<?php
declare(strict_types=1);

ini_set('display_errors', '1');
error_reporting(E_ALL);
session_start();

$config = require __DIR__ . '/../config/database.php';

$dsn = sprintf(
    'mysql:host=%s;dbname=%s;charset=%s',
    $config['host'],
    $config['dbname'],
    $config['charset'] ?? 'utf8mb4'
);

$pdo = new PDO(
    $dsn,
    $config['user'],
    $config['pass'],
    [
        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
        PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    ]
);

$loggedIn = isset($_SESSION['user_id']);
$pageTitle = 'T CrB Lichtkurve';
$headerIntroPre = 'Variabler Stern';
$headerIntroTitle = 'T CrB Lichtkurve';
$headerIntroSub = 'AAVSO-WebObs-Daten mit waehlbaren Filtern in einem gemeinsamen Plotly-Diagramm.';
$errors = [];

function h(?string $value): string
{
    return htmlspecialchars((string) $value, ENT_QUOTES, 'UTF-8');
}

$filterRows = $pdo->query("
    SELECT `filter_code`, COUNT(*) AS `entry_count`
    FROM `aavso_tcrb_observations`
    WHERE `filter_code` IS NOT NULL
      AND `filter_code` <> ''
    GROUP BY `filter_code`
    ORDER BY `filter_code` ASC
")->fetchAll();

$availableFilters = [];
foreach ($filterRows as $filterRow) {
    $filterCode = trim((string) ($filterRow['filter_code'] ?? ''));
    if ($filterCode === '') {
        continue;
    }

    $availableFilters[] = [
        'code' => $filterCode,
        'count' => (int) ($filterRow['entry_count'] ?? 0),
    ];
}

$selectedFilters = array_values(array_unique(array_filter(array_map(
    static fn ($value): string => trim((string) $value),
    is_array($_GET['filters'] ?? null) ? $_GET['filters'] : []
), static fn (string $value): bool => $value !== '')));

if (empty($selectedFilters)) {
    $selectedFilters = in_array('V', array_column($availableFilters, 'code'), true)
        ? ['V']
        : array_column($availableFilters, 'code');
}

$selectedFilters = array_values(array_intersect($selectedFilters, array_column($availableFilters, 'code')));

if (empty($availableFilters)) {
    $errors[] = 'In der Tabelle aavso_tcrb_observations sind noch keine T-CrB-Daten vorhanden.';
}

$observations = [];
$summary = [
    'count' => 0,
    'min_utc' => null,
    'max_utc' => null,
    'min_mag' => null,
    'max_mag' => null,
];

if (empty($errors) && !empty($selectedFilters)) {
    $placeholders = implode(',', array_fill(0, count($selectedFilters), '?'));
    $stmt = $pdo->prepare("
        SELECT
            `observed_at_utc`,
            `jd`,
            `magnitude`,
            `magnitude_error`,
            `filter_code`,
            `observer_code`,
            `notes_raw`
        FROM `aavso_tcrb_observations`
        WHERE `filter_code` IN ({$placeholders})
        ORDER BY `observed_at_utc` ASC, `jd` ASC
    ");
    $stmt->execute($selectedFilters);
    $rows = $stmt->fetchAll();

    foreach ($rows as $row) {
        $observedAtUtc = (string) ($row['observed_at_utc'] ?? '');
        $magnitude = isset($row['magnitude']) ? (float) $row['magnitude'] : null;
        if ($observedAtUtc === '' || $magnitude === null) {
            continue;
        }

        $observations[] = [
            'observed_at_utc' => $observedAtUtc,
            'jd' => isset($row['jd']) ? (float) $row['jd'] : null,
            'magnitude' => $magnitude,
            'magnitude_error' => $row['magnitude_error'] !== null ? (float) $row['magnitude_error'] : null,
            'filter_code' => (string) ($row['filter_code'] ?? ''),
            'observer_code' => (string) ($row['observer_code'] ?? ''),
            'notes_raw' => (string) ($row['notes_raw'] ?? ''),
        ];

