''' <summary>
    ''' General class for demo
    ''' </summary>
    ''' <remarks>Note: you would want to seperate the logic out into seperate classes (tiers)
    ''' in a real world application
    ''' </remarks>
    Public NotInheritable Class MatchMaker
        ''' <summary>
        ''' </summary>
        ''' <remarks>Don't instantiate</remarks>
        Private Sub New()

        End Sub

            

       
        
        ''' <summary>
        ''' Get all the data we have in our simulated database. We would normally keep all this
        ''' information in a database. But this is fine for the demo.
        ''' </summary>
        ''' <returns>A list of tracks an associated user ID's</returns>
        ''' <remarks>Just hard coding values for the demo</remarks>
        Public Shared Function GetAllMusic() As IEnumerable

            Dim databasePath = HttpContext.Current.Server.MapPath("App_Data") + "/userdb.xml"

            If System.IO.File.Exists(databasePath) Then

                Dim userdb = XDocument.Load(databasePath)

                ' Just return a list of our simulated users
                Dim dbSongs = From s In userdb...<song> _
                              Order By s.<UserID>.Value _
                              Select _
                                s.<UserID>.Value, _
                                s.<track>.Value

                Return dbSongs
            Else
                Return Nothing
            End If
        End Function

            

       
        
        ''' <summary>
        ''' Process the uploaded file and get the top tracks baced on how often they
        ''' are played. In a real world we perform this processing offline.
        ''' </summary>
        ''' <param name="iTunesFile">The file location of the uploaded iTunes file</param>
        ''' <returns>A list of top songs for that user</returns>
        ''' <remarks>We are only taking the bare minimun information for this example.
        ''' Note how LINQ feturns a generic list of anonymous types without us having to
        ''' create a class definition for this ;-)
        ''' </remarks>
        Public Shared Function GetUsersTopTracks(ByVal iTunesFile As String) As IEnumerable

            If System.IO.File.Exists(iTunesFile) Then
                Dim iTunes = XDocument.Load(iTunesFile)

                ' Drill into the iTunes XML structure to get the music information
                ' Transform it into a more meaningful XML structure
                Dim tracks = From t In iTunes.<plist>.<dict>.<dict>.<dict> _
                             Select New XElement("song", _
                                 From key In t.<key> _
                                 Select New XElement(key.Value.ToString.Replace(" ", ""), _
                                 CType(key.NextNode, XElement).Value.ToString))

                ' Get the top 25 most played songs
                Dim topTracks = From song In tracks _
                                Order By song.<PlayCount>.Value Descending _
                                Take (25) _
                             Select _
                                Artist = song.<Artist>.Value, _
                                TrackName = song.<Name>.Value

                Return topTracks
            Else
                Return Nothing
            End If

        End Function

       
Namespace Bracora.Demo
    Public Class MatchedEntry
        Public Sub New()
        End Sub

        Private _userID As String
        Public Property UserId() As String
            Get
                Return _userID
            End Get
            Set(ByVal value As String)
                _userID = value
            End Set
        End Property

        Private _trackName As String
        Public Property TrackName() As String
            Get
                Return _trackName
            End Get
            Set(ByVal value As String)
                _trackName = value
            End Set
        End Property

    End Class
End Namespace                                     

       
                                            
        ''' <summary>
        ''' Attempts to find the most matched user based on checking their music information
        ''' against the music information we have in our simulated database
        ''' </summary>
        ''' <param name="userTracks">A list of user tracks to match</param>
        ''' <param name="dbTracks">A list of music tracks against users we have in our 'database'</param>
        ''' <returns>The best matched userID or nothing for no matches</returns>
        ''' <remarks>Don't try this at home. Honestly there are much better ways to do this!</remarks>
        Public Shared Function GetTopMatchedUser(ByVal userTracks As IEnumerable, _
                                                 ByVal dbTracks As IEnumerable) As Object

            ' contains a list of non-unique userIDs when songs are matched
            Dim MusicMatches As New Generic.List(Of MatchedEntry)
            Dim Match As MatchedEntry = Nothing

