Imports System.Drawing
Imports System.Runtime.InteropServices
Imports System.Text
Imports System.Windows.Forms
Imports DigitalData.Modules.Logging

Public Class Window
    Private _Logger As Logger

    Public Enum Anchor
        TopLeft
        BottomLeft
        TopRight
        BottomRight
    End Enum

    Public Class RectangleInfo
        Public Top As Integer = 0
        Public Left As Integer = 0
        Public Right As Integer = 0
        Public Bottom As Integer = 0

        Public Overrides Function ToString() As String
            Return String.Format("Top:{0},Left:{1},Bottom:{2},Right:{3}", Top, Left, Bottom, Right)
        End Function
    End Class

    Public Class WindowInfo
        Public WindowTitle As String = ""
        Public ProcessName As String = ""
        Public ClassName As String = ""
        Public ProcessId As Integer = 0
        Public ControlName As String = ""
        Public hWnd As IntPtr = IntPtr.Zero
    End Class

    Public Sub New(LogConfig As LogConfig)
        _Logger = LogConfig.GetLogger()
    End Sub

    ''' <summary>
    ''' Returns Information about the currently focused window
    ''' </summary>
    Public Function GetWindowInfo() As WindowInfo
        Try
            Dim hWnd As IntPtr = NativeMethods.GetForegroundWindow()
            Return GetWindowInfo(hWnd)
        Catch ex As Exception
            _Logger.Debug("Error in GetWindowInfo/0")
            _Logger.Error(ex)
            Throw ex
        End Try
    End Function

    ''' <summary>
    ''' Returns Information about the Window with `hWnd`
    ''' </summary>
    Public Function GetWindowInfo(ByVal hWnd As IntPtr) As WindowInfo
        Try
            Dim oPID As Integer = 0
            Dim oTitleLength As Int32 = NativeMethods.GetWindowTextLength(hWnd)
            Dim oWindowTitle As String = StrDup(oTitleLength + 1, "*")
            Dim oClassBuilder As New StringBuilder(64)

            NativeMethods.GetWindowText(hWnd, oWindowTitle, oTitleLength + 1)
            NativeMethods.GetWindowThreadProcessId(hWnd, oPID)

            If oPID = 0 Then
                Return Nothing
            End If

            Dim oProcess As Process = Process.GetProcessById(oPID)

            If oProcess Is Nothing Then
                Return Nothing
            End If

            NativeMethods.GetClassName(hWnd, oClassBuilder, 64)

            Return New WindowInfo With {
                .hWnd = hWnd,
                .ClassName = oClassBuilder.ToString,
                .ProcessId = oProcess.Id,
                .ProcessName = oProcess.ProcessName,
                .WindowTitle = oWindowTitle.Replace(vbNullChar, String.Empty)
            }
        Catch ex As Exception
            _Logger.Debug("Error in GetWindowInfo/1")
            _Logger.Error(ex)
            Throw ex
        End Try
    End Function

    ''' <summary>
    ''' Returns the currently focused control
    ''' </summary>
    ''' <param name="WindowHandle">Current window handle; can be obtained from Me.Handle</param>
    Public Function GetFocusedControl(WindowHandle As IntPtr) As WindowInfo
        Try
            Dim oWindow = GetWindowInfo()

            If oWindow Is Nothing Then
                _Logger.Debug("Could not get Window Info!")
                Return Nothing
            End If

            Dim oThreadId As IntPtr = NativeMethods.GetWindowThreadProcessId(oWindow.hWnd, 0)
            Dim oMyThreadId As IntPtr = NativeMethods.GetWindowThreadProcessId(WindowHandle, 0)

            If NativeMethods.AttachThreadInput(oThreadId, oMyThreadId, True) Then
                Try
                    Dim oControlhWnd = NativeMethods.GetFocus()
                    Dim oControl As WindowInfo = GetWindowInfo(oControlhWnd)

                    If oControl Is Nothing Then
                        _Logger.Debug("Could not get Control Info!")
                        Return Nothing
                    End If

                    Dim oName = Utils.GetWinFormsId(oControlhWnd)
                    oControl.ControlName = oName


                    Return oControl
                Catch ex As Exception
                    _Logger.Error(ex)
                Finally
                    NativeMethods.AttachThreadInput(oThreadId, oMyThreadId, False)
                End Try
            End If

            Return Nothing
        Catch ex As Exception
            _Logger.Debug("Error in GetFocusedControl/1")
            _Logger.Error(ex)
            Throw ex
        End Try
    End Function

