calendar-functions.ps1


# http://www.leeholmes.com/blog/2008/12/03/showing-calendars-in-your-oof-messages/

Function Get-Calendar {

    [cmdletbinding(DefaultParameterSetName = "month")]
    [OutputType([System.String])]
    [Alias("cal")]

    Param(
        [Parameter(Position = 1, ParameterSetName = "month")]
        [ValidateNotNullorEmpty()]
        [ValidateScript( {
                $names = Get-MonthsByCulture
                if ($names -contains $_) {
                    $True
                }
                else {
                    Throw "You entered an invalid month. Valid choices are $($names -join ',')"
                    $False
                }
            })]
        [string]$Month = (Get-Date -format MMMM),

        [Parameter(Position = 2, ParameterSetName = "month")]
        [ValidatePattern('^\d{4}$')]
        [int]$Year = (Get-Date).Year,

        [Parameter(Mandatory, HelpMessage = "Enter the start of a month like 1/1/2019", ParameterSetName = "span")]
        [ValidateNotNullOrEmpty()]
        [DateTime]$Start,

        [Parameter(Mandatory, HelpMessage = "Enter an ending date for the month like 2/1/2019", ParameterSetName = "span")]
        [ValidateNotNullOrEmpty()]
        [DateTime]$End,

        [string[]]$HighlightDate = (Get-Date).date.toString()
    )

    Begin {
        Write-Verbose "Starting $($myinvocation.MyCommand)"
        Write-Verbose "Using PowerShell version $($psversiontable.PSVersion)"
        #Call .NET for better results when testing this command in different cultures
        $currCulture = [system.threading.thread]::CurrentThread.CurrentCulture
    }
    Process {
        Write-Verbose "Using parameter set: $($pscmdlet.ParameterSetName)"
        Write-Verbose "Using culture $($currCulture.name)"
        Write-Verbose "Using PSBoundParameters"
        Write-Verbose ($PSBoundParameters | Out-String).trim()

        if ($pscmdlet.ParameterSetName -eq "month") {
            Write-Verbose "Using month $month and year $year"
            Write-Verbose "Getting start date using pattern $($currCulture.DateTimeFormat.ShortDatePattern)"

            #get month number
            $monthint = [datetime]::parse("1 $month $year").month
            $start = [datetime]::new($year, $monthint, 1)

            $end = $start.date
        }
        else {
            #Figure out the first day of the start and end months
            $start = [datetime]::new($start.year, $start.Month, 1)

            $end = [datetime]::new($end.year, $end.month, 1)

        }
        Write-Verbose "Starting at $start"
        Write-Verbose "Ending at $End"

        #Convert the highlight dates into real dates
        #using the .NET Class to parse because this works better for culture-specific datetime strings
        [DateTime[]]$highlightDates = @()
        foreach ($item in $highlightDate) {
            Write-Verbose "Parsing $(($item | Out-String).trim()) to [datetime]"
            $highlightDates += [datetime]::parse($item)
        }

        #re-add today if not one of the highlighted dates
        if ($highlightDates -notcontains ([datetime]::now).date) {
            Write-Verbose "Re-adding today to highlighted dates"
            $highlightDates += ([datetime]::now).date
        }
        write-verbose "Highlighting: $($highlightDates -join ',')"
        #Retrieve the DateTimeFormat information so that we can manipulate the calendar
        $dateTimeFormat = $currCulture.DateTimeFormat
        $firstDayOfWeek = $dateTimeFormat.FirstDayOfWeek

        Write-Verbose "First day of the week is $firstDayofWeek"

        $currentDay = $start

        Write-Verbose "Go through the requested months"
        while ($start -le $end) {
            #We may need to backpedal a bit if the first day of the month
            #falls in the middle of the week
            while ($currentDay.DayOfWeek -ne $dateTimeFormat.FirstDayOfWeek) {
                $currentDay = $currentDay.AddDays(-1)
            }

            #Prepare to store information about this date range
            Write-Verbose "Initializing currentweek"
            $currentWeek = New-Object PsObject
            $dayNames = @()
            $weeks = @()

            Write-Verbose "Go until we've hit the end of the month."
            #Even once we've done that, continue until we fill up the week
            #with days from the next month.
            while (($currentDay -lt $start.AddMonths(1)) -or
                ($currentDay.DayOfWeek -ne $dateTimeFormat.FirstDayOfWeek)) {
                #Figure out the day names we'll be using to label the columns
                $dayName = "{0:ddd}" -f $currentDay
                if ($dayNames -notcontains $dayName) {
                    $dayNames += $dayName
                }

                #Pad the day number for display, highlighting if necessary
                $displayDay = " {0,2} " -f $currentDay.Day

                #See if we should highlight a specific date
                if ($highlightDates) {
                    $compareDate = New-Object DateTime $currentDay.Year, $currentDay.Month, $currentDay.Day
                    if ($highlightDates -contains $compareDate) {
                        $displayDay = "*" + ("{0,2}" -f $currentDay.Day) + "*"
                    }
                }

