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

namespace Penumbra.GameData.Files;

public partial class MtrlFile
{
    public unsafe struct ColorDyeSet
    {
        public struct Row
        {
            private ushort _data;

            public ushort Template
            {
                get => (ushort)(_data >> 5);
                set => _data = (ushort)((_data & 0x1F) | (value << 5));
            }

            public bool Diffuse
            {
                get => (_data & 0x01) != 0;
                set => _data = (ushort)(value ? _data | 0x01 : _data & 0xFFFE);
            }

            public bool Specular
            {
                get => (_data & 0x02) != 0;
                set => _data = (ushort)(value ? _data | 0x02 : _data & 0xFFFD);
            }

            public bool Emissive
            {
                get => (_data & 0x04) != 0;
                set => _data = (ushort)(value ? _data | 0x04 : _data & 0xFFFB);
            }

            public bool Gloss
            {
                get => (_data & 0x08) != 0;
                set => _data = (ushort)(value ? _data | 0x08 : _data & 0xFFF7);
            }

            public bool SpecularStrength
            {
                get => (_data & 0x10) != 0;
                set => _data = (ushort)(value ? _data | 0x10 : _data & 0xFFEF);
            }
        }

        public struct RowArray : IEnumerable<Row>
        {
            public const  int    NumRows = 16;
            private fixed ushort _rowData[NumRows];

            public ref Row this[int i]
            {
                get
                {
                    fixed (ushort* ptr = _rowData)
                    {
                        return ref ((Row*)ptr)[i];
                    }
                }
            }

            public IEnumerator<Row> GetEnumerator()
            {
                for (var i = 0; i < NumRows; ++i)
                    yield return this[i];
            }

            IEnumerator IEnumerable.GetEnumerator()
                => GetEnumerator();

            public ReadOnlySpan<byte> AsBytes()
            {
                fixed (ushort* ptr = _rowData)
                {
                    return new ReadOnlySpan<byte>(ptr, NumRows * sizeof(ushort));
                }
            }
        }

        public RowArray Rows;
        public string   Name;
        public ushort   Index;
    }
}