<?php
ob_start(); // Start Output Buffering

// --- Robust Error Handling for AJAX endpoints ---
set_error_handler(function ($severity, $message, $file, $line) {
    if (error_reporting() === 0) return false;
    throw new ErrorException($message, 0, $severity, $file, $line);
});
set_exception_handler(function ($exception) {
    ob_end_clean(); // Discard any previous output
    header('Content-Type: application/json');
    http_response_code(500);
    echo json_encode([
        'success' => false,
        'message' => 'Internal Server Error: ' . $exception->getMessage(),
        'debug' => ['file' => $exception->getFile(), 'line' => $exception->getLine()]
    ]);
    exit();
});

// Load Composer's autoloader first to make PHPMailer available
require_once __DIR__ . '/../vendor/autoload.php';

require_once '../init.php';
require_once '../configmail.php'; // Global fallback config

use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

// --- Access Control & JSON Header ---
header('Content-Type: application/json');
if (!isset($_SESSION['user'])) {
    echo json_encode(['success' => false, 'message' => 'Authentication required']);
    exit();
}

// --- Get and validate parameters ---
$table_id = (int)($_GET['table_id'] ?? 0);
$record_id = (int)($_GET['id'] ?? 0);
$sig_from_url = trim($_GET['sig'] ?? '');

if ($table_id === 0 || $record_id === 0) {
    echo json_encode(['success' => false, 'message' => 'Table ID or Record ID is missing']);
    exit();
}

// --- Security Check: Validate signature ---
$expected_sig = hash_hmac('sha256', "{$table_id}-{$record_id}", INVITE_SECRET_KEY);
if (!hash_equals($expected_sig, $sig_from_url)) {
    echo json_encode(['success' => false, 'message' => 'Invalid signature.']);
    exit();
}

// --- Fetch Data (Main Record, Preferences, Linked Address) ---
$table_definition = DBGet('custom_tables', $table_id);
$table_owner_team = $table_definition['team'];
$physical_table_name = "data_team_{$table_owner_team}_{$table_id}";
$main_record = DBGet($physical_table_name, $record_id);

if (!$main_record) {
    echo json_encode(['success' => false, 'message' => 'Main record not found.']);
    exit();
}

$user_team = $_SESSION['user']['team'];
$team_preferences_raw = DBGet('preferences', null, ['name', 'value'], 'team = ?', [$user_team]);
$team_preferences = $team_preferences_raw ? array_column($team_preferences_raw, 'value', 'name') : [];

$address_record = null;
$address_lookup_field_name = 'adresse';
if (isset($main_record[$address_lookup_field_name]) && $main_record[$address_lookup_field_name] > 0) {
    $address_record_id = $main_record[$address_lookup_field_name];
    $lookup_field_meta_array = DBGet('custom_fields', null, ['options'], 'custom_table_id = ? AND field_name = ?', [$table_id, $address_lookup_field_name]);
    $lookup_field_meta = $lookup_field_meta_array[0] ?? null;

    if ($lookup_field_meta) {
        $lookup_options = json_decode($lookup_field_meta['options'], true);
        $linked_table_id = $lookup_options['linked_table_id'] ?? $lookup_options['lookup_table_id'] ?? 0;
        if ($linked_table_id > 0) {
            $linked_table_def = DBGet('custom_tables', $linked_table_id);
            if ($linked_table_def) {
                $linked_physical_table = "data_team_{$linked_table_def['team']}_{$linked_table_id}";
                $address_record = DBGet($linked_physical_table, (int)$address_record_id);
            }
        }
    }
}

if (!$address_record || empty($address_record['mail'])) {
    echo json_encode(['success' => false, 'message' => 'The email address could not be found in the linked address record.']);
    exit();
}

