using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Tutorial013.Controls
{
  public class Button : Component
  {
    #region Fields

    private MouseState _currentMouse;

    private SpriteFont _font;

    private bool _isHovering;

    private MouseState _previousMouse;

    private Texture2D _texture;

    #endregion

    #region Properties

    public event EventHandler Click;

    public bool Clicked { get; private set; }

    public Color PenColour { get; set; }

    public Vector2 Position { get; set; }

    public Rectangle Rectangle
    {
      get
      {
        return new Rectangle((int)Position.X, (int)Position.Y, _texture.Width, _texture.Height);
      }
    }

    public string Text { get; set; }

    #endregion

    #region Methods

    public Button(Texture2D texture, SpriteFont font)
    {
      _texture = texture;

      _font = font;

      PenColour = Color.Black;
    }

    public override void Draw(GameTime gameTime, SpriteBatch spriteBatch)
    {
      var colour = Color.White;

      if (_isHovering)
        colour = Color.Gray;

      spriteBatch.Draw(_texture, Rectangle, colour);

      if (!string.IsNullOrEmpty(Text))
      {
        var x = (Rectangle.X + (Rectangle.Width / 2)) - (_font.MeasureString(Text).X / 2);
        var y = (Rectangle.Y + (Rectangle.Height / 2)) - (_font.MeasureString(Text).Y / 2);

        spriteBatch.DrawString(_font, Text, new Vector2(x, y), PenColour);
      }
    }

    public override void Update(GameTime gameTime)
    {
      _previousMouse = _currentMouse;
      _currentMouse = Mouse.GetState();

      var mouseRectangle = new Rectangle(_currentMouse.X, _currentMouse.Y, 1, 1);

      _isHovering = false;

      if (mouseRectangle.Intersects(Rectangle))
      {
        _isHovering = true;

        if (_currentMouse.LeftButton == ButtonState.Released && _previousMouse.LeftButton == ButtonState.Pressed)
        {
          Click?.Invoke(this, new EventArgs());
        }
      }
    }

    #endregion
  }
}