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

namespace WindowsGame1
{
    class AnimatedSprite : EntitySprite
    {

        private Rectangle[] m_Frames;
        private int m_CurrentFrame = 0;
        private float m_Timer = 0f;
        private float m_FrameLength = 1f/5f;

        private bool m_Run = true;

        /// <summary>
        /// The frames per second of the animation;
        /// </summary>
        public int FramesPerSecond
        {
            get { return (int)(1f / m_FrameLength); }
            set { m_FrameLength = 1f / (float)value; }
        }

        /// <summary>
        /// The current frame in the animation.
        /// </summary>
        public Rectangle CurrentFrame
        {
            get { return m_Frames[m_CurrentFrame]; }
        }

        /// <summary>
        /// Constructor: Automatically generates the source rectangles from the sprite sheet texture.
        /// </summary>
        /// <param name="p_Game">The game that this component is associated with.</param>
        /// <param name="p_SpriteSheet">The Texture to use as a sprite sheet.</param>
        /// <param name="p_Position">The position on the screen to draw the animated sprite.</param>
        /// <param name="p_FrameSize">The size of an individual frame in the sprite sheet.</param>
        /// <param name="p_NumFrames">The total number of frames in the sprite sheet.</param>
        public AnimatedSprite(Game p_Game, Texture2D p_SpriteSheet, Vector2 p_Position, Vector2 p_FrameSize, int p_NumFrames) 
            : base(p_Game, p_SpriteSheet, p_Position)
        {
            m_Frames = new Rectangle[p_NumFrames];

            Vector2 curFramePos = Vector2.Zero;

            int frameCount = 0;
            while (curFramePos.Y < p_SpriteSheet.Height && frameCount < p_NumFrames)
            {
                while (curFramePos.X < p_SpriteSheet.Width && frameCount < p_NumFrames)
                {
                    m_Frames[frameCount] = new Rectangle((int)curFramePos.X, (int)curFramePos.Y, (int)p_FrameSize.X, (int)p_FrameSize.Y);
                    curFramePos.X += p_FrameSize.X;
                    frameCount++;
                }
                curFramePos.Y += p_FrameSize.Y;
                curFramePos.X = 0;
            }
        }

        /// <summary>
        /// The update method called by XNA during it's update cycle.
        /// </summary>
        /// <param name="gameTime">The game time object passed in by XNA.</param>
        public override void Update(GameTime gameTime)
        {
            base.Update(gameTime);
            if (m_Run)
            {
                m_Timer += (float)gameTime.ElapsedGameTime.TotalSeconds;

                if (m_Timer >= m_FrameLength)
                {
                    m_Timer = 0f;
                    m_CurrentFrame = (m_CurrentFrame + 1) % m_Frames.Length;
                }
            }
        }

        /// <summary>
        /// Reset the animation from the beginning.
        /// </summary>
        public void Reset()
        {
            m_CurrentFrame = 0;
            m_Timer = 0f;
        }

        /// <summary>
        /// The Draw method called by XNA during it's draw cycle.
        /// </summary>
        /// <param name="gameTime">The game time object passed in by XNA.</param>
        public override void Draw(GameTime gameTime)
        {
            m_SpriteBatch.Begin();
            m_SpriteBatch.Draw(m_Texture, m_Position, m_Frames[m_CurrentFrame], m_Color, m_Rotation, m_RotationOrigin, m_Scale, SpriteEffects.None, m_LayerDepth);
            m_SpriteBatch.End();
        }

        /// <summary>
        /// Used to turn animation on and off.
        /// </summary>
        /// <param name="p_Run">Bool representing whether animation is running or not.</param>
        public void Animate(bool p_Run)
        {
            m_Run = p_Run;
        }
    }
}