using System;
using System.ComponentModel;
using System.Windows.Forms;
using System.Drawing;

namespace AppliStation.Util
{
	public class ToolStripWeb2LikeTextBox : ToolStripTextBox
	{
		public ToolStripWeb2LikeTextBox() : base()
		{
			this.Text = string.Empty;
		}
				
		[Category("Action")]
		public event EventHandler TextChangedTriggerFired;
		
		private int textChangedTriggerInterval = 500;
		
		/// <summary>
		/// Interval time for TextChangedTriggerFired.
		/// </summary>
		[Category("Behavior")]
		[DefaultValue(500)]
		public virtual int TextChangedTriggerInterval {
			get { return textChangedTriggerInterval; }
			set { textChangedTriggerInterval = value; }
		}
		
		
		private string oldText = null;
		public void FireTextChangedTrigger(EventArgs e)
		{
			textChangeTriggerTimerStop();
			
			if (oldText != this.Text) {
				if (TextChangedTriggerFired != null) {
					TextChangedTriggerFired(this, e);
				}
				oldText = this.Text;
			}
		}
		public void FireTextChangedTrigger()
		{
			FireTextChangedTrigger(EventArgs.Empty);
		}
		
		#region TextChange Timers
		
		/// <summary>
		/// Timer for TextChangedTriggerFired.
		/// </summary>
		protected Timer textChangeTriggerTimer = null;
		
		private void onTextUpdate(bool force)
		{
			textChangeTriggerTimerStop();
			
			textChangeTriggerTimer = new Timer();
			textChangeTriggerTimer.Tick += textChangeTriggerTimerTick;
			textChangeTriggerTimer.Interval = TextChangedTriggerInterval;
			textChangeTriggerTimer.Start();
		}
				
		private void textChangeTriggerTimerTick(object sender, EventArgs e)
		{
			FireTextChangedTrigger(e);
		}
		
		private void textChangeTriggerTimerStop()
		{
			if (textChangeTriggerTimer != null) {
				textChangeTriggerTimer.Stop();
				textChangeTriggerTimer = null;
			}
		}
		
		protected override void OnTextChanged(EventArgs e)
		{
			base.OnTextChanged(e);
			
			if (Focused) {
				onTextUpdate(false);
			}
		}
		
		#endregion
		
		protected bool textIsEmpty = true;
		
		public override string Text {
			get { return textIsEmpty? string.Empty : base.Text; }
			set {
				bool changed = false;
				if (string.IsNullOrEmpty(value)) {
					if (! textIsEmpty) {
						changed = true;
					
						textIsEmpty = true;
						base.Text = EmptyText;
					}
				} else if (this.Text != value) {
					changed = true;
					
					textIsEmpty = false;
					base.Text = value;
				}
				
				if (changed) {
					FireTextChangedTrigger(EventArgs.Empty);
					base.OnTextChanged(EventArgs.Empty);
					
					updateForeColorInternal();
				}
			}
		}
		
		private string emptyText = "(none)";
		
		/// <summary>
		/// Gray text when textbox is empty and has not focus
		/// </summary>
		[Category("Appearance")]
		public virtual string EmptyText {
			get { return emptyText; }
			set {
				emptyText = value;
				
				if (textIsEmpty) {
					base.Text = emptyText;
				}
			}
		}
		
		private Color emptyForeColor = SystemColors.GrayText;
		
		/// <summary>
		/// Gray text color when textbox is empty and has not focus
		/// </summary>
		[Category("Appearance")]
		[DefaultValue(typeof(Color), "GrayText")]
		public virtual Color EmptyForeColor {
			get { return emptyForeColor; }
			set {
				emptyForeColor = value;
				updateForeColorInternal();
			}
		}
		
		private Color foreColor = SystemColors.WindowText;
		
		public override Color ForeColor {
			get { return foreColor; }
			set {
				foreColor = value;
				updateForeColorInternal();
			}
		}
		
		protected override void OnEnter(EventArgs e)
		{
			if (textIsEmpty) {
				base.Text = string.Empty;
				textIsEmpty = false;
				updateForeColorInternal();
			}
			
			base.OnEnter(e);
		}
		
		protected override void OnLeave(EventArgs e)
		{
			if (string.IsNullOrEmpty(base.Text)) {
				base.Text = EmptyText;
				textIsEmpty = true;
				updateForeColorInternal();
			}
			
			base.OnLeave(e);
		}
		
		private void updateForeColorInternal()
		{
			base.ForeColor = textIsEmpty? EmptyForeColor : ForeColor;
		}
	}
}