<?php
declare(strict_types=1);

ini_set('display_errors', '1');
error_reporting(E_ALL);
session_start();

if (!isset($_SESSION['user_id'])) {
    header('Location: ../login.php');
    exit;
}

require_once __DIR__ . '/../auth_helpers.php';

$config = require __DIR__ . '/../../config/database.php';
$telegramConfig = require __DIR__ . '/../../config/telegram.php';
require_once __DIR__ . '/lib/message_footer.php';
require_once __DIR__ . '/lib/http.php';

$dsn = sprintf(
    'mysql:host=%s;dbname=%s;charset=%s',
    $config['host'],
    $config['dbname'],
    $config['charset'] ?? 'utf8mb4'
);

$pdo = new PDO(
    $dsn,
    $config['user'],
    $config['pass'],
    [
        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
        PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    ]
);

$currentUserId = (int) $_SESSION['user_id'];
$loggedIn = true;
$publicBasePath = '../';
$pageTitle = 'Telegram-Testversand - AstroTools';
$headerIntroPre = 'Administration';
$headerIntroTitle = 'Telegram-Testversand';
$headerIntroSub = 'Testnachrichten an Nutzer mit verknüpftem Telegram-Konto senden.';
$errors = [];
$successMessage = '';
$resultRows = [];
$messageText = "Testnachricht von SkyView\n\nDer Telegram-Bot ist jetzt erfolgreich verbunden.";
$sendMode = 'self';
$selectedRecipientIds = [];

function h(?string $value): string
{
    return htmlspecialchars((string) $value, ENT_QUOTES, 'UTF-8');
}

function textLength(string $value): int
{
    if (function_exists('mb_strlen')) {
        return mb_strlen($value);
    }

    return strlen($value);
}

function sendTelegramMessage(string $botToken, string $chatId, string $messageText): array
{
    $response = telegramHttpPostJson(
        'https://api.telegram.org/bot' . $botToken . '/sendMessage',
        [
            'chat_id' => $chatId,
            'text' => appendTelegramServiceFooter($messageText),
        ]
    );

    if (!$response['ok']) {
        return [
            'ok' => false,
            'description' => (string) ($response['error'] ?? 'Telegram konnte nicht erreicht werden.'),
        ];
    }

    $decoded = json_decode((string) $response['body'], true);
    if (!is_array($decoded)) {
        return [
            'ok' => false,
            'description' => 'Telegram hat keine gültige JSON-Antwort geliefert.',
        ];
    }

    return [
        'ok' => (bool) ($decoded['ok'] ?? false),
        'description' => (string) ($decoded['description'] ?? ''),
    ];
}

if (empty($_SESSION['telegram_broadcast_csrf'])) {
    $_SESSION['telegram_broadcast_csrf'] = bin2hex(random_bytes(16));
}

$stmtCurrentUser = $pdo->prepare("
    SELECT `id`, `username`, `display_name`, `role`, `is_active`, `telegram_chat_id`
    FROM `app_users`
    WHERE `id` = :id
    LIMIT 1
");
$stmtCurrentUser->execute([':id' => $currentUserId]);
$currentUser = $stmtCurrentUser->fetch();

if (
    !$currentUser ||
    !isMasterRole((string) $currentUser['role']) ||
    (int) $currentUser['is_active'] !== 1
) {
    $_SESSION = [];
    session_destroy();
    header('Location: ../login.php');
    exit;
}

$stmtRecipients = $pdo->query("
    SELECT
        `id`,
        `username`,
        `display_name`,
        `role`,
        `telegram_username`,
        `telegram_chat_id`,
        `telegram_connected_at`
    FROM `app_users`
    WHERE `is_active` = 1
      AND `telegram_chat_id` IS NOT NULL
      AND `telegram_chat_id` <> ''
    ORDER BY COALESCE(`display_name`, `username`) ASC, `id` ASC
");
$recipients = $stmtRecipients->fetchAll();
$recipientIndex = [];
foreach ($recipients as $recipient) {
    $recipientIndex[(int) $recipient['id']] = $recipient;
}

