using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.Windows.Forms;

namespace Simulation  {

/// <summary>
/// SimulationModel is the simulation engine "starter kit" class.  
/// It also provides a simple visual display of directed nodes built with objects 
/// from the SimNode and SimConnector classes.
///
/// Mike Barnes  3/10/07
/// </summary>
public abstract class SimulationModel : Form {
   /// <summary>  boolean, true if directed edge is from left to right </summary>
   protected const bool leftToRight = true;
   /// <summary>  boolean, false if directed edge is from right to left </summary>
   protected const bool rightToLeft = false;
   /// <summary> The enum state of the nodes. 
   ///   IDLE nodes are light blue
   ///   BLOCKED nodes are light red
   ///   BUSY nodes are light green 
   /// </summary>
   protected enum state { IDLE, BLOCKED, BUSY };
   /// <summary> Simulation model time </summary>
   protected int now;
   /// <summary> references the SimNode last selected with a left click </summary>
   protected SimNode activeSimNode;
   /// <summary> 
   /// eventList holds the scheduled events.  
   ///   In starter kit this a generic Queue, but it should be a generic List ordered
   ///   by schedule time for the event.
   ///   eventListNode shows the server's with scheduled events.
   /// </summary>
   protected Queue<Entity> eventList;
   protected SimNode eventListNode;
   /// <summary> SimNode [] the nodes in the simulation. </summary>
   protected SimNode [] serverNode, queueNode;
   /// <summary> List of nodes in the simulation. </summary>
   protected List<SimNode> nodes;
    /// <summary> List of connectors in the simulation. </summary>
   protected List<SimConnector> connectors;
   /// <summary> The Queue collections in the simulation -- used to hold entites </summary>
   protected Queue<Entity> [] queue; 
   /// <summary> Dialog box describes this simulation demo and how to use it. </summary>
   protected About aboutDialog;
   /// <summary> Dialog box describes this simulation demo and how to use it. </summary>
   protected ReportStatistics reportDialog;
   /// <summary> MenuItems to start/pause the simulation and show usage information to user </summary>
   protected MenuItem SimulateItem, StepItem, ReportItem, AboutItem;
   /// <summary> Display messages to the user.  Left click on SimNode to see its location. </summary>
   protected StatusBar statusBar;
   /// <summary> A random number generator </summary>
   protected Random random = new Random();
   /// <summary> Timer, generates events to "demo" the simulation states. </summary>
   protected Timer timer;

   /// <summary>
   /// Construct the SimulationModel by creating:
   ///   server and queue nodes with title, location, direction, and reference to self
   ///   connector nodes with source and destination nodes and direction
   ///   timer and timer interval
   ///   menu items, statusbar, and help dialog 
   /// </summary>
   public SimulationModel() {
      
      //describes usage of this model.  Need to update about.rtf description.
      aboutDialog = new About();
      //displays, or prints, statistics about this model.  
      reportDialog = new ReportStatistics(); 
      // display of information to user in window's status bar
      statusBar = new StatusBar();
      statusBar.Location = new Point(0, 244);
      statusBar.Name = "statusBar";
      statusBar.Size = new System.Drawing.Size(536, 22);
      statusBar.Parent = this;
      statusBar.Text = "Constructor";

      // SimulationModel attributes 
      AutoScaleBaseSize = new Size(5, 13);
      BackColor = Color.White;
      ClientSize = new Size(1000, 600);
      this.Text = "Simulation Model";
      this.MouseUp += new MouseEventHandler(this.moveSimNode);

      // start / pause simulation and display aboutDialog menu items and event handlers
      SimulateItem = new MenuItem("&Simulate", new EventHandler(menuSimulateOnClick));
      
      StepItem = new MenuItem("Step 0.5 sec", new EventHandler(menuStepOnClick));
      ReportItem = new MenuItem("&Report statistics", new EventHandler(menuReportOnClick)); 
      AboutItem = new MenuItem("&About", new EventHandler(menuAboutOnClick));
      // set the menu bar
      Menu = new MainMenu(new MenuItem[] {SimulateItem,  StepItem, ReportItem, AboutItem});
      // use a timer, to step simulation of the model with its event handler timerTick method
      timer = new Timer();
      timer.Interval= 500;  // milliseconds
      timer.Tick += new EventHandler(Simulate);  
      } // end SimulationModel

      /// <summary>
      /// Property refereces the currently selected SimNode.
      /// Set initiated by a left mouse down on a SimNode. 
      /// SimNode's SimNodeMouseDown method handles left mouse down events.
      /// </summary>
      public SimNode ActiveSimNode {
         get { return activeSimNode; }
         set { activeSimNode = value; }
         }

      /// <summary>
      /// Start and pause the simulation of the model.
      /// </summary>
      /// <param name="obj"> SimulateItem </param>
      /// <param name="ea"> EventArgs</param>
      private void menuSimulateOnClick(object obj, EventArgs ea) {
         if ( ! timer.Enabled ) {
               timer.Start();
               SimulateItem.Text = "Pause Simulation";
               statusBar.Text = "Simulation running, click \"Pause Simulation\" to pause."; }
            else {
               timer.Stop();
               SimulateItem.Text = "Simulate";
               statusBar.Text = "Simulation paused, click \"Simulate\" to resume."; }
         }
         
      /// <summary>
      /// Toggle through simulation timer intervals.
      /// Displays current timer interval.
      /// </summary>
      /// <param name="obj"> AboutItem</param>
      /// <param name="ea"> EventArgs </param>
      private void menuStepOnClick(object obj, EventArgs ea) {
         if (timer.Enabled) {
            timer.Interval = (timer.Interval + 2000) % 7000;
            StepItem.Text = String.Format("Step {0:f1} sec", (float)timer.Interval/1000.0);
            }
         }
         
      /// <summary>
      /// Report, or print, stimulation statistics information to the user.
      /// </summary>
      /// <param name="obj"> ReportItem</param>
      /// <param name="ea"> EventArgs </param>
      private void menuReportOnClick(object obj, EventArgs ea) {
         reportDialog.Show();
         }      
      
      /// <summary>
      /// Display usage information to the user.
      /// </summary>
      /// <param name="obj"> AboutItem</param>
      /// <param name="ea"> EventArgs </param>
      private void menuAboutOnClick(object obj, EventArgs ea) {
         aboutDialog.Show();
         }         

      /// <summary>
      /// On Invalidates (repaints) calls OnPaint to redraw all the connectors
      /// </summary>
      /// <param name="pea"></param>
      protected override void OnPaint(PaintEventArgs pea) {
         foreach(SimConnector scm in connectors) scm.draw(pea);         
         }

      /// <summary>
      /// The drag operation on a SimNode has concluded.  Tell the morph to repostion itself.
      /// Reset the activeSimNode and redraw the display.
      /// </summary>
      /// <param name="sender"></param>
      /// <param name="e"></param>
      private void moveSimNode(object sender, MouseEventArgs e)   {
         if (ActiveSimNode != null) {
            ActiveSimNode.moveSimNode(new Point(e.X, e.Y));
            statusBar.Text = "node " + ActiveSimNode.Text + " position is " + ActiveSimNode.Location.ToString();
            ActiveSimNode = null; 
            Invalidate(); }  // redraw the display by implicitly calling OnPaint().
            }

      /// <summary>
      /// Simulation is driven by Timer.
      /// Simulate should invokes the next event's Activity() 
      /// to reflect the end of a service.
      /// </summary>
      /// <param name="obj">  The object sending the timer tick</param>
      /// <param name="ea">   Event Arguments of the timer event</param>
      protected abstract void Simulate(object obj, EventArgs ea);
      }
  }