using ServicePoint;
using TanksServer.GameLogic;
using TanksServer.Interactivity;

namespace TanksServer.Graphics;

internal sealed class GeneratePixelsTickStep(
    IEnumerable<IDrawStep> drawSteps,
    IEnumerable<IFrameConsumer> consumers
) : ITickStep
{
    private GamePixelGrid _lastGamePixelGrid = new(MapService.PixelsPerRow, MapService.PixelsPerColumn);
    private PixelGrid _lastObserverPixelGrid = PixelGrid.New(MapService.PixelsPerRow, MapService.PixelsPerColumn);
    private GamePixelGrid _gamePixelGrid = new(MapService.PixelsPerRow, MapService.PixelsPerColumn);
    private PixelGrid _observerPixelGrid = PixelGrid.New(MapService.PixelsPerRow, MapService.PixelsPerColumn);

    private readonly List<IDrawStep> _drawSteps = drawSteps.ToList();
    private readonly List<IFrameConsumer> _consumers = consumers.ToList();

    public async ValueTask TickAsync(TimeSpan _)
    {
        Draw(_gamePixelGrid, _observerPixelGrid);
        if (_observerPixelGrid.Data.SequenceEqual(_lastObserverPixelGrid.Data))
            return;

        await _consumers.Select(c => c.OnFrameDoneAsync(_gamePixelGrid, _observerPixelGrid))
            .WhenAll();

        (_lastGamePixelGrid, _gamePixelGrid) = (_gamePixelGrid, _lastGamePixelGrid);
        (_lastObserverPixelGrid, _observerPixelGrid) = (_observerPixelGrid, _lastObserverPixelGrid);
    }

    private void Draw(GamePixelGrid gamePixelGrid, PixelGrid observerPixelGrid)
    {
        gamePixelGrid.Clear();
        foreach (var step in _drawSteps)
            step.Draw(gamePixelGrid);

        observerPixelGrid.Fill(false);
        for (var y = 0; y < MapService.PixelsPerColumn; y++)
        for (var x = 0; x < MapService.PixelsPerRow; x++)
        {
            if (gamePixelGrid[x, y].EntityType.HasValue)
                observerPixelGrid[(ushort)x, (ushort)y] = true;
        }
    }
}