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $action = (string) ($_POST['action'] ?? '');
    $csrfToken = (string) ($_POST['csrf_token'] ?? '');
    $messageText = trim((string) ($_POST['message_text'] ?? ''));
    $sendMode = (string) ($_POST['send_mode'] ?? 'self');
    $selectedRecipientIds = array_values(array_unique(array_map(
        static fn ($value): int => (int) $value,
        is_array($_POST['recipient_ids'] ?? null) ? $_POST['recipient_ids'] : []
    )));

    if (!hash_equals($_SESSION['telegram_broadcast_csrf'], $csrfToken)) {
        $errors[] = 'Die Sitzung ist abgelaufen. Bitte die Seite neu laden.';
    }

    if ($action !== 'send_broadcast') {
        $errors[] = 'Die angeforderte Aktion ist ungültig.';
    }

    if ($messageText === '') {
        $errors[] = 'Bitte eine Nachricht eingeben.';
    } elseif (textLength($messageText) > 4000) {
        $errors[] = 'Die Nachricht ist zu lang. Bitte auf maximal 4000 Zeichen kuerzen.';
    }

    $botToken = trim((string) ($telegramConfig['bot_token'] ?? ''));
    if ($botToken === '') {
        $errors[] = 'In config/telegram.php ist noch kein Bot-Token hinterlegt.';
    }

    if (empty($recipients)) {
        $errors[] = 'Es gibt derzeit keine Nutzer mit verknüpftem Telegram-Konto.';
    }

    $targetRecipients = [];
    if (empty($errors)) {
        if ($sendMode === 'self') {
            if (empty($currentUser['telegram_chat_id'])) {
                $errors[] = 'Dein Administrationskonto ist noch nicht mit Telegram verknuepft.';
            } else {
                foreach ($recipients as $recipient) {
                    if ((int) $recipient['id'] === $currentUserId) {
                        $targetRecipients[] = $recipient;
                        break;
                    }
                }

                if (empty($targetRecipients)) {
                    $targetRecipients[] = [
                        'id' => $currentUserId,
                        'username' => (string) $currentUser['username'],
                        'display_name' => (string) ($currentUser['display_name'] ?? ''),
                        'telegram_username' => '',
                        'telegram_chat_id' => (string) $currentUser['telegram_chat_id'],
                        'telegram_connected_at' => null,
                    ];
                }
            }
        } elseif ($sendMode === 'selected') {
            if (empty($selectedRecipientIds)) {
                $errors[] = 'Bitte mindestens einen Empfänger auswählen.';
            } else {
                foreach ($selectedRecipientIds as $recipientId) {
                    if (isset($recipientIndex[$recipientId])) {
                        $targetRecipients[] = $recipientIndex[$recipientId];
                    }
                }

                if (empty($targetRecipients)) {
                    $errors[] = 'Die ausgewählten Empfänger konnten nicht geladen werden.';
                }
            }
        } elseif ($sendMode === 'all') {
            $targetRecipients = $recipients;
        } else {
            $errors[] = 'Der Versandmodus ist ungültig.';
        }
    }

    if (empty($errors)) {
        $successCount = 0;

        foreach ($targetRecipients as $recipient) {
            $chatId = trim((string) ($recipient['telegram_chat_id'] ?? ''));
            $sendResult = sendTelegramMessage($botToken, $chatId, $messageText);
            $wasSuccessful = (bool) ($sendResult['ok'] ?? false);

            if ($wasSuccessful) {
                $successCount++;
            }

            $resultRows[] = [
                'username' => (string) ($recipient['username'] ?? ''),
                'display_name' => (string) ($recipient['display_name'] ?? ''),
                'telegram_username' => (string) ($recipient['telegram_username'] ?? ''),
                'chat_id' => $chatId,
                'ok' => $wasSuccessful,
                'description' => (string) ($sendResult['description'] ?? ''),
            ];
        }

        $successMessage = sprintf(
            'Versand abgeschlossen: %d von %d Empfänger erfolgreich erreicht.',
            $successCount,
            count($targetRecipients)
        );
    }
}
?>
<?php require __DIR__ . '/../header.php'; ?>

<?php if ($successMessage !== ''): ?>
    <p class="msg-success"><?= h($successMessage) ?></p>
<?php endif; ?>

<?php if (!empty($errors)): ?>
    <ul class="msg-error">
        <?php foreach ($errors as $error): ?>
            <li><?= h($error) ?></li>
        <?php endforeach; ?>
    </ul>
<?php endif; ?>

<div class="grid-2">
    <div class="card">
        <h2>Testnachricht senden</h2>
        <p class="hint">
            Diese Seite sendet Testnachrichten an alle aktiven Nutzer mit hinterlegter Telegram-Chat-ID.
        </p>

