollectionEquality(_BaseEquality()).equals(o, item);
  }
}

/// Fixes equality between doubles, since a lot of tests require it.
///
/// Typically two doubles which are both NaN are not equal since
/// `double.NaN != double.NaN`.
///
/// Tests
class _BaseEquality implements Equality<Object?> {
  const _BaseEquality();
  static const _base = DefaultEquality<Object?>();

  @override
  bool equals(Object? e1, Object? e2) {
    if (e1 is double && e2 is double) {
      return e1 == e2 || (e1.isNaN && e2.isNaN);
    }
    return _base.equals(e1, e2);
  }

  @override
  int hash(Object? e) {
    return _base.hash(e);
  }

  @override
  bool isValidKey(Object? o) {
    return _base.isValidKey(o);
  }
}