using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;


namespace McBitFont {
    internal class CanvasHistory {
        private List<bool[,]> stack;
        public int Depth { get; set; }
        public int Index { get; set; }
        public int Count {
            get { return stack.Count - 1; }
        }
        public int Redos {
            get {
                var r = Count - Index - 1;

                return r < 0 ? 0 : r;
            }
        }
        public int Undos {
            get {
                return Index + 1;
            }
        }

        
        public CanvasHistory(int depth = 50) {
            Depth = depth;
            Index = -1;
            stack = [];
        }

        public void Clear() {
            stack.Clear();
            Index = -1;
        }

        public void AddPre(MainForm.FrameMiniature f, bool useIndex = true) {
            if (Count < 0) stack.Add(new bool[f.width, f.height]);
            if (Index < Count - 1) {
                stack.RemoveRange(Index + 1, Count - Index - 1);
            }
            bool[,] d = new bool[f.width, f.height];
            Array.Copy(f.data, d, f.data.Length);
            stack.Insert(Count, d);
            if (useIndex) {
                if (Count > Depth) stack.RemoveAt(0);
                else Index++;
            }
        }

        public void AddPost(MainForm.FrameMiniature f) {
            var d = stack.ElementAt(Count);
            Array.Copy(f.data, d, f.data.Length);
        }

        public void ApplyAdded() {
            while (Count > Depth) stack.RemoveAt(0);
            Index = Count - 1;
        }

        public void Remove(bool useIndex = true) {
            stack.RemoveAt(Count - 1);
            if (useIndex) Index--;
        }

        public void Undo(MainForm.FrameMiniature f) {
            if (Index < 0) return;
            var d = stack.ElementAt(Index);
            Array.Copy(d, f.data, d.Length);
            Index--;
        }

        public void Redo(MainForm.FrameMiniature f) {
            if (Index >= Count - 1) return;
            Index++;
            var d = stack.ElementAt(Index + 1);
            Array.Copy(d, f.data, d.Length);
        }
    }
}