using System;

namespace Vellum.Generator
{
    /// <summary>
    /// Describes a saved member of a [Saveable] type as plain data, which is all it takes to check its type can be
    /// saved.
    /// </summary>
    public sealed class MemberCheck : IEquatable<MemberCheck>
    {
        public readonly string Key;
        public readonly TypeShape Type;
        public readonly SourcePlace Place;

        /// <summary>
        /// Holds the name of the [Saveable] base class that already saves something under this member's key, or null
        /// if none does.
        /// </summary>
        public readonly string HiddenIn;

        public MemberCheck(string key, TypeShape type, SourcePlace place, string hiddenIn)
        {
            Key = key;
            Type = type;
            Place = place;
            HiddenIn = hiddenIn;
        }

        public bool Equals(MemberCheck other)
        {
            return other != null && Key == other.Key && Type.Equals(other.Type) && Place.Equals(other.Place)
                && HiddenIn == other.HiddenIn;
        }

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

        public override int GetHashCode()
        {
            return Key.GetHashCode() * 31 + Type.GetHashCode();
        }
    }
}