<?php
declare(strict_types=1);

/**
 * Task-Definitionen fuer den Telegram-Cron.
 *
 * Diese Datei enthaelt die Liste der Cron-Aufgaben mit Zeitplan, Aktivierung,
 * Anzeigename und Handler-Closure. Die eigentliche fachliche Logik ruft dabei
 * Funktionen aus den Hilfsdateien auf, damit die Task-Liste selbst gut lesbar bleibt.
 */

return [
    [
        'key' => 'send_tcrb_latest_v',
        'label' => 'Letzten T-CrB-Wert mit Filter V senden',
        'enabled' => true,
        'schedule' => 'every-minute',
        'handler' => static function (PDO $pdo, array $telegramConfig, DateTimeImmutable $nowBerlin) use ($stateFile): array {
            $latestObservation = fetchLatestTcrbObservationByFilter($pdo, 'V');
            if ($latestObservation === null) {
                return [
                    'sent' => 0,
                    'updated' => 0,
                    'message' => 'Keine T-CrB-Beobachtung mit Filter V gefunden.',
                ];
            }

            $state = loadCronState($stateFile);
            $taskKey = 'send_tcrb_latest_v';
            $currentSignature = buildTcrbObservationSignature($latestObservation);
            $lastSignature = (string) (($state[$taskKey]['last_signature'] ?? ''));

            if ($currentSignature !== '' && $currentSignature === $lastSignature) {
                return [
                    'sent' => 0,
                    'updated' => 0,
                    'message' => 'Kein neuer V-Messpunkt seit der letzten Telegram-Nachricht.',
                ];
            }

            $recipients = fetchTelegramRecipients($pdo);
            if ($recipients === []) {
                return [
                    'sent' => 0,
                    'updated' => 0,
                    'message' => 'Keine verbundenen Telegram-Empfaenger vorhanden.',
                ];
            }

            $messageText = buildTcrbLatestVMessage($latestObservation, $nowBerlin);
            $chartObservations = fetchRecentTcrbObservationsByFilterWindow($pdo, 'V', '-2 months');
            $chartSvg = buildTcrbVChartSvg($chartObservations, $latestObservation);
            $chartPackage = createTelegramChartPackage($chartSvg);
            $sentCount = 0;
            $chartSentCount = 0;

            try {
                foreach ($recipients as $recipient) {
                    $chatId = trim((string) ($recipient['telegram_chat_id'] ?? ''));
                    if ($chatId === '') {
                        continue;
                    }

                    $messageSent = telegramSendBotMessage($telegramConfig, $chatId, $messageText);
                    $chartSent = false;
                    if (($chartPackage['kind'] ?? '') === 'photo') {
                        $chartSent = telegramSendBotPhoto(
                            $telegramConfig,
                            $chatId,
                            (string) $chartPackage['path'],
                            'T CrB V-Diagramm'
                        );
                    } elseif (($chartPackage['kind'] ?? '') === 'document') {
                        $chartSent = telegramSendBotDocument(
                            $telegramConfig,
                            $chatId,
                            (string) $chartPackage['path'],
                            'T CrB V-Diagramm'
                        );
                    }

                    if ($chartSent) {
                        $chartSentCount++;
                    }

                    if ($messageSent || $chartSent) {
                        $sentCount++;
                    }
                }
            } finally {
                cleanupTelegramChartPackage($chartPackage);
            }

            if ($sentCount < 1) {
                return [
                    'sent' => 0,
                    'updated' => 0,
                    'message' => 'Telegram-Versand konnte keinen Empfaenger erfolgreich erreichen.',
                ];
            }

            $state[$taskKey] = [
                'last_signature' => $currentSignature,
                'last_sent_at' => $nowBerlin->format(DateTimeInterface::ATOM),
                'last_observed_at_utc' => (string) ($latestObservation['observed_at_utc'] ?? ''),
                'last_filter' => 'V',
            ];
            saveCronState($stateFile, $state);

            return [
                'sent' => $sentCount,
                'updated' => 0,
                'message' => sprintf(
                    'T-CrB V-Messpunkt %s an %d Telegram-Empfaenger gesendet, Diagramm an %d.',
                    (string) ($latestObservation['observed_at_utc'] ?? 'unbekannt'),
                    $sentCount,
                    $chartSentCount
                ),
            ];
        },
    ],
    [
        'key' => 'cleanup_expired_link_tokens',
        'label' => 'Abgelaufene Telegram-Verknuepfungscodes aufraeumen',
        'enabled' => true,
        'schedule' => 'every-15-minutes',
        'handler' => static function (PDO $pdo, array $telegramConfig, DateTimeImmutable $nowBerlin): array {
            $stmt = $pdo->prepare("
                UPDATE `app_users`
                SET
                    `telegram_link_token` = NULL,
                    `telegram_link_token_expires_at` = NULL,
                    `updated_at` = NOW()
                WHERE `telegram_link_token` IS NOT NULL
                  AND `telegram_link_token` <> ''
                  AND `telegram_link_token_expires_at` IS NOT NULL
                  AND `telegram_link_token_expires_at` < NOW()
            ");
            $stmt->execute();

            return [
                'sent' => 0,
                'updated' => (int) $stmt->rowCount(),
                'message' => 'Abgelaufene Verbindungscodes bereinigt.',
            ];
        },
    ],
    [
        'key' => 'daily_morning_report_placeholder',
        'label' => 'Morgendlichen Telegram-Bericht vorbereiten',
        'enabled' => false,
        'schedule' => 'daily-08:00',
        'handler' => static function (PDO $pdo, array $telegramConfig, DateTimeImmutable $nowBerlin): array {
            return [
                'sent' => 0,
                'updated' => 0,
                'message' => 'Platzhalter fuer den spaeteren Morgenbericht.',
            ];
        },
    ],
    [
        'key' => 'daily_evening_report_placeholder',
        'label' => 'Abendlichen Telegram-Bericht vorbereiten',
        'enabled' => false,
        'schedule' => 'daily-19:30',
        'handler' => static function (PDO $pdo, array $telegramConfig, DateTimeImmutable $nowBerlin): array {
            return [
                'sent' => 0,
                'updated' => 0,
                'message' => 'Platzhalter fuer den spaeteren Abendbericht.',
            ];
        },
    ],
    [
        'key' => 'connected_users_heartbeat_placeholder',
        'label' => 'Verbundene Telegram-Nutzer pruefen',
        'enabled' => false,
        'schedule' => 'hourly-minute-05',
        'handler' => static function (PDO $pdo, array $telegramConfig, DateTimeImmutable $nowBerlin): array {
            $count = (int) $pdo->query("
                SELECT COUNT(*)
                FROM `app_users`
                WHERE `telegram_chat_id` IS NOT NULL
                  AND `telegram_chat_id` <> ''
            ")->fetchColumn();

            return [
                'sent' => 0,
                'updated' => 0,
                'message' => 'Aktuell verbundene Telegram-Nutzer: ' . $count,
            ];
        },
    ],
];