using System;
using System.Diagnostics.CodeAnalysis;
using System.Drawing;
using System.Runtime.InteropServices;

namespace Foodsoft.Alpm
{
    public class Depend : IEquatable<Depend>
    {
        public enum ModType
        {
            Any = 1,
            Equal,
            GreaterThanOrEqual,
            LessThanOrEqual,
            GreaterThan,
            LessThan
        }

        public string Name { get; }
        public string Version { get; }
        public string Description { get; }
        public ulong NameHash { get; }
        public ModType Mod { get; }

        public override bool Equals(object? obj) => (obj is Depend other) && this.Equals(other);

        public bool Equals(Depend? other) => !ReferenceEquals(other, null) && ReferenceEquals(this, other) &&
                                             Name == other.Name && Version == other.Version && Mod == other.Mod;

        public override int GetHashCode() => HashCode.Combine(Name, Version, (int) Mod);

        [StructLayout(LayoutKind.Sequential)]
        private readonly unsafe struct NativeDepend
        {
            internal readonly sbyte* name;
            internal readonly sbyte* version;
            internal readonly sbyte* description;
            internal readonly ulong name_hash;
            internal readonly Depend.ModType mod;
        }

        internal unsafe Depend(IntPtr ptr)
        {
            var native = (NativeDepend*) ptr;
            Name = new string(native->name);
            Version = new string(native->version);
            Description = new string(native->description);
            NameHash = native->name_hash;
            Mod = native->mod;
        }
    }
}