$appCmdPath = "$env:SystemRoot\system32\inetsrv\appcmd.exe"
$webApplicationName = "Amc76.Web";
$iteration = "0.1"
$applicationPoolName = $webApplicationName + $iteration;

function Test-ApplicationPool([string]$appPoolName)
{
    $appPool = . $appCmdPath list apppools $appPoolName
    return $appPool -ne $null
}

function Set-ApplicationPoolIdentity([string]$appPoolName, [string]$username, [string]$password)
{
    $processModel = "/[name='$appPoolName'].processModel"
    $identityParam = "$processModel.identityType:$identityType"
    $usernameParam = "$processModel.username:$username"
    $passwordParam = "$processModel.password:$password"

    . $appCmdPath set config /section:applicationPools $identityParam $usernameParam $passwordParam
}

function Get-ApplicationPool([ValidateNotNullOrEmpty()][string]$appPoolName)
{
    return . $appCmdPath list apppool $appPoolName
}

function Get-ApplicationPoolIdentity([string]$appPoolName)
{
    if (Test-ApplicationPool -appPoolName $appPoolName -eq $true)
    {
        $processModelXPath = "/system.applicationHost/applicationPools/add[@name='$appPoolName']/processModel"

        $processModel = "/[name='$appPoolName']"
        $appPools = [xml] (. $appCmdPath list config /section:applicationPools)
        $appPool = $appPools.DocumentElement.SelectSingleNode($processModelXPath)
        if ($appPool -ne $null)
        {
            $object = New-Object –TypeName PSObject
            $object |
                Add-Member –MemberType NoteProperty –Name IdentityType –Value $appPool.identityType –PassThru |
                Add-Member –MemberType NoteProperty –Name Username –Value $appPool.userName –PassThru |
                Add-Member –MemberType NoteProperty –Name Password –Value $appPool.password
            return $object
        }
    }
    return $null;
}

function New-ApplicationPool
{
    Param(
        [Parameter(Mandatory=$true)]
        [ValidateNotNullOrEmpty()]
        $Name,
        [Parameter(Mandatory=$true)]
        [ValidateNotNullOrEmpty()]
        [ValidateSet("v4.0","v2.0","None")]
        $ManagedRuntimeVersion,
        [Parameter(Mandatory=$true)]
        [ValidateNotNullOrEmpty()]
        [ValidateSet("Integrated","Classic")]
        $ManagedPipelineMode,
        [Parameter(Mandatory=$true)]
        [ValidateNotNullOrEmpty()]
        [ValidateSet("OnDemand","AlwaysRunning")]
        $StartMode
    )

    if (Test-ApplicationPool -appPoolName $Name) {
        Write-Warning "Application Pool already exists."
        return;
    }

    $runtimeVersion = $ManagedRuntimeVersion

    if ($ManagedRuntimeVersion -eq "None") {
        $runtimeVersion = "";
    }

    . $appCmdPath add apppool /name:$Name /managedRuntimeVersion:$runtimeVersion /managedPipelineMode:$ManagedPipelineMode /startMode:$StartMode
}