<?php
// Content endpoint for the id.andmore.pt / hub social-post generator (hub pull).
//
// Server-to-server, no session: the hub signs each request with the shared
// HUB_CONTENT_SECRET (.env; generated on id.andmore.pt → Plataformas →
// fitme3070 → "Gerar segredo de conteúdo"):
//   X-Hub-Date:  ISO-8601 timestamp (±10 min tolerance)
//   X-Hub-Token: hash_hmac('sha256', date . path, secret)
//
// Response is the generic hub envelope. One item type:
//   event — the weekly class schedule (dias da semana + as aulas nesses dias).
//           Each recurring class is emitted as an event whose date_start is the
//           next occurrence of that weekday/time, so the hub renders the day
//           name automatically; the weekday is also given explicitly in fields.
//
// GET params: from=Y-m-d  to=Y-m-d  type=event (all optional; the schedule is
// recurring, so the date range is not used to filter).

require_once __DIR__ . '/../config/db.php';
require_once __DIR__ . '/../config/functions.php';

header('Content-Type: application/json; charset=utf-8');

$secret = (string) env('HUB_CONTENT_SECRET', '');
if ($secret === '') {
    http_response_code(503);
    echo json_encode(['error' => 'HUB_CONTENT_SECRET não configurado nesta plataforma.']);
    exit;
}

$date  = (string) ($_SERVER['HTTP_X_HUB_DATE'] ?? '');
$token = (string) ($_SERVER['HTTP_X_HUB_TOKEN'] ?? '');
$path  = (string) (parse_url($_SERVER['REQUEST_URI'] ?? '', PHP_URL_PATH) ?? '');
$ts    = $date !== '' ? strtotime($date) : false;

if ($token === '' || $ts === false || abs(time() - $ts) > 600
    || !hash_equals(hash_hmac('sha256', $date . $path, $secret), $token)) {
    http_response_code(403);
    echo json_encode(['error' => 'Assinatura inválida.']);
    exit;
}

session_write_close(); // not needed past auth; release the session lock

$type = (string) ($_GET['type'] ?? '');

// Optional category filter: ?category=segunda or ?categories=segunda,quarta.
// For this platform the category dimension is the weekday. Empty = all.
$cat_filter = array_filter(array_map(
    fn($c) => strtolower(trim($c)),
    preg_split('/[,]/', (string) ($_GET['categories'] ?? $_GET['category'] ?? ''))
));

// Weekday enum → display label and ISO day-of-week (1=Mon … 7=Sun).
$WEEKDAYS = [
    'segunda' => ['Segunda-feira', 1],
    'terça'   => ['Terça-feira',   2],
    'quarta'  => ['Quarta-feira',  3],
    'quinta'  => ['Quinta-feira',  4],
    'sexta'   => ['Sexta-feira',   5],
    'sábado'  => ['Sábado',        6],
    'domingo' => ['Domingo',       7],
];
$LOCALS = ['sala1' => 'Sala 1', 'sala2' => 'Sala 2', 'crossfit' => 'CrossFit'];

// Next occurrence (today or in the coming week) of a given weekday at $time.
$next_occurrence = static function (int $isoDow, string $time): DateTime {
    $dt   = new DateTime('today');
    $diff = ($isoDow - (int) $dt->format('N') + 7) % 7; // 0 = today
    if ($diff > 0) $dt->modify("+{$diff} day");
    [$h, $m, $s] = array_pad(explode(':', $time), 3, '0');
    $dt->setTime((int) $h, (int) $m, (int) $s);
    return $dt;
};

$items = [];

// ── event: weekly class schedule ────────────────────────────────────────────
if ($type === '' || $type === 'event') {
    // db_horario_list() already joins modalidades and orders segunda→domingo,
    // then by start time; restrict to live modalidades (not soft-deleted).
    $rows = $pdo->query("
        SELECT h.id, h.dia_semana, h.local,
               m.nome AS modalidade_nome,
               TIME_FORMAT(h.hora_inicio, '%H:%i') AS hora_inicio_fmt,
               TIME_FORMAT(h.hora_fim,    '%H:%i') AS hora_fim_fmt
        FROM horario h
        JOIN modalidades m ON m.m_id = h.id_modalidade AND m.deleted_at IS NULL
        ORDER BY FIELD(h.dia_semana,'segunda','terça','quarta','quinta','sexta','sábado','domingo'),
                 h.hora_inicio ASC
    ")->fetchAll(PDO::FETCH_ASSOC);

    foreach ($rows as $r) {
        $dia = (string) $r['dia_semana'];
        if (!isset($WEEKDAYS[$dia])) continue; // unknown / NULL weekday — skip
        if ($cat_filter && !in_array($dia, $cat_filter, true)) continue; // category filter
        [$diaLabel, $isoDow] = $WEEKDAYS[$dia];

        $ini = (string) $r['hora_inicio_fmt'];
        $fim = (string) $r['hora_fim_fmt'];
        $hora = $fim !== '' ? ($ini . '–' . $fim) : $ini;
        $local = $LOCALS[(string) $r['local']] ?? '';

        $start = $next_occurrence($isoDow, $ini !== '' ? $ini . ':00' : '00:00:00');
        $end   = $fim !== '' ? $next_occurrence($isoDow, $fim . ':00') : null;

        $fields = ['Dia' => $diaLabel, 'Hora' => $hora];
        if ($local !== '') $fields['Local'] = $local;

        $items[] = [
            'id'             => 'aula-' . (int) $r['id'],
            'type'           => 'event',
            'title'          => (string) $r['modalidade_nome'],
            'subtitle'       => $hora . ($local !== '' ? ' · ' . $local : ''),
            'date_start'     => $start->format('c'),
            'date_end'       => $end ? $end->format('c') : '',
            'url'            => base_url('home/horario'),
            'category'       => $dia,       // machine key (weekday enum value)
            'category_label' => $diaLabel,  // human label
            'fields'         => $fields,
            'media'          => [],
        ];
    }
}

// Distinct categories present, in item order (segunda→domingo), with counts —
// lets the hub offer a category filter without re-deriving it.
$categories = [];
foreach ($items as $it) {
    $k = $it['category'];
    if ($k === '') continue;
    if (!isset($categories[$k])) {
        $categories[$k] = ['key' => $k, 'label' => $it['category_label'], 'count' => 0];
    }
    $categories[$k]['count']++;
}

echo json_encode([
    'app'           => 'fitme3070',
    'generated_at'  => gmdate('c'),
    'item_types'    => array_values(array_unique(array_column($items, 'type'))),
    'category_label'=> 'Dia da semana',          // what the category dimension means here
    'categories'    => array_values($categories),
    'items'         => $items,
], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);