/*
 * GUITextInput.cs
 * Authors: Mike DeMauro
 * Copyright (c) 2007-2008 Cornell University

 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

using System;
using System.Collections.Generic;
using System.Text;
using Util;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework;

namespace tAC_Engine.GUI
{
	/// <summary>
	/// Defines a text input GUI object
	/// </summary>
    public class GUITextInput : GUILabel
	{
		#region Fields

		/// <summary>
		/// Whether or not this text input GUi currently has focus
		/// </summary>
        protected bool mHasFocus = false;

		/// <summary>
		/// A single white pixel image
		/// </summary>
        protected Texture2D whitePixel;

		/// <summary>
		/// Color for the background behind the text
		/// </summary>
        protected Color backgroundColor = Color.White;

		/// <summary>
		/// Color used for the border around the text
		/// </summary>
        protected Color borderColor = Color.Black;

		/// <summary>
		/// Color used for when text is highlighted
		/// </summary>
        protected Color highlightColor = Color.Yellow;

		#endregion

        #region Construct

        /// <summary>
        /// Constructor
        /// </summary>
        public GUITextInput()
            : base()
        {
            mTextOffset = new Vector2(4, 3);
        }
        
        #endregion

        #region Management

        /// <summary>
		/// Loads in all the necessary data for content dependent objects
		/// </summary>
        public override void LoadContent()
        {
            // create pixel
            whitePixel = new Texture2D(ParentScreen.GraphicsDevice, 1, 1, 1, TextureUsage.None, SurfaceFormat.Color);
            Color[] pixels = new Color[1];
            pixels[0] = Color.White;
            whitePixel.SetData(pixels);

            base.LoadContent();
		}

		#endregion

        #region Event Handling

        /// <summary>
        /// The event that is thrown when the text changes due to keyboard input
        /// </summary>
        public event EventHandler TextTyped;

        #endregion

        #region Render

        /// <summary>
		/// Performs rendering of the Gui text input
		/// TODO: optimize Vector2s
		/// </summary>
		/// <param name="gameTime">How much time has passed in game</param>
        public override void Draw(Microsoft.Xna.Framework.GameTime gameTime)
        {
            base.Draw(gameTime);

            // Draw (inset) borders
            // -top
            Batch.Draw(whitePixel, Position - mScreenOffset, null, borderColor, 0f, Vector2.Zero, new Vector2(Size.X, 1f), SpriteEffects.None, mLayerDepth);
            // -right
            Batch.Draw(whitePixel, new Vector2(Position.X + Size.X - 1, Position.Y) - mScreenOffset, null, borderColor, 0f, Vector2.Zero, new Vector2(1f, Size.Y), SpriteEffects.None, mLayerDepth);
            // -bottom
            Batch.Draw(whitePixel, new Vector2(Position.X, Position.Y + Size.Y - 1) - mScreenOffset, null, borderColor, 0f, Vector2.Zero, new Vector2(Size.X, 1f), SpriteEffects.None, mLayerDepth);
            // -left
            Batch.Draw(whitePixel, Position - mScreenOffset, null, borderColor, 0f, Vector2.Zero, new Vector2(1f, Size.Y), SpriteEffects.None, mLayerDepth);

            // Draw (double inset) highlight
            if (mHasFocus)
            {
                // -top
                Batch.Draw(whitePixel, new Vector2(Position.X + 1, Position.Y + 1) - mScreenOffset, null, highlightColor, 0f, Vector2.Zero, new Vector2(Size.X - 2, 1f), SpriteEffects.None, mLayerDepth);
                // -right
                Batch.Draw(whitePixel, new Vector2(Position.X + Size.X - 2, Position.Y + 1) - mScreenOffset, null, highlightColor, 0f, Vector2.Zero, new Vector2(1f, Size.Y - 2), SpriteEffects.None, mLayerDepth);
                // -bottom
                Batch.Draw(whitePixel, new Vector2(Position.X + 1, Position.Y + Size.Y - 2) - mScreenOffset, null, highlightColor, 0f, Vector2.Zero, new Vector2(Size.X - 2, 1f), SpriteEffects.None, mLayerDepth);
                // -left
                Batch.Draw(whitePixel, new Vector2(Position.X + 1, Position.Y + 1) - mScreenOffset, null, highlightColor, 0f, Vector2.Zero, new Vector2(1f, Size.Y - 2), SpriteEffects.None, mLayerDepth);
            }
		}

		#endregion

		#region Input Handle

		/// <summary>
		/// Handles processing of specific key pressed events
		/// </summary>
		/// <param name="e">The key input event that has just occured</param>
		/// <returns>Whether one of the specified keys was pressed or not</returns>
        public override bool HandleKeyEvent(KeyInputEvent e)
        {
            bool retVal = false;

            if (mHasFocus && e != null && e.Trigger == Trigger.Activated)
            {
                if (e.Key == Keys.Back)
                {
                    Text = Text.Substring(0, Math.Max(Text.Length - 1, 0));
                }
                else if (e.Key == Keys.Enter)
                {
                    Text += "\n";
                }
                else if (e.Key == Keys.Escape)
                {
                    mHasFocus = false;
                }
                else
                {
                    Text += e.ToAlphanumericString();
                }

				// Set the event args if they're null
				if (e.EventArgs == null)
				{
					// Set the event args to us
					e.EventArgs = this;
				}

                // Fire the event handler
                if (TextTyped != null) TextTyped(this, EventArgs.Empty);

                retVal = true;
            }
            return retVal;
        }

		/// <summary>
		/// Handles processing of the mouse events
		/// </summary>
		/// <param name="e">The mouse input event that has just occured</param>
		/// <returns>Whether or not the mouse event needed to be handled</returns>
        public override bool HandleMouseEvent(MouseInputEvent e)
        {
            bool retVal = base.HandleMouseEvent(e);
            mHasFocus = retVal;

			if (retVal)
			{
				// Set the event args if they're null
				if (e.EventArgs == null)
				{
					// Set the event args to us
					e.EventArgs = this;
				}
			}

            return retVal;
		}

		#endregion
	}
}