/**
 * api_chat_search.php
 * Searches for cars/categories by brand+model name (fuzzy), and when not found
 * returns alternatives from the same category that ARE available for the period.
 *
 * POST body (JSON or form):
 *   car_name         - string, what the user typed (e.g. "Hyundai i10" or "citadine")
 *   date_pu          - YYYY-MM-DD
 *   date_do          - YYYY-MM-DD
 *   rental_duration  - int (days, optional — auto-computed from dates)
 *
 * No parc/agence filter: availability is fleet-wide via fleet_planning.
 */

header('Content-Type: application/json');
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: POST, OPTIONS');

if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') { http_response_code(200); exit; }

require_once __DIR__ . '/db.php';
require_once __DIR__ . '/functions_process_rate.php';

if (!function_exists('countCarsForCategorySearch')) {
    function countCarsForCategorySearch(PDO $pdo, int $categoryId, string $datePu, string $dateDo): int {
        $stmt = $pdo->prepare("
            SELECT COUNT(*) AS cnt
            FROM fleet_cars fc
            LEFT JOIN fleet_models fm ON fm.id = fc.fk_model_id
            WHERE fm.fk_category_id = :cat_id
              AND fc.status  = 1
              AND fc.transit = 1
              AND NOT EXISTS (
                  SELECT 1 FROM fleet_planning fp
                  WHERE fp.fk_fleet_id = fc.id
                    AND fp.status      = 1
                    AND fp.date_start  < :date_do
                    AND fp.date_end    > :date_pu
              )
        ");
        $stmt->execute([':cat_id' => $categoryId, ':date_pu' => $datePu, ':date_do' => $dateDo]);
        return (int) $stmt->fetchColumn();
    }
}

// ── Parse input ───────────────────────────────────────────────────────────────
$input = json_decode(file_get_contents('php://input'), true);
if (empty($input)) $input = $_POST;

$car_name        = trim($input['car_name']         ?? '');
$date_pu         = trim($input['date_pu']          ?? '');
$date_do         = trim($input['date_do']          ?? '');
$rental_duration = isset($input['rental_duration']) && (int)$input['rental_duration'] > 0
    ? (int)$input['rental_duration']
    : max(1, (int)ceil((strtotime($date_do) - strtotime($date_pu)) / 86400));

if (!$car_name || !$date_pu || !$date_do) {
    http_response_code(400);
    echo json_encode(['error' => 'Paramètres manquants: car_name, date_pu, date_do requis.']);
    exit;
}

// ── 1. Try to find the requested car/category by fuzzy name match ─────────────
$pdo = pdo();

// Search in fleet_categories.name, brand name, model name (case-insensitive LIKE)
$searchTerms = array_filter(explode(' ', $car_name));
$likeClauses = [];
$params = [];
foreach ($searchTerms as $i => $term) {
    $key = ":term$i";
    $likeClauses[] = "(fc.name LIKE $key OR fb.name LIKE $key OR fm.name LIKE $key OR fm.subname LIKE $key)";
    $params[$key] = '%' . $term . '%';
}
$whereSearch = implode(' AND ', $likeClauses);

$searchSql = "
    SELECT fc.id AS category_id, fc.name AS category_name, fc.fk_model_default_id,
           fb.name AS brand_name, fm.name AS model_name,fc.home_public as loable_sur_internet,fc.model_exclu as model_garantie,
           CONCAT_WS(', ', 
                NULLIF(TRIM(CONCAT(IFNULL(fb.name, ''), ' ', IFNULL(fm.name, ''))), ''),
                NULLIF((
                    SELECT GROUP_CONCAT(DISTINCT TRIM(CONCAT(IFNULL(fb_sub.name, ''), ' ', IFNULL(fm_sub.name, ''))) SEPARATOR ', ')
                    FROM fleet_cars car
                    INNER JOIN fleet_models fm_sub ON fm_sub.id = car.fk_model_id
                    INNER JOIN fleet_brands fb_sub ON fb_sub.id = fm_sub.fk_brand_id
                    WHERE fm_sub.fk_category_id = fc.id
                    AND (fc.fk_model_default_id IS NULL OR fm_sub.id != fc.fk_model_default_id)
                    AND car.status = 1
                    AND car.transit = 1
                ), '')
            ) AS model_full_name,
           fc.fk_category_type_id
    FROM fleet_categories fc
    LEFT JOIN fleet_models fm ON fm.id = fc.fk_model_default_id
    LEFT JOIN fleet_brands fb ON fb.id = fm.fk_brand_id AND fb.status = 1
    WHERE fc.status = 1 AND ($whereSearch) AND fc.home_public = 1
    ORDER BY fc.list_order ASC
    LIMIT 5
";
$stmt = $pdo->prepare($searchSql);
$stmt->execute($params);
$found = $stmt->fetchAll(PDO::FETCH_ASSOC);

