using System;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.Serialization;
using System.Windows.Forms;

namespace PaintDotNet
{
    [Serializable]
    public sealed class StitchDocument : IDeserializationCallback, IDisposable
    {
        public StitchSurface surface;
        private int width;
        private int height;
        private NameValueCollection userMetaData;

        [NonSerialized]
        private Vector<Rectangle> updateRegion;

        [NonSerialized]
        private bool dirty;

        [NonSerialized]
        private Metadata metadata = null;

        /// <summary>
        /// Gets or sets the units that are used for measuring the document's physical (printed) size.
        /// </summary>
        /// <remarks>
        /// If this property is set to MeasurementUnit.Pixel, then Dpu will be reset to 1. 
        /// If this property has not been set in the image's metadata, its default value 
        /// will be MeasurementUnit.Inch.
        /// If the EXIF data for the image is invalid (such as "ResolutionUnit = 0" or something),
        /// then the default DpuUnit will be returned.
        /// </remarks>
        public MeasurementUnit DpuUnit
        {
            get
            {
                PropertyItem[] pis = this.Metadata.GetExifValues(ExifTagID.ResolutionUnit);

                if (pis.Length == 0)
                {
                    this.DpuUnit = DefaultDpuUnit;
                    return DefaultDpuUnit;
                }
                else
                {
                    try
                    {
                        ushort unit = Exif.DecodeShortValue(pis[0]);

                        // Guard against bad data in the EXIF store
                        switch ((MeasurementUnit)unit)
                        {
                            case MeasurementUnit.Pixel:
                            case MeasurementUnit.Inch:
                            case MeasurementUnit.Mil:
                            case MeasurementUnit.Centimeter:
                            case MeasurementUnit.Millimeter:
                            case MeasurementUnit.Micron:
                            case MeasurementUnit.Nano:
                                return (MeasurementUnit)unit;

                            default:
                                this.Metadata.RemoveExifValues(ExifTagID.ResolutionUnit);
                                return this.DpuUnit; // recursive call
                        }
                    }
                    catch (Exception)
                    {
                        this.Metadata.RemoveExifValues(ExifTagID.ResolutionUnit);
                        return this.DpuUnit; // recursive call
                    }
                }
            }

            set
            {
                PropertyItem pi = Exif.CreateShort(ExifTagID.ResolutionUnit, (ushort)value);
                this.Metadata.ReplaceExifValues(ExifTagID.ResolutionUnit, new PropertyItem[1] { pi });

                if (value == MeasurementUnit.Pixel)
                {
                    this.DpuX = 1.0;
                    this.DpuY = 1.0;
                }

                Dirty = true;
            }
        }

        public static MeasurementUnit DefaultDpuUnit
        {
            get
            {
                return MeasurementUnit.Inch;
            }
        }

        public static double defaultDpi = 96;

        /// <summary>
        /// 1英寸 = 2.54厘米
        /// </summary>
        public static double CmPerInch = 2.54;
        /// <summary>
        /// 默认值 = dpi / 单位
        /// </summary>
        public double defaultDpcm;

        public const double MinimumDpu = 0.01;
        public const double MaximumDpu = 32767.0;

        public static double GetDefaultDpu(MeasurementUnit units)
        {
            double dpu;

            switch (units)
            {
                case MeasurementUnit.Inch:
                    dpu = defaultDpi;
                    break;

                case MeasurementUnit.Mil:
                    dpu = defaultDpi / 1000;
                    break;

                case MeasurementUnit.Centimeter:
                    dpu = defaultDpi / CmPerInch;
                    break;

                case MeasurementUnit.Millimeter:
                    dpu = defaultDpi / CmPerInch / 10;
                    break;

                case MeasurementUnit.Micron:
                    dpu = defaultDpi / CmPerInch / 10000;
                    break;

                case MeasurementUnit.Nano:
                    dpu = defaultDpi / CmPerInch / 10000000;
                    break;

                case MeasurementUnit.Pixel:
                    dpu = 1.0;
                    break;

