using Accord.Video.FFMPEG;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SortingVisualization {
    public enum SetType {
        Ordererd,
        Reversed,
        Random,
        SingleError
    }
    public class DataSet {
        #region Props
        /// <summary>
        /// Gibt die Größe (Anzahl der zu sortierenden Werte) an.
        /// </summary>
        public int Size { get; private set; }
        /// <summary>
        /// Speichert das initale Datenset um verschiedene Algorithmen auf dasselbe Set anzuwenden (direkter Vergleich).
        /// </summary>
        private readonly int[] _InitialData;
        public int Seed { get; private set; }
        private int[] _Data;
        public int ReadOperations { get; private set; } = 0;
        public int WriteOperations { get; private set; } = 0;
        public int CompareOperations { get; private set; } = 0;
        public int SwapOperations { get; private set; } = 0;
        public long Ticks { get; private set; } = 0;
        public string SortingAlgorithm {
            get => _sortingAlgorithm;
            set {
                _sortingAlgorithm = value;
                if (!Directory.Exists(this.SortingAlgorithm)) {
                    Directory.CreateDirectory(this.SortingAlgorithm);
                }
                _Directory = Path.Combine(this.SortingAlgorithm, DataSet.SetTypeToString(this.SetType));
                if (!Directory.Exists(_Directory)) {
                    Directory.CreateDirectory(_Directory);
                }
                _Directory = Path.Combine(_Directory, this.Size.ToString());
                if (!Directory.Exists(_Directory)) {
                    Directory.CreateDirectory(_Directory);
                }
                if (this.SetType == SetType.Random || this.SetType == SetType.SingleError) {
                    _Directory = Path.Combine(_Directory, this.Seed.ToString());
                    if (!Directory.Exists(_Directory)) {
                        Directory.CreateDirectory(_Directory);
                    }
                }
                if (!VideoRenderer.IsOpen) {
                    VideoRenderer.Open(Path.Combine(_Directory, this.SortingAlgorithm + ".mkv"), 3000, 2000, new Accord.Math.Rational(60), VideoCodec.Default, int.MaxValue);
                }
            }
        }
        private string _Directory = "uninitialized";
        private long _StartTime = 0;
        public SetType SetType { get; }
        private int _ExpectedFrameCount = 1;
        private bool _simulateMode;
        private int _frameSkipping = 0;
        private int _skippedFrames = 0;
        public bool SimulateMode {
            get => _simulateMode;
            set {
                if (value) {
                    _ExpectedFrameCount = int.MaxValue;
                    Console.WriteLine("Simulating {0} with {1} values (Set: {2} - Seed {3})...", this.SortingAlgorithm, this.Size, DataSet.SetTypeToString(this.SetType), this.Seed);
                } else {
                    Console.WriteLine("Simulation ended! Results:\n\t{0} Reads\n\t{1} Writes\n\t{2} Comparisons\n\t{3} Swaps\n\t{4} Frames", this.ReadOperations, this.WriteOperations, this.CompareOperations, this.SwapOperations, this.FrameCount + this.Size);
                    _ExpectedFrameCount = this.FrameCount + this.Size;
                    this.ResetToInitial();
                    _frameSkipping = _ExpectedFrameCount / 3600;
                    Console.WriteLine("Drawing 1 in every {0} frames", _frameSkipping + 1);
                    Console.SetOut(TextWriter.Null);
                }
                _simulateMode = value;
            }
        }
        #endregion
        #region Constructors
        public DataSet(int size, SetType type, int seed) {
            this.SetType = type;
            this.Seed = seed;
            this.Size = size;
            _InitialData = new int[size];
            var rnd = new Random(seed);
            switch (type) {
                case SetType.Ordererd:
                    for (int i = 0; i < size; i++)
                        _InitialData[i] = i + 1;
                    break;
                case SetType.Reversed:
                    for (int i = 0; i < size; i++)
                        _InitialData[i] = size - i;
                    break;
                case SetType.Random:
                    for (int i = 0; i < size; i++) {
                        int tmp;
                        do {
                            tmp = rnd.Next(1, size + 1); // TODO: Do this better!
                        } while (_InitialData.Contains(tmp));
                        _InitialData[i] = tmp;
                    }
                    break;
                case SetType.SingleError:
                    for (int i = 1; i < size - 1; i++)
                        _InitialData[i] = i + 1;
                    _InitialData[0] = size;
                    _InitialData[size - 1] = 1;
                    break;
                default:
                    throw new ArgumentException("Unhandled Enumeration type when initializing the dataset values!", "type");
            }
            _Data = new int[size];
            _InitialData.CopyTo(_Data, 0);
            _yScale = (double)_FrameHeight / (double)(this.Size);
            _xScale = (double)_FrameWidth / (double)(this.Size);
