<?php
declare(strict_types=1);


namespace OneClickFormSync\Queue;

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

use OneClickFormSync\Contracts\QueueRepositoryInterface;

/**
 * Handles database operations for the QueueItem entities using WPDB.
 */
class QueueRepository implements QueueRepositoryInterface
{
    /**
     * @var string
     */
    private string $tableName;

    /**
     * QueueRepository constructor.
     */
    public function __construct()
    {
        global $wpdb;
        $this->tableName = $wpdb->prefix . 'oneclickformsync_queue';
    }

    /**
     * @inheritDoc
     */
    public function find(int $id): ?QueueItem
    {
        global $wpdb;

        $row = $wpdb->get_row(
            $wpdb->prepare("SELECT * FROM {$this->tableName} WHERE id = %d", $id),
            ARRAY_A
        );

        if (!$row) {
            return null;
        }

        return new QueueItem($row);
    }

    /**
     * @inheritDoc
     */
    public function findPending(int $limit = 10): array
    {
        global $wpdb;
        $now = current_time('mysql', true);

        // Select items that are pending and ready to be processed.
        $rows = $wpdb->get_results(
            $wpdb->prepare(
                "SELECT * FROM {$this->tableName} 
                 WHERE status = 'pending' AND (next_attempt_at IS NULL OR next_attempt_at <= %s) 
                 ORDER BY created_at ASC LIMIT %d",
                $now,
                $limit
            ),
            ARRAY_A
        );

        $items = [];
        foreach ($rows as $row) {
            $items[] = new QueueItem($row);
        }

        return $items;
    }

    /**
     * @inheritDoc
     */
    public function save(QueueItem $item): bool
    {
        global $wpdb;

        $data = $item->toArray();
        $data['updated_at'] = current_time('mysql', true);

        if ($item->getId() !== null) {
            $result = $wpdb->update(
                $this->tableName,
                $data,
                ['id' => $item->getId()]
            );
            return $result !== false;
        } else {
            // Remove null ID for auto-increment.
            unset($data['id']);
            $result = $wpdb->insert($this->tableName, $data);
            if ($result) {
                $item->setId((int)$wpdb->insert_id);
                return true;
            }
            return false;
        }
    }

    /**
     * @inheritDoc
     */
    public function delete(int $id): bool
    {
        global $wpdb;

        $result = $wpdb->delete(
            $this->tableName,
            ['id' => $id]
        );

        return $result !== false;
    }
}