<?php
declare(strict_types=1);

session_start();

$loggedIn = isset($_SESSION['user_id']);
$pageTitle = 'Meteorstroeme - AstroTools';
$bodyClass = 'meteorshowers-page';
$publicBasePath = './';
$locationIsGlobal = true;
$pdo = null;
$defaultLocation = [
    'name' => 'Sternwarte Sonneberg',
    'latitude' => 50.3547,
    'longitude' => 11.1900,
    'elevation' => 640.0,
    'timezone' => 'Europe/Berlin',
];
$meteorRows = [];
$pageError = null;

function normalizeMeteorDegree(float $value): float
{
    $normalized = fmod($value, 360.0);
    if ($normalized < 0.0) {
        $normalized += 360.0;
    }

    return $normalized;
}

function meteorSolarLongitude(DateTimeImmutable $dateTime): float
{
    $julianDay = ((float) $dateTime->format('U')) / 86400.0 + 2440587.5;
    $daysSinceJ2000 = $julianDay - 2451545.0;
    $meanLongitude = normalizeMeteorDegree(280.46 + 0.9856474 * $daysSinceJ2000);
    $meanAnomalyRad = deg2rad(normalizeMeteorDegree(357.528 + 0.9856003 * $daysSinceJ2000));

    return normalizeMeteorDegree(
        $meanLongitude
        + 1.915 * sin($meanAnomalyRad)
        + 0.020 * sin(2.0 * $meanAnomalyRad)
    );
}

function meteorForwardDegreeDistance(float $from, float $to): float
{
    return normalizeMeteorDegree($to - $from);
}

function meteorRadiantIsVisible(float $latitudeDeg, ?float $declinationDeg): bool
{
    if ($declinationDeg === null) {
        return false;
    }

    return abs($latitudeDeg - $declinationDeg) < 90.0;
}

function findMeteorSolarLongitudeCrossing(
    DateTimeImmutable $rangeStartLocal,
    DateTimeImmutable $rangeEndLocal,
    float $targetLongitude,
    DateTimeZone $displayTimezone
): ?DateTimeImmutable {
    $utc = new DateTimeZone('UTC');
    $rangeStartUtc = $rangeStartLocal->setTimezone($utc);
    $rangeEndUtc = $rangeEndLocal->setTimezone($utc);

    $startLongitude = meteorSolarLongitude($rangeStartUtc);
    $endLongitude = meteorSolarLongitude($rangeEndUtc);
    $targetDelta = meteorForwardDegreeDistance($startLongitude, $targetLongitude);
    $rangeDelta = meteorForwardDegreeDistance($startLongitude, $endLongitude);

    if ($targetDelta > $rangeDelta + 0.0001) {
        return null;
    }

    $low = (int) $rangeStartUtc->format('U');
    $high = (int) $rangeEndUtc->format('U');

    for ($i = 0; $i < 40; $i++) {
        $mid = (int) floor(($low + $high) / 2);
        $midLongitude = meteorSolarLongitude(new DateTimeImmutable('@' . $mid));
        $midDelta = meteorForwardDegreeDistance($startLongitude, $midLongitude);

        if ($midDelta < $targetDelta) {
            $low = $mid;
        } else {
            $high = $mid;
        }
    }

    return (new DateTimeImmutable('@' . $high))->setTimezone($displayTimezone);
}

try {
    $dbConfig = require __DIR__ . '/../config/database.php';
    $dsn = sprintf(
        'mysql:host=%s;dbname=%s;charset=%s',
        $dbConfig['host'],
        $dbConfig['dbname'],
        $dbConfig['charset'] ?? 'utf8mb4'
    );
    $pdo = new PDO(
        $dsn,
        $dbConfig['user'],
        $dbConfig['pass'],
        [
            PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
        ]
    );

    if ($loggedIn && isset($_SESSION['user_id'])) {
        $stmtLocation = $pdo->prepare(
            'SELECT id, name, latitude, longitude, elevation, timezone
             FROM app_user_locations
             WHERE user_id = ? AND is_default = 1
             LIMIT 1'
        );
        $stmtLocation->execute([(int) $_SESSION['user_id']]);
        $userLocation = $stmtLocation->fetch();
        if (is_array($userLocation)) {
            $defaultLocation = $userLocation;
            $locationIsGlobal = false;
        }
    }

