/*
 * ScriptManager.cs
 * Authors:     August Zinsser
 * 
 * Copyright Matthew Belmonte 2007
 */


using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Storage;
using Nuclex.Fonts;
using Pina3D.Particles;


namespace tAC_Engine
{
    /// <summary>
    /// Interprets Lua commands, waiting between commands if appropriate.
    /// </summary>
    public static class ScriptManager
    {
        private static SpriteBatch mSpriteBatch = new SpriteBatch(GenericBaseApplication.GameManager.GraphicsDevice);
        private static List<string> mScriptEventQueue = new List<string>();         // Holds the events (lua commands) to execute
        private static List<Entity> mEntities = new List<Entity>();                 // Entities to draw
        private static float mSleepTimer = 0f;                                      // Time to sleep before executing the next lua command
        private static List<string> mWaitingFor = new List<string>();               // Codes to receive before waking up


        /// <summary>
        /// Causes the ScriptManager to wait for the specified time before executing the next command
        /// </summary>
        /// <param name="seconds"></param>
        public static void Sleep(float seconds)
        {
            mSleepTimer = seconds;
        }


        /// <summary>
        /// Causes the ScriptManager to wait until it recieves the specified code before executing the next command
        /// </summary>
        /// <param name="code">Case-insensitive</param>
        public static void Sleep(string code)
        {
            mWaitingFor.Add(code.ToLower());
        }


        /// <summary>
        /// Tells the ScriptManager to stop waiting for the specified code and continue execution
        /// </summary>
        /// <param name="code">Case-insensitive</param>
        public static void SendEventCode(string code)
        {
            mWaitingFor.Remove(code.ToLower());
        }


        /// <summary>
        /// Enqueues the lua command into the interpreter queue.
        /// </summary>
        /// <param name="luaCommand"></param>
        public static void Enqueue(string luaCommand)
        {
            mScriptEventQueue.Add(luaCommand);
        }


        /// <summary>
        /// Inserts the lua command at the head of the interpreter queue.
        /// </summary>
        /// <param name="luaCommand"></param>
        public static void Insert(string luaCommand)
        {
            mScriptEventQueue.Insert(0, luaCommand);
        }


        /// <summary>
        /// Adds an entity to be updated and drawn
        /// </summary>
        /// <param name="entity"></param>
        public static void AddEntity(Entity entity)
        {
            mEntities.Add(entity);
            mEntities.Sort();
        }


        /// <summary>
        /// Removes an entity from the update/draw list
        /// </summary>
        /// <param name="entity"></param>
        public static void RemoveEntity(Entity entity)
        {
            mEntities.Remove(entity);
        }


        /// <summary>
        /// Removes all entities from the update/draw list
        /// </summary>
        /// <param name="entity"></param>
        public static void FlushEntities()
        {
            mEntities.Clear();
        }


        /// <summary>
        /// Process the event queue
        /// </summary>
        public static void Update()
        {
            // Update sleep timer
            mSleepTimer -= GenericBaseApplication.GameManager.ElapsedSeconds;

            // Execute each command until a sleep has been reached or all commands have been executed
            while (mSleepTimer <= 0f && mWaitingFor.Count <= 0 && mScriptEventQueue.Count > 0)
            {
                string currentCommand = mScriptEventQueue[0];
                mScriptEventQueue.RemoveAt(0);
                GenericBaseApplication.GameManager.ExecuteLuaCommand(currentCommand);
            }

            // Update all entities in memory
            for (int i = 0; i < mEntities.Count; i++)
            {
                mEntities[i].Update();
            }
        }


        /// <summary>
        /// Draw all the entities held in the ScriptManager's Memory
        /// </summary>
        /// <param name="device"></param>
        /// <param name="gameTime"></param>
        public static void Draw()
        {
            if (mEntities.Count > 0)
            {
                mSpriteBatch.Begin(SpriteBlendMode.AlphaBlend, SpriteSortMode.Immediate, SaveStateMode.None);
                GenericBaseApplication.GameManager.GraphicsDevice.Clear(ClearOptions.DepthBuffer, Color.Black, 1f, 0);
                GenericBaseApplication.GameManager.GraphicsDevice.RenderState.DepthBufferEnable = true;
                GenericBaseApplication.GameManager.GraphicsDevice.RenderState.DepthBufferWriteEnable = true;

                for (int i = 0; i < mEntities.Count; i++)
                {
                    mEntities[i].Draw(mSpriteBatch);
                }

                mSpriteBatch.End();
            }
        }
    }
}