<?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 = 'Diagramm über alle Filter';
$errors = [];
$eruptionIntervalDays = 227.5687;
$lastEruptionUtc = new DateTimeImmutable('1946-02-09 00:00:00', new DateTimeZone('UTC'));
$todayUtc = new DateTimeImmutable('now', new DateTimeZone('UTC'));
$secondsPerDay = 86400;
$eruptionIntervalSeconds = (int) round($eruptionIntervalDays * $secondsPerDay);
$elapsedSecondsSinceLastEruption = max(0, $todayUtc->getTimestamp() - $lastEruptionUtc->getTimestamp());
$elapsedIntervals = (int) floor($elapsedSecondsSinceLastEruption / $eruptionIntervalSeconds);
$nextPossibleEruptionUtc = $lastEruptionUtc->modify('+' . (($elapsedIntervals + 1) * $eruptionIntervalSeconds) . ' seconds');
$daysUntilNextEruption = ($nextPossibleEruptionUtc->getTimestamp() - $todayUtc->getTimestamp()) / $secondsPerDay;

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

function formatGermanDate(?string $value, bool $includeTime = true): string
{
    if ($value === null || trim($value) === '') {
        return 'â€”';
    }

    try {
        $date = new DateTimeImmutable($value, new DateTimeZone('UTC'));
    } catch (Exception) {
        return $value;
    }

    return $date->format($includeTime ? 'd.m.Y H:i:s' : 'd.m.Y');
}

$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($errors) && !empty($availableFilters)) {
    $queryFilters = array_column($availableFilters, 'code');
    $placeholders = implode(',', array_fill(0, count($queryFilters), '?'));
    $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
    ");
    $stmt->execute($queryFilters);
    $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.';
}

$filterMetadata = [];
$filterMetadataPath = __DIR__ . '/../config/filter_colors.json';
if (is_file($filterMetadataPath)) {
    $filterMetadataRaw = file_get_contents($filterMetadataPath);
    $filterMetadataDecoded = is_string($filterMetadataRaw) ? json_decode($filterMetadataRaw, true) : null;
    if (is_array($filterMetadataDecoded)) {
        $filterMetadata = $filterMetadataDecoded;
    }
}

$filterPalette = [];
$filterDescriptions = [];
foreach ($filterMetadata as $filterCode => $filterConfig) {
    if (!is_array($filterConfig)) {
        continue;
    }

    $filterPalette[$filterCode] = (string) ($filterConfig['color'] ?? '');
    $filterDescriptions[$filterCode] = (string) ($filterConfig['description'] ?? $filterCode);
}

$chartDatasets = [];
foreach ($availableFilters as $availableFilter) {
    $filterCode = $availableFilter['code'];
    $chartDatasets[$filterCode] = [
        'filter' => $filterCode,
        'color' => $filterPalette[$filterCode] ?? sprintf('#%06X', crc32($filterCode) & 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'] : 'â€”',
            $point['magnitude_error'] !== null ? number_format((float) $point['magnitude_error'], 3, '.', '') : 'â€”',
        ];
    }

    $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>',
    ];
}

$plotlyPayload = [
    'traces' => $plotlyTraces,
    'datasets' => $chartDatasets,
    'selectedFilters' => $selectedFilters,
    '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-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
    margin-bottom: 0.9rem;
}

