// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System;
using System.Collections.Generic;
using System.Linq;

namespace Microsoft.AspNetCore.Razor.Language
{
	public abstract class TagMatchingRuleDescriptor : IEquatable<TagMatchingRuleDescriptor>
	{
		private int? _hashCode;
		private IEnumerable<RazorDiagnostic> _allDiagnostics;

		public string TagName { get; protected set; }

		public IReadOnlyList<RequiredAttributeDescriptor> Attributes { get; protected set; }

		public string ParentTag { get; protected set; }

		public TagStructure TagStructure { get; protected set; }

		public bool CaseSensitive { get; protected set; }

		public IReadOnlyList<RazorDiagnostic> Diagnostics { get; protected set; }


		public bool HasErrors
		{
			get
			{
				var allDiagnostics = GetAllDiagnostics();
				var errors = allDiagnostics.Any( diagnostic => diagnostic.Severity == RazorDiagnosticSeverity.Error );

				return errors;
			}
		}

		public virtual IEnumerable<RazorDiagnostic> GetAllDiagnostics()
		{
			if ( _allDiagnostics == null )
			{
				var attributeDiagnostics = Attributes.SelectMany( attribute => attribute.Diagnostics );
				var combinedDiagnostics = Diagnostics.Concat( attributeDiagnostics );
				_allDiagnostics = combinedDiagnostics.ToArray();
			}

			return _allDiagnostics;
		}

		public bool Equals( TagMatchingRuleDescriptor other )
		{
			return TagMatchingRuleDescriptorComparer.Default.Equals( this, other );
		}

		public override bool Equals( object obj )
		{
			return Equals( obj as TagMatchingRuleDescriptor );
		}

		public override int GetHashCode()
		{
			_hashCode ??= TagMatchingRuleDescriptorComparer.Default.GetHashCode( this );
			return _hashCode.Value;
		}
	}
}
