using System.Collections;
using System.Collections.Generic;
using Unity.Mathematics;

namespace DanieleMarotta.RiversongCodeShowcase
{
    public struct TileRange : IEnumerable<int2>
    {
        public int2 Min;

        public int2 Max;

        private TileRange(int2 min, int2 max)
        {
            Min = min;
            Max = max;
        }

        public static TileRange From(in TileRect rect)
        {
            return new TileRange(rect.Min, rect.Max);
        }

        public static TileRange From(int2 min, int2 max)
        {
            return From(new TileRect(min, max));
        }

        public Enumerator GetEnumerator()
        {
            return new Enumerator(Min, Max);
        }

        IEnumerator<int2> IEnumerable<int2>.GetEnumerator()
        {
            return GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }

        public struct Enumerator : IEnumerator<int2>
        {
            public int2 Min;

            public int2 Max;

            public int2 Current { get; private set; }

            object IEnumerator.Current => Current;

            public Enumerator(int2 min, int2 max) : this()
            {
                Min = min;
                Max = max;
                Reset();
            }

            public bool MoveNext()
            {
                if (Current.x < Max.x)
                {
                    Current = new int2(Current.x + 1, Current.y);
                    return true;
                }

                if (Current.y < Max.y)
                {
                    Current = new int2(Min.x, Current.y + 1);
                    return true;
                }

                return false;
            }

            public void Reset()
            {
                Current = new int2(Min.x - 1, Min.y);
            }

            public void Dispose()
            {
            }
        }
    }
}