<?php
declare(strict_types=1);

namespace Cf7stg;

final class Queue
{
    public const STATUS_PENDING = 'pending';
    public const STATUS_SENT    = 'sent';
    public const STATUS_FAILED  = 'failed';

    public static function table_name(): string
    {
        global $wpdb;
        return $wpdb->prefix . 'cf7stg_queue';
    }

    public static function enqueue(array $row): int
    {
        global $wpdb;
        $defaults = [
            'flamingo_post_id' => null,
            'form_id'          => null,
            'source_key'       => 'cf7',
            'payload_json'     => '',
            'label'            => 'unclear',
            'is_retro'         => 0,
            'status'           => self::STATUS_PENDING,
            'attempts'         => 0,
            'last_error'       => null,
            'next_try_at'      => current_time('mysql'),
            'created_at'       => current_time('mysql'),
            'sent_at'          => null,
        ];
        $data = array_merge($defaults, $row);
        $wpdb->insert(self::table_name(), $data);
        return (int)$wpdb->insert_id;
    }

    public static function exists_for_flamingo(int $post_id, bool $is_retro): bool
    {
        global $wpdb;
        $t = self::table_name();
        $sql = $wpdb->prepare(
            "SELECT id FROM {$t} WHERE flamingo_post_id = %d AND is_retro = %d LIMIT 1",
            $post_id,
            $is_retro ? 1 : 0
        );
        return (bool)$wpdb->get_var($sql);
    }

    /** @return array<int,object> */
    public static function fetch_pending(int $limit = 5): array
    {
        global $wpdb;
        $t = self::table_name();
        $sql = $wpdb->prepare(
            "SELECT * FROM {$t}
             WHERE status = %s
               AND (next_try_at IS NULL OR next_try_at <= %s)
             ORDER BY id ASC
             LIMIT %d",
            self::STATUS_PENDING,
            current_time('mysql'),
            $limit
        );
        $rows = $wpdb->get_results($sql);
        return is_array($rows) ? $rows : [];
    }

    public static function mark_sent(int $id): void
    {
        global $wpdb;
        $wpdb->update(
            self::table_name(),
            ['status' => self::STATUS_SENT, 'sent_at' => current_time('mysql'), 'last_error' => null],
            ['id' => $id]
        );
    }

    public static function reschedule(int $id, int $attempts, string $error, int $backoff_seconds): void
    {
        global $wpdb;
        $next = gmdate('Y-m-d H:i:s', time() + $backoff_seconds);
        $wpdb->update(
            self::table_name(),
            [
                'attempts'    => $attempts,
                'last_error'  => $error,
                'next_try_at' => $next,
            ],
            ['id' => $id]
        );
    }

    public static function mark_failed(int $id, string $error, int $attempts): void
    {
        global $wpdb;
        $wpdb->update(
            self::table_name(),
            [
                'status'     => self::STATUS_FAILED,
                'last_error' => $error,
                'attempts'   => $attempts,
            ],
            ['id' => $id]
        );
    }

    public static function count_by_status(string $status): int
    {
        global $wpdb;
        $t = self::table_name();
        return (int)$wpdb->get_var($wpdb->prepare(
            "SELECT COUNT(*) FROM {$t} WHERE status = %s", $status
        ));
    }

    public static function count_failed(): int
    {
        return self::count_by_status(self::STATUS_FAILED);
    }

    public static function count_sent_last_24h(): int
    {
        global $wpdb;
        $t = self::table_name();
        $cutoff = gmdate('Y-m-d H:i:s', time() - 86400);
        return (int)$wpdb->get_var($wpdb->prepare(
            "SELECT COUNT(*) FROM {$t} WHERE status = %s AND sent_at >= %s",
            self::STATUS_SENT, $cutoff
        ));
    }

    /** @return array<int,object> */
    public static function list_failed(int $limit = 10): array
    {
        global $wpdb;
        $t = self::table_name();
        $rows = $wpdb->get_results($wpdb->prepare(
            "SELECT id, created_at, last_error FROM {$t}
             WHERE status = %s
             ORDER BY id DESC LIMIT %d",
            self::STATUS_FAILED, $limit
        ));
        return is_array($rows) ? $rows : [];
    }

    public static function retry_all_failed(): int
    {
        global $wpdb;
        $t = self::table_name();
        $now = current_time('mysql');
        $count = $wpdb->query($wpdb->prepare(
            "UPDATE {$t}
             SET status = %s, attempts = 0, last_error = NULL, next_try_at = %s
             WHERE status = %s",
            self::STATUS_PENDING, $now, self::STATUS_FAILED
        ));
        return (int)$count;
    }

    public static function purge_sent(): int
    {
        global $wpdb;
        $t = self::table_name();
        return (int)$wpdb->query($wpdb->prepare(
            "DELETE FROM {$t} WHERE status = %s", self::STATUS_SENT
        ));
    }

    public static function cleanup_old_sent(int $days = 30): int
    {
        global $wpdb;
        $t = self::table_name();
        $cutoff = gmdate('Y-m-d H:i:s', time() - $days * 86400);
        return (int)$wpdb->query($wpdb->prepare(
            "DELETE FROM {$t} WHERE status = %s AND sent_at < %s",
            self::STATUS_SENT, $cutoff
        ));
    }
}