<?php

/**
 * api_teacher_classes.php
 * --------------------------------------------------------------------------
 * Classi programmate in un mese, CON i partecipanti di ciascuna.
 * Solo staff (Admin=1 / teacher=3). Sola lettura.
 *
 * Posizione: public/api/api_teacher_classes.php
 * Metodo:    GET
 * Auth:      Bearer token (Sanctum) via _bootstrap.php
 * Query:     ?month=YYYY-MM  (default: mese corrente)
 *
 * Replica la logica di adminpanel.php:
 *   - schedule del mese (serviceschedule + service)
 *   - bookings con status='booked' (le "perse" sono booked + lostlesson='Y')
 *   - conteggio posti = tutti i booked (perse incluse)
 * --------------------------------------------------------------------------
 */

require_once __DIR__ . '/_bootstrap.php';

// --- Gate di sicurezza: solo staff ---
$roleId = (int) $user->role_id;
if (!in_array($roleId, [1, 3], true)) {
    http_response_code(403);
    echo json_encode(['success' => false, 'message' => 'Forbidden']);
    exit;
}

// --- Mese richiesto (default: corrente) ---
$month = isset($_GET['month']) ? preg_replace('/[^0-9\-]/', '', $_GET['month']) : date('Y-m');
if (!preg_match('/^\d{4}-\d{2}$/', $month)) {
    $month = date('Y-m');
}
$monthStart = $month . '-01';
if (strtotime($monthStart) === false) {
    $monthStart = date('Y-m-01');
}
$monthEnd = date('Y-m-t', strtotime($monthStart));

// --- Classi del mese ---
$sqlSchedule = "SELECT serviceschedule.idserviceschedule,
                       serviceschedule.idservice,
                       serviceschedule.dateschedule,
                       service.servicename,
                       service.colorclass,
                       service.maxcapacity
                FROM serviceschedule
                LEFT JOIN service ON serviceschedule.idservice = service.idservice
                WHERE serviceschedule.dateschedule BETWEEN :start AND DATE_ADD(:end, INTERVAL 1 DAY)
                ORDER BY serviceschedule.dateschedule";
$stmt = $db->prepare($sqlSchedule);
$stmt->execute([':start' => $monthStart, ':end' => $monthEnd]);
$scheduleRows = $stmt->fetchAll(PDO::FETCH_ASSOC);

// --- Bookings di tutte le classi del mese (una query sola) ---
$bookingsBySchedule = [];
$scheduleIds = array_filter(array_map(fn($r) => (int) $r['idserviceschedule'], $scheduleRows));

if (!empty($scheduleIds)) {
    $ph = implode(',', array_fill(0, count($scheduleIds), '?'));
    $sqlBookings = "SELECT bookingclass.idbookingclass,
                           bookingclass.idserviceschedule,
                           bookingclass.lostlesson,
                           bookingclass.status,
                           auth_users.first_name,
                           auth_users.last_name,
                           auth_users.avatar
                    FROM bookingclass
                    LEFT JOIN auth_users ON bookingclass.iduser = auth_users.id
                    WHERE bookingclass.idserviceschedule IN ($ph)
                      AND bookingclass.status IN ('booked', 'pending')
                    ORDER BY auth_users.last_name, auth_users.first_name";
    $stmtB = $db->prepare($sqlBookings);
    $stmtB->execute(array_values($scheduleIds));
    foreach ($stmtB->fetchAll(PDO::FETCH_ASSOC) as $b) {
        $sid = (int) $b['idserviceschedule'];
        $first = trim((string) ($b['first_name'] ?? ''));
        $last  = trim((string) ($b['last_name'] ?? ''));
        $avatar = trim((string) ($b['avatar'] ?? ''));

        $bookingsBySchedule[$sid][] = [
            'booking_id' => (int) $b['idbookingclass'],
            'first_name' => $first,
            'last_name'  => $last,
            'full_name'  => trim($first . ' ' . $last),
            'is_lost'    => ($b['lostlesson'] === 'Y'),
            'is_pending' => ($b['status'] === 'pending'),
            // avatar: solo il filename; l'app compone l'URL se serve
            'avatar'     => $avatar !== '' ? $avatar : null,
        ];
    }
}

// --- Composizione risposta ---
$classes = [];
foreach ($scheduleRows as $sch) {
    $sid = (int) $sch['idserviceschedule'];
    $participants = $bookingsBySchedule[$sid] ?? [];
    // contatore: solo confermati (booked, perse incluse); i pending NON contano
    $count = 0;
    foreach ($participants as $pp) {
        if (empty($pp['is_pending'])) {
            $count++;
        }
    }
    $maxcap = (int) $sch['maxcapacity'];

    $classes[] = [
        'schedule_id'  => $sid,
        'service_id'   => (int) $sch['idservice'],
        'class_name'   => (string) ($sch['servicename'] ?? ''),
        'color_class'  => $sch['colorclass'] ?: null,
        'date_time'    => $sch['dateschedule'],        // "YYYY-MM-DD HH:MM:SS"
        'max_capacity' => $maxcap,
        'booked_count' => $count,
        'is_full'      => $maxcap > 0 && $count >= $maxcap,
        'participants' => $participants,
    ];
}

echo json_encode([
    'success' => true,
    'month'   => $month,
    'classes' => $classes,
], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);