        $summary['count']++;
        $summary['min_utc'] = $summary['min_utc'] === null || $observedAtUtc < $summary['min_utc'] ? $observedAtUtc : $summary['min_utc'];
        $summary['max_utc'] = $summary['max_utc'] === null || $observedAtUtc > $summary['max_utc'] ? $observedAtUtc : $summary['max_utc'];
        $summary['min_mag'] = $summary['min_mag'] === null || $magnitude < $summary['min_mag'] ? $magnitude : $summary['min_mag'];
        $summary['max_mag'] = $summary['max_mag'] === null || $magnitude > $summary['max_mag'] ? $magnitude : $summary['max_mag'];
    }
}

if (empty($errors) && empty($observations)) {
    $errors[] = 'Fuer die ausgewaehlten Filter wurden keine Daten gefunden.';
}

$filterPalette = [
    'U' => '#4c6ef5',
    'B' => '#1c7ed6',
    'V' => '#2b8a3e',
    'R' => '#c92a2a',
    'I' => '#862e9c',
    'CV' => '#495057',
    'TG' => '#0b7285',
    'TB' => '#364fc7',
    'TR' => '#d9480f',
];

$chartDatasets = [];
foreach ($selectedFilters as $selectedFilter) {
    $chartDatasets[$selectedFilter] = [
        'filter' => $selectedFilter,
        'color' => $filterPalette[$selectedFilter] ?? sprintf('#%06X', crc32($selectedFilter) & 0xFFFFFF),
        'points' => [],
    ];
}

foreach ($observations as $observation) {
    $filterCode = $observation['filter_code'];
    if (!isset($chartDatasets[$filterCode])) {
        continue;
    }

    $chartDatasets[$filterCode]['points'][] = $observation;
}

$chartDatasets = array_values(array_filter($chartDatasets, static fn (array $dataset): bool => !empty($dataset['points'])));

$plotlyTraces = [];
foreach ($chartDatasets as $dataset) {
    $xValues = [];
    $yValues = [];
    $errorValues = [];
    $customData = [];
    $hasErrors = false;

    foreach ($dataset['points'] as $point) {
        $xValues[] = (string) $point['observed_at_utc'];
        $yValues[] = (float) $point['magnitude'];
        $errorValue = $point['magnitude_error'] !== null ? (float) $point['magnitude_error'] : 0.0;
        $errorValues[] = $errorValue;
        if ($errorValue > 0) {
            $hasErrors = true;
        }

        $customData[] = [
            $point['jd'],
            $point['observer_code'] !== '' ? $point['observer_code'] : '—',
            $point['magnitude_error'] !== null ? number_format((float) $point['magnitude_error'], 3, '.', '') : '—',
        ];
    }

    $plotlyTraces[] = [
        'type' => 'scatter',
        'mode' => 'lines+markers',
        'name' => $dataset['filter'],
        'x' => $xValues,
        'y' => $yValues,
        'line' => [
            'color' => $dataset['color'],
            'width' => 2,
        ],
        'marker' => [
            'color' => $dataset['color'],
            'size' => 7,
            'line' => [
                'color' => '#0f172a',
                'width' => 1,
            ],
        ],
        'error_y' => [
            'type' => 'data',
            'array' => $errorValues,
            'visible' => $hasErrors,
            'thickness' => 1.1,
            'width' => 3,
            'color' => $dataset['color'],
        ],
        'customdata' => $customData,
        'hovertemplate' => 'Filter %{fullData.name}<br>'
            . 'Magnitude %{y:.3f}<br>'
            . 'Fehler %{customdata[2]}<br>'
            . 'UTC %{x}<br>'
            . 'JD %{customdata[0]}<br>'
            . 'Observer %{customdata[1]}<extra></extra>',
    ];
}

$meanSourcePoints = [];
foreach ($chartDatasets as $dataset) {
    foreach ($dataset['points'] as $point) {
        $meanSourcePoints[] = $point;
    }
}

usort($meanSourcePoints, static function (array $a, array $b): int {
    return strcmp((string) $a['observed_at_utc'], (string) $b['observed_at_utc']);
});

if (count($meanSourcePoints) >= 3) {
    $windowSize = min(11, count($meanSourcePoints));
    if ($windowSize % 2 === 0) {
        $windowSize--;
    }