            _BarWidth = (int)Math.Ceiling(_xScale);
        }
        public DataSet(int size, SetType type) : this(size, type, Guid.NewGuid().GetHashCode()) { }
        public override string ToString() => $"{this.SortingAlgorithm} - {this.Size} Values - {DataSet.SetTypeToString(this.SetType)} Set - Seed {this.Seed}";
        #endregion
        #region Operations
        public static string SetTypeToString(SetType type) {
            switch (type) {
                case SetType.Ordererd:
                    return "Ordered";
                case SetType.Reversed:
                    return "Reversed";
                case SetType.Random:
                    return "Random";
                case SetType.SingleError:
                    return "SingleError";
                default:
                    return "Unkown";
            }
        }
        /// <summary>
        /// Gibt das Element des Datensets aus, das an (index + 1)-ter Stelle steht.
        /// </summary>
        /// <param name="index">Zugriffsindex, wirft einen Fehler, wenn der Index nicht gültig ist.</param>
        /// <returns>Kopie des Werts aus dem Datenset.</returns>
        private int this[int index] {
            get {
                this.ReadOperations++;
                return _Data[index];
            }
            set {
                this.WriteOperations++;
                _Data[index] = value;
            }
        }
        /// <summary>
        /// Reads the value at an index (same as this[index]) but generates a frame.
        /// </summary>
        /// <param name="index"></param>
        /// <returns></returns>
        public int ReadOperation(int index) {
            this.DrawReadFrame(index);
            return this[index];
        }
        public void WriteOperation(int index, int value) {
            this[index] = value;
            this.DrawWriteFrame(index);
        }
        private void Comparation(int left, int right) {
            this.CompareOperations++;
            this.DrawCompareFrame(left, right);
        }
        public bool GreaterThan(int left, int right) {
            this.Comparation(left, right);
            return (this[left] > this[right]);
        }
        public bool GreaterThanOrEqual(int left, int right) {
            this.Comparation(left, right);
            return (this[left] >= this[right]);
        }
        public bool LessThan(int left, int right) {
            this.Comparation(left, right);
            return (this[left] < this[right]);
        }
        public bool LessThanOrEqual(int left, int right) {
            this.Comparation(left, right);
            return (this[left] <= this[right]);
        }
        public bool Equal(int left, int right) {
            this.Comparation(left, right);
            return (this[left] == this[right]);
        }
        public bool Unequal(int left, int right) {
            this.Comparation(left, right);
            return (this[left] != this[right]);
        }
        public void Swap(int left, int right) {
            int tmp = this[left];
            this[left] = this[right];
            this[right] = tmp;
            this.SwapOperations++;
            this.DrawSwapFrame(left, right);
        }
        #endregion
        #region Timing
        public void StartTimer() => _StartTime = DateTime.Now.Ticks;
        public void StopTimer() => this.Ticks = DateTime.Now.Ticks - _StartTime;
        #endregion
        #region Visualizing
        public Brush BackgroundBrush = new SolidBrush(Color.Black);
        public Brush ReadColor = new SolidBrush(Color.Blue);
        public Brush WriteColor = new SolidBrush(Color.Magenta);
        public Brush CheckColor = new SolidBrush(Color.Green);
        public Brush BarColor = new SolidBrush(Color.White);
        public Brush CompareColor = new SolidBrush(Color.Red);
        public Brush SwapColor = new SolidBrush(Color.Yellow);
        private Bitmap _Frame = new Bitmap(_FrameWidth, _FrameHeight);
        private VideoFileWriter VideoRenderer = new VideoFileWriter();
        int _progress = 0;
        private int FrameCount {
            get => _FrameCount;
            set {
                if (!this.SimulateMode)
                    VideoRenderer.WriteVideoFrame(_Frame);
                // _Frame.Save(Path.Combine(this.SortingAlgorithm, DataSet.SetTypeToString(this.SetType), $"Image{ _FrameCount.ToString("d6")}.png"), ImageFormat.Png);
                _FrameCount = value;
                int newprogress = (_FrameCount * 100) / _ExpectedFrameCount;
                if (newprogress > _progress) {
                    _progress = newprogress;
                    Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) {
                        AutoFlush = true
                    });
                    Console.Write("\rProgress: {0}% - {1} frames", newprogress, _FrameCount);
                    Console.SetOut(TextWriter.Null);
                }
            }
        }
        private static readonly int _FrameHeight = 2000;
        private static readonly int _FrameWidth = 3000;
        private readonly double _yScale = 1;
        private readonly double _xScale = 1;
        private readonly int _BarWidth = 1;
        private int _FrameCount = 0;
        private string _sortingAlgorithm = "DefaultAlgorithm";

