skyview.astronomiemuseum.de/public/observation_suggestions_helpers.php

<?php
declare(strict_types=1);

/** Catalog values are server-owned; the client only supplies selection filters. */
function observationDsoImage(array $row): ?string
{
    $catalogs = [
        ['messier', 'messier', 'm'],
        ['ngc', 'ngc', 'ngc'],
        ['ic', 'ic', 'ic'],
    ];
    foreach ($catalogs as [$field, $folder, $prefix]) {
        $number = preg_replace('/\D+/', '', trim((string) ($row[$field] ?? '')));
        if ($number === '' || !ctype_digit($number)) {
            continue;
        }
        $relative = 'images/dso/' . $folder . '/' . $prefix . $number . '.png';
        if (is_file(__DIR__ . '/' . $relative)) {
            return $relative;
        }
    }
    return null;
}

function observationCatalog(PDO $pdo, array $types): array
{
    $mapping = [
        'open_clusters' => ['OCl'], 'globular_clusters' => ['GCl'],
        'galaxies' => ['G', 'GPair', 'GTrpl', 'GGroup'],
        'nebulae' => ['Neb', 'EmN', 'HII', 'RfN', 'SNR', 'Cl+N'],
        'planetary_nebulae' => ['PN'], 'double_stars' => ['**'],
    ];
    $codes = [];
    foreach ($mapping as $group => $groupCodes) {
        if (in_array($group, $types, true)) {
            foreach ($groupCodes as $code) {
                $codes[$code] = $group;
            }
        }
    }
    $objects = [];
    if ($codes !== []) {
        $placeholders = implode(',', array_fill(0, count($codes), '?'));
        $stmt = $pdo->prepare("SELECT id, name, messier, ngc, ic, common_names_german, common_names, object_type_abrev, ra_deg, dec_deg, major_axis, v_mag
            FROM dso_objects WHERE object_type_abrev IN ($placeholders)
            AND ra_deg IS NOT NULL AND dec_deg IS NOT NULL");
        $stmt->execute(array_keys($codes));
        foreach ($stmt as $row) {
            $messier = trim((string) ($row['messier'] ?? ''));
            $messierLabel = preg_replace('/^M\s*/i', 'M', $messier);
            if ($messierLabel !== '' && !preg_match('/^M/i', $messierLabel)) {
                $messierLabel = 'M' . $messierLabel;
            }
            $commonName = trim((string) ($row['common_names_german'] ?? ''));
            if ($commonName === '') {
                $commonName = trim((string) ($row['common_names'] ?? ''));
            }
            $displayName = $row['name'];
            if ($messierLabel !== '') {
                $displayName .= ' / ' . $messierLabel;
            }
            $objects[] = [
                'id' => 'dso-' . $row['id'],
                'name' => $displayName,
                'common_name' => $commonName,
                'group' => $codes[$row['object_type_abrev']],
                'image' => observationDsoImage($row),
                'ra_deg' => (float) $row['ra_deg'], 'dec_deg' => (float) $row['dec_deg'],
                // OpenNGC MajAx is in arcminutes; GUI and Python use arcseconds.
                'size_arcsec' => $row['major_axis'] !== null && (float) $row['major_axis'] > 0
                    ? (float) $row['major_axis'] * 60 : null,
                'magnitude' => $row['v_mag'] !== null ? (float) $row['v_mag'] : null,
            ];
        }
    }
    if (in_array('variable_stars', $types, true)) {
        $stmt = $pdo->query("SELECT id, hip, proper, var, con, ra, `dec`, mag FROM star_hipparcos
            WHERE var IS NOT NULL AND TRIM(var) <> '' AND ra IS NOT NULL AND `dec` IS NOT NULL");
        foreach ($stmt as $row) {
            $name = trim((string) ($row['proper'] ?? ''));
            $objects[] = [
                'id' => 'star-' . $row['id'], 'name' => $name !== '' ? $name : trim($row['var'] . ' ' . ($row['con'] ?? '')),
                'group' => 'variable_stars', 'ra_deg' => (float) $row['ra'] * 15,
                'dec_deg' => (float) $row['dec'], 'size_arcsec' => null,
                'magnitude' => $row['mag'] !== null ? (float) $row['mag'] : null,
                'note' => 'HIP ' . $row['hip'] . ' · Keine Minima-/Maxima-Vorhersage',
            ];
        }
    }
    if (in_array('comets', $types, true)) {
        $stmt = $pdo->query('SELECT id, designation_and_name, year_of_perihelion, month_of_perihelion,
            day_of_perihelion, perihelion_dist_au, eccentricity, arg_perihelion_deg, ascending_node_deg,
            inclination_deg, absolute_magnitude_h, slope_parameter_g, epoch_date FROM comets_mpc');
        foreach ($stmt as $row) {
            $objects[] = ['id' => 'comet-' . $row['id'], 'name' => $row['designation_and_name'],
                'group' => 'comets', 'size_arcsec' => null, 'orbit' => $row,
                'note' => 'Bahnepoche: ' . ($row['epoch_date'] ?? 'unbekannt')];
        }
    }
    return $objects;
}

function runObservationSuggestions(array $payload): array
{
    $file = tempnam(sys_get_temp_dir(), 'skyview_observation_');
    if ($file === false) {
        throw new RuntimeException('Temporäre Datei konnte nicht angelegt werden.');
    }
    try {
        if (file_put_contents($file, json_encode($payload, JSON_THROW_ON_ERROR | JSON_UNESCAPED_UNICODE)) === false) {
            throw new RuntimeException('Berechnungsdaten konnten nicht geschrieben werden.');
        }
        $candidates = PHP_OS_FAMILY === 'Windows' ? ['python', 'py'] : ['/usr/bin/python3', 'python3', 'python'];
        foreach ($candidates as $binary) {
            // Array command bypasses the shell; no user input is interpolated into a command.
            $process = @proc_open([$binary, __DIR__ . '/py/observation_suggestions_api.py', $file],
                [0 => ['pipe', 'r'], 1 => ['pipe', 'w'], 2 => ['pipe', 'w']], $pipes);
            if (!is_resource($process)) {
                continue;
            }
            fclose($pipes[0]);
            stream_set_blocking($pipes[1], false);
            stream_set_blocking($pipes[2], false);
            $output = '';
            $errors = '';
            $deadline = microtime(true) + 90;
            $timedOut = false;
            do {
                $output .= stream_get_contents($pipes[1]);
                $errors .= stream_get_contents($pipes[2]);
                $status = proc_get_status($process);
                if (!$status['running']) {
                    break;
                }
                if (microtime(true) > $deadline) {
                    $timedOut = true;
                    proc_terminate($process);
                    break;
                }
                usleep(20000);
            } while (true);
            $output .= stream_get_contents($pipes[1]);
            $errors .= stream_get_contents($pipes[2]);
            fclose($pipes[1]);
            fclose($pipes[2]);
            proc_close($process);
            if ($timedOut) {
                throw new RuntimeException('Die Berechnung dauert zu lange. Bitte weniger Objekttypen auswählen.');
            }
            $decoded = json_decode($output, true);
            if (is_array($decoded) && array_key_exists('ok', $decoded)) {
                return $decoded;
            }
            error_log('Observation suggestions Python: ' . substr($errors, 0, 2000));
        }
        throw new RuntimeException('Die Berechnung ist derzeit nicht verfügbar. Bitte die Python-Installation prüfen.');
    } finally {
        @unlink($file);
    }
}