// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
namespace Roslyn.LanguageServer.Protocol;
 
using System;
using System.Text.Json.Serialization;
 
/// <summary>
/// Class that contains the base kind and modifiers used to describe a response item.
/// </summary>
internal sealed class VSInternalKindAndModifier : IEquatable<VSInternalKindAndModifier>
{
    /// <summary>
    /// Gets or sets the ImageIds for a certain kind.
    /// </summary>
    [JsonPropertyName("_vs_kind")]
    public string Kind
    {
        get;
        set;
    }
 
    /// <summary>
    /// Gets or sets the modifier of the kind.
    /// </summary>
    [JsonPropertyName("_vs_modifier")]
    [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
    public string[]? Modifier
    {
        get;
        set;
    }
 
    public static bool operator ==(VSInternalKindAndModifier? value1, VSInternalKindAndModifier? value2)
    {
        if (ReferenceEquals(value1, value2))
        {
            return true;
        }
 
        // Is null?
        if (ReferenceEquals(null, value2))
        {
            return false;
        }
 
        return value1?.Equals(value2) ?? false;
    }
 
    public static bool operator !=(VSInternalKindAndModifier? value1, VSInternalKindAndModifier? value2)
    {
        return !(value1 == value2);
    }
 
    /// <inheritdoc/>
    public override bool Equals(object obj)
    {
        return this.Equals(obj as VSInternalKindAndModifier);
    }
 
    /// <inheritdoc/>
    public bool Equals(VSInternalKindAndModifier? other)
    {
        return other != null &&
            string.Equals(this.Kind, other.Kind, StringComparison.Ordinal) &&
            this.CheckModifierEquality(other.Modifier);
    }
 
    /// <inheritdoc/>
    public override int GetHashCode()
    {
        var hashCode = 1850642763;
        hashCode = (hashCode * -1521134295) + (this.Kind == null ? 0 : StringComparer.Ordinal.GetHashCode(this.Kind));
        if (this.Modifier != null)
        {
            for (var i = 0; i < this.Modifier.Length; i++)
            {
                if (this.Modifier[i] != null)
                {
                    hashCode = (hashCode * -1521134295) + StringComparer.Ordinal.GetHashCode(this.Modifier[i]);
                }
            }
        }
 
        return hashCode;
    }
 
    private bool CheckModifierEquality(string[]? modifiers)
    {
        if (modifiers == null ^ this.Modifier == null)
        {
            return false;
        }
 
        if (modifiers != null &&
            this.Modifier != null &&
            modifiers.Length == this.Modifier.Length)
        {
            for (var i = 0; i < modifiers.Length; i++)
            {
                if (!string.Equals(modifiers[i], this.Modifier[i], StringComparison.Ordinal))
                {
                    return false;
                }
            }
        }
 
        return true;
    }
}