param(
    [Parameter(Mandatory = $true)]
    [string]$To
)

$envFile = Join-Path $PSScriptRoot "..\.env"
if (-not (Test-Path $envFile)) {
    throw "Missing .env. Copy .env.example to .env and enter the SMTP settings."
}

Get-Content $envFile | ForEach-Object {
    if ($_ -match "^\s*([^#=\s]+)\s*=\s*(.*)\s*$") {
        [Environment]::SetEnvironmentVariable($matches[1], $matches[2], "Process")
    }
}

$required = "MAIL_HOST", "MAIL_PORT", "MAIL_USERNAME", "MAIL_PASSWORD", "MAIL_FROM"
$missing = $required | Where-Object { [string]::IsNullOrWhiteSpace([Environment]::GetEnvironmentVariable($_, "Process")) }
if ($missing) {
    throw "Missing required SMTP settings: $($missing -join ', ')"
}

$message = [System.Net.Mail.MailMessage]::new($env:MAIL_FROM, $To)
$message.Subject = "Eternity Project SMTP verification"
$message.Body = "SMTP delivery verification completed at $(Get-Date -Format o)."

$client = [System.Net.Mail.SmtpClient]::new($env:MAIL_HOST, [int]$env:MAIL_PORT)
$client.EnableSsl = $true
$client.Credentials = [System.Net.NetworkCredential]::new($env:MAIL_USERNAME, $env:MAIL_PASSWORD)

try {
    $client.Send($message)
    Write-Output "SMTP_TEST_SENT_TO=$To"
}
finally {
    $message.Dispose()
    $client.Dispose()
}