.tcrb-filter-actions .btn {
    flex: 1 1 auto;
}

.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" id="tcrbFilterForm">
            <div class="tcrb-filter-actions">
                <button type="button" class="btn btn-secondary" id="tcrbSelectAll">Alle an</button>
                <button type="button" class="btn btn-secondary" id="tcrbSelectNone">Alle aus</button>
            </div>
            <div class="tcrb-filter-list">
                <?php foreach ($availableFilters as $filter): ?>
                    <?php
                    $filterCode = $filter['code'];
                    $filterColor = $filterPalette[$filterCode] ?? sprintf('#%06X', crc32($filterCode) & 0xFFFFFF);
                    $filterDescription = $filterDescriptions[$filterCode] ?? $filterCode;
                    ?>
                    <div class="tcrb-filter-option" title="<?= h($filterDescription) ?>">
                        <label title="<?= h($filterDescription) ?>">
                            <input
                                type="checkbox"
                                name="filters[]"
                                value="<?= h($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>
        </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) $summary['count'] ?></strong>
                    <span>Messpunkte</span>
                </div>
                <div class="tcrb-summary-box">
                    <strong><?= h(formatGermanDate($summary['min_utc'])) ?></strong>
                    <span>Erster Beobachtungszeitpunkt</span>
                </div>
                <div class="tcrb-summary-box">
                    <strong><?= h(formatGermanDate($summary['max_utc'])) ?></strong>
                    <span>Letzter Beobachtungszeitpunkt</span>
                </div>
                <div class="tcrb-summary-box">
                    <strong><?= number_format((float) $summary['min_mag'], 3, '.', '') ?> bis <?= number_format((float) $summary['max_mag'], 3, '.', '') ?></strong>
                    <span>Magnitudenbereich</span>
                </div>
                <div class="tcrb-summary-box">
                    <strong><?= h($nextPossibleEruptionUtc->format('d.m.Y')) ?></strong>
                    <span>Nächster möglicher Ausbruch<br>(in <?= number_format($daysUntilNextEruption, 1, ',', '.') ?> Tagen)</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): ?>
                    <?php $filterDescription = $filterDescriptions[$dataset['filter']] ?? $dataset['filter']; ?>
                    <div class="tcrb-chart-legend-item" title="<?= h($filterDescription) ?>">
                        <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');
    const filterForm = document.getElementById('tcrbFilterForm');
    const selectAllEl = document.getElementById('tcrbSelectAll');
    const selectNoneEl = document.getElementById('tcrbSelectNone');
    const filterCheckboxes = filterForm ? Array.from(filterForm.querySelectorAll('input[name="filters[]"]')) : [];

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

    if (filterForm) {
        filterForm.addEventListener('submit', function (event) {
            event.preventDefault();
        });
    }

    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' },
            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']
    };

    function buildDatasetTrace(dataset) {
        const errorValues = [];
        let hasErrors = false;

        dataset.points.forEach(function (point) {
            const errorValue = point.magnitude_error !== null ? Number(point.magnitude_error) : 0;
            errorValues.push(errorValue);
            if (errorValue > 0) {
                hasErrors = true;
            }
        });

        return {
            type: 'scatter',
            mode: 'lines+markers',
            name: dataset.filter,
            x: dataset.points.map(function (point) { return point.observed_at_utc; }),
            y: dataset.points.map(function (point) { return Number(point.magnitude); }),
            line: {
                color: dataset.color,
                width: 2,
                shape: 'spline',
                smoothing: 0.65
            },
            marker: {
                color: dataset.color,
                size: 3,
                line: {
                    color: '#0f172a',
                    width: 1
                }
            },
            error_y: {
                type: 'data',
                array: errorValues,
                visible: hasErrors,
                thickness: 1.1,
                width: 3,
                color: dataset.color
            },
            customdata: dataset.points.map(function (point) {
                return [
                    point.jd,
                    point.observer_code !== '' ? point.observer_code : '-',
                    point.magnitude_error !== null ? Number(point.magnitude_error).toFixed(3) : '-'
                ];
            }),
            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>'
        };
    }

    function getActiveFilterCodes() {
        return filterCheckboxes
            .filter(function (checkbox) { return checkbox.checked; })
            .map(function (checkbox) { return checkbox.value; });
    }

    function renderPlot() {
        const activeFilterCodes = getActiveFilterCodes();
        const activeDatasets = payload.datasets.filter(function (dataset) {
            return activeFilterCodes.includes(dataset.filter);
        });
        const traces = activeDatasets.map(buildDatasetTrace);

        if (traces.length === 0) {
            Plotly.react(plotEl, [], layout, config);
            return;
        }

        Plotly.react(plotEl, traces, layout, config);
    }

    const initiallySelected = Array.isArray(payload.selectedFilters) && payload.selectedFilters.length > 0
        ? payload.selectedFilters
        : ['V'];

    filterCheckboxes.forEach(function (checkbox) {
        checkbox.checked = initiallySelected.includes(checkbox.value);
        checkbox.addEventListener('change', renderPlot);
    });

    if (selectAllEl) {
        selectAllEl.addEventListener('click', function () {
            filterCheckboxes.forEach(function (checkbox) {
                checkbox.checked = true;
            });
            renderPlot();
        });
    }

    if (selectNoneEl) {
        selectNoneEl.addEventListener('click', function () {
            filterCheckboxes.forEach(function (checkbox) {
                checkbox.checked = false;
            });
            renderPlot();
        });
    }

    renderPlot();
})();
</script>
<?php endif; ?>

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