#region License
/*
Microsoft Public License (Ms-PL)
MonoGame - Copyright © 2009-2012 The MonoGame Team

All rights reserved.

This license governs use of the accompanying software. If you use the software,
you accept this license. If you do not accept the license, do not use the
software.

1. Definitions

The terms "reproduce," "reproduction," "derivative works," and "distribution"
have the same meaning here as under U.S. copyright law.

A "contribution" is the original software, or any additions or changes to the
software.

A "contributor" is any person that distributes its contribution under this
license.

"Licensed patents" are a contributor's patent claims that read directly on its
contribution.

2. Grant of Rights

(A) Copyright Grant- Subject to the terms of this license, including the
license conditions and limitations in section 3, each contributor grants you a
non-exclusive, worldwide, royalty-free copyright license to reproduce its
contribution, prepare derivative works of its contribution, and distribute its
contribution or any derivative works that you create.

(B) Patent Grant- Subject to the terms of this license, including the license
conditions and limitations in section 3, each contributor grants you a
non-exclusive, worldwide, royalty-free license under its licensed patents to
make, have made, use, sell, offer for sale, import, and/or otherwise dispose of
its contribution in the software or derivative works of the contribution in the
software.

3. Conditions and Limitations

(A) No Trademark License- This license does not grant you rights to use any
contributors' name, logo, or trademarks.

(B) If you bring a patent claim against any contributor over patents that you
claim are infringed by the software, your patent license from such contributor
to the software ends automatically.

(C) If you distribute any portion of the software, you must retain all
copyright, patent, trademark, and attribution notices that are present in the
software.

(D) If you distribute any portion of the software in source code form, you may
do so only under this license by including a complete copy of this license with
your distribution. If you distribute any portion of the software in compiled or
object code form, you may only do so under a license that complies with this
license.

(E) The software is licensed "as-is." You bear the risk of using it. The
contributors give no express warranties, guarantees or conditions. You may have
additional consumer rights under your local laws which this license cannot
change. To the extent permitted under your local laws, the contributors exclude
the implied warranties of merchantability, fitness for a particular purpose and
non-infringement.
*/
#endregion License

using System;
using System.Drawing;

using MonoTouch.Foundation;
using MonoTouch.UIKit;

namespace Microsoft.Xna.Framework {
	class KeyboardInputView : UIScrollView {
		private static readonly PaddingF TitleMargin = new PaddingF (10, 7, 10, 2);
		private static readonly PaddingF DescriptionMargin = new PaddingF (12, 2, 10, 5);
		private static readonly PaddingF TextFieldMargin = new PaddingF (10, 5, 10, 5);

		private readonly UIToolbar _toolbar;
		private readonly UILabel _title;
		private readonly UILabel _description;
		private readonly UITextField _textField;
		private readonly UIScrollView _textFieldContainer;

		public KeyboardInputView (RectangleF frame)
			: base(frame)
		{
			_toolbar = new UIToolbar (frame);

			var toolbarItems = new UIBarButtonItem[] {
				new UIBarButtonItem (UIBarButtonSystemItem.Cancel, CancelButton_Tapped),
				new UIBarButtonItem (UIBarButtonSystemItem.FlexibleSpace, null),
				new UIBarButtonItem (UIBarButtonSystemItem.Done, DoneButton_Tapped)
			};

			_toolbar.SetItems (toolbarItems, false);
			_toolbar.SizeToFit ();

			_title = new UILabel (RectangleF.Empty);
			_title.Font = UIFont.SystemFontOfSize (UIFont.LabelFontSize * 1.2f);
			_title.BackgroundColor = UIColor.Clear;
			_title.LineBreakMode = UILineBreakMode.TailTruncation;
			_title.Lines = 2;

			_description = new UILabel (RectangleF.Empty);
			_description.Font = UIFont.SystemFontOfSize (UIFont.LabelFontSize);
			_description.TextColor = UIColor.DarkTextColor.ColorWithAlpha (0.95f);
			_description.BackgroundColor = UIColor.Clear;
			_title.LineBreakMode = UILineBreakMode.TailTruncation;
			_description.Lines = 2;

			_textFieldContainer = new UIScrollView(new RectangleF(0, 0, 100, 100));

			_textField = new UITextField (_textFieldContainer.Bounds);
			_textField.AutoresizingMask =
				UIViewAutoresizing.FlexibleWidth |
				UIViewAutoresizing.FlexibleHeight;
			_textField.BorderStyle = UITextBorderStyle.RoundedRect;
			_textField.Delegate = new TextFieldDelegate (this);

			_textFieldContainer.Add (_textField);

