<?php

const CONTENTPANEL_NEWS_PNG_DIRECTORY = __DIR__ . '/../news/png';
const CONTENTPANEL_AUSHANG_TEMPLATE = __DIR__ . '/../template/aushang-template.docx';
const CONTENTPANEL_AUSHANG_WORKER = '/opt/intranet/worker/contentpanel_aushang/process.py';
const CONTENTPANEL_PYTHON = '/opt/intranet-venv/bin/python';

function contentpanel_sanitize_news_title(string $name): string
{
    return trim(preg_replace('/[^A-Za-z0-9_-]/', '_', $name), '_-');
}

function contentpanel_is_valid_news_file_base(string $fileBase): bool
{
    return preg_match('/^\d{4}-\d{2}-\d{2}-[A-Za-z0-9_-]+$/D', $fileBase) === 1;
}

function contentpanel_delete_news_files(string $fileBase): bool
{
    if (!contentpanel_is_valid_news_file_base($fileBase)) {
        return false;
    }

    return contentpanel_news_locked(function () use ($fileBase) {
        $success = true;
        foreach (glob(CONTENTPANEL_NEWS_PNG_DIRECTORY . '/' . $fileBase . '_page_*.png') ?: [] as $file) {
            $success = @unlink($file) && $success;
        }
        return $success;
    });
}

function contentpanel_news_locked(callable $operation)
{
    $lock = fopen(CONTENTPANEL_NEWS_PNG_DIRECTORY . '/.publish.lock', 'c');
    if (!$lock) throw new RuntimeException('Aushang-Verzeichnis konnte nicht gesperrt werden.');
    try {
        if (!flock($lock, LOCK_EX)) throw new RuntimeException('Aushang-Verzeichnis konnte nicht gesperrt werden.');
        return $operation();
    } finally {
        fclose($lock);
    }
}


function contentpanel_cleanup_expired_news(): void
{
    $today = new DateTimeImmutable('today');
    foreach (glob(CONTENTPANEL_NEWS_PNG_DIRECTORY . '/*_page_1.png') ?: [] as $file) {
        $fileBase = basename($file, '_page_1.png');
        if (!contentpanel_is_valid_news_file_base($fileBase)) {
            continue;
        }

        $dateString = substr($fileBase, 0, 10);
        $expiryDate = DateTimeImmutable::createFromFormat('!Y-m-d', $dateString);
        if ($expiryDate !== false && $expiryDate->format('Y-m-d') === $dateString && $today > $expiryDate) {
            contentpanel_delete_news_files($fileBase);
        }
    }
}

function contentpanel_render_news(
    string $pdfPath, string $outputDirectory, string $fileBase, string $mode, ?string $date = null
): array {
    $timeout = $mode === 'template' ? filter_var(getenv('CONTENTPANEL_JOB_TIMEOUT_SECONDS') ?: '3600', FILTER_VALIDATE_INT,
        ['options' => ['min_range' => 60, 'max_range' => 86400]]) : 600;
    if ($timeout === false) throw new RuntimeException('Ungültiges Verarbeitungstimeout.');
    $output = contentpanel_run([CONTENTPANEL_PYTHON, CONTENTPANEL_AUSHANG_WORKER,
        '--pdf', $pdfPath, '--template', CONTENTPANEL_AUSHANG_TEMPLATE,
        '--output-dir', $outputDirectory, '--base-name', $fileBase,
        '--date', $date ?? date('Y-m-d'), '--mode', $mode], $timeout, [
            2 => 'Die KI-Ausgabe enthält eine nicht belegte Zahl oder Kontaktangabe. Bitte erneut versuchen oder die Original-PDF-Darstellung verwenden.',
            3 => 'Die KI-Verarbeitung ist fehlgeschlagen. Für Bild-PDFs muss das konfigurierte Modell Bilder lesen können. Bitte erneut versuchen oder die Original-PDF-Darstellung verwenden.',
            4 => 'Die PDF konnte nicht vollständig gelesen werden. Bitte prüfen Sie die Datei und ihre Lesbarkeit.',
            124 => 'Die PDF-Verarbeitung hat zu lange gedauert. Bitte verwenden Sie eine kleinere PDF oder die Original-PDF-Darstellung.',
        ]);
    $result = json_decode($output, true, 32, JSON_THROW_ON_ERROR);
    if (($result['ok'] ?? false) !== true || !is_int($result['pages'] ?? null) || $result['pages'] < 1) {
        throw new RuntimeException('Der Aushang-Worker meldet ein unvollständiges Ergebnis.');
    }
    return $result;
}