    $stmt = $pdo->query(
        "SELECT designation, shower_code, radiant_delta_deg, peak_sol, zhr, zhr_variable
         FROM meteorshowers
         WHERE peak_sol IS NOT NULL
         ORDER BY peak_sol ASC, designation ASC"
    );
    $meteorRows = $stmt->fetchAll();
} catch (Throwable $e) {
    $pageError = $e->getMessage();
}

require __DIR__ . '/header.php';

$displayTimezoneName = (string) (($currentLocation['timezone'] ?? null) ?: ($defaultLocation['timezone'] ?? 'Europe/Berlin'));
$displayTimezone = new DateTimeZone($displayTimezoneName);
$displayLocationName = (string) (($currentLocation['name'] ?? null) ?: ($defaultLocation['name'] ?? 'Sternwarte Sonneberg'));
$displayLatitude = isset($currentLocation['latitude']) ? (float) $currentLocation['latitude'] : (float) $defaultLocation['latitude'];
$currentYear = (int) (new DateTimeImmutable('now', $displayTimezone))->format('Y');
$yearStart = new DateTimeImmutable(sprintf('%04d-01-01 00:00:00', $currentYear), $displayTimezone);
$yearEnd = $yearStart->modify('+1 year');
$meteorEvents = [];

foreach ($meteorRows as $row) {
    if (!is_array($row) || !isset($row['peak_sol'])) {
        continue;
    }

    $peakDateTime = findMeteorSolarLongitudeCrossing(
        $yearStart,
        $yearEnd,
        (float) $row['peak_sol'],
        $displayTimezone
    );
    if (!$peakDateTime instanceof DateTimeImmutable) {
        continue;
    }

    $visible = meteorRadiantIsVisible(
        $displayLatitude,
        $row['radiant_delta_deg'] !== null ? (float) $row['radiant_delta_deg'] : null
    );

    $zhrText = '-';
    if ($row['zhr'] !== null && (int) $row['zhr'] >= 0) {
        $zhrText = 'ca. ' . (int) $row['zhr'];
    } elseif (trim((string) ($row['zhr_variable'] ?? '')) !== '') {
        $zhrText = 'ca. ' . trim((string) $row['zhr_variable']);
    }

    $meteorEvents[] = [
        'designation' => trim((string) ($row['designation'] ?? '')),
        'shower_code' => trim((string) ($row['shower_code'] ?? '')),
        'peak' => $peakDateTime,
        'visible' => $visible,
        'visible_label' => $visible ? 'vom Standort sichtbar' : 'vom Standort nicht sichtbar',
        'zhr_text' => $zhrText,
    ];
}

usort(
    $meteorEvents,
    static fn (array $a, array $b): int => $a['peak'] <=> $b['peak']
);
?>

<section class="card meteorshowers-card">
  <div class="meteorshowers-shell">
    <div class="meteorshowers-header">
      <h2>Meteorstroeme <?= htmlspecialchars((string) $currentYear, ENT_QUOTES, 'UTF-8') ?></h2>
      <p>
        Einfache Jahresliste der Meteorstrom-Maxima fuer
        <strong><?= htmlspecialchars($displayLocationName, ENT_QUOTES, 'UTF-8') ?></strong>
        in <?= htmlspecialchars($displayTimezoneName, ENT_QUOTES, 'UTF-8') ?>.
      </p>
    </div>

