<?php

namespace BSR\Lib\Search;

use BSR\Lib\Configuration;
use BSR\Lib\Exception\WebException;

mb_http_output('UTF-8');

class BookSearch
{
    /** @var \SolrClient  */
    private $client;
    /** @var \SolrQuery  */
    private $query;
    private $queryParts = array();

    public function __construct()
    {
        $options = array
        (
            'hostname' => Configuration::get('solr.server'),
            'port' => Configuration::get('solr.port'),
            'login' => Configuration::get('solr.username'),
            'password' => Configuration::get('solr.password'),
            'path' => Configuration::get('solr.path'),
        );

        $this->client = new \SolrClient($options);
        $this->query = new \SolrQuery();
        $this->query->setQuery('*:*');

        $this->query->addField('*');

        $this->query->addParam('q.op', 'AND');
    }

    public function addQuery($queryText, $queryField = null, $escape = true)
    {
        if($escape) {
            $queryText = \SolrUtils::escapeQueryChars($queryText);
        }

        if (strlen($queryField) > 0) {
            $queryText = "$queryField:\"$queryText\"";
        }

        $this->queryParts[] = $queryText;
    }

    public function addSortField($field, $order = \SolrQuery::ORDER_DESC)
    {
        $this->query->addSortField($field, $order);
    }

    /**
     * @param int $start
     * @param int $count
     * @return array
     * @throws WebException
     */
    public function getResults($start = 0, $count = 15)
    {
        if (count($this->queryParts) == 0)
            $query = '*:*';
        else {
            $query = implode(' AND ', $this->queryParts);
        }
        $this->query->setQuery($query);
        $this->query->setStart($start);
        $this->query->setRows($count);

        try {
            $results = $this->client->query($this->query)->getResponse();
        } catch(\SolrClientException $e) {
            throw new WebException ("SolrError", $e->getMessage(), -700);
        }

        $books = isset($results['response']['docs']) && $results['response']['docs'] ?
            array_map(function($o) { return (array) $o; }, $results['response']['docs']) :
            array();

        return array(
            'count' => $results['response']['numFound'],
            'facets' => $results['facet_counts']['facet_fields'],
            'books' => $books,
        );
    }


    /**
     * Retrieve books from Solr based on their code (NoticeNr).
     *
     * @param array $codes
     * @param string $field the field to use for the search
     * @return array Books information
     * @throws WebException
     */
    public static function GetBooks(array $codes, $field = 'code') {
        // it is faster to do multiple small request to Solr rather than one big so separate
        // in chunks if we are above the limit. 15 was found by testing and seems to be a sweet spot
        $limit = 15;
        $count = count($codes);
        if($count > $limit) {
            $parts = array_chunk($codes, $limit);
            $books = array();
            foreach($parts as $p) {
                $books = array_merge($books, self::GetBooks($p));
            }
            return $books;
        }

        $bs = new static();
        $query = sprintf('%s:(%s)', $field, implode(' OR ', $codes));
        $bs->addQuery($query, null, false);
        $results = $bs->getResults(0, $count);
        return $results['books'];
    }
}