<#
.SYNOPSIS
Instructional demonstration

.DESCRIPTION
This script demonstrates the following:
    How to structure a switch statement
    How to nest a switch statement in a while loop
    How to use exception handling for general and specific error types
    How to write and document a function
    How to implement Comment Based Help

.INPUTS
None

.OUTPUTS
Outputs the selected option to the screen

.EXAMPLE
PS> ......

.NOTES
Author:
StudentID:
Date:
#>

Function Get-UserInput{
    <#
    .SYNOPSIS
    Function to display menu and collect user input
    .DESCRIPTION
    The function uses a StringBuilder to build and display
    the menu that is presented to the user. It then returns
    the results of the Read-Host command.
    #>

    $Menu = New-Object -TypeName System.Text.StringBuilder
    [void]$Menu.AppendLine("...  Task 1 ...")
    [void]$Menu.AppendLine("-------------------")
    [void]$Menu.AppendLine("1. This will list all log files in requirements1 folder, with current date preceeding.")
    [void]$Menu.AppendLine("2. This will list all files in requirements1 folder in tabular format, ascending alphabetical order, in a file called c916contents.txt")
    [void]$Menu.AppendLine("3. This will current CPU and Memory Usage.")
    [void]$Menu.AppendLine("4. This will list all running processes within system, by virtual size least to greatest, in grid format.")
    [void]$Menu.AppendLine("5. Exit Script.")
    [void]$Menu.AppendLine("6. This will cause an error on purpose to test exception handling")
    [void]$Menu.AppendLine("-------------------")
    Write-Host -ForegroundColor Cyan $Menu.ToString()
    return $(Write-Host -ForegroundColor Cyan ">> Select a command (1-6):"; Read-Host)
}

#Variable to hold user input
$UserInput = 1
Try{
    while ($UserInput -ne 6)
    {
        # Prompt for User Input
        $UserInput = Get-UserInput
        # Run specfic code based on User Input
         switch ($UserInput)
        {
                    1 # User chose option 1
                    {
                        #This will list all log files in requirements1 folder, with current date preceeding
                        Write-Host "Attempting to run Option 1"
                        "Timestamp: " + (Get-Date) | Out-File -FilePath $PSScriptRoot\DailyLog.txt -Append
                        Get-ChildItem -Path $PSScriptRoot -Filter *.log | Out-File -FilePath $PSScriptRoot\DailyLog.txt -Append
                    }

                    2 # User chose option 2
                    {
                         #This will list all files in requirements1 folder in tabular format, ascending alphabetical order, in a file called c916contents.txt
                         Get-ChildItem "$PSScriptRoot" | Sort-Object Name | Format-Table -AutoSize -Wrap | Out-File "$PSScriptRoot\C916Contents.txt"
                    }

                    3 # User chose option 1
                    {
                        #This will current CPU and Memory Usage
                        $CounterList = "\Processor(_Total)\% Processor Time", "\Memory\Committed Bytes"
                        Get-Counter -Counter $CounterList -MaxSamples 4 -SampleInterval 5
                    }

                    4
                    {
                        #This will list all running processes within system, by virtual size least to greatest, in grid format
                        Get-Process | Select-Object ID, Name, VM | Sort-Object Name | Out-GridView
                    }

                    5 # User chose option 5
                    {
                        #Quit
                        Write-Host -ForegroundColor Red "Exiting Script"
                    }

        }
    }
}
#Catch a specific error type
Catch[System.OutOfMemoryException]
{
        Write-Host -ForegroundColor Red "An Error Occurred."
        Write-Host -ForegroundColor Red "$($PSItem.ToString())'n'n$($PSItem.ScriptStackTrace)"
}
Finally
{
    # Close any open resources
    # This code runs right before script ends
}