Backend/WEBROOT/services/berichte_arbeit_gen.php

<?php
// Zugriff nur, wenn angemeldet
if (empty($_SESSION['user_logged_in'])) {
    echo "<p>Zugriff verweigert.</p>";
    exit;
}

$conn = db_connect();

$conn->query("SET @row := 0");

$wochenQuery = "
SELECT MIN(DATUM) AS start_date,
        MAX(DATUM) AS end_date
FROM (
    SELECT DATUM,
        DATE_SUB(DATUM, INTERVAL (@row := @row + 1) DAY) AS grp
    FROM Firmenberichte
    ORDER BY DATUM
) AS t
GROUP BY grp
ORDER BY start_date;
";

$resultWochen = $conn->query($wochenQuery);

$wochenArray = [];
while($row = $resultWochen->fetch_assoc()){
    $wochenArray[] = $row;
}

// Standard-Datenbereich: letzte 5 Tage
$startDate = $_POST['start_date'] ?? date('Y-m-d', strtotime('-5 days'));
$endDate   = $_POST['end_date'] ?? date('Y-m-d');

$berichteQuery = "SELECT `DATUM`, `PROZESS_1`, `PROZESS_2`, `PROZESS_3`, `PROZESS_4`
                FROM Firmenberichte
                WHERE `DATUM` BETWEEN ? AND ?";

$stmt = $conn->prepare($berichteQuery);
$stmt->bind_param("ss", $startDate, $endDate);
$stmt->execute();
$result = $stmt->get_result();

$berichteArray = [];
while($row = $result->fetch_assoc()){
    $berichteArray[] = $row;
}

$stmt->close();
$conn->close();

// PDF-Generierung
function generatePDF($berichteArray) {
    $Einzelstunden = "2";
    $Gesamtstunden = "8";
    $data = [
        'Text1' => '', // Nr
        'Text2' => $berichteArray[0]['DATUM'] ?? '',
        'Text3' => end($berichteArray)['DATUM'] ?? '',
        'Text4' => 'Eckhardt',
        'Text5' => 'Bruno Renato',
        'Text6' => '1',
    ];

    $fieldIndex = 7;
    foreach ($berichteArray as $bericht) {
        for ($i = 1; $i <= 4; $i++) {
            $data["Text$fieldIndex"] = $bericht["PROZESS_$i"] ?? '';
            $fieldIndex++;
            $data["Text$fieldIndex"] = $Einzelstunden;
            $fieldIndex++;
        }
        $data["Text$fieldIndex"] = $Gesamtstunden;
        $fieldIndex++;
    }

    $fdfFields = array_map(function($field, $value){
        $value = str_replace(['(', ')'], ['\(', '\)'], $value);
        return "<< /T ($field) /V ($value) >>";
    }, array_keys($data), $data);

    $fdf = "%FDF-1.2\n1 0 obj\n<<\n/FDF << /Fields [\n" .
            implode("\n", $fdfFields) .
            "\n] >> >>\nendobj\ntrailer\n<< /Root 1 0 R >>\n%%EOF";

    $fdfFile = tempnam(sys_get_temp_dir(), 'fdf_') . '.fdf';
    file_put_contents($fdfFile, $fdf);

    $inputPdf  = (new getSpecificData())->getDocumentRoot() . '/templates/ausbildungsnachweis.pdf';
    ConsoleLog((new getSpecificData())->getDocumentRoot() . '/templates/ausbildungsnachweis.pdf');
    $outputPdf = (new getSpecificData())->getDocumentRoot() . '/static/ausbildungsnachweis_' . $berichteArray[0]['DATUM'] . '-' . end($berichteArray)['DATUM'] . '.pdf';

    exec("pdftk $inputPdf fill_form $fdfFile output $outputPdf flatten");

    unlink($fdfFile);

    return $outputPdf;
}

// Handle PDF generation
$pdfFile = null;
if (isset($_POST['generate_pdf']) && count($berichteArray) > 0) {
    $pdfFile = generatePDF($berichteArray);
}
?>

<div class="content-box">
    <h2>Ausbildungsberichte PDF erstellen</h2>

    <form method="post" class="overtime-container">
        <label for="start_date">Von:</label>
        <input type="date" name="start_date" id="start_date" value="<?= htmlspecialchars($startDate) ?>">

        <label for="end_date">Bis:</label>
        <input type="date" name="end_date" id="end_date" value="<?= htmlspecialchars($endDate) ?>">

        <button type="submit" name="generate_pdf">PDF erstellen</button>
    </form>

    <?php if ($pdfFile): ?>
    <div class="overtime-result">
        <?= htmlspecialchars(basename($pdfFile)) ?> erfolgreich erstellt!
    </div>
    <?php elseif(isset($_POST['generate_pdf'])): ?>
    <div class="overtime-result negative">
        Keine Berichte im gewählten Zeitraum gefunden.
    </div>
    <?php endif; ?>
    <?php if(!empty($wochenArray)): ?>
    <div class="wochen-liste">
        <h3>Verfügbare Wochenabschnitte:</h3>
        <ul>
            <?php
        $outputDir = (new getSpecificData())->getDocumentRoot() . '/static/';
        foreach($wochenArray as $woche):
            $pdfName = 'ausbildungsnachweis_' . $woche['start_date'] . '-' . $woche['end_date'] . '.pdf';
            $pdfPath = $outputDir . $pdfName;
            $exists = file_exists($pdfPath);
        ?>
            <li>
                <code><?= htmlspecialchars($woche['start_date']) ?></code> bis
                <code><?= htmlspecialchars($woche['end_date']) ?></code>
                <?php if($exists): ?>
                <span style="color:green;">(PDF vorhanden)</span>
                <a href="<?= htmlspecialchars('/static/' . $pdfName) ?>" download class="btn btn-success">
                    Download
                </a>


                <?php else: ?>
                <span style="color:red;">(noch keine PDF)</span>
                <form method="post" style="display:inline;">
                    <input type="hidden" name="start_date" value="<?= htmlspecialchars($woche['start_date']) ?>">
                    <input type="hidden" name="end_date" value="<?= htmlspecialchars($woche['end_date']) ?>">
                    <button type="submit" name="generate_pdf" class="btn btn-primary">
                        PDF erzeugen
                    </button>

                </form>
                <?php endif; ?>

            </li>
            <?php endforeach; ?>
        </ul>
    </div>
    <?php endif; ?>



</div>