using System;
using System.Diagnostics;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Runtime.Serialization;
namespace Netron.Diagramming.Core {
  /// <summary>
  /// Static class of utility methods
  /// </summary>
  public static class Utils {
    public static void DrawRoundRect(Graphics g, Pen p, Rectangle rectangle) {
      DrawRoundRect(g, p, rectangle.X, rectangle.Y, rectangle.Width, rectangle.Height, 7F);
    }
    public static void DrawRoundRect(Graphics g, Pen p, float X, float Y, float width, float height, float radius) {

      GraphicsPath path = new GraphicsPath();
      path.AddLine(X + radius, Y, X + width - (radius * 2), Y);
      path.AddArc(X + width - (radius * 2), Y, radius * 2, radius * 2, 270, 90);
      path.AddLine(X + width, Y + radius, X + width, Y + height - (radius * 2));
      path.AddArc(X + width - (radius * 2), Y + height - (radius * 2), radius * 2, radius * 2, 0, 90);
      path.AddLine(X + width - (radius * 2), Y + height, X + radius, Y + height);
      path.AddArc(X, Y + height - (radius * 2), radius * 2, radius * 2, 90, 90);
      path.AddLine(X, Y + height - (radius * 2), X, Y + radius);
      path.AddArc(X, Y, radius * 2, radius * 2, 180, 90);
      path.CloseFigure();

      g.DrawPath(p, path);
      path.Dispose();
    }

    /// <summary>
    /// Returns the bounding rectangle of the given collection of entities.
    /// </summary>
    /// <param name="collection"></param>
    /// <returns></returns>
    public static Rectangle BoundingRectangle(CollectionBase<IDiagramEntity> collection) {
      //get the bounding rectangle
      bool first = true;
      Rectangle rec = Rectangle.Empty;
      foreach (IDiagramEntity entity in collection) {
        if (first) {
          rec = entity.Rectangle;
          first = false;
        } else
          rec = Rectangle.Union(rec, entity.Rectangle);
      }
      return rec;
    }

    /// <summary>
    /// Depth-first traversal of an <see cref="IGroup"/>
    /// </summary>
    /// <param name="group"></param>
    /// <param name="collection"></param>
    public static void TraverseCollect(IGroup group, ref CollectionBase<IDiagramEntity> collection) {
      #region Checks
      if (group == null)
        throw new InconsistencyException("Cannot collect entities of a 'null' IGroup");
      if (collection == null)
        throw new InconsistencyException("You need to instantiate a collection before using this method.");
      #endregion

      foreach (IDiagramEntity entity in group.Entities) {
        if (entity is IGroup)
          TraverseCollect(entity as IGroup, ref collection);
        else
          collection.Add(entity);
      }

    }

    // Given H,S,L in range of 0-1

    // Returns a Color (RGB struct) in range of 0-255

    /// <summary>
    /// HSL to RGB conversion.
    /// </summary>
    /// <param name="h">The h.</param>
    /// <param name="sl">The sl.</param>
    /// <param name="l">The l.</param>
    /// <returns></returns>
    public static ColorRGB HSL2RGB(double h, double sl, double l) {

      double v;
      double r, g, b;
      r = l;   // default to gray
      g = l;
      b = l;
      v = (l <= 0.5) ? (l * (1.0 + sl)) : (l + sl - l * sl);
      if (v > 0) {
        double m;
        double sv;
        int sextant;
        double fract, vsf, mid1, mid2;

        m = l + l - v;
        sv = (v - m) / v;
        h *= 6.0;
        sextant = (int)h;
        fract = h - sextant;
        vsf = v * sv * fract;
        mid1 = m + vsf;
        mid2 = v - vsf;
        switch (sextant) {
          case 0:
            r = v;
            g = mid1;
            b = m;
            break;
          case 1:
            r = mid2;
            g = v;
            b = m;
            break;
          case 2:
            r = m;
            g = v;
            b = mid1;
            break;
          case 3:
            r = m;
            g = mid2;
            b = v;
            break;
          case 4:
            r = mid1;
            g = m;
            b = v;
            break;
          case 5:
            r = v;
            g = m;
            b = mid2;
            break;
        }
      }
      ColorRGB rgb = new ColorRGB();
      rgb.R = Convert.ToByte(r * 255.0f);
      rgb.G = Convert.ToByte(g * 255.0f);
      rgb.B = Convert.ToByte(b * 255.0f);
      return rgb;

