<?php
/**
 * Reads the current status of adverts at the marketplace (read-only) and stores it, with the marketplace's
 * reason when an advert was rejected or blocked.
 *
 * @package Tidelist
 */

namespace Tidelist\Sync;

use Tidelist\Channel\ChannelInterface;
use Tidelist\Channel\Exception\ChannelException;
use Tidelist\Data\ListingStatus;
use Tidelist\Data\ListingStore;
use Tidelist\Log\Logger;
use Tidelist\Errors\ErrorExplainer;

/**
 * Status poller.
 */
final class StatusPoller {

	/**
	 * Listings.
	 *
	 * @var ListingStore
	 */
	private $rows;

	/**
	 * Marketplace channel.
	 *
	 * @var ChannelInterface
	 */
	private $channel;

	/**
	 * Logger.
	 *
	 * @var Logger
	 */
	private $log;

	/**
	 * Constructor.
	 *
	 * @param ListingStore     $rows    Listings.
	 * @param ChannelInterface $channel Marketplace channel.
	 * @param Logger           $log     Logger.
	 */
	public function __construct( ListingStore $rows, ChannelInterface $channel, Logger $log ) {
		$this->rows    = $rows;
		$this->channel = $channel;
		$this->log     = $log;
	}

	/**
	 * Reads and stores the status of one listing.
	 *
	 * @param int $id Listing ID.
	 * @return array|null The new row, or null when there is nothing to check or the marketplace could not be reached.
	 */
	public function poll( int $id ): ?array {
		$row = $this->rows->find( $id );
		if ( null === $row || '' === (string) $row['remote_id'] ) {
			return null;
		}
		try {
			$outcome = $this->channel->status( (string) $row['remote_id'] );
			$fields  = $outcome->fields();
			$reason  = '';
			if ( in_array( $outcome->state, array( ListingStatus::PENDING_REVIEW, ListingStatus::ERROR ), true ) && 'new' !== $outcome->remote_status ) {
				$reason = ErrorExplainer::for_channel( $this->channel )->explain_message( $this->channel->rejection_reason( (string) $row['remote_id'] ) );
			}
			$fields['last_error']     = $reason;
			$fields['last_synced_at'] = gmdate( 'Y-m-d H:i:s' );
			$this->rows->update( $id, $fields );
		} catch ( ChannelException $e ) {
			$this->log->log( Logger::WARNING, 'status', sprintf( 'Status check of listing %d failed: %s', $id, $e->getMessage() ) );
			return null;
		}
		return $this->rows->find( $id );
	}

	/**
	 * Polls every listing of this channel that is waiting to be accepted or paid.
	 *
	 * @return array{checked:int, failed:int}
	 */
	public function poll_waiting(): array {
		$stats = array(
			'checked' => 0,
			'failed'  => 0,
		);
		foreach ( $this->rows->all(
			array(
				'status'  => array( ListingStatus::PENDING_REVIEW, ListingStatus::LIMITED ),
				'channel' => $this->channel->id(),
			)
		) as $row ) {
			if ( null === $this->poll( (int) $row['id'] ) ) {
				++$stats['failed'];
			} else {
				++$stats['checked'];
			}
		}
		return $stats;
	}
}