param(
    [Parameter(Mandatory = $true)][string]$RequestPath,
    [Parameter(Mandatory = $true)][string]$ResultPath
)
$ErrorActionPreference = 'Stop'
$result = @{ Success = $false; Output = ''; Error = '' }
try {
    $projectRoot = Split-Path -Parent $PSScriptRoot
    $tempRoot = [System.IO.Path]::GetFullPath((Join-Path $projectRoot 'temp'))
    foreach ($path in @($RequestPath, $ResultPath)) {
        $resolved = [System.IO.Path]::GetFullPath($path)
        if (-not $resolved.StartsWith($tempRoot + [System.IO.Path]::DirectorySeparatorChar,
            [StringComparison]::OrdinalIgnoreCase)) {
            throw 'Hidden helper files must be under the project temp folder'
        }
    }
    $request = Get-Content -LiteralPath $RequestPath -Raw -Encoding UTF8 | ConvertFrom-Json
    $allowed = @('test-smtp-message.ps1', 'import-template.ps1', 'preview-template.ps1',
        'review-campaign.ps1', 'send-campaign-test.ps1', 'approve-campaign.ps1',
        'dispatch-control.ps1', 'dispatch-once.ps1', 'send-approved-campaign-test.ps1',
        'export-report.ps1')
    if ($request.ScriptName -notin $allowed) { throw 'Unsupported hidden helper script' }
    $scriptPath = Join-Path $PSScriptRoot $request.ScriptName
    if (-not (Test-Path -LiteralPath $scriptPath -PathType Leaf)) {
        throw 'Hidden helper script is missing'
    }
    $parameters = @{ ConfigPath = [string]$request.ConfigPath }
    foreach ($property in $request.Parameters.PSObject.Properties) {
        if ($property.Name -notmatch '^[A-Za-z][A-Za-z0-9]*$' -or
            $property.Name -eq 'ConfigPath') { throw 'Invalid hidden helper parameter' }
        $parameters[$property.Name] = $property.Value
    }
    $result.Output = ((& $scriptPath @parameters | Out-String).Trim())
    $result.Success = $true
}
catch {
    $result.Error = $_.Exception.Message
}
finally {
    $json = ConvertTo-Json -InputObject $result -Compress -Depth 4
    $temporaryPath = $ResultPath + '.writing'
    [System.IO.File]::WriteAllText($temporaryPath, $json,
        (New-Object System.Text.UTF8Encoding($false)))
    [System.IO.File]::Move($temporaryPath, $ResultPath)
}
if (-not $result.Success) { exit 1 }