    ''' <summary>
    ''' Returns Bounds of `ControlHandle`. Relative to `WindowHandle` and `Anchor` value.
    ''' </summary>
    Public Function GetControlLocation(ControlHandle As IntPtr, WindowHandle As IntPtr, Optional Anchor As Anchor = Anchor.TopLeft) As RectangleInfo
        Dim oWindowRect As New NativeMethods.RectangleAPI
        Dim oControlRect As New NativeMethods.RectangleAPI
        Dim oResult As New RectangleInfo

        _Logger.Debug("Getting Control Location")

        Try
            _Logger.Debug("Trying to get Window Rectangle")
            If NativeMethods.GetWindowRect(New HandleRef(Me, WindowHandle), oWindowRect) = False Then
                Return Nothing
            End If

            _Logger.Debug("Trying to get Control Rectangle")
            If NativeMethods.GetWindowRect(New HandleRef(Me, ControlHandle), oControlRect) = False Then
                Return Nothing
            End If

            Dim oRect As New NativeMethods.RectangleAPI

            ' Calculate Coordinates relative to parent window
            oRect = GetRelativeRectangle(oControlRect, oWindowRect, Anchor)

            _Logger.Debug("Control Location for Anchor {0}: {1}", Anchor, oRect)

            oResult.Left = oRect.Left
            oResult.Right = oRect.Right
            oResult.Top = oRect.Top
            oResult.Bottom = oRect.Bottom

            Return oResult
        Catch ex As Exception
            _Logger.Debug("Error in GetControlLocation/3")
            _Logger.Error(ex)
            Throw ex
        End Try
    End Function

    Public Function GetControlLocations(ControlHandle As IntPtr, WindowHandle As IntPtr) As Dictionary(Of String, RectangleInfo)
        Dim oWindowRect As New NativeMethods.RectangleAPI
        Dim oControlRect As New NativeMethods.RectangleAPI
        Dim oResults As New Dictionary(Of String, RectangleInfo)

        _Logger.Debug("Getting Control Locations")

        Try
            _Logger.Debug("Trying to get Window Rectangle")
            If NativeMethods.GetWindowRect(New HandleRef(Me, WindowHandle), oWindowRect) = False Then
                Return Nothing
            End If

            _Logger.Debug("Trying to get Control Rectangle")
            If NativeMethods.GetWindowRect(New HandleRef(Me, ControlHandle), oControlRect) = False Then
                Return Nothing
            End If


            For Each oAnchor As Anchor In [Enum].GetValues(GetType(Anchor))
                Dim oRect As NativeMethods.RectangleAPI = GetRelativeRectangle(oControlRect, oWindowRect, oAnchor)

                _Logger.Debug("Control Location for Anchor {0}: {1}", oAnchor, oRect)

                oResults.Add(oAnchor.ToString, New RectangleInfo() With {
                    .Left = oRect.Left,
                    .Right = oRect.Right,
                    .Top = oRect.Top,
                    .Bottom = oRect.Bottom
                })
            Next

            Return oResults
        Catch ex As Exception
            _Logger.Debug("Error in GetControlLocations/2")
            _Logger.Error(ex)
            Throw ex
        End Try
    End Function

    ''' <summary>
    ''' Returns Bounds of the focused control. Relative to current form and `Anchor` value.
    ''' </summary>
    Public Function GetFocusedControlLocation(WindowHandle As IntPtr, Anchor As Anchor) As RectangleInfo
        Dim oForegroundWindow As WindowInfo
        Dim oFocusedControl As WindowInfo

        Try
            oForegroundWindow = GetWindowInfo()
            oFocusedControl = GetFocusedControl(WindowHandle)

            If IsNothing(oForegroundWindow) Then
                _Logger.Debug("Foreground Window is nothing!")
            End If

            If IsNothing(oFocusedControl) Then
                _Logger.Debug("Focused Contol is nothing!")
            End If

            _Logger.Debug("Control Handle: {0}", oFocusedControl.hWnd)
            _Logger.Debug("Window Handle: {0}", oForegroundWindow.hWnd)

            Return GetControlLocation(oFocusedControl.hWnd, oForegroundWindow.hWnd, Anchor)
        Catch ex As Exception
            _Logger.Debug("Error in GetFocusedControlLocation/2")
            _Logger.Error(ex)
            Throw ex
        End Try
    End Function

    Public Function GetFocusedControlLocation(WindowHandle As IntPtr) As Dictionary(Of String, RectangleInfo)
        Dim oForegroundWindow As WindowInfo
        Dim oFocusedControl As WindowInfo

        Try
            oForegroundWindow = GetWindowInfo()
            oFocusedControl = GetFocusedControl(WindowHandle)

            If oForegroundWindow Is Nothing Then
                _Logger.Warn("Foreground Window is Nothing!")
            End If

            If oFocusedControl Is Nothing Then
                _Logger.Warn("Focused Control is Nothing!")
            End If

