using Godot;
using System.Collections.Generic;
using Chessistics.Engine.Model;

namespace Chessistics.Scripts.Board;

public partial class BoardView : Node2D
{
	public const int CellSize = 80;

	private readonly Dictionary<Coords, CellView> _cells = new();
	private int _width;
	private int _height;

	public void BuildBoard(LevelDef level)
	{
		// Clear existing children
		foreach (var child in GetChildren())
			child.QueueFree();
		_cells.Clear();

		_width = level.Width;
		_height = level.Height;

		var boardState = BoardState.FromLevel(level);

		for (int col = 0; col < level.Width; col++)
		{
			for (int row = 0; row < level.Height; row++)
			{
				var coords = new Coords(col, row);
				var cellView = new CellView();
				cellView.Setup(coords, boardState.GetCell(coords), CellSize);
				AddChild(cellView);
				_cells[coords] = cellView;
			}
		}

		// Label productions and demands
		foreach (var prod in level.Productions)
		{
			if (_cells.TryGetValue(prod.Position, out var cell))
				cell.SetLabel(prod.Name);
		}

		foreach (var demand in level.Demands)
		{
			if (_cells.TryGetValue(demand.Position, out var cell))
				cell.SetLabel(demand.Name);
		}
	}

	public void BuildBoardFromSnapshot(BoardSnapshot snap)
	{
		// Clear existing children
		foreach (var child in GetChildren())
			child.QueueFree();
		_cells.Clear();

		_width = snap.Width;
		_height = snap.Height;

		for (int col = 0; col < snap.Width; col++)
		{
			for (int row = 0; row < snap.Height; row++)
			{
				var coords = new Coords(col, row);
				var cellView = new CellView();
				cellView.Setup(coords, snap.Grid[col, row], CellSize);
				AddChild(cellView);
				_cells[coords] = cellView;
			}
		}

		// Label productions and demands
		foreach (var prod in snap.Productions)
		{
			if (_cells.TryGetValue(prod.Position, out var cell))
				cell.SetLabel(prod.Name);
		}

		foreach (var demand in snap.Demands)
		{
			if (_cells.TryGetValue(demand.Position, out var cell))
				cell.SetLabel(demand.Name);
		}

		foreach (var transformer in snap.Transformers)
		{
			if (_cells.TryGetValue(transformer.Position, out var cell))
				cell.SetLabel(transformer.Name);
		}
	}

	public Coords? PixelToCoords(Vector2 localPos)
	{
		int col = Mathf.FloorToInt(localPos.X / CellSize);
		// Cell at row R has top-left Y = -R*CellSize, extending downward.
		// floor(-Y/Size) != -floor(Y/Size) for non-integers, so use the latter.
		int row = -Mathf.FloorToInt(localPos.Y / CellSize);

		var coords = new Coords(col, row);
		return coords.IsOnBoard(_width, _height) ? coords : null;
	}

	public Vector2 CoordsToPixel(Coords coords)
	{
		return new Vector2(
			coords.Col * CellSize + CellSize / 2f,
			-coords.Row * CellSize + CellSize / 2f
		);
	}

	public CellView? GetCellView(Coords coords)
		=> _cells.GetValueOrDefault(coords);

	public void SetHoverCell(Coords? coords)
	{
		foreach (var cell in _cells.Values)
			cell.SetHover(false);

		if (coords != null && _cells.TryGetValue(coords.Value, out var cellView))
			cellView.SetHover(true);
	}

	public void ClearHighlights()
	{
		foreach (var cell in _cells.Values)
			cell.SetHighlight(false);
	}

	public void HighlightCells(IEnumerable<Coords> cells, Color color)
	{
		foreach (var coords in cells)
		{
			if (_cells.TryGetValue(coords, out var cellView))
				cellView.SetHighlightColor(color);
		}
	}
}