<?php
/**
 * Centrale Systeeminstellingen Helper voor Fociz
 * Beheert organisatie-brede werkdagstandaarden (v1.4) en AI configuratie (v1.5).
 */

require_once __DIR__ . '/../config/database.php';

/**
 * Zorgt ervoor dat de system_settings tabel bestaat in MariaDB
 */
function ensure_system_settings_table(?PDO $db = null): void {
    static $ensured = false;
    if ($ensured) return;

    try {
        $pdo = $db ?: get_db_connection();
        $pdo->exec("
            CREATE TABLE IF NOT EXISTS `system_settings` (
                `setting_key` VARCHAR(64) PRIMARY KEY,
                `setting_value` TEXT NULL,
                `updated_at` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
            ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
        ");
        $ensured = true;
    } catch (Throwable $e) {
        error_log("ensure_system_settings_table error: " . $e->getMessage());
    }
}

/**
 * Haalt alle systeeminstellingen in 1 geoptimaliseerde query op en bewaart deze in het static runtime geheugen
 */
function get_all_system_settings(bool $forceRefresh = false): array {
    static $settingsCache = null;
    if ($settingsCache !== null && !$forceRefresh) {
        return $settingsCache;
    }

    $settingsCache = [];
    try {
        $db = get_db_connection();
        ensure_system_settings_table($db);

        $stmt = $db->query("SELECT setting_key, setting_value FROM system_settings");
        while ($row = $stmt->fetch()) {
            $val = $row['setting_value'];
            $decoded = json_decode($val, true);
            $settingsCache[$row['setting_key']] = (json_last_error() === JSON_ERROR_NONE) ? $decoded : $val;
        }
    } catch (Throwable $e) {
        error_log("get_all_system_settings error: " . $e->getMessage());
    }

    return $settingsCache;
}

/**
 * Haalt een enkele instelling op uit het geheugen (of fallback default)
 */
function get_system_setting(string $key, $default = null) {
    $all = get_all_system_settings();
    return array_key_exists($key, $all) ? $all[$key] : $default;
}

/**
 * Slaat een instelling op in MariaDB en ververst direct het cachegeheugen
 */
function set_system_setting(string $key, $value): bool {
    try {
        $db = get_db_connection();
        ensure_system_settings_table($db);

        $valToStore = is_array($value) || is_object($value) ? json_encode($value) : (string)$value;

        $stmt = $db->prepare("
            INSERT INTO system_settings (setting_key, setting_value)
            VALUES (?, ?)
            ON DUPLICATE KEY UPDATE setting_value = VALUES(setting_value), updated_at = NOW()
        ");
        $ok = $stmt->execute([$key, $valToStore]);
        if ($ok) {
            get_all_system_settings(true);
        }
        return $ok;
    } catch (Throwable $e) {
        error_log("set_system_setting error for {$key}: " . $e->getMessage());
        return false;
    }
}

/**
 * Haalt alle organisatie werkdag standaarden op (Release v1.4)
 */
function get_workday_settings(): array {
    return [
        'workday_start'         => get_system_setting('workday_start', '08:30'),
        'workday_end'           => get_system_setting('workday_end', '17:30'),
        'lunch_start'           => get_system_setting('lunch_start', '12:30'),
        'lunch_end'             => get_system_setting('lunch_end', '13:00'),
        'pomodoro_focus'        => (int)get_system_setting('pomodoro_focus', 25),
        'pomodoro_deep'         => (int)get_system_setting('pomodoro_deep', 50),
        'pomodoro_break'        => (int)get_system_setting('pomodoro_break', 5),
        'default_task_duration' => (int)get_system_setting('default_task_duration', 30),
    ];
}

/**
 * Haalt AI configuratie-instellingen op (Release v1.5)
 */
function get_ai_settings(): array {
    $envKey = fociz_env('OPENAI_API_KEY', '');
    $savedKeyRaw = get_system_setting('ai_api_key', '');
    $savedKey = '';
    if (!empty($savedKeyRaw)) {
        if (!function_exists('fociz_decrypt')) {
            require_once __DIR__ . '/auth.php';
        }
        $savedKey = fociz_decrypt($savedKeyRaw);
    }
    $apiKey = !empty($savedKey) ? $savedKey : $envKey;

    return [
        'ai_enabled'  => (bool)get_system_setting('ai_enabled', !empty($apiKey)),
        'ai_provider' => get_system_setting('ai_provider', 'openai'),
        'ai_api_key'  => $apiKey,
        'ai_model'    => get_system_setting('ai_model', 'gpt-4o-mini'),
        'has_key'     => !empty($apiKey),
    ];
}

/**
 * Haalt geconfigureerde sessie idle timeout in seconden op conform NIST SP 800-63B / ISO 27001
 * Toegestane waarden: 900 (15m), 1800 (30m - default), 3600 (60m), 7200 (120m)
 */
function get_session_idle_timeout(): int {
    $timeout = (int)get_system_setting('session_idle_timeout', 1800);
    $validTimeouts = [900, 1800, 3600, 7200];
    return in_array($timeout, $validTimeouts, true) ? $timeout : 1800;
}