using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;

namespace Vocaluxe.Menu
{
    public enum EParticeType
    {
        Twinkle,
        Star,
        Snow,
        Flare,
        PerfNoteStar
    }

    class CParticle
    {
        #region private vars
        private int _PartyModeID;
        private Basic _Base;
        private string _TextureName;
        private STexture _Texture;
        private SRectF _Rect;
        private float _Size;
        private SColorF _Color;
        private float _Alpha;
        private float _Angle;       //0..360°
        private float _MaxAge;      //[s]
        private float _Age;         //[s]
        private float _Vx;          //movement speed in x-axis [pix/s]
        private float _Vy;          //movement speed in y-axis [pix/s]
        private float _Vr;          //rotation speed [rpm]
        private float _Rotation;    //start rotation 0..360°
        private float _Vsize;       //size changing speed: period [s]
        private float _LastTime;
        private EParticeType _Type;

        private Stopwatch _Timer;
        #endregion private vars

        #region public vars
        //public bool Visible;
        public float Alpha2 = 1f;

        public float X
        {
            get { return _Rect.X; }
            set { _Rect.X = value; }
        }

        public float Y
        {
            get { return _Rect.Y; }
            set { _Rect.Y = value; }
        }

        public float Size
        {
            get { return _Size; }
            set
            {
                _Rect.W = value;
                _Rect.H = value;
                _Size = value;
            }
        }

        public float Alpha
        {
            get { return _Alpha; }
            set { _Alpha = value; }
        }

        public SColorF Color
        {
            get { return _Color; }
            set { _Color = value; }
        }

        public bool IsAlive
        {
            get { return (_Age < _MaxAge || _MaxAge == 0f); }
        }
        #endregion public vars

        #region Constructors
        public CParticle(Basic Base, int PartyModeID, string textureName, SColorF color, float x, float y, float size, float maxage, float z, float vx, float vy, float vr, float vsize, EParticeType type)
        {
            _PartyModeID = PartyModeID;
            _Base = Base;
            _TextureName = textureName;
            _Texture = new STexture(-1);
            _Color = color;
            _Rect = new SRectF(x, y, size, size, z);
            _Size = size;
            _Alpha = 1f;
            _Angle = 0f;
            _Vx = vx;
            _Vy = vy;
            _Vr = vr;
            _Vsize = vsize;
            _LastTime = 0f;
            _Type = type;

            _Timer = new Stopwatch();
            _Age = 0f;
            _MaxAge = maxage;
            _Rotation = (float)(_Base.Game.GetRandomDouble() * 360.0);
        }

        public CParticle(Basic Base, int PartyModeID, STexture texture, SColorF color, float x, float y, float size, float maxage, float z, float vx, float vy, float vr, float vsize, EParticeType type)
        {
            _PartyModeID = PartyModeID;
            _Base = Base;
            _TextureName = String.Empty;
            _Texture = texture;
            _Color = color;
            _Rect = new SRectF(x, y, size, size, z);
            _Size = size;
            _Alpha = 1f;
            _Angle = 0f;
            _Vx = vx;
            _Vy = vy;
            _Vr = vr;
            _Vsize = vsize;
            _LastTime = 0f;
            _Type = type;

            _Timer = new Stopwatch();
            _Age = 0f;
            _MaxAge = maxage;
            _Rotation = (float)(_Base.Game.GetRandomDouble() * 360.0);
        }
        #endregion Constructors

        public void Update()
        {
            if (!IsAlive)
                return;

            if (!_Timer.IsRunning)
                _Timer.Start();

            float CurrentTime = _Timer.ElapsedMilliseconds / 1000f;
            float timediff = CurrentTime - _LastTime;

            _Age = CurrentTime;

            // update alpha
            if (_MaxAge > 0f)
            {
                switch (_Type)
                {
                    case EParticeType.Twinkle:
                        _Alpha = 1f - _Age / _MaxAge;
                        break;

                    case EParticeType.Star:
                        _Alpha = 1f - _Age / _MaxAge;
                        break;

                    case EParticeType.Snow:
                        _Alpha = (float)Math.Sqrt((Math.Sin(_Age / _MaxAge * Math.PI * 2 - 0.5 * Math.PI) + 1) / 2);
                        break;

                    case EParticeType.Flare:
                        _Alpha = 1f - _Age / _MaxAge;
                        break;

                    case EParticeType.PerfNoteStar:
                        _Alpha = 1f - _Age / _MaxAge;
                        break;

                    default:
                        break;
                }

            }

            // update position
            switch (_Type)
            {
                case EParticeType.Twinkle:
                    X += _Vx * timediff;
                    Y += _Vy * timediff;
                    break;

                case EParticeType.Star:
                    X += _Vx * timediff;
                    Y += _Vy * timediff;
                    break;

                case EParticeType.Snow:
                    int maxy = (int)Math.Round(_Base.Settings.GetRenderH() - _Size * 0.4f);

                    if (Math.Round(Y) < maxy)
                    {
                        float vdx = 0f;
                        if (_Vx != 0)
                            vdx = (float)Math.Sin(CurrentTime / _Vx * Math.PI);