            ' loop round each of the users favourite tracks and try to match this
            ' against the list of tracks we have in our  simulated database. If
            ' a match occurs the add the userId. The more instances of that userId
            ' then the more music they have in common.
            For Each track In userTracks
                For Each song In dbTracks
                    If track.TrackName = song.track Then
                        Match = New MatchedEntry()
                        Match.UserId = song.UserID
                        Match.TrackName = song.track
                        MusicMatches.Add(Match)
                    End If
                Next
            Next

            ' Group by the userID and then work out the count for each one
            Dim top = From u In MusicMatches _
                        Group By u.UserId Into g = Group _
                        Order By g.Count() Descending _
                      Select _
                            UserId, _
                            NumberOfMatches = g.Count()

            If top.Count() > 0 Then

                Dim topMatchedUser = top.First()

                ' Get the matched songs based on the userId
                Dim matchedSongs = From u In MusicMatches _
                                    Where u.UserId = topMatchedUser.UserId _
                                   Select u.TrackName Distinct

                Dim MatchedUser = New With {.User = topMatchedUser.UserId, .Songs = matchedSongs.ToArray}

                Return MatchedUser

            End If

            Return Nothing
        End Function

                                            

       
       
        ''' <summary>
        ''' Main entry point for the demo and controller 
        ''' </summary>
        ''' <remarks></remarks>
        Public Shared Function FindMeMyMatch(ByVal fileName As String) As Object

            Dim userSongs As IEnumerable = GetUsersTopTracks(fileName)
            Dim allUsersSongs As IEnumerable = GetAllMusic()

            Return GetTopMatchedUser(userSongs, allUsersSongs)

        End Function
 
           

       

        <!-- need to increase the size of the permitted upload size -->
        <httpRuntime maxRequestLength="20480" />

       
    Protected Sub btnUpload_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnUpload.Click
        Dim savePath As String = HttpContext.Current.Server.MapPath("uploads") + "/"

        If (FileUpload1.HasFile) Then
            'make sure it's an XML file
            If (FileUpload1.PostedFile.ContentType.ToLower <> "text/xml") Then
                message.Text = "This is not a valid iTunes file. Please make sure you upload the proper file."
                Exit Sub
            End If

            ' create a unique name for the uploaded file.
            Dim fileName As String = Guid.NewGuid().ToString + ".xml"

            ' Append the name of the file to upload to the path.
            savePath += fileName

            FileUpload1.SaveAs(savePath)

            Dim MyMatch = Bracora.Demo.MatchMaker.FindMeMyMatch(savePath)
            Dim HeaderText As String = String.Empty
            Dim ImageOfMatchedUserUrl As String = String.Empty
            Dim DisplaySongs As String = String.Empty
            If MyMatch IsNot Nothing Then
                Select Case MyMatch.User
                    Case "1"
                        ImageOfMatchedUserUrl = "App_Themes/Standard/images/user1.jpg"
                    Case "2"
                        ImageOfMatchedUserUrl = "App_Themes/Standard/images/user2.jpg"
                    Case "3"
                        ImageOfMatchedUserUrl = "App_Themes/Standard/images/user3.jpg"
                    Case Else
                        ImageOfMatchedUserUrl = "App_Themes/Standard/images/user4.jpg"
                End Select

                For i As Int32 = 0 To MyMatch.Songs.Length() - 1
                    DisplaySongs += String.Format("<li>{0}</li>", MyMatch.Songs(i))
                Next
                HeaderText = String.Format("<h3>{0}</h3>", "Success, we found a match!")
            Else
                ' No matches show the user who has been waiting longest :-)
                ImageOfMatchedUserUrl = "App_Themes/Standard/images/user4.jpg"
                DisplaySongs = String.Format("<li>{0}</li>", "You have no songs in common, here is your closest match")
                HeaderText = String.Format("<h3>{0}</h3>", "No luck I'm afraid!")
            End If

            Me.headerMatch.Text = HeaderText
            Me.songList.Text = DisplaySongs
            imageOfMatchedUser.ImageUrl = ImageOfMatchedUserUrl
            imageOfMatchedUser.Visible = True
        Else
            ' Error message for no file
            message.Text = "<p class=""error"">You did not specify an iTunes file to upload.</p>"
        End If
    End Sub