<?php
/**
 * QBWS_Cache — DB-backed cache+TTL, same purpose as qb_cache.php's
 * qbc_getItems() in the OC integration: avoid re-pulling the full QB
 * Item/Customer list on every sync run within the TTL window, while still
 * supporting a forced bypass for on-demand "Sync Now" clicks.
 */

if (!defined('ABSPATH')) exit;

// phpcs:disable WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- This plugin reads/writes only its own custom tables (live sync state), which must never be served from an object cache.

class QBWS_Cache
{
    public static function get(string $key)
    {
        global $wpdb;
        $row = $wpdb->get_row($wpdb->prepare(
            "SELECT cache_value FROM {$wpdb->prefix}qbws_cache WHERE cache_key = %s AND expires_at > NOW()",
            $key
        ));
        if (!$row) return null;
        return json_decode($row->cache_value, true);
    }

    public static function set(string $key, $value, int $ttlSeconds = null): void
    {
        global $wpdb;
        $ttl = $ttlSeconds ?? (int) QBWS_Config::get('cache_ttl_seconds');

        $wpdb->query($wpdb->prepare(
            "INSERT INTO {$wpdb->prefix}qbws_cache (cache_key, cache_value, expires_at)
             VALUES (%s, %s, DATE_ADD(NOW(), INTERVAL %d SECOND))
             ON DUPLICATE KEY UPDATE cache_value = VALUES(cache_value), expires_at = VALUES(expires_at)",
            $key, wp_json_encode($value), $ttl
        ));
    }

    public static function forget(string $key): void
    {
        global $wpdb;
        $wpdb->delete($wpdb->prefix . 'qbws_cache', ['cache_key' => $key]);
    }

    /**
     * Fetch all active QB Items, cache-aware. $forceRefresh bypasses TTL
     * (used by the "Sync Now" admin button and by CDC-triggered runs).
     */
    public static function getItems(QBWS_Api_Client $api, bool $forceRefresh = false): array
    {
        $cacheKey = 'qb_items_active';

        if (!$forceRefresh) {
            $cached = self::get($cacheKey);
            if ($cached !== null) return $cached;
        }

        $items    = [];
        $pageSize = (int) QBWS_Config::get('page_size');
        $start    = 1;

        do {
            $sql = "SELECT * FROM Item WHERE Active = true STARTPOSITION {$start} MAXRESULTS {$pageSize}";
            $chunk = $api->query($sql)['Item'] ?? [];

            foreach ($chunk as $item) {
                $items[$item['Id']] = $item;
            }

            $start += $pageSize;
        } while (count($chunk) === $pageSize);

        self::set($cacheKey, $items);
        return $items;
    }

    /** Same pattern as getItems() but for the Customer entity. */
    public static function getCustomers(QBWS_Api_Client $api, bool $forceRefresh = false): array
    {
        $cacheKey = 'qb_customers_active';

        if (!$forceRefresh) {
            $cached = self::get($cacheKey);
            if ($cached !== null) return $cached;
        }

        $customers = [];
        $pageSize  = (int) QBWS_Config::get('page_size');
        $start     = 1;

        do {
            $sql = "SELECT * FROM Customer WHERE Active = true STARTPOSITION {$start} MAXRESULTS {$pageSize}";
            $chunk = $api->query($sql)['Customer'] ?? [];

            foreach ($chunk as $customer) {
                $customers[$customer['Id']] = $customer;
            }

            $start += $pageSize;
        } while (count($chunk) === $pageSize);

        self::set($cacheKey, $customers);
        return $customers;
    }
}