    }

    // Given a Color (RGB Struct) in range of 0-255

    // Return H,S,L in range of 0-1

    /// <summary>
    /// RGB to HSL conversion
    /// </summary>
    /// <param name="rgb">The RGB.</param>
    /// <param name="h">The h.</param>
    /// <param name="s">The s.</param>
    /// <param name="l">The l.</param>
    public static void RGB2HSL(ColorRGB rgb, out double h, out double s, out double l) {
      double r = rgb.R / 255.0;
      double g = rgb.G / 255.0;
      double b = rgb.B / 255.0;
      double v;
      double m;
      double vm;
      double r2, g2, b2;

      h = 0; // default to black
      s = 0;
      l = 0;
      v = Math.Max(r, g);
      v = Math.Max(v, b);
      m = Math.Min(r, g);
      m = Math.Min(m, b);

      l = (m + v) / 2.0;
      if (l <= 0.0) {
        return;
      }
      vm = v - m;
      s = vm;
      if (s > 0.0) {
        s /= (l <= 0.5) ? (v + m) : (2.0 - v - m);
      } else {
        return;
      }
      r2 = (v - r) / vm;
      g2 = (v - g) / vm;
      b2 = (v - b) / vm;
      if (r == v) {
        h = (g == m ? 5.0 + b2 : 1.0 - g2);
      } else if (g == v) {
        h = (b == m ? 1.0 + r2 : 3.0 - b2);
      } else {
        h = (r == m ? 3.0 + g2 : 5.0 - r2);
      }
      h /= 6.0;
    }
    /// <summary>
    /// Constrains the type.
    /// </summary>
    /// <param name="type">The type.</param>
    public static void ConstrainType(Type type) {
      bool serializable = type.IsSerializable;
      if (serializable == false) {
        string message = "The type " + type + " is not serializable";
        throw new SerializationException(message);
      }
      bool genericType = type.IsGenericType;

      if (genericType) {
        Type[] typeArguments = type.GetGenericArguments();
        Debug.Assert(typeArguments.Length >= 1);
        Array.ForEach(typeArguments, ConstrainType);
      }
    }


  }
  /// <summary>
  /// Utility struct for color conversions
  /// </summary>
  public struct ColorRGB {
    #region Fields
    private byte r;
    private byte g;
    private byte b;
    #endregion

    /// <summary>
    /// Gets or sets the Red value.
    /// </summary>
    /// <value>The R.</value>
    public byte R {
      get { return r; }
      set { r = value; }
    }


    /// <summary>
    /// Gets or sets the Green value.
    /// </summary>
    /// <value>The G.</value>
    public byte G {
      get { return g; }
      set { g = value; }
    }



    /// <summary>
    /// Gets or sets the Blue value.
    /// </summary>
    /// <value>The B.</value>
    public byte B {
      get { return b; }
      set { b = value; }
    }
    /// <summary>
    /// Initializes a new instance of the <see cref="T:ColorRGB"/> class.
    /// </summary>
    /// <param name="value">The value.</param>
    public ColorRGB(Color value) {
      this.r = value.R;
      this.g = value.G;
      this.b = value.B;
    }
    /// <summary>
    /// Implicit conversion of the specified RGB.
    /// </summary>
    /// <param name="rgb">The RGB.</param>
    /// <returns></returns>
    public static implicit operator Color(ColorRGB rgb) {
      Color c = Color.FromArgb(rgb.R, rgb.G, rgb.B);
      return c;
    }
    /// <summary>
    /// Explicit conversion of the specified c.
    /// </summary>
    /// <param name="c">The c.</param>
    /// <returns></returns>
    public static explicit operator ColorRGB(Color c) {
      return new ColorRGB(c);
    }
  }




}