// ── 2. Get pricing for all categories (fleet-wide, no parc filter) ────────────
$quotation = [
    'date_pu_full'         => $date_pu . ' 10:00:00',
    'date_do_full'         => $date_do . ' 10:00:00',
    'rental_duration'      => $rental_duration,
    'fk_parc_id'           => 0,   // no parc filter
    'fk_category_group_id' => 0,
    'fk_category_id'       => 0,
    'special_id_pu'        => 0,
    'special_id_do'        => 0,
];

$allPriced = getQuotationCategoriesPrice($quotation, null, null);

// Override nb_car fleet-wide for each category
$availableById = [];
foreach ($allPriced as $cat) {
    $nbCar = countCarsForCategorySearch($pdo, (int)$cat['id'], $date_pu . ' 00:00:00', $date_do . ' 23:59:59');
    if ($nbCar > 0) {
        $cat['nb_car'] = $nbCar;
        $availableById[$cat['id']] = $cat;
    }
}

$exactMatches = [];
$unavailableMatches = [];

foreach ($found as $f) {
    $catId = (int)$f['category_id'];
    if (isset($availableById[$catId])) {
        $cat = $availableById[$catId];
        $exactMatches[] = [
            'id'              => $catId,
            'category_name'   => $cat['name'],
            'model_full_name' => $cat['model_full_name'] ?? '',
            'total_amount'    => round($cat['period_amount'], 2),
            'day_rate'        => $rental_duration > 0 ? round($cat['period_amount'] / $rental_duration, 2) : 0,
            'nb_car'          => $cat['nb_car'],
            'is_exact'        => true,
            'model_garantie'  => $cat['model_garantie'],
        ];
    } else {
        $unavailableMatches[] = $f;
    }
}

// ── 3. For unavailable: find alternatives from same category type ──────────────
$allAvailable = $availableById; // reuse for suggestions
$suggested = [];
if (!empty($unavailableMatches) && empty($exactMatches)) {
    $typeIds = array_unique(array_column($unavailableMatches, 'fk_category_type_id'));

    foreach ($allAvailable as $cat) {
        $stypeStmt = $pdo->prepare("SELECT fk_category_type_id FROM fleet_categories WHERE id = :id LIMIT 1");
        $stypeStmt->execute([':id' => $cat['id']]);
        $catType = $stypeStmt->fetchColumn();

        if (in_array($catType, $typeIds)) {
            $suggested[] = [
                'id'              => $cat['id'],
                'category_name'   => $cat['name'],
                'model_full_name' => $cat['model_full_name'] ?? '',
                'total_amount'    => round($cat['period_amount'], 2),
                'day_rate'        => $rental_duration > 0 ? round($cat['period_amount'] / $rental_duration, 2) : 0,
                'nb_car'          => $cat['nb_car'],
                'is_exact'        => false,
                'model_garantie'  => false,
            ];
        }
    }
}

if (empty($exactMatches) && empty($suggested) && !empty($allAvailable)) {
    $byPrice = array_values($allAvailable);
    usort($byPrice, fn($a, $b) => $a['period_amount'] <=> $b['period_amount']);
    foreach (array_slice($byPrice, 0, 3) as $cat) {
        $suggested[] = [
            'id'              => $cat['id'],
            'category_name'   => $cat['name'],
            'model_full_name' => $cat['model_full_name'] ?? '',
            'total_amount'    => round($cat['period_amount'], 2),
            'day_rate'        => $rental_duration > 0 ? round($cat['period_amount'] / $rental_duration, 2) : 0,
            'nb_car'          => $cat['nb_car'],
            'is_exact'        => false,
            'model_garantie'  => false,
        ];
    }
}

// ── 5. Build response ─────────────────────────────────────────────────────────
$status = 'not_found';
if (!empty($exactMatches)) {
    $status = 'found';
} elseif (!empty($suggested)) {
    $status = 'alternatives';
}

echo json_encode([
    'status'           => $status,
    'searched_for'     => $car_name,
    'exact_matches'    => $exactMatches,
    'alternatives'     => $suggested,
]);