                        X += _Vx * timediff * (0.5f + vdx);

                        Y += _Vy * timediff * (vdx * vdx / 2f + 0.5f);
                        if (Y >= maxy)
                            Y = maxy;
                    }
                    break;

                case EParticeType.Flare:
                    X += _Vx * timediff;
                    Y += _Vy * timediff;
                    break;

                case EParticeType.PerfNoteStar:
                    X += _Vx * timediff;
                    Y += _Vy * timediff;
                    break;

                default:
                    break;
            }


            // update size
            if (_Vsize != 0f)
            {
                float size = _Size;
                switch (_Type)
                {
                    case EParticeType.Twinkle:
                        size = _Size * (1f - CurrentTime / _Vsize);
                        break;

                    case EParticeType.Star:
                        size = _Size * (1f - CurrentTime / _Vsize);
                        break;

                    case EParticeType.Snow:
                        size = _Size * (float)Math.Sqrt((Math.Sin(CurrentTime / _Vsize * Math.PI * 2 - 0.5 * Math.PI) + 1) / 2);
                        break;

                    case EParticeType.Flare:
                        size = _Size * (1f - CurrentTime / _Vsize);
                        break;

                    case EParticeType.PerfNoteStar:
                        size = _Size * (1f - CurrentTime / _Vsize);
                        break;

                    default:
                        break;
                }

                _Rect.X += (_Rect.W - size) / 2f;
                _Rect.Y += (_Rect.H - size) / 2f;
                _Rect.W = size;
                _Rect.H = size;
            }

            // update rotation
            if (_Vr != 0f)
            {
                float r = CurrentTime * _Vr / 60f;
                _Angle = _Rotation + 360f * (r - (float)Math.Floor(r));
                _Rect.Rotation = _Angle;
            }

            _LastTime = CurrentTime;
        }

        public void Pause()
        {
            _Timer.Stop();
        }

        public void Resume()
        {
            _Timer.Start();
        }

        public void Draw()
        {
            if (_TextureName != String.Empty)
                _Base.Drawing.DrawTexture(_Base.Theme.GetSkinTexture(_TextureName), _Rect, new SColorF(_Color.R, _Color.G, _Color.B, _Color.A * Alpha2 * _Alpha));
            else
                _Base.Drawing.DrawTexture(_Texture, _Rect, new SColorF(_Color.R, _Color.G, _Color.B, _Color.A * Alpha2 * _Alpha));
        }
    }

    public class CParticleEffect
    {
        private int _PartyModeID;
        private Basic _Base;
        private List<CParticle> _Stars;
        private string _TextureName;
        private STexture _Texture;
        private int _MaxNumber;
        private SRectF _Area;
        private SColorF _Color;
        private float _Size;
        private EParticeType _Type;
        private Stopwatch _SpawnTimer;
        private float _NextSpawnTime;

        public float Alpha = 1f;

        public bool IsAlive
        {
            get
            {
                return (_Stars.Count > 0 || !_SpawnTimer.IsRunning);
            }
        }

        public SRectF Area
        {
            get { return _Area; }
            set { _Area = value; }
        }

        public CParticleEffect(Basic Base, int PartyModeID, int MaxNumber, SColorF Color, SRectF Area, string TextureName, float Size, EParticeType Type)
        {
            _PartyModeID = PartyModeID;
            _Base = Base;
            _Stars = new List<CParticle>();
            _Area = Area;
            _Color = Color;
            _TextureName = TextureName;
            _Texture = new STexture(-1);
            _MaxNumber = MaxNumber;
            _Size = Size;
            _Type = Type;
            _SpawnTimer = new Stopwatch();
            _NextSpawnTime = 0f;
        }

        public CParticleEffect(Basic Base, int PartyModeID, int MaxNumber, SColorF Color, SRectF Area, STexture texture, float Size, EParticeType Type)
        {
            _PartyModeID = PartyModeID;
            _Base = Base;
            _Stars = new List<CParticle>();
            _Area = Area;
            _Color = Color;
            _TextureName = String.Empty;
            _Texture = texture;
            _MaxNumber = MaxNumber;
            _Size = Size;
            _Type = Type;
            _SpawnTimer = new Stopwatch();
            _NextSpawnTime = 0f;
        }

        public void Update()
        {
            bool DoSpawn = false;
            if (!_SpawnTimer.IsRunning)
            {
                _SpawnTimer.Start();
                _NextSpawnTime = 0f;
                DoSpawn = true;
            }