        <table class="data-table mb-lg">
            <tr><td>Nutzer mit Telegram verknüpft</td><td><?= count($recipients) ?></td></tr>
            <tr><td>Bot</td><td><?= h(($telegramConfig['bot_username'] ?? '') !== '' ? '@' . (string) $telegramConfig['bot_username'] : 'nicht konfiguriert') ?></td></tr>
        </table>

        <form method="post" action="" class="form-stack">
            <input type="hidden" name="action" value="send_broadcast">
            <input type="hidden" name="csrf_token" value="<?= h($_SESSION['telegram_broadcast_csrf']) ?>">

            <div class="form-group">
                <label>Empfänger</label>
                <label>
                    <input type="radio" name="send_mode" value="self" <?= $sendMode === 'self' ? 'checked' : '' ?>>
                    Nur an mich senden
                </label>
                <label>
                    <input type="radio" name="send_mode" value="selected" <?= $sendMode === 'selected' ? 'checked' : '' ?>>
                    An ausgewählte Nutzer senden
                </label>
                <label>
                    <input type="radio" name="send_mode" value="all" <?= $sendMode === 'all' ? 'checked' : '' ?>>
                    An alle verknüpften Nutzer senden
                </label>
            </div>

            <div class="form-group">
                <label for="recipient_ids">Auswahl für "ausgewählte Nutzer"</label>
                <select id="recipient_ids" name="recipient_ids[]" multiple size="8">
                    <?php foreach ($recipients as $recipient): ?>
                        <?php $recipientId = (int) $recipient['id']; ?>
                        <?php $recipientLabel = ($recipient['display_name'] !== '' ? $recipient['display_name'] : $recipient['username']) . ' (' . $recipient['username'] . ')'; ?>
                        <option value="<?= $recipientId ?>" <?= in_array($recipientId, $selectedRecipientIds, true) ? 'selected' : '' ?>>
                            <?= h($recipientLabel) ?>
                        </option>
                    <?php endforeach; ?>
                </select>
                <p class="hint">Mit gedrueckter Strg-Taste lassen sich mehrere Benutzer markieren.</p>
            </div>

            <div class="form-group">
                <label for="message_text">Nachricht</label>
                <textarea
                    id="message_text"
                    name="message_text"
                    rows="8"
                    maxlength="4000"
                    required
                ><?= h($messageText) ?></textarea>
            </div>

            <button type="submit" class="btn btn-primary">Testnachricht senden</button>
        </form>
    </div>

    <div class="card">
        <h2>Empfänger</h2>
        <?php if (empty($recipients)): ?>
            <p class="hint">Noch keine Nutzer mit verknüpftem Telegram-Konto vorhanden.</p>
        <?php else: ?>
            <table class="data-table">
                <thead>
                    <tr>
                        <th>Benutzer</th>
                        <th>Telegram</th>
                        <th>Chat-ID</th>
                    </tr>
                </thead>
                <tbody>
                    <?php foreach ($recipients as $recipient): ?>
                        <tr>
                            <td>
                                <strong><?= h($recipient['display_name'] !== '' ? $recipient['display_name'] : $recipient['username']) ?></strong><br>
                                <span class="hint"><?= h($recipient['username']) ?></span>
                            </td>
                            <td><?= h(($recipient['telegram_username'] ?? '') !== '' ? '@' . ltrim((string) $recipient['telegram_username'], '@') : '—') ?></td>
                            <td><?= h((string) $recipient['telegram_chat_id']) ?></td>
                        </tr>
                    <?php endforeach; ?>
                </tbody>
            </table>
        <?php endif; ?>
    </div>
</div>

<?php if (!empty($resultRows)): ?>
    <div class="card">
        <h2>Versandprotokoll</h2>
        <table class="data-table">
            <thead>
                <tr>
                    <th>Benutzer</th>
                    <th>Chat-ID</th>
                    <th>Status</th>
                    <th>Rueckmeldung</th>
                </tr>
            </thead>
            <tbody>
                <?php foreach ($resultRows as $row): ?>
                    <tr>
                        <td><?= h($row['display_name'] !== '' ? $row['display_name'] : $row['username']) ?></td>
                        <td><?= h($row['chat_id']) ?></td>
                        <td><?= $row['ok'] ? 'OK' : 'Fehler' ?></td>
                        <td><?= h($row['description'] !== '' ? $row['description'] : 'Nachricht gesendet.') ?></td>
                    </tr>
                <?php endforeach; ?>
            </tbody>
        </table>
    </div>
<?php endif; ?>

<?php require __DIR__ . '/../footer.php'; ?>