                default:
                    throw new InvalidEnumArgumentException("DpuUnit", (int)units, typeof(MeasurementUnit));
            }

            return dpu;
        }

        private byte[] GetDoubleAsRationalExifData(double value)
        {
            uint numerator;
            uint denominator;

            if (Math.IEEERemainder(value, 1.0) == 0)
            {
                numerator = (uint)value;
                denominator = 1;
            }
            else
            {
                double s = value * 1000.0;
                numerator = (uint)Math.Floor(s);
                denominator = 1000;
            }

            return Exif.EncodeRationalValue(numerator, denominator);
        }

        /// <summary>
        /// Gets or sets the Document's dots-per-unit scale in the X direction.
        /// </summary>
        /// <remarks>
        /// If DpuUnit is equal to MeasurementUnit.Pixel, then this property may not be set
        /// to any value other than 1.0. Setting DpuUnit to MeasurementUnit.Pixel will reset
        /// this property to 1.0. This property may only be set to a value greater than 0.
        /// One dot is always equal to one pixel. This property will not return a value less
        /// than MinimumDpu, nor a value larger than MaximumDpu.
        /// </remarks>
        public double DpuX
        {
            get
            {
                PropertyItem[] pis = this.Metadata.GetExifValues(ExifTagID.XResolution);

                if (pis.Length == 0)
                {
                    double defaultDpu = GetDefaultDpu(this.DpuUnit);
                    this.DpuX = defaultDpu;
                    return defaultDpu;
                }
                else
                {
                    try
                    {
                        uint numerator;
                        uint denominator;

                        Exif.DecodeRationalValue(pis[0], out numerator, out denominator);

                        if (denominator == 0)
                        {
                            throw new DivideByZeroException(); // will be caught by the below catch{}
                        }
                        else
                        {
                            return Math.Min(MaximumDpu, Math.Max(MinimumDpu, (double)numerator / (double)denominator));
                        }
                    }

                    catch
                    {
                        this.Metadata.RemoveExifValues(ExifTagID.XResolution);
                        return this.DpuX; // recursive call;
                    }
                }
            }

            set
            {
                if (value <= 0.0)
                {
                    throw new ArgumentOutOfRangeException("value", value, "must be > 0.0");
                }

                if (this.DpuUnit == MeasurementUnit.Pixel && value != 1.0)
                {
                    throw new ArgumentOutOfRangeException("value", value, "if DpuUnit == Pixel, then value must equal 1.0");
                }

                byte[] data = GetDoubleAsRationalExifData(value);

                PropertyItem pi = Exif.CreatePropertyItem(ExifTagID.XResolution, ExifTagType.Rational, data);
                this.Metadata.ReplaceExifValues(ExifTagID.XResolution, new PropertyItem[1] { pi });
                Dirty = true;
            }
        }

        /// <summary>
        /// Gets or sets the Document's dots-per-unit scale in the Y direction.
        /// </summary>
        /// <remarks>
        /// If DpuUnit is equal to MeasurementUnit.Pixel, then this property may not be set
        /// to any value other than 1.0. Setting DpuUnit to MeasurementUnit.Pixel will reset
        /// this property to 1.0. This property may only be set to a value greater than 0.
        /// One dot is always equal to one pixel. This property will not return a value less
        /// than MinimumDpu, nor a value larger than MaximumDpu.
        /// </remarks>
        public double DpuY
        {
            get
            {
                PropertyItem[] pis = this.Metadata.GetExifValues(ExifTagID.YResolution);

                if (pis.Length == 0)
                {
                    // If there's no DpuY setting, default to the DpuX setting
                    double dpu = this.DpuX;
                    this.DpuY = dpu;
                    return dpu;
                }
                else
                {
                    try
                    {
                        uint numerator;
                        uint denominator;

                        Exif.DecodeRationalValue(pis[0], out numerator, out denominator);