        private void DrawFrame() {
            this.ClearFrame();
        }

        private void ClearFrame() {
            DrawRect(0, 0, _FrameWidth, _FrameHeight, ref this.BackgroundBrush);
        }

        private void DrawRect(int x1, int y1, int w, int h, ref Brush brush) {
            int wn = w - 1;
            if (wn <= 0)
                wn = 1;
            int hn = h - 1;
            if (hn <= 0)
                hn = 1;
            using (var graphics = Graphics.FromImage(_Frame)) {
                graphics.FillRectangle(brush, x1, y1, wn, hn);
            }
        }

        private void DrawCompareFrame(int left, int right) {
            if (this.SimulateMode) {
                this.FrameCount++;
            } else {
                if (this.SkipFrame())
                    return;
                DrawFrame();
                for (int i = 0; i < this.Size; i++) {
                    int xpos = (int)(_xScale * i);
                    int ypos = (int)(_yScale * this._Data[i]);
                    if (i == left || i == right)
                        DrawRect(xpos, _FrameHeight - ypos, _BarWidth, ypos, ref this.CompareColor);
                    else
                        DrawRect(xpos, _FrameHeight - ypos, _BarWidth, ypos, ref this.BarColor);
                }
                ++this.FrameCount;
                //Console.WriteLine("Compare frame {0} was drawn",this.FrameCount);
            }
        }

        private void DrawReadFrame(int index) {
            DataSet dataSet = this;
            if (dataSet.SimulateMode) {
                this.FrameCount++;
            } else {
                if (this.SkipFrame())
                    return;
                DrawFrame();
                for (int i = 0; i < this.Size; i++) {
                    int xpos = (int)(_xScale * i);
                    int ypos = (int)(_yScale * this._Data[i]);
                    if (i == index)
                        DrawRect(xpos, _FrameHeight - ypos, _BarWidth, ypos, ref this.ReadColor);
                    else
                        DrawRect(xpos, _FrameHeight - ypos, _BarWidth, ypos, ref this.BarColor);
                }
                ++this.FrameCount;
                //Console.WriteLine("Read frame {0} was drawn", this.FrameCount);
            }
        }