                #Add in the day of week and day number as note properties.
                $currentWeek | Add-Member NoteProperty $dayName $displayDay

              # Write-Verbose "Move to the next day in the month"
                $currentDay = $currentDay.AddDays(1)

                #If we've reached the next week, store the current week
                #in the week list and continue on.
                if ($currentDay.DayOfWeek -eq $dateTimeFormat.FirstDayOfWeek) {
                    $weeks += $currentWeek
                    $currentWeek = New-Object PsObject
                }
            }

            Write-Verbose "Format our weeks into a table"
            $calendar = $weeks | Format-Table $dayNames -auto | Out-String

            Write-Verbose "Add a centered header"
            $width = ($calendar.Split("`n") | Measure-Object -Max Length).Maximum
            $header = "{0:MMMM yyyy}" -f $start
            $padding = " " * (($width - $header.Length) / 2)
            #use this line to insert a blank line before the calendar
            $displayCalendar = " `n" + $padding + $header + "`n " + $calendar

            #use this line to not insert a blank line before the calendar
            #$displayCalendar = $padding + $header + "`n " + $calendar
            $displayCalendar.TrimEnd()

            #And now move onto the next month
            $start = $start.AddMonths(1)
        }
    } #process

    End {
        Write-verbose "Ending $($myinvocation.MyCommand)"
    }
} #end Get-Calendar


#display a colorized calendar in the console

Function Show-Calendar {

    [cmdletbinding()]
    [Alias("scal")]
    Param(

        [Parameter(Position = 1, ParameterSetName = "month")]
        [ValidateNotNullorEmpty()]
        [ValidateScript( {
                $names = Get-MonthsByCulture
                #((Get-Culture).DateTimeFormat.MonthNames).Where( {$_ -match "\w+"})
                if ($names -contains $_) {
                    $True
                }
                else {
                    Throw "You entered an invalid month. Valid choices are $($names -join ',')"
                    $False
                }
            })]
        [string]$Month = (Get-Date -format MMMM),

        [Parameter(Position = 2,ParameterSetName = "month")]
        [ValidatePattern('^\d{4}$')]
        [int]$Year = (Get-Date).Year,

        [string[]]$HighlightDate = (Get-Date).date.toString(),

        [ValidateNotNullOrEmpty()]
        [consolecolor]$HighlightColor = "Green"
    )

    #add default values if not bound
    $params = "Month", "Year", "HighlightDate"
    foreach ($param in $params) {
        if (-not $PSBoundParameters.ContainsKey($param)) {
            $PSBoundParameters.Add($param, $((get-variable -Name $param).value))
        }
    }

    #remove color parameter if specified
    if ($PSBoundParameters.Containskey("HighlightColor")) {
        $PSBoundParameters.Remove("HighlightColor")
    }
    $cal = Get-Calendar @PSBoundParameters

    #turn the calendar into an array of strings
    $calarray = $cal.split("`n")

    # a regular expression pattern to match on highlighted days
    [regex]$m = "(\*)?[\s|\*]\d{1,2}(\*)?"

    #go through each line and write it back to the console using Write-Host
    foreach ($line in $calarray) {
        if ($line -match "\d{4}") {
            #write the line with the month and year
            write-Host $line -ForegroundColor Yellow
        }
        elseif ($line -match "\w{3}|-{3}") {
            #write the day names and underlines
            Write-Host $line -ForegroundColor cyan
        }
        elseif ($line -match "\*") {
            #break apart lines with asterisks
            $week = $line

            $m.Matches($week).Value| foreach-object {

                $day = "$_"

                if ($day -match "\*") {
                    write-host "$($day.replace('*','').padleft(3," ")) " -NoNewline -ForegroundColor $HighlightColor
                }
                else {
                    write-host "$($day.PadLeft(3," ")) " -nonewline
                }
            }
            write-host ""
        }
        else {
            Write-host $line
        }
    } #foreach line in calarray
} #end Show-Calendar

Function Show-GuiCalendar {
    [cmdletbinding()]
    [alias("gcal")]
    Param(
        [ValidateNotNullOrEmpty()]
        [datetime]$Start = [datetime]::new([datetime]::now.year, [datetime]::now.month, 1),
        [ValidateNotNullOrEmpty()]
        [datetime]$End = $start,
        [datetime[]]$HighlightDate,
        [ValidateSet("Segoi UI", "QuickType", "Tahoma", "Lucida Console", "Century Gothic")]
        [string]$Font = "Segoi UI",
        [ValidateSet("Normal", "Italic", "Oblique")]
        [string]$FontStyle = "Normal",
        [ValidateSet("Normal", "DemiBold", "Light", "Bold")]
        [string]$FontWeight = "Normal"
    )

    if ($psedition -eq 'Core') {
        Write-Warning "This function requires Windows PowerShell."
        #bail out
        Return
    }

    $months = do {
        $start
        $start = $start.AddMonths(1)
    } while ($start -le $end)

    if ($months.count -gt 3) {
        Write-Warning "You can't display more than 3 months at a time with this command."
        #bail out
        Return
    }


