<?php
ini_set('display_errors', 1);
error_reporting(E_ALL);

if (session_status() === PHP_SESSION_NONE) session_start();
include('include/headscript.php');

$dbHandler = DBHandlerSelect::getInstance();
$pdo = $dbHandler->getConnection();

if (!isset($iduserlogin)) {
    header("Location: login.php");
    exit;
}

function setFlash(string $type, string $text): void
{
    $_SESSION['flash'] = ['type' => $type, 'text' => $text];
}

// Verifica che sia una richiesta POST
if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    setFlash('danger', 'Richiesta non valida.');
    header("Location: appointments.php");
    exit;
}

// Recupera i dati dal form
$date         = trim($_POST['date'] ?? '');
$start_time   = trim($_POST['start_time'] ?? '');
$staff_id     = (int)($_POST['staff_id'] ?? 0);
$customer_name = trim($_POST['customer_name'] ?? '');
$customer_phone = trim($_POST['customer_phone'] ?? '');
$service_id   = (int)($_POST['service_id'] ?? 0);
$notes        = trim($_POST['notes'] ?? '');

// Validazione base
if (!$date || !$start_time || !$staff_id || !$service_id || !$customer_name) {
    setFlash('danger', 'Compila tutti i campi obbligatori.');
    header("Location: appointments.php?date=" . urlencode($date));
    exit;
}

try {
    // 1. Verifica che lo staff appartenga al salone dell'utente
    $stmt = $pdo->prepare("
        SELECT s.shop_id, srv.duration_minutes
        FROM staff s
        JOIN shops sh ON s.shop_id = sh.id
        LEFT JOIN services srv ON srv.id = ? AND srv.shop_id = sh.id
        WHERE s.id = ? AND sh.owner_id = ?
        LIMIT 1
    ");
    $stmt->execute([$service_id, $staff_id, $iduserlogin]);
    $check = $stmt->fetch(PDO::FETCH_ASSOC);

    if (!$check) {
        setFlash('danger', 'Staff o servizio non valido.');
        header("Location: appointments.php?date=" . urlencode($date));
        exit;
    }

    $shop_id = (int)$check['shop_id'];
    $duration = (int)$check['duration_minutes'];

    // 2. Calcola start_at e end_at
    $start_at = $date . ' ' . $start_time . ':00';
    $end_timestamp = strtotime($start_at) + ($duration * 60);
    $end_at = date('Y-m-d H:i:s', $end_timestamp);

    // 3. Verifica disponibilità (evita sovrapposizioni)
    $stmt = $pdo->prepare("
        SELECT COUNT(*) FROM appointments
        WHERE staff_id = ?
          AND status NOT IN ('cancelled', 'no_show')
          AND (
              (start_at < ? AND end_at > ?) OR
              (start_at < ? AND end_at > ?) OR
              (start_at >= ? AND end_at <= ?)
          )
    ");
    $stmt->execute([
        $staff_id,
        $end_at,
        $start_at,  // nuovo finisce dopo inizio esistente
        $end_at,
        $start_at,  // nuovo inizia prima fine esistente
        $start_at,
        $end_at   // nuovo è contenuto
    ]);

    if ((int)$stmt->fetchColumn() > 0) {
        setFlash('warning', 'Slot già occupato. Scegli un altro orario.');
        header("Location: appointments.php?date=" . urlencode($date) . "&staff_id=" . $staff_id);
        exit;
    }

    // 4. Cerca o crea il cliente
    $customer_id = null;

    if ($customer_phone) {
        // Cerca cliente esistente per telefono
        $stmt = $pdo->prepare("
            SELECT id FROM customers 
            WHERE shop_id = ? AND phone = ?
            LIMIT 1
        ");
        $stmt->execute([$shop_id, $customer_phone]);
        $existing = $stmt->fetch(PDO::FETCH_ASSOC);

        if ($existing) {
            $customer_id = (int)$existing['id'];
        }
    }

    // Se non trovato, crea nuovo cliente
    if (!$customer_id) {
        $names = explode(' ', $customer_name, 2);
        $first_name = $names[0];
        $last_name = $names[1] ?? '';

        $stmt = $pdo->prepare("
            INSERT INTO customers (shop_id, first_name, last_name, phone, created_at)
            VALUES (?, ?, ?, ?, NOW())
        ");
        $stmt->execute([$shop_id, $first_name, $last_name, $customer_phone]);
        $customer_id = (int)$pdo->lastInsertId();
    }

    // 5. Inserisci l'appuntamento
    $stmt = $pdo->prepare("
        INSERT INTO appointments (
            shop_id, customer_id, staff_id, service_id,
            start_at, end_at, status, notes, created_at
        ) VALUES (?, ?, ?, ?, ?, ?, 'confirmed', ?, NOW())
    ");
    $stmt->execute([
        $shop_id,
        $customer_id,
        $staff_id,
        $service_id,
        $start_at,
        $end_at,
        $notes
    ]);

    setFlash('success', 'Appuntamento creato con successo!');
    header("Location: appointments.php?date=" . urlencode($date) . "&staff_id=" . $staff_id);
    exit;
} catch (Exception $e) {
    error_log("Errore creazione appuntamento: " . $e->getMessage());
    setFlash('danger', 'Errore durante la creazione: ' . $e->getMessage());
    header("Location: appointments.php?date=" . urlencode($date));
    exit;
}