			Add (_toolbar);
			Add (_title);
			Add (_description);
			Add (_textFieldContainer);

			AutoresizingMask = UIViewAutoresizing.FlexibleWidth | UIViewAutoresizing.FlexibleHeight;
			AutosizesSubviews = false;
			Opaque = true;
			BackgroundColor = UIColor.FromRGB (0xC5, 0xCC, 0xD4);

			SetNeedsLayout ();
		}

		#region Properties

		public string Title {
			get { return _title.Text; }
			set {
				if (_title.Text != value) {
					_title.Text = value;
					SetNeedsLayout ();
				}
			}
		}

		public string Description {
			get { return _description.Text; }
			set {
				if (_description.Text != value) {
					_description.Text = value;
					SetNeedsLayout ();
				}
			}
		}

		public string Text {
			get { return _textField.Text; }
			set {
				if (_textField.Text != value) {
					_textField.Text = value;
				}
			}
		}

		public bool UsePasswordMode {
			get { return _textField.SecureTextEntry; }
			set {
				if (_textField.SecureTextEntry != value) {
					_textField.SecureTextEntry = value;
				}
			}
		}

		#endregion Properties

		#region Events

		public event EventHandler<EventArgs> InputAccepted;
		public event EventHandler<EventArgs> InputCanceled;

		#endregion Events

		public void ActivateFirstField ()
		{
			_textField.BecomeFirstResponder ();
		}

		public void ScrollActiveFieldToVisible ()
		{
			if (!_textField.IsFirstResponder)
				return;

			var bounds = Bounds;
			bounds.X += ContentInset.Left;
			bounds.Width -= (ContentInset.Left + ContentInset.Right);
			bounds.Y += ContentInset.Top;
			bounds.Height -= (ContentInset.Top + ContentInset.Bottom);

			if (!bounds.Contains(_textFieldContainer.Frame)) {
				ScrollRectToVisible (_textFieldContainer.Frame, true);
			}
		}

		public override void TouchesEnded(NSSet touches, UIEvent evt)
		{
			base.TouchesEnded(touches, evt);
			_textField.ResignFirstResponder ();
		}

		public override void LayoutSubviews ()
		{
			_toolbar.SizeToFit ();

			var titleSize = SizeThatFitsWidth (_title, Bounds.Width - TitleMargin.Horizontal);
			_title.Frame = new RectangleF (
				TitleMargin.Left, _toolbar.Bounds.Bottom + TitleMargin.Top,
				titleSize.Width, titleSize.Height);

			var descriptionSize = SizeThatFitsWidth (
				_description, Bounds.Width - DescriptionMargin.Horizontal);
			_description.Frame = new RectangleF (
				DescriptionMargin.Left,
				_title.Frame.Bottom + TitleMargin.Bottom + DescriptionMargin.Top,
				descriptionSize.Width, descriptionSize.Height);

			var textFieldSize = _textField.SizeThatFits (
				new SizeF(Bounds.Width - TextFieldMargin.Horizontal, Bounds.Height));
			_textFieldContainer.Frame = new RectangleF (
				TextFieldMargin.Left,
				_description.Frame.Bottom + DescriptionMargin.Bottom + TextFieldMargin.Top,
				Bounds.Width - TextFieldMargin.Horizontal, textFieldSize.Height);

			ContentSize = new SizeF(Bounds.Width, _textFieldContainer.Frame.Bottom + TextFieldMargin.Bottom);
		}

		private static SizeF SizeThatFitsWidth(UILabel label, float width)
		{
			var font = label.Font;
			return label.StringSize (
				label.Text, font, new SizeF(width, font.LineHeight * label.Lines),
				label.LineBreakMode);
		}

		private void DoneButton_Tapped (object sender, EventArgs e)
		{
			OnInputAccepted (e);
		}

		private void CancelButton_Tapped (object sender, EventArgs e)
		{
			OnInputCanceled (e);
		}

		private void OnInputAccepted(EventArgs e)
		{
			var handler = InputAccepted;
			if (handler != null)
				handler (this, e);
		}

		private void OnInputCanceled(EventArgs e)
		{
			var handler = InputCanceled;
			if (handler != null)
				handler (this, e);
		}

		private class TextFieldDelegate : UITextFieldDelegate
		{
			private readonly KeyboardInputView _owner;
			public TextFieldDelegate (KeyboardInputView owner)
			{
				if (owner == null)
					throw new ArgumentNullException ("owner");
				_owner = owner;
			}

			public override bool ShouldReturn(UITextField textField)
			{
				_owner.OnInputAccepted (EventArgs.Empty);
				return true;
			}
		}
	}
}