# Function to generate a random 5-letter string
function Get-RandomString {
    param(
        [int]$length
    )

    $characters = 'abcdefghijklmnopqrstuvwxyz'
    $random = New-Object Random
    $randomString = -join (1..$length | ForEach-Object { $characters[$random.Next(0, $characters.Length)] })
    return $randomString
}

# Function to sanitize agent name
function Sanitize-AgentName {
    param(
        [string]$name
    )

    # Allow only A-Z, a-z characters
    $sanitizedName = $name -replace '[^A-Za-z]', ''
    return $sanitizedName
}

# Get and sanitize the computer name
$agentName = Sanitize-AgentName -name $env:COMPUTERNAME

# Generate a random 5-letter string and append it to the agent name
$randomString = Get-RandomString -length 5
$agentNameWithRandom = $agentName + $randomString

# Download and install Wazuh agent
Invoke-WebRequest -Uri https://packages.wazuh.com/4.x/windows/wazuh-agent-4.7.0-1.msi -OutFile "${env:temp}\wazuh-agent"
msiexec.exe /i "${env:temp}\wazuh-agent" /q WAZUH_MANAGER='41.111.227.139' WAZUH_AGENT_GROUP='default' WAZUH_AGENT_NAME="$agentNameWithRandom" WAZUH_REGISTRATION_SERVER='41.111.227.139'

# Add a delay to allow installation to complete
Start-Sleep -Seconds 10

# Get the service name
$serviceName = Get-Service | Where-Object {$_.DisplayName -like '*Wazuh*'} | Select-Object -ExpandProperty ServiceName

# Set service startup type and start service
if ($serviceName -ne $null) {
    Set-Service -Name $serviceName -StartupType Automatic
    Start-Service -Name $serviceName
} else {
    Write-Host "Wazuh service not found."
}