# ___ ___ _____ ___
#| _ \ _ \_   _/ __|
#|  _/   / | || (_ |
#|_| |_|_\ |_| \___|
#    NETWORK MONITOR
#-------------------
# Description: Monitors if a login on a website with a HTML login form works properly
# Parameters:
# -URL: The URL to the login form
# -Username: A valid username for the page
# -Password: The user's password
# -FormId: The ID of the login form
# -UsernameID: The CSS ID of the username field
# -PasswordID: The CSS ID of the password field
# -CheckString: A string element that only occurs if the login worked

# ------------------
# (c) 2017 Stephan Linke | Paessler AG
Param(
    [string]$url = "www.acme.com",
    [string]$logout = "www.acme.com/logout",
    [string]$username="<login>",
    [string]$password="<password>",
    [int]$formId = 0,
    [string]$usernameId = "username",
    [string]$passwordId = "password",
    [string]$checkString = "Abmelden"
)

$loginPage = (Invoke-WebRequest -Uri  "$url" -SessionVariable PRTG)
Start-Sleep 1


$LoginForm = $loginPage.Forms[$formId];
$LoginForm.Fields[$usernameId] = $username;
$LoginForm.Fields[$passwordId] = $password;
$LoginForm.Fields['body_0_content_0_sectioned_0_SignInButton'] = "Sign In";

$result = (Invoke-WebRequest -Uri ($url) -WebSession $PRTG -Method POST -Body $LoginForm.Fields)

if($result.Content.Contains($checkString))
{
    Write-Host "0:Login successful - '$($Checkstring)' found.";
    # Logout
    Invoke-WebRequest -Uri $logout -SessionVariable PRTG | Out-Null;
    Remove-Variable PRTG;
    exit 0;

}
else
{
    Write-Host "0:Login failed or checkstring not found. Please check the check if the username/password combination and the checkstring is correct!";
    # Logout
    Invoke-WebRequest -Uri $logout -SessionVariable PRTG | Out-Null;
    Remove-Variable PRTG;
    exit 1;
}