// --- Placeholder replacement logic ---
$placeholder_callback = function ($matches) use ($main_record, $address_record, $team_preferences) {
    $placeholder_key = $matches[1];
    if (str_starts_with($placeholder_key, 'adresse.') && $address_record) {
        $sub_key = substr($placeholder_key, 8);
        return htmlspecialchars($address_record[$sub_key] ?? '');
    }
    if (isset($main_record[$placeholder_key])) {
        return in_array($placeholder_key, ['text']) ? $main_record[$placeholder_key] : htmlspecialchars($main_record[$placeholder_key]);
    }
    if (isset($team_preferences[$placeholder_key])) {
        return nl2br(htmlspecialchars($team_preferences[$placeholder_key]));
    }
    return $matches[0];
};

// --- Define Mail Content ---
$recipient_email = $address_record['mail'];
$recipient_name = trim(($address_record['vorname'] ?? '') . ' ' . ($address_record['nachname'] ?? ''));

$subject_template = $main_record['betreff'] ?? 'Your Inquiry';
$body_template = "<p>{adresse.anrede} {adresse.nachname},</p>" . ($main_record['text'] ?? '<p>Thank you for your message.</p>') . "<p>{team_signature}</p>";

$subject = preg_replace_callback('/{([a-zA-Z0-9_.]+)}/', $placeholder_callback, $subject_template);
$body = preg_replace_callback('/{([a-zA-Z0-9_.]+)}/', $placeholder_callback, $body_template);

// --- Configure and Send with PHPMailer ---
$mail = new PHPMailer(true);

try {
    // Enable verbose debug output for troubleshooting
    $mail->SMTPDebug = 0; // Set to 2 for detailed client-server communication
    $mail->isSMTP();

    // Check if all necessary team-specific SMTP settings are present
    $use_team_smtp = isset($team_preferences['mail_smtp_host'], $team_preferences['mail_smtp_user'], $team_preferences['mail_smtp_pass'], $team_preferences['mail_smtp_port'], $team_preferences['mail_smtp_secure']);

    if ($use_team_smtp) {
        $mail->Host       = $team_preferences['mail_smtp_host'];
        $mail->Username   = $team_preferences['mail_smtp_user'];
        $mail->Password   = $team_preferences['mail_smtp_pass'];
        $mail->SMTPSecure = $team_preferences['mail_smtp_secure'];
        $mail->Port       = (int)$team_preferences['mail_smtp_port'];
    } else {
        // Fallback to global configuration from configmail.php
        $mail->Host       = MAIL_HOST;
        $mail->Username   = MAIL_USERNAME;
        $mail->Password   = MAIL_PASSWORD;
        $mail->SMTPSecure = MAIL_ENCRYPTION;
        $mail->Port       = (int)MAIL_PORT;
    }

    $mail->SMTPAuth   = true;
    $mail->CharSet    = 'UTF-8';

    // This is often needed for shared hosting or misconfigured mail servers
    $mail->SMTPOptions = ['ssl' => ['verify_peer' => false, 'verify_peer_name' => false, 'allow_self_signed' => true]];

    // Sender and Recipient
    $from_address = $team_preferences['mail_from_address'] ?? MAIL_USERNAME;
    $from_name = $team_preferences['mail_from_name'] ?? lang('my_website');
    $mail->setFrom($from_address, $from_name);
    $mail->addAddress($recipient_email, $recipient_name);
    $mail->addReplyTo($from_address, $from_name);

    // Content
    $mail->isHTML(true);
    $mail->Subject = $subject;
    $mail->Body    = $body;

    $mail->send();

    // Log the action
    log_user_action($_SESSION['user']['id'], 'mail_sent', $table_definition['table_name'], "Email sent to {$recipient_email}. Subject: {$subject} (Record-ID: {$record_id})");

    echo json_encode(['success' => true, 'message' => "Email was successfully sent to <strong>" . htmlspecialchars($recipient_email) . "</strong>."]);

} catch (Exception $e) {
    $error_message = "The email could not be sent. Error: " . ($mail->ErrorInfo ?: $e->getMessage());
    log_user_action($_SESSION['user']['id'], 'mail_error', $table_definition['table_name'], "Failed to send email to {$recipient_email} (Record-ID: {$record_id}): " . $error_message);
    error_log("PHPMailer Error in send_mail_smtp.php: " . $error_message);
    
    echo json_encode(['success' => false, 'message' => $error_message]);
}

ob_end_flush();