//---------------------------------------------------------------------------------------------------------------------------------------------------
// <copyright file="GameScreen.cs" company="DarkWynter Studios">
//     Copyright (C)2007 DarkWynter Studios.  All rights reserved.
// </copyright>
//---------------------------------------------------------------------------------------------------------------------------------------------------
// {Contact : darkwynter.com for licensing information
//---------------------------------------------------------------------------------------------------------------------------------------------------

namespace DarkWynterEngine.Menus
{
    #region Using Statements
    using System;
    using System.Collections.Generic;
    using Microsoft.Xna.Framework;
    using Microsoft.Xna.Framework.Graphics;
    #endregion

    using DarkWynterEngine.Audio;
    using DarkWynterEngine.Globals;
    using DarkWynterEngine.Controllers;
    using DarkWynterEngine.ObjectLib;

    /// <summary>
    /// Generic Game Screen.
    /// </summary>
    public class GameScreen
    {
        /// <summary>
        /// Menu Object used by this screen.
        /// </summary>
        protected GameMenu menu;

        /// <summary>
        /// Stores the EngineState associated with this screen
        /// </summary>
        protected Enums.EngineState engineState;

        /// <summary>
        /// Background texture used by this screen.
        /// </summary>
        protected Texture2D backgroundTexture;

        /// <summary>
        /// Alpha value to draw this screen with.
        /// </summary>
        protected float backgroundAlpha = 1.0f;

        /// <summary>
        /// Game Screen constructor.
        /// </summary>
        /// <param name="GameEngineState">Tells this screen what EngineState it will run under.</param>
        public GameScreen(Enums.EngineState GameEngineState)
        {
            engineState = GameEngineState;
        }

        /// <summary>
        /// Returns the Engine State associated with this screen.
        /// </summary>
        /// <returns></returns>
        public Enums.EngineState GetEngineState()
        {
            return engineState;
        }
        
        /// <summary>
        /// Returns the game menu.
        /// </summary>
        /// <returns>This screen's game menu.</returns>
        public GameMenu GetMenu()
        {
            return menu;
        }

        /// <summary>
        /// Set the background texture
        /// </summary>
        /// <param name="backgroundTexture">Texture used in background.</param>
        public void SetBackground(Texture2D backgroundTexture)
        {
            this.backgroundTexture = backgroundTexture;
            backgroundAlpha = 1.0f;
        }

        /// <summary>
        /// Set the background texture with a specific alpha value.
        /// </summary>
        /// <param name="backgroundTexture">Texture used in background.</param>
        /// <param name="alpha">Alpha value used to draw.</param>
        public void SetBackground(Texture2D backgroundTexture, float alpha)
        {
            this.backgroundTexture = backgroundTexture;
            backgroundAlpha = alpha;
        }

        /// <summary>
        /// Draw this game screen.
        /// </summary>
        /// <param name="spriteBatch">SpriteBatch used to draw used to draw.</param>
        public virtual void Draw(SpriteBatch spriteBatch)
        {
            // First draw the background texture if it is not null
            if (backgroundTexture != null)
            {
                spriteBatch.Draw(backgroundTexture,
                                 new Rectangle(0, 0, Statics.RenderSettings.GAME_WINDOW_WIDTH, Statics.RenderSettings.GAME_WINDOW_HEIGHT),
                                 new Color(255, 255, 255, (byte)(255 * backgroundAlpha)));
            }

            //now draw the menu elements
            menu.Draw(spriteBatch);
        }

        /// <summary>
        /// Check to see if menu has been updated by user.
        /// </summary>
        /// <param name="objectLibrary">Current ObjectLibrary.</param>
        /// <param name="menuController">Menu controller used to update input.</param>
        public virtual void Update(ObjectLibrary objectLibrary)
        {
            bool nextGameState = false;

            // Block double input
            if (DarkWynterGame.menuController.menuInput.IsStartBackInputBlocked)
            {
                if (DarkWynterGame.menuController.menuInput.GetMenuStartBackReleased == true)
                {
                    DarkWynterGame.menuController.SetBlockStartBackInput(false);
                }
            }

