using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xunit;

namespace Terminal.Gui.Views {
	public class ScrollViewTests {
		[Fact]
		public void Constructors_Defaults ()
		{
			var sv = new ScrollView ();
			Assert.Equal (LayoutStyle.Computed, sv.LayoutStyle);
			Assert.True (sv.CanFocus);
			Assert.Equal (new Rect (0, 0, 0, 0), sv.Frame);
			Assert.Equal (Rect.Empty, sv.Frame);
			Assert.Null (sv.X);
			Assert.Null (sv.Y);
			Assert.Null (sv.Width);
			Assert.Null (sv.Height);
			Assert.Equal (Point.Empty, sv.ContentOffset);
			Assert.Equal (Size.Empty, sv.ContentSize);
			Assert.True (sv.AutoHideScrollBars);
			Assert.True (sv.KeepContentAlwaysInViewport);

			sv = new ScrollView (new Rect (1, 2, 20, 10));
			Assert.Equal (LayoutStyle.Absolute, sv.LayoutStyle);
			Assert.True (sv.CanFocus);
			Assert.Equal (new Rect (1, 2, 20, 10), sv.Frame);
			Assert.Null (sv.X);
			Assert.Null (sv.Y);
			Assert.Null (sv.Width);
			Assert.Null (sv.Height);
			Assert.Equal (Point.Empty, sv.ContentOffset);
			Assert.Equal (Size.Empty, sv.ContentSize);
			Assert.True (sv.AutoHideScrollBars);
			Assert.True (sv.KeepContentAlwaysInViewport);
		}

		[Fact]
		public void Adding_Views ()
		{
			var sv = new ScrollView (new Rect (0, 0, 20, 10)) {
				ContentSize = new Size (30, 20)
			};
			sv.Add (new View () { Width = 10, Height = 5 },
				new View () { X = 12, Y = 7, Width = 10, Height = 5 });

			Assert.Equal (new Size (30, 20), sv.ContentSize);
			Assert.Equal (2, sv.Subviews [0].Subviews.Count);
		}

		[Fact]
		public void KeyBindings_Command ()
		{
			var sv = new ScrollView (new Rect (0, 0, 20, 10)) {
				ContentSize = new Size (40, 20)
			};
			sv.Add (new View () { Width = 20, Height = 5 },
				new View () { X = 22, Y = 7, Width = 10, Height = 5 });

			Assert.True (sv.KeepContentAlwaysInViewport);
			Assert.True (sv.AutoHideScrollBars);
			Assert.Equal (new Point (0, 0), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.CursorUp, new KeyModifiers ())));
			Assert.Equal (new Point (0, 0), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.CursorDown, new KeyModifiers ())));
			Assert.Equal (new Point (0, -1), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.CursorUp, new KeyModifiers ())));
			Assert.Equal (new Point (0, 0), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.PageUp, new KeyModifiers ())));
			Assert.Equal (new Point (0, 0), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.PageDown, new KeyModifiers ())));
			Assert.Equal (new Point (0, -10), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.PageDown, new KeyModifiers ())));
			Assert.Equal (new Point (0, -10), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.CursorDown, new KeyModifiers ())));
			Assert.Equal (new Point (0, -10), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent ((Key)'v' | Key.AltMask, new KeyModifiers ())));
			Assert.Equal (new Point (0, 0), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.V | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (0, -10), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.CursorLeft, new KeyModifiers ())));
			Assert.Equal (new Point (0, -10), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.CursorRight, new KeyModifiers ())));
			Assert.Equal (new Point (-1, -10), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.CursorLeft, new KeyModifiers ())));
			Assert.Equal (new Point (0, -10), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.PageUp | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (0, -10), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.PageDown | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (-20, -10), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.CursorRight, new KeyModifiers ())));
			Assert.Equal (new Point (-20, -10), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.Home, new KeyModifiers ())));
			Assert.Equal (new Point (-20, 0), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.Home, new KeyModifiers ())));
			Assert.Equal (new Point (-20, 0), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.End, new KeyModifiers ())));
			Assert.Equal (new Point (-20, -10), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.End, new KeyModifiers ())));
			Assert.Equal (new Point (-20, -10), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.Home | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (0, -10), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.Home | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (0, -10), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.End | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (-20, -10), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.End | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (-20, -10), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.Home, new KeyModifiers ())));
			Assert.Equal (new Point (-20, 0), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.Home | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (0, 0), sv.ContentOffset);

			sv.KeepContentAlwaysInViewport = false;
			Assert.False (sv.KeepContentAlwaysInViewport);
			Assert.True (sv.AutoHideScrollBars);
			Assert.Equal (new Point (0, 0), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.CursorUp, new KeyModifiers ())));
			Assert.Equal (new Point (0, 0), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.CursorDown, new KeyModifiers ())));
			Assert.Equal (new Point (0, -1), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.CursorUp, new KeyModifiers ())));
			Assert.Equal (new Point (0, 0), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.PageUp, new KeyModifiers ())));
			Assert.Equal (new Point (0, 0), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.PageDown, new KeyModifiers ())));
			Assert.Equal (new Point (0, -10), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.PageDown, new KeyModifiers ())));
			Assert.Equal (new Point (0, -19), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.PageDown, new KeyModifiers ())));
			Assert.Equal (new Point (0, -19), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.CursorDown, new KeyModifiers ())));
			Assert.Equal (new Point (0, -19), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent ((Key)'v' | Key.AltMask, new KeyModifiers ())));
			Assert.Equal (new Point (0, -9), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.V | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (0, -19), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.CursorLeft, new KeyModifiers ())));
			Assert.Equal (new Point (0, -19), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.CursorRight, new KeyModifiers ())));
			Assert.Equal (new Point (-1, -19), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.CursorLeft, new KeyModifiers ())));
			Assert.Equal (new Point (0, -19), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.PageUp | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (0, -19), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.PageDown | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (-20, -19), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.PageDown | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (-39, -19), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.PageDown | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (-39, -19), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.CursorRight, new KeyModifiers ())));
			Assert.Equal (new Point (-39, -19), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.PageUp | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (-19, -19), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.Home, new KeyModifiers ())));
			Assert.Equal (new Point (-19, 0), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.Home, new KeyModifiers ())));
			Assert.Equal (new Point (-19, 0), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.End, new KeyModifiers ())));
			Assert.Equal (new Point (-19, -19), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.End, new KeyModifiers ())));
			Assert.Equal (new Point (-19, -19), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.Home | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (0, -19), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.Home | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (0, -19), sv.ContentOffset);
			Assert.True (sv.ProcessKey (new KeyEvent (Key.End | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (-39, -19), sv.ContentOffset);
			Assert.False (sv.ProcessKey (new KeyEvent (Key.End | Key.CtrlMask, new KeyModifiers ())));
			Assert.Equal (new Point (-39, -19), sv.ContentOffset);
		}
	}
}