    $halfWindow = intdiv($windowSize, 2);
    $meanX = [];
    $meanY = [];
    $meanCustomData = [];

    foreach ($meanSourcePoints as $index => $point) {
        $start = max(0, $index - $halfWindow);
        $end = min(count($meanSourcePoints) - 1, $index + $halfWindow);
        $sum = 0.0;
        $count = 0;

        for ($i = $start; $i <= $end; $i++) {
            $sum += (float) $meanSourcePoints[$i]['magnitude'];
            $count++;
        }

        if ($count === 0) {
            continue;
        }

        $meanValue = $sum / $count;
        $meanX[] = (string) $point['observed_at_utc'];
        $meanY[] = $meanValue;
        $meanCustomData[] = [$count];
    }

    if (!empty($meanX)) {
        $plotlyTraces[] = [
            'type' => 'scatter',
            'mode' => 'lines',
            'name' => 'Mittelkurve',
            'x' => $meanX,
            'y' => $meanY,
            'line' => [
                'color' => '#f4d35e',
                'width' => 3,
                'dash' => 'solid',
                'shape' => 'spline',
                'smoothing' => 0.7,
            ],
            'customdata' => $meanCustomData,
            'hovertemplate' => 'Mittelkurve<br>'
                . 'Magnitude %{y:.3f}<br>'
                . 'UTC %{x}<br>'
                . 'Fenster %{customdata[0]} Punkte<extra></extra>',
        ];
    }
}

$plotlyPayload = [
    'traces' => $plotlyTraces,
    'summary' => $summary,
];
?>
<?php require __DIR__ . '/header.php'; ?>
<script src="https://cdn.plot.ly/plotly-3.2.0.min.js" charset="utf-8"></script>

<?php if (!empty($errors)): ?>
    <ul class="msg-error">
        <?php foreach ($errors as $error): ?>
            <li><?= h($error) ?></li>
        <?php endforeach; ?>
    </ul>
<?php endif; ?>

<style>
.tcrb-layout {
    display: grid;
    grid-template-columns: minmax(18rem, 22rem) minmax(0, 1fr);
    gap: 1.2rem;
    align-items: start;
}

.tcrb-filter-list {
    display: grid;
    gap: 0.55rem;
}

.tcrb-filter-option {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.8rem;
    padding: 0.55rem 0.7rem;
    border: 1px solid rgba(255,255,255,0.12);
    border-radius: 0.7rem;
    background: rgba(255,255,255,0.03);
}

.tcrb-filter-option label {
    display: flex;
    align-items: center;
    gap: 0.55rem;
    margin: 0;
    cursor: pointer;
}

.tcrb-filter-swatch {
    width: 0.9rem;
    height: 0.9rem;
    border-radius: 999px;
    border: 1px solid rgba(255,255,255,0.4);
}

.tcrb-filter-count {
    color: var(--text-dim);
    font-size: 0.9rem;
}

.tcrb-chart-card {
    overflow: hidden;
}

.tcrb-chart-wrap {
    position: relative;
    min-height: 32rem;
    border-radius: 1rem;
    background:
        radial-gradient(circle at top, rgba(200, 168, 75, 0.12), transparent 45%),
        linear-gradient(180deg, rgba(17, 24, 39, 0.96), rgba(7, 10, 18, 0.98));
    border: 1px solid rgba(200, 168, 75, 0.2);
    overflow: hidden;
}

.tcrb-plot {
    width: 100%;
    height: 100%;
}

.tcrb-chart-legend {
    display: flex;
    flex-wrap: wrap;
    gap: 0.7rem 1rem;
    margin-top: 1rem;
}

.tcrb-chart-legend-item {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    color: #dfe7ff;
    font-size: 0.92rem;
}

.tcrb-chart-legend-item span {
    width: 0.85rem;
    height: 0.85rem;
    border-radius: 999px;
}

.tcrb-summary-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0.8rem;
    margin-bottom: 1rem;
}

.tcrb-summary-box {
    padding: 0.8rem 0.9rem;
    border-radius: 0.9rem;
    background: rgba(255,255,255,0.04);
    border: 1px solid rgba(255,255,255,0.08);
}

.tcrb-summary-box strong {
    display: block;
    font-size: 1.05rem;
    color: #f9fafb;
}

.tcrb-summary-box span {
    display: block;
    color: var(--text-dim);
    font-size: 0.88rem;
    margin-top: 0.2rem;
}

.tcrb-chart-empty {
    padding: 2rem 1.2rem;
    color: var(--text-dim);
}

@media (max-width: 960px) {
    .tcrb-layout {
        grid-template-columns: 1fr;
    }