    <?php if ($pageError !== null): ?>
      <div class="meteorshowers-empty meteorshowers-empty-error">
        Daten konnten nicht geladen werden: <?= htmlspecialchars($pageError, ENT_QUOTES, 'UTF-8') ?>
      </div>
    <?php elseif ($meteorEvents === []): ?>
      <div class="meteorshowers-empty">
        Fuer das aktuelle Jahr wurden keine Meteorstrom-Daten gefunden.
      </div>
    <?php else: ?>
      <div class="meteorshowers-table-wrap">
        <table class="meteorshowers-table">
          <thead>
            <tr>
              <th>Datum</th>
              <th>Uhrzeit</th>
              <th>Meteorstrom</th>
              <th>Code</th>
              <th>ZHR</th>
              <th>Sichtbarkeit</th>
            </tr>
          </thead>
          <tbody>
            <?php foreach ($meteorEvents as $event): ?>
              <tr class="<?= $event['visible'] ? 'is-visible' : 'is-hidden' ?>">
                <td><?= htmlspecialchars($event['peak']->format('d.m.Y'), ENT_QUOTES, 'UTF-8') ?></td>
                <td><?= htmlspecialchars($event['peak']->format('H:i'), ENT_QUOTES, 'UTF-8') ?></td>
                <td><?= htmlspecialchars($event['designation'] !== '' ? $event['designation'] : 'Unbenannter Meteorstrom', ENT_QUOTES, 'UTF-8') ?></td>
                <td><?= htmlspecialchars($event['shower_code'] !== '' ? $event['shower_code'] : '-', ENT_QUOTES, 'UTF-8') ?></td>
                <td><?= htmlspecialchars($event['zhr_text'], ENT_QUOTES, 'UTF-8') ?></td>
                <td><?= htmlspecialchars($event['visible_label'], ENT_QUOTES, 'UTF-8') ?></td>
              </tr>
            <?php endforeach; ?>
          </tbody>
        </table>
      </div>
    <?php endif; ?>
  </div>
</section>

<style>
.meteorshowers-page main > .container {
  max-width: min(1180px, calc(100% - 28px));
}

.meteorshowers-card {
  padding: 18px;
}

.meteorshowers-shell {
  display: grid;
  gap: 18px;
}

.meteorshowers-header,
.meteorshowers-table-wrap,
.meteorshowers-empty {
  border: 1px solid rgba(201, 168, 76, 0.14);
  border-radius: calc(var(--radius) + 4px);
  background:
    radial-gradient(circle at top left, rgba(74, 158, 255, 0.1), transparent 34%),
    linear-gradient(180deg, rgba(10, 15, 30, 0.96) 0%, rgba(7, 11, 22, 0.98) 100%);
}

.meteorshowers-header {
  padding: 22px 20px;
}

.meteorshowers-header h2 {
  margin: 0 0 8px;
}

.meteorshowers-header p,
.meteorshowers-empty {
  margin: 0;
  color: rgba(222, 232, 255, 0.86);
  line-height: 1.7;
}

.meteorshowers-empty {
  padding: 18px 20px;
}

.meteorshowers-empty-error {
  border-color: rgba(200, 90, 90, 0.36);
  color: rgba(255, 214, 214, 0.92);
}

.meteorshowers-table-wrap {
  overflow: hidden;
}

.meteorshowers-table {
  width: 100%;
  border-collapse: collapse;
}

.meteorshowers-table th,
.meteorshowers-table td {
  padding: 12px 14px;
  text-align: left;
  border-bottom: 1px solid rgba(201, 168, 76, 0.08);
}

.meteorshowers-table th {
  color: rgba(235, 242, 255, 0.95);
  font-size: 0.92rem;
  letter-spacing: 0.04em;
}

.meteorshowers-table td {
  color: rgba(232, 238, 250, 0.92);
}

.meteorshowers-table tbody tr.is-visible {
  background: rgba(70, 150, 95, 0.22);
}

.meteorshowers-table tbody tr.is-hidden {
  background: rgba(190, 168, 54, 0.22);
}

.meteorshowers-table tbody tr:hover {
  background-color: rgba(255, 255, 255, 0.06);
}

.meteorshowers-table tbody tr:last-child td {
  border-bottom: 0;
}

@media (max-width: 900px) {
  .meteorshowers-table-wrap {
    overflow-x: auto;
  }

  .meteorshowers-table {
    min-width: 760px;
  }
}
</style>

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