<?php

namespace DeliciousBrains\WPMDB\Common\Queue;

use DeliciousBrains\WPMDB\Common\Util\Util;
use WP_Error;
use wpdb;

class Connection extends Connections\DatabaseConnection {
	/**
	 * DatabaseQueue constructor.
	 *
	 * @param wpdb   $wpdb                WP database object, default global object.
	 * @param array  $allowed_job_classes Job classes that may be handled, default any Job subclass.
	 * @param string $prefix              Table prefix, default temp_prefix.
	 */
	public function __construct( $wpdb = null, $allowed_job_classes = [], $prefix = null ) {
		if ( null === $wpdb || ! is_a( $wpdb, 'wpdb' )) {
			$wpdb = $GLOBALS['wpdb'];
		}
		if ( null === $prefix ) {
			$prefix = $GLOBALS['wpmdbpro']->get( 'temp_prefix' );
		}

		// We should be able to call parent to set database
		// and allowed_job_classes, but unit test setup is broken
		// and throws a wobbly in Mockery. Yay, mocks. 😞
		// parent::__construct($wpdb, $allowed_job_classes);
		$this->database            = $wpdb;
		$this->allowed_job_classes = $allowed_job_classes;

		$this->jobs_table     = $prefix . 'queue_jobs';
		$this->failures_table = $prefix . 'queue_failures';
	}

	/**
	 * Get list of jobs in queue
	 *
	 * @param int  $limit
	 * @param int  $offset
	 * @param bool $raw if true, method will return serialized instead of instantiated objects
	 *
	 * @return array|WP_Error
	 */
	public function list_jobs( $limit, $offset, $raw = false ) {
		$offset  = null === $offset ? 0 : $offset;
		$limit   = null === $limit ? 9999999 : $limit;
		$raw_sql = "
			SELECT * FROM {$this->jobs_table}
			WHERE reserved_at IS NULL
			AND available_at <= %s
			ORDER BY id ASC
			LIMIT %d,%d
		";
		$sql     = $this->database->prepare( $raw_sql, Util::sql_formatted_datetime(), $offset, $limit );
		$results = $this->database->get_results( $sql );

		if ( ! is_array( $results ) || $this->database->last_error ) {
			return new WP_Error( 'database-error', $this->database->last_error );
		}

		if ( $raw ) {
			return $results;
		}

		$jobs = [];
		foreach ( $results as $raw_job ) {
			$job = $this->vitalize_job( $raw_job );

			if ( $job && is_a( $job, Job::class ) ) {
				$jobs[ $raw_job->id ] = $job;
			} else {
				return new WP_Error(
					'invalid-queue-job',
					__( 'An invalid item was found in the queue of files to be transferred.', 'wp-migrate-db' )
				);
			}
		}

		return $jobs;
	}
}