using System;
using Encompass;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using PongFE.Components;
using PongFE.Enums;

namespace PongFE.Renderers
{
    public class CenterLineRenderer : GeneralRenderer
    {
        public SpriteBatch SpriteBatch { get; }
        public Texture2D WhitePixel { get; }

        public CenterLineRenderer(SpriteBatch spriteBatch, Texture2D whitePixel)
        {
            SpriteBatch = spriteBatch;
            WhitePixel = whitePixel;
        }

        public override void Render()
        {
            ref readonly var gameStateComponent = ref ReadComponent<GameStateComponent>();

            if (gameStateComponent.GameState == GameState.Game)
            {
                ref readonly var playAreaComponent = ref ReadComponent<PlayAreaComponent>();

                DrawDottedLine(playAreaComponent.Width / 2, 0, playAreaComponent.Width / 2, playAreaComponent.Height, 20, 20);
            }
        }

        private void DrawDottedLine(float x1, float y1, float x2, float y2, int dash, int gap)
        {
            var dx = x2 - x1;
            var dy = y2 - y1;
            var angle = Math.Atan2(dy, dx);
            var st = dash + gap;
            var len = Math.Sqrt(dx * dx + dy * dy);
            var nm = (len - dash) / st;

            SpriteBatch.End();
            SpriteBatch.Begin(
                SpriteSortMode.Deferred,
                null,
                null,
                null,
                null,
                null,
                Matrix.CreateRotationZ((float)angle) * Matrix.CreateTranslation(x1, y1, 0)
            );

            for (var i = 0; i < nm; i++)
            {
                SpriteBatch.Draw(
                    WhitePixel,
                    new Rectangle(
                        (int)(i * st + gap * 0.5),
                        0,
                        dash,
                        1
                    ),
                    Color.White
                );
            }

            SpriteBatch.End();
            SpriteBatch.Begin(SpriteSortMode.Deferred, BlendState.NonPremultiplied);
        }
    }
}