using AppLauncher.Models;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;

namespace AppLauncher.Windows.Forms
{
    public class TileLayoutPanel : AUserControl
    {
        public class Item
        {
            public TilePanel Tile { get; set; }
            public Point Coord { get; set; } = new Point(0, 0);
        }

        protected readonly int tileSize = 70;
        protected readonly int margin = 3;

        protected int collapseHeight = 0;
        protected int expandedHeight = 0;

        protected List<Item> items = new List<Item>();

        public TileLayoutPanel() : base()
        {
            this.BackColor = System.Drawing.Color.Transparent;
        }

        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);

            OnResize(e);
        }

        public Point GridSize
        {
            get
            {
                int w = (int)Math.Floor(decimal.Divide(this.Width, this.TileSize));
                int h = (int)Math.Floor(decimal.Divide(this.Height, this.TileSize));

                return new Point(w, h);
            }
        }

        public TileContainer TileContainer
        {
            get
            {
                if (this.Parent == null)
                {
                    return null;
                }

                if (this.Parent.GetType() != typeof(TileContainer))
                {
                    return null;
                }

                return (TileContainer)this.Parent;
            }
        }

        public int TileSize => (tileSize + margin);

        public int CollapseHeight => collapseHeight;

        public int ExpandedHeight => expandedHeight;

        public void AddTile(TileModel tile)
        {
            Point gridSize = this.GridSize;

            if (items.Count >= (gridSize.X * gridSize.Y))
            {
                this.SetGridSize(gridSize.X, (gridSize.Y + 1));
            }

            Point? newCoord = findLastFreeCoord();
            if (newCoord == null)
            {
                return;
            }

            tile.Position = newCoord.Value;

            TilePanel panel = new TilePanel();
            panel.LoadInfo(tile);
            panel.Location = convertCoordToLocation(tile.Position);

            items.Add(new Item()
            {
                Tile = panel,
                Coord = tile.Position
            });

            this.Controls.Add(panel);
        }

        public void Clear()
        {
            this.Controls.Clear();
        }

        public Point GetTilePosition(int posX, int posY)
        {
            int x = (int)Math.Round(decimal.Divide(posX, this.TileSize));
            int y = (int)Math.Round(decimal.Divide(posY, this.TileSize));

            if (x < 0) x = 0;
            if (y < 0) y = 0;

            return new Point((x * this.TileSize), (y * this.TileSize));
        }

        public void LoadTiles(List<TileModel> tiles)
        {
            if (tiles == null)
            {
                return;
            }

            if (tiles.Count() <= 0)
            {
                return;
            }

            foreach (TileModel item in tiles)
            {
                // resolve final grid position
                Point? confirmedPosition = resolveCoord(item.Position);
                if (confirmedPosition == null)
                {
                    continue;

                }

                // place control
                TilePanel panel = new TilePanel();
                panel.LoadInfo(item);
                panel.Location = convertCoordToLocation(confirmedPosition.Value);

                items.Add(new Item()
                {
                    Tile = panel,
                    Coord = confirmedPosition.Value
                });

                this.Controls.Add(panel);
            }
        }

        public void MoveTile(TilePanel panel, int posX, int posY)
        {
            Item item = items.Where(x => x.Tile.Equals(panel)).FirstOrDefault();
            if (item == null)
            {
                return;
            }

            Point newPosition = convertLocationToCoord(posX, posY);
            if (!isTileInBounds(newPosition))
            {
                return;
            }

            if (hasTile(newPosition))
            {
                Item swapItem = items.Where(x => x.Coord.Equals(newPosition)).FirstOrDefault();
                if (swapItem != null)
                {
                    swapItem.Coord = item.Coord;
                    swapItem.Tile.Location = convertCoordToLocation(item.Coord);
                }

                item.Coord = newPosition;
                panel.Location = convertCoordToLocation(newPosition);
            }
            else
            {
                item.Coord = newPosition;
                panel.Location = convertCoordToLocation(newPosition);
            }
        }

        public void Remove(TilePanel panel)
        {
            Item m = items.Where(x => x.Tile.Equals(panel)).FirstOrDefault();
            if (m != null)
            {
                items.Remove(m);
            }

            this.Controls.Remove(panel);
        }

        public void SetGridSize(int width, int height)
        {
            expandedHeight = (this.TileSize * height);

            this.Size = new Size((this.TileSize * width), expandedHeight);
        }

        protected Point convertCoordToLocation(Point position) => new Point((position.X * this.TileSize), (position.Y * this.TileSize));

        protected Point convertLocationToCoord(int posX, int posY)
        {
            int x = (int)Math.Round(decimal.Divide(posX, this.TileSize));
            int y = (int)Math.Round(decimal.Divide(posY, this.TileSize));

            if (x < 0) x = 0;
            if (y < 0) y = 0;

            return new Point(x, y);
        }

        protected Point? findLastFreeCoord()
        {
            Point gridSize = this.GridSize;

            // none available
            if (items.Count >= (gridSize.X * gridSize.Y))
            {
                return null;
            }

            // only one available
            if (items.Count >= ((gridSize.X * gridSize.Y) - 1))
            {
                return findFirstFreeCoord();
            }

            Point? rv = null;

            for (int y = (gridSize.Y - 1); y >= 0; y--)
            {
                for (int x = (gridSize.X - 1); x >= 0; x--)
                {
                    if (hasTile(new Point(x, y)))
                    {
                        if (rv.HasValue)
                        {
                            return rv;
                        }
                    }
                    else
                    {
                        rv = new Point(x, y);
                    }
                }
            }

            return null;
        }

        protected Point? findFirstFreeCoord()
        {
            Point gridSize = this.GridSize;

            for (int y = 0; y < gridSize.Y; y++)
            {
                for (int x = 0; x < gridSize.X; x++)
                {
                    if (hasTile(new Point(x, y)))
                    {
                        continue;
                    }

                    return new Point(x, y);
                }
            }

            return null;
        }

        protected Point? resolveCoord(Point coord)
        {
            if (!isTileInBounds(coord))
            {
                return null;
            }

            if (!hasTile(coord))
            {
                return coord;
            }

            return resolveNextCoord(coord);
        }

        protected Point? resolveNextCoord(Point coord)
        {
            Point gridSize = this.GridSize;
            Point newCoord = coord;

            while (true)
            {
                newCoord.X++;

                if (newCoord.X >= gridSize.X)
                {
                    newCoord.Y++;
                    newCoord.X = 0;
                }

                if (!isTileInBounds(newCoord))
                {
                    return null;
                }

                if (hasTile(newCoord))
                {
                    continue;
                }

                return newCoord;
            }
        }

        protected bool hasTile(Point position)
        {
            if (items == null)
            {
                return false;
            }

            if (items.Count <= 0)
            {
                return false;
            }

            return (items.Count(x => x.Coord.Equals(position)) > 0);
        }

        protected bool isTileInBounds(Point position)
        {
            Point gridSize = this.GridSize;

            if (position.X >= gridSize.X)
            {
                return false;
            }

            if (position.Y >= gridSize.Y)
            {
                return false;
            }

            return true;
        }

    }
}