function contentpanel_publish_news_pages(array $generatedFiles, string $fileBase): void
{
    if (!$generatedFiles || !contentpanel_is_valid_news_file_base($fileBase)) {
        throw new RuntimeException('Es wurden keine gültigen Aushangseiten erzeugt.');
    }
    foreach (array_values($generatedFiles) as $index => $source) {
        if (!is_file($source) || basename($source) !== $fileBase . '_page_' . ($index + 1) . '.png') {
            throw new RuntimeException('Die erzeugten Aushangseiten sind unvollständig.');
        }
    }
    contentpanel_news_locked(function () use ($generatedFiles, $fileBase) {
        $token = bin2hex(random_bytes(6));
        $backups = $published = [];
        try {
            foreach (glob(CONTENTPANEL_NEWS_PNG_DIRECTORY . '/' . $fileBase . '_page_*.png') ?: [] as $existing) {
                $backup = $existing . '.bak-' . $token;
                if (!rename($existing, $backup)) throw new RuntimeException('Aushang konnte nicht gesichert werden.');
                $backups[$backup] = $existing;
            }
            foreach ($generatedFiles as $source) {
                $target = CONTENTPANEL_NEWS_PNG_DIRECTORY . '/' . basename($source);
                if (!rename($source, $target)) throw new RuntimeException('Aushangseite konnte nicht veröffentlicht werden.');
                $published[] = $target;
            }
        } catch (Throwable $exception) {
            foreach ($published as $file) @unlink($file);
            $restored = true;
            foreach ($backups as $backup => $original) $restored = @rename($backup, $original) && $restored;
            if (!$restored) {
                // Failed backups are retained as the last copy of the original announcement.
                throw new RuntimeException('Veröffentlichung fehlgeschlagen. Sicherungsdateien konnten nicht vollständig zurückgespielt werden.', 0, $exception);
            }
            throw $exception;
        }
        foreach ($backups as $backup => $original) @unlink($backup);
    });
}

function contentpanel_upload_news(array $input, array $file, PDO $pdo, array $user): string
{
    $expiryDate = contentpanel_date($input['date'] ?? '', 'Ungültiges Verfallsdatum.');
    $title = contentpanel_sanitize_news_title(trim((string) ($input['name'] ?? '')));
    if ($title === '') {
        throw new InvalidArgumentException('Bitte einen gültigen Titel eingeben.');
    }

    $mode = trim((string) ($input['format_mode'] ?? 'original'));
    if (!in_array($mode, ['original', 'template'], true)) {
        throw new InvalidArgumentException('Ungültiger Aushang-Modus.');
    }

    $pdfPath = contentpanel_validate_pdf_upload(
        $file,
        'Bitte eine gültige PDF-Datei hochladen.',
        'Bitte eine gültige PDF-Datei hochladen.'
    );
    $job = ['base' => $expiryDate->format('Y-m-d') . '-' . $title, 'title' => trim((string) $input['name']),
        'mode' => $mode, 'date' => date('Y-m-d')];
    if ($mode === 'template') {
        return contentpanel_enqueue_news($pdo, $user, $pdfPath, $job);
    }
    contentpanel_process_news($pdfPath, $job);
    return 'Aushang wurde veröffentlicht.';
}

function contentpanel_process_news(string $pdfPath, array $job, ?callable $beforePublish = null): array
{
    if (!is_dir(CONTENTPANEL_NEWS_PNG_DIRECTORY) && !mkdir(CONTENTPANEL_NEWS_PNG_DIRECTORY, 0755, true)) {
        throw new RuntimeException('Das Aushang-Verzeichnis konnte nicht angelegt werden.');
    }

    $fileBase = $job['base'];
    // Same filesystem as the final images: publishing only needs atomic renames.
    $tempDirectory = CONTENTPANEL_NEWS_PNG_DIRECTORY . '/.upload-' . (isset($job['id']) ? 'job-' . (int) $job['id'] : bin2hex(random_bytes(8)));
    if (!is_dir($tempDirectory) && !mkdir($tempDirectory, 0700, true)) {
        throw new RuntimeException('Temporäres Aushang-Verzeichnis konnte nicht angelegt werden.');
    }

    try {
        // A restarted queue job may have left incomplete render output.
        foreach (glob($tempDirectory . '/*') ?: [] as $path) if (is_file($path)) unlink($path);
        $result = contentpanel_render_news($pdfPath, $tempDirectory, $fileBase, $job['mode'], $job['date']);
        $generatedFiles = glob($tempDirectory . '/' . $fileBase . '_page_*.png') ?: [];
        natsort($generatedFiles);
        if (count($generatedFiles) !== $result['pages']) {
            throw new RuntimeException('Die erzeugte Seitenzahl ist unvollständig.');
        }
        if ($beforePublish) $beforePublish();
        contentpanel_publish_news_pages($generatedFiles, $fileBase);

        return $result;
    } finally {
        foreach (glob($tempDirectory . '/*') ?: [] as $filePath) {
            if (is_file($filePath)) {
                @unlink($filePath);
            }
        }
        @rmdir($tempDirectory);
    }
}

function contentpanel_list_news(): array
{
    $items = [];
    foreach (glob(CONTENTPANEL_NEWS_PNG_DIRECTORY . '/*_page_1.png') ?: [] as $file) {
        $base = basename($file, '_page_1.png');
        if (!is_file($file) || !contentpanel_is_valid_news_file_base($base)) {
            continue;
        }
        $items[] = [
            'base' => $base,
            'title' => substr($base, 11),
            'pages' => count(glob(CONTENTPANEL_NEWS_PNG_DIRECTORY . '/' . $base . '_page_[0-9]*.png') ?: []),
            'expiry' => contentpanel_format_display_date(substr($base, 0, 10)),
            'image_url' => '/intranet_repo/projects/contentpanel/insertion/news/png/'
                . rawurlencode(basename($file)) . '?v=' . (int) filemtime($file),
        ];
    }
    return $items;
}