            // Exit 
            if (DarkWynterGame.menuController.menuInput.GetMenuBackPressed)
            {
                Audio.MenuBack();           // Play a sound

                if (Statics.SystemSettings.gameState != Enums.EngineState.EXIT)
                {
                    Statics.SystemSettings.gameState--;        // Exit
                }

                Statics.SystemSettings.screenSaverTimer.Reset();
                Statics.SystemSettings.screenSaverTimer.Start();
            }
            // Start
            else if (DarkWynterGame.menuController.menuInput.GetMenuStartPressed)
            {
                if (Statics.SystemSettings.gameState != Enums.EngineState.GAME_PAUSE)
                {
                    nextGameState = true;
                    Statics.SystemSettings.gameState++;
                }

                Statics.SystemSettings.screenSaverTimer.Reset();
                Statics.SystemSettings.screenSaverTimer.Start();
            }
            // Up
            else if (DarkWynterGame.menuController.menuInput.GetMenuUp)
            {
                Audio.MenuUp();
                GetMenu().PreviousMenuElement();
            }
            // Down
            else if (DarkWynterGame.menuController.menuInput.GetMenuDown)
            {
                Audio.MenuDown();
                GetMenu().NextMenuElement();
            }
            // Left
            else if (DarkWynterGame.menuController.menuInput.GetMenuLeft)
            {
                UpdateMenuController(GetMenu().GetActiveMenuElement());
            }
            // Right
            else if (DarkWynterGame.menuController.menuInput.GetMenuRight)
            {
                UpdateMenuController(GetMenu().GetActiveMenuElement());
            }


            // Commit Game and Player
            if (Statics.SystemSettings.gameState == Enums.EngineState.LOAD_LEVEL && nextGameState)
            {
                XML.LoadLevelIndex();
            }
        }

        /// <summary>
        /// Update the active element based on user input
        /// </summary>
        /// <param name="activeElement">Active menu element</param>
        /// <param name="menuController">Controller attached to this GameScreen</param>
        public void UpdateMenuController(GameMenuElement activeElement)
        {
            // OptionBox
            if (activeElement.GetElementType() == Enums.MenuElementType.OPTION)
            {
                // Cast as option and change value
                GameMenuOption option = (GameMenuOption)activeElement;
                // If they pressed left, get previous option
                if (DarkWynterGame.menuController.menuInput.GetMenuLeft)
                {
                    Audio.MenuLeft();
                    option.PreviousOption();
                }
                // Or if they pressed right, get next option
                else if (DarkWynterGame.menuController.menuInput.GetMenuRight)
                {
                    Audio.MenuRight();
                    option.NextOption();
                }
            }

            // ValueSlider
            else if (activeElement.GetElementType() == Enums.MenuElementType.VALUE)
            {
                // Cast as ValueInput type and change value
                GameMenuValueInput valueInput = (GameMenuValueInput)activeElement;
                //int activeIndex = playerSetup.GetMenu().GetActiveIndex();

                // If they pressed left, decrease the value
                if (DarkWynterGame.menuController.menuInput.GetMenuLeft)
                {
                    Audio.MenuLeft();
                    valueInput.Decrement();
                }
                // Or if they pressed right, increase it
                else if (DarkWynterGame.menuController.menuInput.GetMenuRight)
                {
                    Audio.MenuRight();
                    valueInput.Increment();
                }
            }

            else if (activeElement.GetElementType() == Enums.MenuElementType.IMAGE_SCROLL)
            {
                // Cast as ValueInput type and change value
                GameMenuImageScroller scroller = (GameMenuImageScroller)activeElement;
                //int activeIndex = playerSetup.GetMenu().GetActiveIndex();

                // If they pressed left, decrease the value
                if (DarkWynterGame.menuController.menuInput.GetMenuLeft)
                {
                    Audio.MenuLeft();
                    scroller.PreviousItem();
                }
                // Or if they pressed right, increase it
                else if (DarkWynterGame.menuController.menuInput.GetMenuRight)
                {
                    Audio.MenuRight();
                    scroller.NextItem();
                }
            }
        }

    }
}