// Copyright 2014-2017 ClassicalSharp | Licensed under BSD-3
using System;
using ClassicalSharp.Gui.Widgets;
using ClassicalSharp.GraphicsAPI;
using OpenTK.Input;

namespace ClassicalSharp.Gui {
	public delegate void SimpleClickHandler(Game g, Widget w);
		
	public delegate void ClickHandler(Game g, Widget w, MouseButton btn, int mouseX, int mouseY);
	
	public abstract class GuiElement : IDisposable {
		
		protected Game game;
		protected IGraphicsApi gfx;
		
		public GuiElement(Game game) {
			this.game = game;
			gfx = game.Graphics;
		}
		
		public abstract void Init();
		
		public abstract void Render(double delta);
		
		public abstract void Dispose();
		
		/// <summary> Causes the gui element to recreate all of its sub-elements and/or textures. </summary>
		/// <remarks> Typically used when bitmap font changes. </remarks>
		public virtual void Recreate() { Dispose(); Init(); }
		
		public virtual bool HandlesKeyDown(Key key) { return false; }
		
		public virtual bool HandlesKeyPress(char key) { return false; }
		
		public virtual bool HandlesKeyUp(Key key) { return false; }
		
		public virtual bool HandlesMouseClick(int mouseX, int mouseY, MouseButton button) { return false; }
		
		public virtual bool HandlesMouseMove(int mouseX, int mouseY) { return false; }
		
		public virtual bool HandlesMouseScroll(float delta) { return false; }
		
		public virtual bool HandlesMouseUp(int mouseX, int mouseY, MouseButton button) { return false; }
		
		protected static int CalcPos(Anchor anchor, int offset, int size, int axisLen) {
			if (anchor == Anchor.LeftOrTop) return offset;
			if (anchor == Anchor.BottomOrRight) return axisLen - size - offset;
			return (axisLen - size) / 2 + offset;
		}
		
		public static bool Contains(int recX, int recY, int width, int height, int x, int y) {
			return x >= recX && y >= recY && x < recX + width && y < recY + height;
		}
	}
}