            if (_SpawnTimer.ElapsedMilliseconds / 1000f > _NextSpawnTime && _NextSpawnTime >= 0f)
            {
                DoSpawn = true;
                _SpawnTimer.Reset();
                _SpawnTimer.Start();
            }

            while (_Stars.Count < _MaxNumber && DoSpawn)
            {
                float size = _Base.Game.GetRandom((int)_Size / 2) + _Size / 2;
                float lifetime = 0f;
                float vx = 0f;
                float vy = 0f;
                float vr = 0f;
                float vsize = 0f;
                _NextSpawnTime = 0f;

                switch (_Type)
                {
                    case EParticeType.Twinkle:
                        size = _Base.Game.GetRandom((int)_Size / 2) + _Size / 2;
                        lifetime = _Base.Game.GetRandom(500) / 1000f + 0.5f;
                        vx = -_Base.Game.GetRandom(10000) / 50f + 100f;
                        vy = -_Base.Game.GetRandom(10000) / 50f + 100f;
                        vr = -_Base.Game.GetRandom(500) / 100f + 2.5f;
                        vsize = lifetime * 2f;
                        break;

                    case EParticeType.Star:
                        size = _Base.Game.GetRandom((int)_Size / 2) + _Size / 2;
                        lifetime = _Base.Game.GetRandom(1000) / 500f + 0.2f;
                        vx = -_Base.Game.GetRandom(1000) / 50f + 10f;
                        vy = -_Base.Game.GetRandom(1000) / 50f + 10f;
                        vr = -_Base.Game.GetRandom(500) / 100f + 2.5f;
                        vsize = lifetime * 2f;
                        break;

                    case EParticeType.Snow:
                        size = _Base.Game.GetRandom((int)_Size / 2) + _Size / 2;
                        lifetime = _Base.Game.GetRandom(5000) / 50f + 10f;
                        vx = -_Base.Game.GetRandom(1000) / 50f + 10f;
                        vy = _Base.Game.GetRandom(1000) / 50f + Math.Abs(vx) + 10f;
                        vr = -_Base.Game.GetRandom(200) / 50f + 2f;
                        vsize = lifetime * 2f;

                        _NextSpawnTime = lifetime / _MaxNumber;
                        DoSpawn = false;
                        break;

                    case EParticeType.Flare:
                        size = _Base.Game.GetRandom((int)_Size / 2) + _Size / 2;
                        lifetime = _Base.Game.GetRandom(500) / 1000f + 0.1f;
                        vx = -_Base.Game.GetRandom(2000) / 50f;
                        vy = -_Base.Game.GetRandom(2000) / 50f + 20f;
                        vr = -_Base.Game.GetRandom(2000) / 50f + 20f;
                        vsize = lifetime * 2f;
                        break;

                    case EParticeType.PerfNoteStar:
                        size = _Base.Game.GetRandom((int)_Size / 2) + _Size / 2;
                        lifetime = _Base.Game.GetRandom(1000) / 500f + 1.2f;
                        vx = 0f;
                        vy = 0f;
                        vr = _Base.Game.GetRandom(500) / 50f + 10f;
                        vsize = lifetime * 2f;
                        break;

                    default:
                        break;
                }

                int w = (int)(_Area.W - size / 4f);
                int h = (int)(_Area.H - size / 4f);

                if (w < 0)
                    w = 0;

                if (h < 0)
                    h = 0;

                CParticle star;
                if (_TextureName != String.Empty)
                {
                    star = new CParticle(_Base, _PartyModeID, _TextureName, _Color,
                        _Base.Game.GetRandom(w) + _Area.X - size / 4f,
                        _Base.Game.GetRandom(h) + _Area.Y - size / 4f,
                        size, lifetime, _Area.Z, vx, vy, vr, vsize, _Type);
                }
                else
                {
                    star = new CParticle(_Base, _PartyModeID, _Texture, _Color,
                        _Base.Game.GetRandom(w) + _Area.X - size / 4f,
                        _Base.Game.GetRandom(h) + _Area.Y - size / 4f,
                        size, lifetime, _Area.Z, vx, vy, vr, vsize, _Type);
                }

                _Stars.Add(star);
            }

            if (_Type == EParticeType.Flare || _Type == EParticeType.PerfNoteStar || _Type == EParticeType.Twinkle)
                _NextSpawnTime = -1f;

            int i = 0;
            while (i < _Stars.Count)
            {
                _Stars[i].Update();
                if (!_Stars[i].IsAlive)
                {
                    _Stars.RemoveAt(i);
                }
                else
                    i++;
            }
        }

        public void Pause()
        {
            foreach (CParticle star in _Stars)
            {
                star.Pause();
            }
        }

        public void Resume()
        {
            foreach (CParticle star in _Stars)
            {
                star.Resume();
            }
        }

        public void Draw()
        {
            foreach (CParticle star in _Stars)
            {
                star.Alpha2 = Alpha;
                star.Draw();
            }
        }
    }
}