    (($myinvocation.MyCommand.ParameterSets).where( { $_.name -eq $pscmdlet.ParameterSetName })).parameters |
    Select-Object Name, @{Name = "Value"; Expression = { $pscmdlet.GetVariableValue($_.name) } } |
    Where-Object Value | foreach-object -begin { $myParams = @{ } } -process {
        $myparams.Add($_.name, $_.value)
    }

    $myparams.add("Months", $months)
    $myparams.Add("Height", (200 * $months.count))
    $myparams.Add("Title", "MyCalendar")

    Write-Verbose "Using these parameters"
    $myparams | Out-String | Write-Verbose

    $newRunspace = [RunspaceFactory]::CreateRunspace()
    $newRunspace.ApartmentState = "STA"
    $newRunspace.ThreadOptions = "ReuseThread"
    $newRunspace.Open()

    $psCmd = [PowerShell]::Create().AddScript( {

            Param (
                [datetime]$Start,
                [datetime]$End,
                [datetime[]]$HighlightDate,
                [string]$Font,
                [string]$FontStyle,
                [string]$FontWeight,
                [int]$Height,
                [string]$Title,
                [datetime[]]$Months
            )

            #add the necessary type library and bail out if there are errors
            #which probably means you are running PowerShell Core
            Try {


                #create a window form. If this fails, bail out.
                $form = New-Object System.Windows.Window

            }
            Catch {
                Write-Warning "Failed to load a required type library. $($_.exception.message)"
                #bail out
                Return
            }

            $form.AllowsTransparency = $True
            $form.WindowStyle = "none"
            #the title won't be shown when window style is set to none
            $form.Title = $Title
            $form.Height = $height
            $form.Width = 200

            $bg = new-object System.Windows.Media.SolidColorBrush

            $form.Background = $bg

            $form.Background.Color = "green"
            $form.background.Opacity = 0

            $form.Add_MouseLeftButtonDown( { $form.DragMove() })

            $form.add_KeyDown( {
                    $_.key | out-string | write-host
                    switch ($_.key) {
                        { 'Add', 'OemPlus' -contains $_ } {
                            If ($cal.Opacity -lt 1) {
                                $cal.Opacity = $cal.opacity + .1
                                $cal.UpdateLayout()
                            }
                        }
                        { 'Subtract', 'OemMinus' -contains $_ } {
                            If ($cal.Opacity -gt .2) {
                                $cal.Opacity = $cal.Opacity - .1
                                $cal.UpdateLayout()
                            }
                            write-host $cal.Opacity
                        }
                    }
                })


            $stack = $stack = New-object System.Windows.Controls.StackPanel
            $stack.Width = $form.Width
            $stack.Height = $form.Height
            $stack.HorizontalAlignment = "center"
            $stack.VerticalAlignment = "top"

            foreach ($month in $months) {
                $cal = New-Object System.Windows.Controls.Calendar
                $cal.DisplayMode = "Calendar"

                $cal.Opacity = 1
                $cal.FontFamily = $font
                $cal.FontSize = 24
                $cal.FontWeight = $FontWeight
                $cal.FontStyle = $fontStyle

                $cal.DisplayDateStart = $month

                $cal.HorizontalAlignment = "center"
                $cal.VerticalAlignment = "top"

                #$cal.SelectedDate = "9/13/2018"
                $cal.SelectionMode = "multipleRange"
                if ($highlightdate) {
                    foreach ($d in $HighlightDate) {
                        if ($d.month -eq $month.Month) {
                            $cal.SelectedDates.add($d)

                        }
                    }
                }

                $cal.add_DisplayDateChanged( {
                        # add the selected days for the currently displayed month
                        $cal | out-string | write-host
                        [datetime]$month = $cal.Displaydate
                        if ($highlightdate) {
                            foreach ($d in $HighlightDate) {
                                if ($d.month -eq $month.Month) {
                                    $cal.SelectedDates.add($d)
                                }
                            }
                        }
                        $cal.UpdateLayout()
                    })

                $stack.addchild($cal)
            }


            $btn = New-Object System.Windows.Controls.Button
            $btn.Content = "_Close"
            $btn.Width = 75
            $btn.VerticalAlignment = "Bottom"
            $btn.HorizontalAlignment = "Center"
            $btn.Opacity = 1
            $btn.Add_click( { $form.close() })

            $stack.AddChild($btn)

            $form.AddChild($stack)
            $form.ShowDialog() | out-null
        })


    $pscmd.AddParameters($myparams) | Out-Null
    $psCmd.Runspace = $newRunspace
    $psCmd.BeginInvoke() | Out-Null

}


#a helper function to retrieve names
function Get-MonthsbyCulture {
    [cmdletbinding()]
    Param([string]$Culture = ([system.threading.thread]::currentThread).CurrentCulture)
    Write-Verbose "Getting months for culture $Culture"
    [cultureinfo]::GetCultureInfo($culture).DateTimeFormat.Monthnames
}