                        if (denominator == 0)
                        {
                            throw new DivideByZeroException(); // will be caught by the below catch{}
                        }
                        else
                        {
                            return Math.Min(MaximumDpu, Math.Max(MinimumDpu, (double)numerator / (double)denominator));
                        }
                    }

                    catch
                    {
                        this.Metadata.RemoveExifValues(ExifTagID.YResolution);
                        return this.DpuY; // recursive call;
                    }
                }
            }

            set
            {
                if (value <= 0.0)
                {
                    throw new ArgumentOutOfRangeException("value", value, "must be > 0.0");
                }

                if (this.DpuUnit == MeasurementUnit.Pixel && value != 1.0)
                {
                    throw new ArgumentOutOfRangeException("value", value, "if DpuUnit == Pixel, then value must equal 1.0");
                }

                byte[] data = GetDoubleAsRationalExifData(value);

                PropertyItem pi = Exif.CreatePropertyItem(ExifTagID.YResolution, ExifTagType.Rational, data);
                this.Metadata.ReplaceExifValues(ExifTagID.YResolution, new PropertyItem[1] { pi });
                Dirty = true;
            }
        }

        /// <summary>
        /// 像素换算到物理长度
        /// </summary>
        /// <param name="pixel"></param>
        /// <param name="resultUnit"></param>
        /// <returns></returns>
        public double PixelToPhysicalY(double pixel, MeasurementUnit resultUnit)
        {
            double result;

            if (resultUnit == MeasurementUnit.Pixel)
            {
                result = pixel;
            }
            else
            {
                MeasurementUnit dpuUnit = this.DpuUnit;

                if (resultUnit == dpuUnit)
                {
                    double defaultDpuY = GetDefaultDpu(dpuUnit);
                    result = pixel / defaultDpuY;
                    //result = pixel / this.DpuY;
                }
                else if (dpuUnit == MeasurementUnit.Pixel)
                {
                    double defaultDpuY = GetDefaultDpu(dpuUnit);
                    result = pixel / defaultDpuY;
                }
                else if (dpuUnit == MeasurementUnit.Inch && resultUnit == MeasurementUnit.Mil)
                {
                    double defaultDpuY = GetDefaultDpu(MeasurementUnit.Mil);
                    result = pixel / defaultDpuY; // pixel / (CmPerInch * this.DpuY);
                }
                else if (dpuUnit == MeasurementUnit.Inch && resultUnit == MeasurementUnit.Centimeter)
                {
                    double defaultDpuY = GetDefaultDpu(MeasurementUnit.Centimeter);
                    result = pixel / defaultDpuY; // pixel / (CmPerInch * this.DpuY);
                }
                else if (dpuUnit == MeasurementUnit.Inch && resultUnit == MeasurementUnit.Millimeter)
                {
                    double defaultDpuY = GetDefaultDpu(MeasurementUnit.Millimeter);
                    result = pixel / defaultDpuY;
                }
                else if (dpuUnit == MeasurementUnit.Inch && resultUnit == MeasurementUnit.Micron)
                {
                    double defaultDpuY = GetDefaultDpu(MeasurementUnit.Micron);
                    result = pixel / defaultDpuY;
                }
                else if (dpuUnit == MeasurementUnit.Inch && resultUnit == MeasurementUnit.Nano)
                {
                    double defaultDpuY = GetDefaultDpu(MeasurementUnit.Nano);
                    result = pixel / defaultDpuY;
                }
                else
                {
                    result = pixel / this.DpuX;//(pixel * CmPerInch) / this.DpuY;
                }
            }

            return result;
        }

        [field: NonSerialized]
        public event EventHandler DirtyChanged;

        private void OnDirtyChanged()
        {
            if (DirtyChanged != null)
            {
                DirtyChanged(this, EventArgs.Empty);
            }
        }

