<?php
header('Content-Type: application/json; charset=utf-8');

// Vain POST-pyynnöt
if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    http_response_code(405);
    echo json_encode(['success' => false, 'error' => 'Virheellinen pyyntö']);
    exit;
}

// Rate limiting (yksinkertainen, IP-pohjainen)
$rateLimitDir = __DIR__ . '/data';
if (!is_dir($rateLimitDir)) {
    mkdir($rateLimitDir, 0755, true);
}
$ip = $_SERVER['REMOTE_ADDR'] ?? 'unknown';
$rateLimitFile = $rateLimitDir . '/ratelimit_' . md5($ip) . '.txt';
$now = time();
if (file_exists($rateLimitFile)) {
    $lastSent = (int) file_get_contents($rateLimitFile);
    if ($now - $lastSent < 60) {
        http_response_code(429);
        echo json_encode(['success' => false, 'error' => 'Odota hetki ennen uutta lähetystä']);
        exit;
    }
}

// Honeypot-kenttä (botisuoja)
if (!empty($_POST['website'])) {
    http_response_code(200);
    echo json_encode(['success' => true]);
    exit;
}

// Kentät
$company = trim($_POST['company'] ?? '');
$email = trim($_POST['email'] ?? '');
$address = trim($_POST['address'] ?? '');
$city = trim($_POST['city'] ?? '');
$message = trim($_POST['message'] ?? '');

// Validointi
if (empty($company) || empty($email) || empty($address) || empty($city)) {
    http_response_code(400);
    echo json_encode(['success' => false, 'error' => 'Täytä kaikki pakolliset kentät']);
    exit;
}

if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
    http_response_code(400);
    echo json_encode(['success' => false, 'error' => 'Tarkista sähköpostiosoite']);
    exit;
}

// Sanitointi
$company = htmlspecialchars($company, ENT_QUOTES, 'UTF-8');
$email = htmlspecialchars($email, ENT_QUOTES, 'UTF-8');
$address = htmlspecialchars($address, ENT_QUOTES, 'UTF-8');
$city = htmlspecialchars($city, ENT_QUOTES, 'UTF-8');
$message = htmlspecialchars($message, ENT_QUOTES, 'UTF-8');

// Sähköpostin sisältö
$to = 'asiakaspalvelu@cuitunet.fi';
$subject = "Saatavuuskysely: $company – $address, $city";

$body = "Uusi saatavuuskysely cuitunet.fi-sivustolta\n";
$body .= "=========================================\n\n";
$body .= "Yritys:       $company\n";
$body .= "Sähköposti:   $email\n";
$body .= "Osoite:       $address\n";
$body .= "Kaupunki:     $city\n";
if (!empty($message)) {
    $body .= "Lisätiedot:   $message\n";
}
$body .= "\n-----------------------------------------\n";
$body .= "Lähetetty: " . date('d.m.Y H:i') . "\n";
$body .= "IP: $ip\n";

$headers = "From: sivusto@cuitunet.fi\r\n";
$headers .= "Reply-To: $email\r\n";
$headers .= "Content-Type: text/plain; charset=UTF-8\r\n";
$headers .= "X-Mailer: Cuitunet-Web\r\n";

// SMTP-lähetys mail2.fi:n kautta (STARTTLS + auth)
function sendViaSMTP(string $to, string $subject, string $body, string $replyTo): string {
    $smtpHost = 'smtp.mail2.fi';
    $smtpPort = 587;
    $smtpUser = 'sivusto@cuitunet.fi';
    $smtpPass = 'Passus123!';
    $fromEmail = 'sivusto@cuitunet.fi';
    $fromName = 'Cuitunet Saatavuuskysely';
    $hostname = 'cuitunet.fi';

    $sock = @fsockopen($smtpHost, $smtpPort, $errno, $errstr, 10);
    if (!$sock) return "SMTP-yhteys epäonnistui: $errstr ($errno)";

    $resp = fgets($sock, 512);
    if (substr($resp, 0, 3) !== '220') { fclose($sock); return "SMTP hylkäsi: $resp"; }

