<?php

/**
 * SchoolSettings
 * Impostazioni della scuola (tabella `option`, una riga per scuola).
 * Sostituisce tutti i "SELECT * FROM `option` LIMIT 1".
 *
 * Uso:
 *   $timetocancel = (int) SchoolSettings::get('maxbeforetimecancell', 24);
 *   $all          = SchoolSettings::all();
 *   SchoolSettings::save(['show_teacher' => 'Y']);
 *
 * Nei cron (senza sessione) passare l'idschool esplicito:
 *   SchoolSettings::get('show_teacher', 'N', $idschool);
 */

if (!class_exists('DBHandlerSelect')) {
    require_once __DIR__ . '/db-functions.php';
}

class SchoolSettings
{
    /** @var array cache per scuola: idschool => riga option */
    private static $cache = [];

    /** Colonne che non si possono modificare con save() */
    const PROTECTED_COLUMNS = ['idption', 'idschool'];

    /** Tutte le impostazioni della scuola (riga creata se mancante) */
    public static function all(?int $idschool = null): array
    {
        $idschool = self::schoolId($idschool);

        if (!isset(self::$cache[$idschool])) {
            $pdo = self::pdo();
            $st = $pdo->prepare("SELECT * FROM `option` WHERE idschool = ? LIMIT 1");
            $st->execute([$idschool]);
            $row = $st->fetch();

            if (!$row) {
                // Nuova scuola: crea la riga con i default delle colonne
                try {
                    $pdo->prepare("INSERT INTO `option` (idschool) VALUES (?)")->execute([$idschool]);
                    $st->execute([$idschool]);
                    $row = $st->fetch();
                } catch (PDOException $e) {
                    error_log('SchoolSettings: impossibile creare option per scuola ' . $idschool . ': ' . $e->getMessage());
                    $row = [];
                }
            }

            self::$cache[$idschool] = $row ?: [];
        }

        return self::$cache[$idschool];
    }

    /** Singola impostazione, con default se mancante o NULL */
    public static function get(string $key, $default = null, ?int $idschool = null)
    {
        $all = self::all($idschool);
        return (array_key_exists($key, $all) && $all[$key] !== null) ? $all[$key] : $default;
    }

    /**
     * Salva una o più impostazioni. Accetta solo colonne esistenti in `option`
     * (le altre chiavi vengono ignorate).
     */
    public static function save(array $data, ?int $idschool = null): void
    {
        $idschool = self::schoolId($idschool);
        $current = self::all($idschool);

        $set = [];
        $params = [];
        foreach ($data as $col => $val) {
            if (!array_key_exists($col, $current) || in_array($col, self::PROTECTED_COLUMNS, true)) {
                continue;
            }
            $set[] = "`$col` = ?";
            $params[] = $val;
        }
        if (empty($set)) {
            return;
        }

        $params[] = $idschool;
        self::pdo()->prepare("UPDATE `option` SET " . implode(', ', $set) . " WHERE idschool = ?")
            ->execute($params);

        unset(self::$cache[$idschool]);
    }

    private static function schoolId(?int $idschool): int
    {
        if ($idschool !== null && $idschool > 0) {
            return $idschool;
        }
        return SchoolContext::id();
    }

    private static function pdo(): PDO
    {
        return DBHandlerSelect::getInstance()->getConnection();
    }
}