    .tcrb-summary-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}
</style>

<div class="tcrb-layout">
    <div class="card">
        <h2>Filter</h2>
        <form method="get" action="" class="form-stack">
            <div class="tcrb-filter-list">
                <?php foreach ($availableFilters as $filter): ?>
                    <?php
                    $filterCode = $filter['code'];
                    $filterColor = $filterPalette[$filterCode] ?? sprintf('#%06X', crc32($filterCode) & 0xFFFFFF);
                    ?>
                    <div class="tcrb-filter-option">
                        <label>
                            <input
                                type="checkbox"
                                name="filters[]"
                                value="<?= h($filterCode) ?>"
                                <?= in_array($filterCode, $selectedFilters, true) ? 'checked' : '' ?>
                            >
                            <span class="tcrb-filter-swatch" style="background: <?= h($filterColor) ?>"></span>
                            <span><?= h($filterCode) ?></span>
                        </label>
                        <span class="tcrb-filter-count"><?= (int) $filter['count'] ?></span>
                    </div>
                <?php endforeach; ?>
            </div>
            <button type="submit" class="btn btn-primary">Diagramm aktualisieren</button>
        </form>
    </div>

    <div class="card tcrb-chart-card">
        <h2>Lichtkurve</h2>

        <?php if (empty($errors) && !empty($observations)): ?>
            <div class="tcrb-summary-grid">
                <div class="tcrb-summary-box">
                    <strong><?= (int) $summary['count'] ?></strong>
                    <span>Messpunkte</span>
                </div>
                <div class="tcrb-summary-box">
                    <strong><?= h((string) $summary['min_utc']) ?></strong>
                    <span>Erster UTC-Zeitpunkt</span>
                </div>
                <div class="tcrb-summary-box">
                    <strong><?= h((string) $summary['max_utc']) ?></strong>
                    <span>Letzter UTC-Zeitpunkt</span>
                </div>
                <div class="tcrb-summary-box">
                    <strong><?= number_format((float) $summary['min_mag'], 3, '.', '') ?> bis <?= number_format((float) $summary['max_mag'], 3, '.', '') ?></strong>
                    <span>Magnitudenbereich</span>
                </div>
            </div>

            <div class="tcrb-chart-wrap">
                <div class="tcrb-plot" id="tcrbPlot" aria-label="T-CrB-Lichtkurve"></div>
            </div>

            <div class="tcrb-chart-legend">
                <?php foreach ($chartDatasets as $dataset): ?>
                    <div class="tcrb-chart-legend-item">
                        <span style="background: <?= h($dataset['color']) ?>"></span>
                        <?= h($dataset['filter']) ?>
                    </div>
                <?php endforeach; ?>
            </div>
        <?php else: ?>
            <div class="tcrb-chart-empty">Noch keine darstellbaren Daten vorhanden.</div>
        <?php endif; ?>
    </div>
</div>

<?php if (empty($errors) && !empty($observations)): ?>
<script>
(function () {
    const payload = <?= json_encode($plotlyPayload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES) ?>;
    const plotEl = document.getElementById('tcrbPlot');

    if (!plotEl || typeof Plotly === 'undefined' || !payload || !Array.isArray(payload.traces) || payload.traces.length === 0) {
        return;
    }

    const layout = {
        margin: { t: 20, r: 24, b: 56, l: 72 },
        paper_bgcolor: 'rgba(0,0,0,0)',
        plot_bgcolor: 'rgba(0,0,0,0)',
        hovermode: 'closest',
        showlegend: false,
        xaxis: {
            title: { text: 'Beobachtungszeitpunkt (UTC)' },
            type: 'date',
            gridcolor: 'rgba(255,255,255,0.08)',
            linecolor: '#f8fafc',
            tickfont: { color: '#cbd5e1' },
            zeroline: false
        },
        yaxis: {
            title: { text: 'Magnitude (kleiner = heller)' },
            autorange: 'reversed',
            gridcolor: 'rgba(255,255,255,0.12)',
            linecolor: '#f8fafc',
            tickfont: { color: '#cbd5e1' },
            zeroline: false
        },
        font: {
            color: '#f8fafc'
        }
    };

    const config = {
        responsive: true,
        displaylogo: false,
        modeBarButtonsToRemove: ['select2d', 'lasso2d']
    };

    Plotly.newPlot(plotEl, payload.traces, layout, config);
})();
</script>
<?php endif; ?>

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