using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
namespace Netron.Diagramming.Core {
  /// <summary>
  /// This layout places nodes inside the visible area at a random location. The animation generated by this layout
  /// allows you to see how nodes move from one location to another. Although it seems this layout does not
  /// generate a clean organization is does help to perceive information in different perspectives and can be at times
  /// really useful.
  /// </summary>
  class RandomLayout : LayoutBase {
    #region Fields

    private const double speed = 0.1D;

    private Random rnd;
    double vectorx;
    double vectory;

    CollectionBase<IDiagramEntity> entities;
    Dictionary<IDiagramEntity, SpeedVector> speeds;
    int width;
    int height;
    int x, y;
    int time;
    BackgroundWorker worker;
    #endregion

    #region Constructor
    ///<summary>
    ///Default constructor
    ///</summary>
    public RandomLayout(IController controller)
      : base("Random layout", controller) {
    }
    #endregion

    #region Methods



    /// <summary>
    /// Runs this instance.
    /// </summary>
    public override void Run() {
      width = this.Bounds.Width;
      height = this.Bounds.Height;
      Run(DefaultRunSpan);


    }
    /// <summary>
    /// Stops this instance.
    /// </summary>
    public override void Stop() {
      if (worker != null && worker.IsBusy)
        worker.CancelAsync();
    }
    /// <summary>
    /// Runs the layout for a specified time.
    /// </summary>
    /// <param name="time">The time.</param>
    public override void Run(int time) {
      rnd = new Random();
      entities = this.Model.CurrentPage.DefaultLayer.Entities;
      speeds = new Dictionary<IDiagramEntity, SpeedVector>();
      foreach (IDiagramEntity entity in entities) {

        if (entity is IShape) {
          vectorx = -20 + 40 * rnd.NextDouble();
          vectory = -20 + 40 * rnd.NextDouble();
          speeds.Add(entity, new SpeedVector(vectorx, vectory));
        }
      }

      this.time = time;
      worker = new BackgroundWorker();
      worker.DoWork += new DoWorkEventHandler(worker_DoWork);
      worker.RunWorkerAsync(time);

    }

    void worker_DoWork(object sender, DoWorkEventArgs e) {
      DateTime start = DateTime.Now;
      while (DateTime.Now < start.AddMilliseconds((int)e.Argument)) {
        RunStep();
      }

    }

    /// <summary>
    /// Runs a single step.
    /// </summary>
    private void RunStep() {
      lock (entities)
        lock (speeds) {
          foreach (IDiagramEntity entity in entities) {

            if (entity is IShape) {

              x = Convert.ToInt32(speed * speeds[entity].X);
              y = Convert.ToInt32(speed * speeds[entity].Y);
              if (entity.Rectangle.X + x < width - entity.Rectangle.Width - 10 && entity.Rectangle.X + x > 10 && entity.Rectangle.Y + y < height - entity.Rectangle.Height - 10 && entity.Rectangle.Y + y > 10)
                entity.MoveBy(new Point(x, y));
            }
          }
        }
    }



    #endregion
  }
}