<?php
/*  Name:           toggle_availability.php
    Beschreibung:   Verfuegbarkeit eintragen/entfernen (AJAX-Endpoint)
                    Liefert JSON-Response, sendet SMS+Mail bei Match */

header('Content-Type: application/json; charset=utf-8');
session_start();

if (!isset($_SESSION["user_id"]) || !isset($_POST["date"])) {
    http_response_code(400);
    echo json_encode(['ok' => false, 'error' => 'Fehlende Parameter']);
    exit;
}

$date = $_POST["date"];
$formattedDate = date("d.m.Y", strtotime($date));
$userId = (int) $_SESSION["user_id"];

$pdo = require($_SERVER['DOCUMENT_ROOT'] . "/intranet_repo/general_files/ini/database.php");

// Pruefen ob Verfuegbarkeit bereits besteht
$stmt = $pdo->prepare("SELECT COUNT(*) AS count FROM verfuegbarkeiten WHERE datum = ? AND user_id = ?");
$stmt->execute([$date, $userId]);
$wasAvailable = $stmt->fetch()['count'] > 0;

// Eintragen oder Austragen
if ($wasAvailable) {
    $stmt = $pdo->prepare("DELETE FROM verfuegbarkeiten WHERE datum = ? AND user_id = ?");
} else {
    $stmt = $pdo->prepare("INSERT INTO verfuegbarkeiten (datum, user_id) VALUES (?, ?)");
}

if (!$stmt->execute([$date, $userId])) {
    http_response_code(500);
    echo json_encode(['ok' => false, 'error' => 'Datenbankfehler']);
    $pdo = null;
    exit;
}

$nowAvailable = !$wasAvailable;
$notifications = [];

// Bei neuem Eintrag: Match pruefen und benachrichtigen
if ($nowAvailable) {
    // E-Mail-Spalte dynamisch ermitteln
    $emailCol = null;
    $emailCandidates = ['email', 'mail', 'email_address', 'e_mail', 'user_email'];
    $inList = "'" . implode("','", $emailCandidates) . "'";
    $res = $pdo->query("SELECT column_name FROM information_schema.columns WHERE table_name = 'user_general_information' AND column_name IN ($inList) LIMIT 1");
    if ($res && $r = $res->fetch()) { $emailCol = $r['column_name']; }

    $emailSelect = $emailCol ? ", u.\"{$emailCol}\" AS email" : ", '' AS email";
    $sql = "SELECT u.user_id, u.first_name, u.last_name, u.phone{$emailSelect}
            FROM verfuegbarkeiten v
            JOIN user_general_information u ON v.user_id = u.user_id
            WHERE v.datum = ?";
    $stmt = $pdo->prepare($sql);
    $stmt->execute([$date]);

    $matchUsers = $stmt->fetchAll();

    if (count($matchUsers) > 1) {
        $nameList = implode(', ', array_map(fn($u) => trim($u['first_name'] . ' ' . $u['last_name']), $matchUsers));
        $smsText = mb_convert_encoding(
            "Intranet NAK Reinickendorf\n\nIt's a match!\n\n{$nameList} haben am {$formattedDate} fuer einen Seelsorgebesuch Zeit!",
            'UTF-8', 'auto'
        );

        // SMS an alle Beteiligten
        foreach ($matchUsers as $u) {
            if (!empty($u['phone'])) {
                $smsData = json_encode([
                    'phone'   => '+49' . $u['phone'],
                    'message' => $smsText
                ], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);

                $ctx = stream_context_create(['http' => [
                    'header'  => "Content-Type: application/json; charset=utf-8",
                    'method'  => 'POST',
                    'content' => $smsData,
                    'timeout' => 5
                ]]);
                @file_get_contents(rtrim(intranet_env('SMS_GATEWAY_URL'), '/') . '/send_sms', false, $ctx);
                $notifications[] = "SMS → " . $u['first_name'];
            }
        }

        // E-Mail an alle Beteiligten
        require_once $_SERVER['DOCUMENT_ROOT'] . '/intranet_repo/general_files/ini/send_mail.php';
        $mailBetreff = "Seelsorge-Match am {$formattedDate}";
        $mailNachricht = "It's a match!\n\n{$nameList} haben am {$formattedDate} für einen Seelsorgebesuch Zeit.\n\nBitte stimmt euch untereinander ab.";
        $host = $_SERVER['HTTP_HOST'] ?? intranet_env('INTRANET_FQDN');
        $btnUrl = "https://{$host}/intranet_repo/projects/seelsorge/seelsorge.php";

        foreach ($matchUsers as $u) {
            $email = trim($u['email'] ?? '');
            if (!empty($email) && filter_var($email, FILTER_VALIDATE_EMAIL)) {
                @send_intranet_mail($email, $mailBetreff, $mailNachricht, null, 'intranet@nak-reinickendorf.de', 'Zum Seelsorgeplaner', $btnUrl);
                $notifications[] = "Mail → " . $u['first_name'];
            }
        }
    }
}

// Aktuellen Count der verfuegbaren Diakon*innen fuer diesen Tag zurueckgeben
$stmt = $pdo->prepare("SELECT COUNT(*) AS cnt FROM verfuegbarkeiten WHERE datum = ?");
$stmt->execute([$date]);
$availCount = $stmt->fetch()['cnt'];

$pdo = null;

echo json_encode([
    'ok'            => true,
    'nowAvailable'  => $nowAvailable,
    'availCount'    => (int) $availCount,
    'notifications' => $notifications
], JSON_UNESCAPED_UNICODE);
?>