using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.DirectX.Direct3D;
using Microsoft.DirectX;
using System.Drawing;

namespace SalsaModel {
  public class BasicDrawing {
    protected Device DXDevice;

    public Mesh BallMesh;
    public Microsoft.DirectX.Direct3D.Font Font;

    public const double LineWidth = 2.0;
    public const double BallRadius = 4.0;

    public Dictionary<Color, Material> _materials = new Dictionary<Color, Material>();
    public Material Material(Color color) {
      Material ret;
      if (!_materials.TryGetValue(color, out ret)) {
        ret = new Material();
        ret.Ambient = color;
        ret.Diffuse = color;
        ret.Specular = Color.White;
        _materials.Add(color, ret);
      }
      return ret;
    }

    public void Setup(Device dev) {
      DXDevice = dev;

      float radius = (float)BallRadius;
      BallMesh = Mesh.Sphere(DXDevice, radius, 4, 4);

      Font = new Microsoft.DirectX.Direct3D.Font(DXDevice, new System.Drawing.Font(FontFamily.GenericSansSerif, 12));
    }

    public void Line(Location a, Location b, Color color) {
      float radius = (float)LineWidth;
      using (Mesh cylinder = Mesh.Cylinder(DXDevice, radius, radius, (float)a.DistanceTo(b), 8, 1)) {
        SetOriginAndZOrientationTo(a.HalfWayTo(b), b.Minus(a));
        DXDevice.Material = Material(color);
        cylinder.DrawSubset(0);
      }
    }

    public void FlatLine(Location a, Location b, Color color) {
      CustomVertex.PositionOnly[] vertices = new CustomVertex.PositionOnly[4];

      Location off = b.Minus(a);
      Location radius = off.CrossWithZ().Normalised().Scale(LineWidth);

      int v = 0;
      double raise = 0.0;
      vertices[v++] = new CustomVertex.PositionOnly(Vec3(a.Plus(radius).Plus(0, 0, raise)));
      vertices[v++] = new CustomVertex.PositionOnly(Vec3(b.Plus(radius).Plus(0, 0, raise)));
      vertices[v++] = new CustomVertex.PositionOnly(Vec3(a.Minus(radius).Plus(0, 0, raise)));
      vertices[v++] = new CustomVertex.PositionOnly(Vec3(b.Minus(radius).Plus(0, 0, raise)));

      //vertices[0] = new CustomVertex.PositionOnly(-floorSize, floorSize, 1f);
      //vertices[1] = new CustomVertex.PositionOnly(-floorSize, -floorSize, 1f);
      //vertices[2] = new CustomVertex.PositionOnly(floorSize, floorSize, 1f);
      //vertices[3] = new CustomVertex.PositionOnly(floorSize, -floorSize, 1f);

      DXDevice.VertexFormat = CustomVertex.PositionOnly.Format;
      DXDevice.Material = Material(color);
      DXDevice.DrawUserPrimitives(PrimitiveType.TriangleStrip, 2, vertices);
    }
    public void FlatBall(Location a, Color color) {
      CustomVertex.PositionOnly[] vertices = new CustomVertex.PositionOnly[4];

      int v = 0;
      double raise = 0.01;
      double radius = BallRadius;
      vertices[v++] = new CustomVertex.PositionOnly(Vec3(a.Plus(-radius, radius, raise)));
      vertices[v++] = new CustomVertex.PositionOnly(Vec3(a.Plus(-radius, -radius, raise)));
      vertices[v++] = new CustomVertex.PositionOnly(Vec3(a.Plus(radius, radius, raise)));
      vertices[v++] = new CustomVertex.PositionOnly(Vec3(a.Plus(radius, -radius, raise)));

      //vertices[0] = new CustomVertex.PositionOnly(-floorSize, floorSize, 1f);
      //vertices[1] = new CustomVertex.PositionOnly(-floorSize, -floorSize, 1f);
      //vertices[2] = new CustomVertex.PositionOnly(floorSize, floorSize, 1f);
      //vertices[3] = new CustomVertex.PositionOnly(floorSize, -floorSize, 1f);

      DXDevice.VertexFormat = CustomVertex.PositionOnly.Format;
      DXDevice.Material = Material(color);
      DXDevice.DrawUserPrimitives(PrimitiveType.TriangleStrip, 2, vertices);
    }

    public void Ball(Location a, Color color) {
      DXDevice.Material = Material(color);
      SetOriginTo(a);
      BallMesh.DrawSubset(0);
      SetOrigin();
    }

    public static Vector3 Vec3(Location loc) {
      return new Vector3((float)loc.X, (float)loc.Y, (float)loc.Z);
    }

    public void SetOriginTo(Location loc) {
      DXDevice.Transform.World = OriginTo(loc);
    }

    public static Matrix OriginTo(Location loc) {
      return Matrix.Translation(Vec3(loc));
    }

    public void SetOriginAndZOrientationTo(Location loc, Location direction) {
      DXDevice.Transform.World = OriginAndZOrientationTo(loc, direction);
    }

    public static Matrix OriginAndZOrientationTo(Location loc, Location direction) {
      Matrix transform = Matrix.Identity;
      //transform.Multiply(Matrix.RotationZ(angle));

      Location zAxis = new Location(0, 0, 1);
      Location dir = direction.Normalised();

      Location axis = dir.CrossProduct(zAxis);
      float by = (float)Math.Acos(dir.DotProduct(zAxis));
      transform.Multiply(Matrix.RotationAxis(Vec3(axis), -by));

      transform.Multiply(Matrix.Translation(Vec3(loc)));
      return transform;
    }
    public void SetOrigin() {
      SetOriginTo(new Location(0, 0, 0));
    }

    public void Status(string text) {
      Font.DrawText(null, text, 0, 0, Color.WhiteSmoke);
    }
  }
}