Edit nessus scan details, including schedule, name, and policy data, extracted of Scan.ps1 from Posh-Nessus

Edit-NessusScanDetail.ps1

<#
.Synopsis
   Edit nessus scan details, including schedule, name, and policy data
.DESCRIPTION
   Long description
.EXAMPLE
   Example of how to use this cmdlet
.EXAMPLE
   Another example of how to use this cmdlet
#>
function Edit-NessusScanDetail
{
    [CmdletBinding()]
    Param
    (
        # Nessus session Id
        [Parameter(Mandatory=$true,
                   Position=0,
                   ValueFromPipelineByPropertyName=$true)]
        [Alias('Index')]
        [int32[]]
        $SessionId = @(),

        [Parameter(Mandatory=$true,
                   Position=1,
                   ValueFromPipelineByPropertyName=$true)]
        [int32]
        $ScanId,
        [String]$Name,
        [String]$Description,
        [Int]$PolicyID,
        [Int]$FolderID,
        [Int]$ScannerID,
        [Bool]$Enabled = $true,
        [ValidateSet('Onetime','Daily','Weekly','Monthly','Yearly')]$Frequency,
        [Int]$Interval,
        [String[]]$ByDay,
        [ValidateSet('Day of Month','Week of Month')][String]$RepeatBy,
        [String]$Timezone=([System.TimeZoneInfo]::Local).Id,
        [datetime]$StartTime,
        [String[]]$TargetGroups,
        [String[]]$AgentGroups,
        [String[]]$TextTargets,
        [String]$FileTargets,
        [String[]]$Emails
    )

    Begin
    {
        # Return the day and week of a date (1st Tuesday is 1TU, 3rd Wednesday is 3WE, etc.)
        Function Get-WeekDay {
            Param([datetime]$DateTime)
            if ($DateTime.Day -le 7) {
                $week = 1
            }
            else {
                $week = (1..$DateTime.Day).ForEach{
                    Get-Date "$($DateTime.Year)-$($DateTime.Month)-$_"
                }.Where{$_.DayOfWeek -eq $DateTime.DayOfWeek}.Count
            }
            "$week$($DateTime.DayOfWeek.ToString().Substring(0,2))".ToUpper()
        }
        $origin = New-Object -Type DateTime -ArgumentList 1970, 1, 1, 0, 0, 0, 0
    }
    Process
    {
        $ToProcess = @()

        foreach($i in $SessionId)
        {
            $Connections = $Global:NessusConn

            foreach($Connection in $Connections)
            {
                if ($Connection.SessionId -eq $i)
                {
                    $ToProcess += $Connection
                }
            }
        }

        foreach($Connection in $ToProcess)
        {
            $ScanDetails =  InvokeNessusRestRequest -SessionObject $Connection -Path "/scans/$($ScanId)" -Method 'Get' -Parameter $Params

            if ($ScanDetails -is [psobject])
            {
                # Set the rrules based on the frequency type
                switch ($Frequency) {
                    'Onetime' {
                        $rRules = 'FREQ=ONETIME'
                    }
                    'Daily' {
                        $rRules = "FREQ=$Frequency;INTERVAL=$Interval"
                    }
                    'Weekly' {
                        if (!$ByDay) {$ByDay = $StartTime.DayOfWeek.ToString().Substring(0,2)}
                        $rRules = "FREQ=$Frequency;INTERVAL=$Interval;BYDAY=$($ByDay -join ',')"
                    }
                    'Monthly' {
                        switch ($RepeatBy) {
                            'Day of Month' {
                                $rRules = "FREQ=$Frequency;INTERVAL=$Interval;BYMONTHDAY=$($StartTime.Day)"
                            }
                            'Week of Month' {
                                $byDay = Get-WeekDay $StartTime
                                $rRules = "FREQ=$Frequency;INTERVAL=$Interval;BYDAY=$ByDay"
                            }
                        }
                    }
                }

                # Set the 'static' settings
                $settings = @{
                    enabled = $enabled
                    timezone = $Timezone
                }

                # If no targets are specified, use the targets from the previous scan
                if (!($TargetGroups -or $AgentGroups -or $FileTargets -or $TextTargets)) {
                    $TextTargets = $ScanDetails.info.targets
                }

                # Set the 'dynamic' parameters. If these items are not sent to the API, they will remain unchanged
                if ($Name) {$settings.name = $Name}
                if ($Description) {$settings.description = $Description}
                if ($PolicyID) {$settings.policy_id = $PolicyID}
                if ($FolderID) {$settings.folder_id = $FolderID}
                if ($ScannerID) {$settings.scanner_id = $ScannerID}
                if ($rRules) {$settings.rrules = $rRules.ToUpper()}
                if ($StartTime) {$settings.starttime = $StartTime.ToString('yyyyMMddTHHmmss')}
                if ($rRules -and $Frequency -notlike 'Onetime') {$settings.launch = $Frequency.ToUpper()}
                if ($LaunchNow) {$settings.launch_now = $true}
                if ($TargetGroups) {$settings.target_groups = $TargetGroups}
                if ($AgentGroups) {$settings.agent_groups = $AgentGroups}
                if ($TextTargets) {$settings.text_targets = $TextTargets -join ','}
                if ($FileTargets) {$settings.file_targets = $FileTargets}
                if ($Emails) {$settings.emails = $Emails -join ','}

                # Convert the settings to JSON format for use by the API
                $scanParams = @{
                    settings = $settings
                }
                $json = ConvertTo-Json -InputObject $scanParams -Compress
                $ServerTypeParams = @{
                     'SessionObject' = $Connection
                     'Path' = "/scans/$ScanId"
                     'Method' = 'PUT'
                     'ContentType' = 'application/json'
                     'Parameter' = $json
                }
                InvokeNessusRestRequest @ServerTypeParams
            }
        }
    }
    End{}
}