// <copyright file="TrackMultiScaleImage.cs" company="Microsoft">

// Copyright (c) 2010 Microsoft All Rights Reserved

// </copyright>

// <author>Microsoft</author>

// <email>mischero@microsoft.com</email>

// <date>2010-01-01</date>

// <summary>Web analytics service behavior class definition</summary>



namespace Microsoft.WebAnalytics.Media

{

    using System;

    using System.Collections.ObjectModel;

    using System.ComponentModel.Composition;

    using System.Linq;

    using System.Windows;

    using System.Windows.Controls;

    using System.Windows.Interactivity;

    using System.Windows.Markup;

    using Microsoft.WebAnalytics;



    /// <summary>

    /// <img src="../media/Microsoft.WebAnalytics.Media.TrackMultiScaleImage.24x24.png"/> 

    /// Track Deep Zoom Events 

    /// </summary>

    [ContentProperty("Locations")]

    public class TrackMultiScaleImage : Behavior<MultiScaleImage>

    {

        /// <summary>

        /// Initializes a new instance of the TrackMultiScaleImage class.

        /// </summary>

        public TrackMultiScaleImage()

        {

            this.Locations = new ObservableCollection<MultiScaleImageLocation>();

        }



        #region Properties



        /// <summary>

        /// Gets the locations to track

        /// </summary>

        public ObservableCollection<MultiScaleImageLocation> Locations { get; private set; }



        /// <summary>

        /// Gets or sets the event Logging method

        /// </summary>

        [Import("Log")]

        public Action<AnalyticsEvent> Log { get; set; }

        #endregion



        #region Methods

        /// <summary>

        /// Attach events and initialize parts

        /// </summary>

        protected override void OnAttached()

        {

            base.OnAttached();



#if WINDOWS_PHONE

            CompositionInitializer.SatisfyImports(this);

#else

            PartInitializer.SatisfyImports(this);

#endif



            this.AssociatedObject.ViewportChanged += new RoutedEventHandler(this.OnViewportChanged);

        }



        /// <summary>

        /// Detach events

        /// </summary>

        protected override void OnDetaching()

        {

            base.OnDetaching();



            this.AssociatedObject.ViewportChanged -= new RoutedEventHandler(this.OnViewportChanged);

        }



        #endregion



        #region Implementation

        /// <summary>

        /// Use the Pythagorean Theorum to get the distance between two points

        /// </summary>

        /// <param name="p1">the first point</param>

        /// <param name="p2">the second point</param>

        /// <returns>the distance between the two points</returns>

        private static double Distance(Point p1, Point p2)

        {

            return Math.Sqrt(Math.Pow(p1.X - p2.X, 2) + Math.Pow(p1.Y - p2.Y, 2));

        }



        /// <summary>

        /// Viewport changed event handler

        /// </summary>

        /// <param name="sender">the multiscale image</param>

        /// <param name="e">the routed event argument</param>

        private void OnViewportChanged(object sender, RoutedEventArgs e)

        {

            var hitLocations = from location in this.Locations

                               where Math.Abs(this.AssociatedObject.ViewportWidth - location.ViewportWidth) <= location.WidthTolerance &&

                                    Distance(this.AssociatedObject.ViewportOrigin, location.ViewportOrigin) <= location.OriginTolerance

                               select new AnalyticsEvent()

                               {

                                   EventArgs    = location.CustomProperties,

                                   Name         = "LocationNear",

                                   ObjectName   = this.AssociatedObject.Name,

                                   ObjectType   = this.AssociatedObject.GetType().ToString(),

                                   ActionValue  = location.Name,

                               };



            foreach (var logEvent in hitLocations)

            {

                this.Log(logEvent);

            }

        }



        #endregion

    }

}