using System;

namespace GUIapp
{

  public abstract class GuiMenuCreator
  {
    public abstract GuiManager Instantiate(string option, System.Action exit);
  }

  public class GuiConstructor : GuiMenuCreator
  {
    public override GuiManager Instantiate(string option, System.Action exit)
    {
      GuiManager guiManager = new GUIapp.GuiManager();
      switch (option)
      {
        default:
          {
            GuiElementCreator buttonConstructor = new ButtonConstructor();
            GuiElementCreator labelConstructor = new LabelConstructor();
            guiManager.elements = new List<GuiElement>();
            guiManager.elements.Add(new Clickable(labelConstructor.Instantiate("Click me new", new Point(0, 200), 10, Colour.Black), 100, 20, () => exit()));
            guiManager.elements.Add(new Clickable(labelConstructor.Instantiate("Click me", new Point(0, 100), 10, Colour.Black
                                                        ), 100, 20,  () => {
                                                          guiManager.elements = new List<GuiElement>();
                                                          guiManager.elements.Add(new Clickable(labelConstructor.Instantiate("Exit ExitExitExitExitExitExit", new Point(0, 0), 10, Colour.Black), 250, 20, () => {
                                                                          exit();
                                                                        }));
                                                          }));

            // guiManager.elements.Add(buttonConstructor.Instantiate("Click me", new Point(0, 100), 10, Colour.Black, 100, 30,
            //                                             () => {
            //                                               guiManager.elements = new List<GuiElement>();
            //                                               guiManager.elements.Add(buttonConstructor.Instantiate("Exit", new Point(0, 0), 10, Colour.Black, 100, 30,
            //                                                       () => {
            //                                                               exit();
            //                                                             }
            //                                                       ));
            //                                             }
            //                                             ));
            break;
          }
      }
      return guiManager;
    }
  }

  public abstract class GuiElementCreator
  {
    public abstract GuiElement Instantiate(string content, Point top_left_corner, int size, Colour color);
    public abstract GuiElement Instantiate(string text, Point top_left_corner, int size, Colour color, float width, float height, Action action);
  }

  public interface GuiElement : Drawable, Updateable {
    Point Position();
  }

  public abstract class GuiDecorator : GuiElement {
    protected GuiElement element;

    public GuiDecorator(GuiElement element) {
      this.element = element;
    }

    public Point Position() {
      return element.Position();
    }

    public virtual void Draw(DrawVisitor visitor)
    {
      element.Draw(visitor);
    }
    public virtual void Update(UpdateVisitor visitor, float dt)
    {
      element.Update(visitor, dt);
    }
  }

  public class Clickable : GuiDecorator {
    private GuiElementCreator buttonConstructor = new ButtonConstructor();
    private GuiElement button;

    public Clickable(GuiElement element, float width, float height, Action action): base(element) {

      this.button = buttonConstructor.Instantiate("", element.Position(), 10, Colour.Black, width, height, action);
    }


    public new Point Position() {
      return element.Position();
    }
    public override void Draw(DrawVisitor visitor)
    {
      button.Draw(visitor);
      element.Draw(visitor);
    }
    public override void Update(UpdateVisitor visitor, float dt)
    {
      button.Update(visitor, dt);
      element.Update(visitor, dt);
    }
  }

  public class ButtonConstructor : GuiElementCreator
  {
    public override GuiElement Instantiate(string text, Point top_left_corner, int size, Colour color)
    {
      return new Button(text, top_left_corner, size, color, 40, 40, () => { });
    }

    public override GuiElement Instantiate(string text, Point top_left_corner, int size, Colour color, float width, float height, Action action)
    {
      return new Button(text, top_left_corner, size, color, width, height, action);
    }
  }
  public class LabelConstructor : GuiElementCreator
  {
    public override GuiElement Instantiate(string text, Point top_left_corner, int size, Colour color)
    {
      return new Label(text, top_left_corner, size, color);
    }

    public override GuiElement Instantiate(string text, Point top_left_corner, int size, Colour color, float width, float height, Action action)
    {
      return new Label(text, top_left_corner, size, color);
    }
  }
  public class Label : GuiElement
  {
    public string content;

    public int size;
    public Colour color;
    public Point p;
    public Label(string content, Point top_left_corner, int size, Colour color)
    {
      this.size = size;
      this.color = color;
      this.content = content;
      this.p = top_left_corner;
    }

    public Point Position() {
      return p;
    }

    public void Draw(DrawVisitor visitor)
    {
      visitor.DrawLabel(this);
    }
    public void Update(UpdateVisitor visitor, float dt)
    {
      visitor.UpdateLabel(this, dt);
    }


  }
  public class Button : GuiElement
  {
    public float width, height;
    public Action action;
    public Colour color;

    public Point p;
    public Button(string text, Point top_left_corner, int size, Colour color, float width, float height, Action action)
    {
      this.action = action;
      this.width = width;
      this.height = height;
      this.color = color;
      this.p = top_left_corner;
    }

    public Point Position() {
      return this.p;
    }
    public void Draw(DrawVisitor visitor)
    {
      visitor.DrawButton(this);
    }
    public bool is_intersecting(Point point)
    {
      return point.X > p.X && point.Y > p.Y &&
             point.X < p.X + width && point.Y < p.Y + height;
    }
    public void Update(UpdateVisitor visitor, float dt)
    {
      visitor.UpdateButton(this, dt);
    }


  }


  public class GuiManager : Updateable, Drawable
  {
    public List<GuiElement> elements;

    public void Draw(DrawVisitor visitor)
    {
      visitor.DrawGui(this);
    }

    public void Update(UpdateVisitor visitor, float dt)
    {
      visitor.UpdateGui(this, dt);
    }
  }



}