            Dim oDict As Dictionary(Of String, RectangleInfo) = GetControlLocations(oFocusedControl.hWnd, oForegroundWindow.hWnd)

            Return oDict
        Catch ex As Exception
            _Logger.Debug("Error in GetFocusedControlLocation/1")
            _Logger.Error(ex)
            Throw ex
        End Try
    End Function

    ''' <summary>
    ''' Returns Bounds of the control under the cursor. Relative to current form and `Anchor` value.
    ''' </summary>
    Public Function GetHoveredControlLocation(Optional Anchor As Anchor = Anchor.TopLeft) As RectangleInfo
        Dim oPoint As New NativeMethods.PointAPI
        Dim oWindowRect As New NativeMethods.RectangleAPI
        Dim oControlRect As New NativeMethods.RectangleAPI
        Dim oForegroundWindow As IntPtr
        Dim oControlUnderCursor As IntPtr
        Dim oResult As New RectangleInfo

        Try
            If NativeMethods.GetCursorPos(oPoint) = False Then
                Return Nothing
            End If

            oForegroundWindow = NativeMethods.GetForegroundWindow()
            oControlUnderCursor = NativeMethods.WindowFromPoint(oPoint)

            Return GetControlLocation(oControlUnderCursor, oForegroundWindow, Anchor)
        Catch ex As Exception
            _Logger.Debug("Error in GetHoveredControlLocation/1")
            _Logger.Error(ex)
            Throw ex
        End Try
    End Function

    Public Function GetWindowRect(Handle As IntPtr)
        Try
            Dim oWindowRect As New NativeMethods.RectangleAPI

            If NativeMethods.GetWindowRect(New HandleRef(Me, Handle), oWindowRect) = False Then
                Return Nothing
            End If

            Return oWindowRect
        Catch ex As Exception
            _Logger.Debug("Error in GetWindowRect/1")
            _Logger.Error(ex)
            Throw ex
        End Try
    End Function

    Private Function GetRelativeRectangle(ControlRect As NativeMethods.RectangleAPI, WindowRect As NativeMethods.RectangleAPI, Anchor As Anchor) As NativeMethods.RectangleAPI
        Try
            Dim oScreenRect As Rectangle = Screen.PrimaryScreen.Bounds
            Dim oLeft, oBottom, oTop, oRight As Integer

            _Logger.Debug("Calculating Rectangle for Anchor {0}", Anchor.ToString)

            Select Case Anchor
                Case Anchor.TopLeft
                    oLeft = ControlRect.Left - WindowRect.Left
                    oTop = ControlRect.Top - WindowRect.Top
                Case Anchor.BottomLeft
                    oLeft = ControlRect.Left - WindowRect.Left
                    oBottom = ControlRect.Bottom - WindowRect.Bottom
                Case Anchor.TopRight
                    oRight = ControlRect.Right - WindowRect.Right
                    oTop = ControlRect.Top - WindowRect.Top
                Case Anchor.BottomRight
                    oRight = ControlRect.Right - WindowRect.Right
                    oBottom = ControlRect.Bottom - WindowRect.Bottom
            End Select

            _Logger.Debug("Done Calculating Rectangle for Anchor {0}", Anchor.ToString)

            Return New NativeMethods.RectangleAPI() With {
                .Top = oTop,
                .Bottom = oBottom,
                .Left = oLeft,
                .Right = oRight
            }
        Catch ex As Exception
            _Logger.Debug("Error in GetRelativeRectangle/3")
            _Logger.Error(ex)
            Throw ex
        End Try
    End Function

    Private Function GetRect(Rect As NativeMethods.RectangleAPI, ParentRect As NativeMethods.RectangleAPI) As Rectangle
        Try
            Dim oX, oY, oWidth, oHeight As Integer

            oWidth = Rect.Right - Rect.Left
            oHeight = Rect.Bottom - Rect.Top
            oX = Rect.Left - ParentRect.Left
            oY = Rect.Top - ParentRect.Top

            Return New Rectangle(oX, oY, oWidth, oHeight)
        Catch ex As Exception
            _Logger.Debug("Error in GetRect/2")
            _Logger.Error(ex)
            Throw ex
        End Try
    End Function

    Private Function GetRect(Rect As NativeMethods.RectangleAPI, ParentRect As Rectangle) As Rectangle
        Try
            Dim oX, oY, oWidth, oHeight As Integer

            oWidth = Rect.Right - Rect.Left
            oHeight = Rect.Bottom - Rect.Top
            oX = Rect.Left - ParentRect.X
            oY = Rect.Top - ParentRect.Y

            Return New Rectangle(oX, oY, oWidth, oHeight)
        Catch ex As Exception
            _Logger.Debug("Error in GetRect/2")
            _Logger.Error(ex)
            Throw ex
        End Try
    End Function
End Class