        private void DrawWriteFrame(int index) {
            if (this.SimulateMode) {
                this.FrameCount++;
            } else {
                if (this.SkipFrame())
                    return;
                DrawFrame();
                for (int i = 0; i < this.Size; i++) {
                    int xpos = (int)(_xScale * i);
                    int ypos = (int)(_yScale * this._Data[i]);
                    if (i == index)
                        DrawRect(xpos, _FrameHeight - ypos, _BarWidth, ypos, ref this.WriteColor);
                    else
                        DrawRect(xpos, _FrameHeight - ypos, _BarWidth, ypos, ref this.BarColor);
                }
                ++this.FrameCount;
                //Console.WriteLine("Write frame {0} was drawn", this.FrameCount);
            }
        }

        private void DrawSwapFrame(int left, int right) {
            if (this.SimulateMode) {
                this.FrameCount++;
            } else {
                if (this.SkipFrame())
                    return;
                DrawFrame();
                for (int i = 0; i < this.Size; i++) {
                    int xpos = (int)(_xScale * i);
                    int ypos = (int)(_yScale * this._Data[i]);
                    if (i == left || i == right)
                        DrawRect(xpos, _FrameHeight - ypos, _BarWidth, ypos, ref this.SwapColor);
                    else
                        DrawRect(xpos, _FrameHeight - ypos, _BarWidth, ypos, ref this.BarColor);
                }
                ++this.FrameCount;
                //Console.WriteLine("Swap frame {0} was drawn", this.FrameCount);
            }
        }

        private bool SkipFrame() {
            if (_skippedFrames++ < _frameSkipping) {
                ++this._FrameCount; // Avoid automatic drawing trough property
                return true;
            } else {
                _skippedFrames = 0;
                return false;
            }
        }

        public void FinalizeVideo() {
            Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) {
                AutoFlush = true
            });
            Console.WriteLine("\n\nFinalizing...");
            for (int i = 0; i < this.Size; i++) {
                int xpos = (int)(_xScale * i);
                int ypos = (int)(_yScale * this._Data[i]);
                DrawRect(xpos, _FrameHeight - ypos, _BarWidth, ypos, ref this.BarColor);
            }
            //if (!this.SkipFrame())
                ++this.FrameCount;
            //Console.WriteLine("Finalizing Frame {0} was drawn", this.FrameCount);
            for (int d = 0; d < this.Size; d++) { // Add 1 checked bar per frame
                int xpos = (int)(_xScale * d);
                int ypos = (int)(_yScale * this._Data[d]);
                DrawRect(xpos, _FrameHeight - ypos, _BarWidth, ypos, ref this.CheckColor);
                //if (this.SkipFrame())
                //    continue;
                ++this.FrameCount;
                //Console.WriteLine("Finalizing Frame {0} was drawn", this.FrameCount);
            }
            Console.WriteLine("Encoding video from frames...");
            //var startInfo = new System.Diagnostics.ProcessStartInfo {
            //    WorkingDirectory = _Directory,
            //    WindowStyle = System.Diagnostics.ProcessWindowStyle.Normal,
            //    FileName = "ffmpeg.exe",
            //    Arguments = $"-r 60 -f image2 -s {_FrameWidth}x{_FrameHeight} -i Image%06d.png -vcodec libx264 -crf 25  -pix_fmt yuv420p {this.SortingAlgorithm}.mp4",
            //    RedirectStandardInput = true,
            //    UseShellExecute = false,
            //    RedirectStandardOutput = true,
            //    CreateNoWindow = false
            //};
            //Process.Start(startInfo);
            VideoRenderer.Close();
            VideoRenderer.Dispose();
            VideoRenderer = null;
            VideoRenderer = new VideoFileWriter();
            Console.WriteLine("Video encoded!");
        }
        #endregion
        #region Resetting
        public void ResetToInitial() {
            _Data = null;
            _Data = new int[this.Size];
            _InitialData.CopyTo(_Data, 0);
            _Frame?.Dispose();
            _Frame = null;
            _Frame = new Bitmap(_FrameWidth, _FrameHeight);
            this.ReadOperations = 0;
            this.WriteOperations = 0;
            this.CompareOperations = 0;
            this.Ticks = 0;
            this.FrameCount = 0;
            this._progress = 0;
            this._skippedFrames = 0;
        }
        #endregion
    }
}