param(
    [Parameter(Mandatory=$false)][int]$CUSTOMER_ID=1,
    [Parameter(Mandatory=$false)][string]$INTEGRATOR_ID,
    [Parameter(Mandatory=$false)][string]$AGENT_FILENAME="AteraAgentSetup.msi",
    [Parameter(Mandatory=$false)][switch]$FORCE
)

# Make sure $INTEGRATOR_ID exists, otherwise exit this script as an agent cannot be downloaded
#If ( ($INTEGRATOR_ID -eq $null) -or ($INTEGRATOR_ID -eq '') ) { Exit }

# Source the Tools.ps1 script
Function SourceTools
{ . $([Scriptblock]::Create((New-Object Net.WebClient).DownloadString('https://dev.emberkom.com/emberkom/management-scripts/raw/branch/master/Tools.ps1'))) }
. SourceTools

# Build the path for $AGENT_INSTALLER
$AGENT_INSTALLER = '{0}{1}' -f (Get-TempPath), $AGENT_FILENAME

# Make sure we need to install the agent
If ( (Test-Path "${Env:ProgramFiles}\ATERA Networks\AteraAgent\AteraAgent.exe") -or (Test-Path "${Env:ProgramFiles(x86)}\ATERA Networks\AteraAgent\AteraAgent.exe") )
{ $INSTALL = $false ; $PreviousInstall = $true ; Write-Output "Atera agent is already installed on this endpoint" } Else { $INSTALL = $true ; $PreviousInstall = $false }

If ( $FORCE ) { $INSTALL = $true }

If ( $INSTALL ) {

    # Uninstall if $FORCE is true
    If ( $PreviousInstall ) {
        Write-Output "Getting information from existing installation"
        $ACCOUNT_ID = (Get-ItemPropertyValue -Path 'HKLM:SOFTWARE\ATERA Networks\AlphaAgent' -Name 'AccountId' -ErrorAction SilentlyContinue)
        $AGENT_ID = (Get-ItemPropertyValue -Path 'HKLM:SOFTWARE\ATERA Networks\AlphaAgent' -Name 'AgentId' -ErrorAction SilentlyContinue)
        $CUSTOMER_ID = (Get-ItemPropertyValue -Path 'HKLM:SOFTWARE\ATERA Networks\AlphaAgent' -Name 'CompanyId' -ErrorAction SilentlyContinue)
        $INTEGRATOR_ID = (Get-ItemPropertyValue -Path 'HKLM:SOFTWARE\ATERA Networks\AlphaAgent' -Name 'IntegratorLogin' -ErrorAction SilentlyContinue)
        Write-Output "AccountID   : ${ACCOUNT_ID}"
        Write-Output "AgentID     : ${AGENT_ID}"
        Write-Output "CustomerID  : ${CUSTOMER_ID}"
        Write-Output "IntegratorID: ${INTEGRATOR_ID}"

        #Download and run the uninstall script
        $UninstallScript = Download-File -URL 'https://dev.emberkom.com/emberkom/management-scripts/raw/branch/master/Uninstall-AteraAgent.ps1'
        Try { Start-Process "powershell.exe" -ArgumentList "-ExecutionPolicy Bypass -Noninteractive -File ""${UninstallScript}""" -Wait }
        Catch { LogErr $_.Exception.Message }
    }

    # Replace the '@' with '%40' - not sure why this is necessary, but it is
    $INTEGRATOR_ID = $INTEGRATOR_ID.Replace('@','%40')

    # Download agent installer
    Download-File -URL "https://app.atera.com/GetAgent/Msi/?customerId=${CUSTOMER_ID}&integratorLogin=${INTEGRATOR_ID}" -File "${AGENT_INSTALLER}"

    # Install the agent
    Write-Output "Installing Atera agent from ""${AGENT_INSTALLER}"""
    Try { Start-Process "msiexec.exe" -ArgumentList "/i ""${AGENT_INSTALLER}"" /qn /norestart" -Wait }
    Catch { LogErr $_.Exception.Message }

    # Delete the agent installer
    Write-Output "Deleting ""${AGENT_INSTALLER}"""
    Try { Remove-Item $AGENT_INSTALLER -Force }
    Catch { LogErr $_.Exception.Message }

    If ( $PreviousInstall -and $ACCOUNT_ID -and $AGENT_ID -and $CUSTOMER_ID) {
        Write-Output "Restoring agent information from previous install"
        Write-Output "  - Stopping AteraAgent service"
        Stop-Service -Name 'AteraAgent' -Force
        Write-Output "  - Restoring AgentID and AccountID from previous install"
        Set-ItemProperty -Path 'HKLM:SOFTWARE\ATERA Networks\AlphaAgent' -Name 'AccountId' -Value $ACCOUNT_ID
        Set-ItemProperty -Path 'HKLM:SOFTWARE\ATERA Networks\AlphaAgent' -Name 'AgentId' -Value $AGENT_ID
        Write-Output "  - Starting AteraAgent service"
        Start-Service -Name 'AteraAgent'
    }

}

# Delete this script
Remove-Item $MyInvocation.MyCommand.Path -Force