<?php
require_once 'include/headscript.php'; // Include il file con la connessione al database

// Connessione al database
$dbHandler = DBHandlerSelect::getInstance();
$pdo = $dbHandler->getConnection();

try {
    // Inizia una transazione
    $pdo->beginTransaction();

    // Seleziona gli ordini con status 'completed' e lezioni disponibili
    $stmt = $pdo->prepare("
        SELECT o.id, o.user_id, o.class_type_id, o.available_entries, o.school_id
        FROM orders o
        WHERE o.status = 'completed' AND o.available_entries > 0
    ");
    $stmt->execute();
    $orders = $stmt->fetchAll(PDO::FETCH_ASSOC);

    $bookings_created = 0;
    $orders_propagated = 0;

    foreach ($orders as $order) {
        $order_id = $order['id'];
        $user_id = $order['user_id'];
        $class_type_id = $order['class_type_id'];
        $available_entries = $order['available_entries'];
        $school_id = $order['school_id'];

        // Recupera i giorni di chiusura della scuola
        $offStmt = $pdo->prepare("
            SELECT start_date, end_date 
            FROM day_off 
            WHERE school_id = ? AND (
                (start_date >= CURDATE()) OR 
                (end_date >= CURDATE()) OR 
                (start_date <= CURDATE() AND end_date >= CURDATE())
            )
        ");
        $offStmt->execute([$school_id]);
        $off_periods = $offStmt->fetchAll(PDO::FETCH_ASSOC);

        // Crea un array di date di chiusura
        $off_dates = [];
        foreach ($off_periods as $period) {
            $start_date = new DateTime($period['start_date']);
            $end_date = new DateTime($period['end_date']);
            $interval = new DateInterval('P1D');
            $date_range = new DatePeriod($start_date, $interval, $end_date->modify('+1 day'));
            foreach ($date_range as $date) {
                $off_dates[] = $date->format('Y-m-d');
            }
        }

        // Trova le prossime sessioni disponibili per questo class_type_id
        $sessionStmt = $pdo->prepare("
            SELECT id, session_date
            FROM class_sessions
            WHERE class_type_id = ? AND session_date >= CURDATE() AND status = 'scheduled'
            ORDER BY session_date ASC, start_time ASC
            LIMIT ?
        ");
        $sessionStmt->execute([$class_type_id, $available_entries]);
        $sessions = $sessionStmt->fetchAll(PDO::FETCH_ASSOC);

        $bookings_for_order = 0;

        foreach ($sessions as $session) {
            $session_id = $session['id'];
            $session_date = $session['session_date'];

            // Salta se la data è un giorno di chiusura
            if (in_array($session_date, $off_dates)) {
                continue;
            }

            // Verifica la capacità massima della sessione
            $capacityStmt = $pdo->prepare("
                SELECT max_capacity
                FROM class_sessions
                WHERE id = ?
            ");
            $capacityStmt->execute([$session_id]);
            $max_capacity = $capacityStmt->fetchColumn();

            $bookingCountStmt = $pdo->prepare("
                SELECT COUNT(*)
                FROM session_bookings
                WHERE session_id = ? AND status IN ('booked', 'attended', 'rescheduled')
            ");
            $bookingCountStmt->execute([$session_id]);
            $current_bookings = $bookingCountStmt->fetchColumn();

            if ($max_capacity !== null && $current_bookings >= $max_capacity) {
                continue; // Salta se la sessione è piena
            }

            // Inserisci la prenotazione in session_bookings
            $insertStmt = $pdo->prepare("
                INSERT INTO session_bookings (
                    session_id, user_id, status, booked_at, created_at, updated_at
                )
                VALUES (?, ?, 'booked', NOW(), NOW(), NOW())
            ");
            $insertStmt->execute([
                $session_id,
                $user_id
            ]);
            $bookings_created++;
            $bookings_for_order++;
        }

        // Aggiorna available_entries e lo stato dell'ordine
        if ($bookings_for_order > 0) {
            $updateStmt = $pdo->prepare("
                UPDATE orders
                SET available_entries = available_entries - ?,
                    status = 'propagated'
                WHERE id = ?
            ");
            $updateStmt->execute([$bookings_for_order, $order_id]);
            $orders_propagated++;
        }
    }

    // Conferma la transazione
    $pdo->commit();

    echo "Propagazione completata con successo: $bookings_created prenotazioni create, $orders_propagated ordini aggiornati.";
} catch (PDOException $e) {
    // In caso di errore, annulla la transazione
    $pdo->rollBack();
    echo "Errore durante la propagazione: " . $e->getMessage();
}