    // EHLO
    fwrite($sock, "EHLO $hostname\r\n");
    $resp = fgets($sock, 512);
    while (substr($resp, 3, 1) === '-') { $resp = fgets($sock, 512); }

    // STARTTLS
    fwrite($sock, "STARTTLS\r\n");
    $resp = fgets($sock, 512);
    if (substr($resp, 0, 3) !== '220') { fclose($sock); return "STARTTLS epäonnistui: $resp"; }
    if (!stream_socket_enable_crypto($sock, true, STREAM_CRYPTO_METHOD_TLSv1_2_CLIENT | STREAM_CRYPTO_METHOD_TLSv1_3_CLIENT)) {
        fclose($sock); return "TLS handshake epäonnistui";
    }

    // EHLO uudelleen TLS:n jälkeen
    fwrite($sock, "EHLO $hostname\r\n");
    $resp = fgets($sock, 512);
    while (substr($resp, 3, 1) === '-') { $resp = fgets($sock, 512); }

    // AUTH LOGIN
    fwrite($sock, "AUTH LOGIN\r\n");
    $resp = fgets($sock, 512);
    if (substr($resp, 0, 3) !== '334') { fclose($sock); return "AUTH ei tuettu: $resp"; }
    fwrite($sock, base64_encode($smtpUser) . "\r\n");
    $resp = fgets($sock, 512);
    if (substr($resp, 0, 3) !== '334') { fclose($sock); return "Käyttäjänimi hylätty: $resp"; }
    fwrite($sock, base64_encode($smtpPass) . "\r\n");
    $resp = fgets($sock, 512);
    if (substr($resp, 0, 3) !== '235') { fclose($sock); return "Kirjautuminen epäonnistui: $resp"; }

    // MAIL FROM / RCPT TO / DATA
    fwrite($sock, "MAIL FROM:<$fromEmail>\r\n");
    $resp = fgets($sock, 512);
    if ($resp[0] !== '2') { fclose($sock); return "MAIL FROM hylätty: $resp"; }

    fwrite($sock, "RCPT TO:<$to>\r\n");
    $resp = fgets($sock, 512);
    if ($resp[0] !== '2') { fclose($sock); return "RCPT TO hylätty: $resp"; }

    fwrite($sock, "DATA\r\n");
    $resp = fgets($sock, 512);
    if (substr($resp, 0, 3) !== '354') { fclose($sock); return "DATA hylätty: $resp"; }

    // Viesti
    $msg = "From: $fromName <$fromEmail>\r\n";
    $msg .= "To: $to\r\n";
    $msg .= "Reply-To: $replyTo\r\n";
    $msg .= "Subject: $subject\r\n";
    $msg .= "Content-Type: text/plain; charset=UTF-8\r\n";
    $msg .= "Date: " . date('r') . "\r\n";
    $msg .= "Message-ID: <" . uniqid('cuitunet-') . "@$hostname>\r\n";
    $msg .= "\r\n";
    $msg .= str_replace("\n.", "\n..", $body);
    $msg .= "\r\n.\r\n";

    fwrite($sock, $msg);
    $resp = fgets($sock, 512);
    fwrite($sock, "QUIT\r\n");
    fclose($sock);

    return (substr($resp, 0, 3) === '250') ? '' : "Lähetys epäonnistui: $resp";
}

$smtpError = sendViaSMTP($to, $subject, $body, $email);

if (empty($smtpError)) {
    // Tallenna rate limit
    file_put_contents($rateLimitFile, $now);

    // Tallenna kopio kyselyistä
    $logFile = $rateLimitDir . '/kyselyt.log';
    $logEntry = date('Y-m-d H:i:s') . " | $company | $email | $address, $city | $message\n";
    file_put_contents($logFile, $logEntry, FILE_APPEND | LOCK_EX);

    echo json_encode(['success' => true]);
} else {
    error_log("cuitunet.fi send.php SMTP error: $smtpError");
    http_response_code(500);
    echo json_encode(['success' => false, 'error' => 'Viestin lähetys epäonnistui. Yritä myöhemmin uudelleen.']);
}