        /// <summary>
        /// Keeps track of whether the document has changed at all since it was last opened
        /// or saved. This is something that is not reset to true by any method in the Document
        /// class, but is set to false anytime anything is changed.
        /// This way we can prompt the user to save a changed document when they go to quit.
        /// </summary>
        public bool Dirty
        {
            get
            {
                if (this.disposed)
                {
                    throw new ObjectDisposedException("Document");
                }

                return this.dirty;
            }

            set
            {
                if (this.disposed)
                {
                    throw new ObjectDisposedException("Document");
                }

                if (this.dirty != value)
                {
                    this.dirty = value;
                    OnDirtyChanged();
                }
            }
        }

        /// <summary>
        /// Width of the document, in pixels. All contained layers must be this wide as well.
        /// </summary>
        public int Width
        {
            get
            {
                return width;
            }
        }

        /// <summary>
        /// Height of the document, in pixels. All contained layers must be this tall as well.
        /// </summary>
        public int Height
        {
            get
            {
                return height;
            }
        }

        /// <summary>
        /// The size of the document, in pixels. This is a convenience property that wraps up
        /// the Width and Height properties in one Size structure.
        /// </summary>
        public Size Size
        {
            get
            {
                return new Size(Width, Height);
            }
        }

        public Rectangle Bounds
        {
            get
            {
                return new Rectangle(0, 0, Width, Height);
            }
        }

        public Metadata Metadata
        {
            get
            {
                if (metadata == null)
                {
                    metadata = new Metadata(userMetaData);
                }

                return metadata;
            }
        }

        /// <summary>
        /// Constructs a blank document (zero layers) of the given width and height.
        /// </summary>
        /// <param name="width"></param>
        /// <param name="height"></param>
        public StitchDocument(int width, int height)
        {
            this.width = width;
            this.height = height;
            this.Dirty = true;
            this.updateRegion = new Vector<Rectangle>();
            userMetaData = new NameValueCollection();
            Invalidate();
        }

        /// <summary>
        /// Called after deserialization occurs so that certain things that are non-serializable
        /// can be set up.
        /// </summary>
        /// <param name="sender"></param>
        public void OnDeserialization(object sender)
        {
            this.updateRegion = new Vector<Rectangle>();
            this.updateRegion.Add(this.Bounds);
            Dirty = true;
        }

        [field: NonSerialized]
        public event InvalidateEventHandler Invalidated;

        /// <summary>
        /// Raises the Invalidated event.
        /// </summary>
        /// <param name="e"></param>
        private void OnInvalidated(InvalidateEventArgs e)
        {
            if (Invalidated != null)
            {
                Invalidated(this, e);
            }
        }

        /// <summary>
        /// Causes the whole document to be invalidated, forcing a full rerender on
        /// the next call to Update.
        /// </summary>
        public void Invalidate()
        {
            Dirty = true;
            Rectangle rect = new Rectangle(0, 0, Width, Height);
            updateRegion.Clear();
            updateRegion.Add(rect);
            OnInvalidated(new InvalidateEventArgs(rect));
        }

        public unsafe static StitchDocument FromMat(OpenCvSharp.Mat mat)
        {
            if (mat == null) throw new ArgumentNullException("image"); //Console.WriteLine("size:" + new ColorBgra()); //Console.WriteLine("size2:" + sizeof(ColorBgrB));
            StitchDocument document = new StitchDocument(mat.Width, mat.Height);
            if (mat.Channels() == 4)
            {
                OpenCvSharp.Cv2.CvtColor(mat, mat, OpenCvSharp.ColorConversionCodes.BGRA2BGR);
            }
            StitchSurface surface = new StitchSurface(new Size(mat.Width, mat.Height), mat.Channels(), mat); //surface.Clear(ColorBgrB.FromColor(Color.Red));
            surface.PixelFormat = mat.Channels() == 3 ? PixelFormat.Format24bppRgb : PixelFormat.Format32bppArgb;
            surface.scan0.VoidStar = (void*)mat.Data;
            surface.Stride = (int)mat.Step();
            document.surface = surface;
            document.Invalidate();
            return document;
        }

        ~StitchDocument()
        {
            Dispose(false);
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        private bool disposed = false;
        private void Dispose(bool disposing)
        {
            if (!disposed) disposed = true;
        }
    }
}