using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using RhythmBullet.Zer01HD.Game.Screens;
using RhythmBullet.Zer01HD.Utilities.UI;
using System;
using System.Diagnostics;

namespace RhythmBullet.Zer01HD.Game
{
    class LoadingScreen : Screen
    {
        private const float ENTER_RATE = 2f;
        private const float EXIT_RATE = 1f;
        readonly Texture2D texture;
        Color color;
        Rectangle textureBounds;
        readonly float proportion;
        bool recorded;
        float rR, rG, rB;
        float progR, progG, progB;
        float progC = 254;
        float rotation;
        readonly bool rotate;
        Vector2 origin;

        public LoadingScreen(Texture2D texture, float proportion, Rectangle dimensions, bool rotate = false) : base(true)
        {
            color = Color.White;
            this.texture = texture;
            this.proportion = proportion;
            this.rotate = rotate;
            textureBounds.Width = (int)(dimensions.Height * proportion);
            textureBounds.Height = (int)(dimensions.Height * proportion);
            textureBounds.X = (dimensions.Width) / 2;
            textureBounds.Y = (dimensions.Height) / 2;
            origin.X = texture.Width / 2;
            origin.Y = texture.Height / 2;
        }

        public override void Update(GameTime gameTime)
        {
            base.Update(gameTime);
        }

        public override void EnteringTransition(double delta, bool assetsLoaded, ref Color BGColor, RenderTarget2D previousScreenExitFrame)
        {
            float deltaf = (float)delta;
            if (rotate)
            {
                DoRotate(deltaf);
            }
            if (assetsLoaded)
            {
                if (progR < 254 || progG < 254 || progB < 254)
                {
                    if (!recorded)
                    {
                        rR = (Color.White.R - BGColor.R) / ENTER_RATE;
                        rG = (Color.White.G - BGColor.G) / ENTER_RATE;
                        rB = (Color.White.B - BGColor.B) / ENTER_RATE;
                        recorded = true;
                    }
                    progR += rR * deltaf;
                    progR = Math.Min(progR, 254);
                    progG += rG * deltaf;
                    progG = Math.Min(progG, 254);
                    progB += rB * deltaf;
                    progB = Math.Min(progB, 254);
                    BGColor.R = (byte)progR;
                    BGColor.G = (byte)progG;
                    BGColor.B = (byte)progB;
                }
                else
                {
                    DoneEnterTransition();
                    StartExitTransition(true);
                }
            }
        }

        public override bool ExitingTransition(double delta, bool assetsLoaded, ref Color backgroundColor)
        {
            float deltaf = (float)delta;
            if (rotate)
            {
                DoRotate(deltaf);
            }
            if (progC > 0)
            {
                float rate = deltaf * 255 / EXIT_RATE;
                progC -= rate;
                progC = Math.Max(progC, 0);
                color.R = (byte)progC;
                color.G = (byte)progC;
                color.B = (byte)progC;
                color.A = (byte)progC;
            }
            else
            {
                return true;
            }
            return false;
        }

        void DoRotate(float deltaf)
        {
            rotation += (2f / 3f) * (float)Math.PI * deltaf;
            if (rotation >= 2 * Math.PI)
            {
                rotation = 0;
            }
        }

        public override void Draw(SpriteBatch spriteBatch)
        {
            spriteBatch.Draw(texture, textureBounds, null, color, rotation, origin, SpriteEffects.None, 0f);
            base.Draw(spriteBatch);
        }

    }
}