<?php

namespace CorpusParole\Services;

use Cache;

use CorpusParole\Services\LexvoResolverInterface;

class LexvoResolver implements LexvoResolverInterface {

    public function __construct($sparqlClient) {

        $this->sparqlClient = $sparqlClient;

    }

    private function checkLexvoId($id) {

        $lexvoid = $id;

        if(strpos($id, config('corpusparole.lexvo_base_url')) !== 0) {

            $lexvoid = config('corpusparole.lexvo_base_url').$id;

        }

        $lexvoid = rtrim($lexvoid, '/');

        if(preg_match("/^".preg_quote(config('corpusparole.lexvo_base_url'),"/")."[[:alpha:]]{3}$/", $lexvoid) !== 1) {

            throw new LexvoResolverException("the provided id \"$id\" is not a Lexvo id");

        }

        return $lexvoid;

    }

    /**

     * Get name from Viaf id

     * @param string $id The id to resolve. Can be an url starting with http://viaf.org/viaf/

     * @return a string with the name

     */

    public function getName($id) {

        $res = $this->getNames([$id,]);

        assert(array_key_exists($id,$res), "the result must contains $id");

        return $res[$id];

    }

    /**

     * Get a list of names from an array of viaf ids.

     * @param array $ids The array of ids to resolve.

     *                   Each id can be an url starting with http://viaf.org/viaf/

     * @return array key is id, value is the name

     */

    public function getNames(array $ids) {

        $lexvoids = array_map([$this, 'checkLexvoId'], $ids);

        $lexvoidsMap = array_combine($lexvoids, $ids);

        $results = [];

        $missingLexvoids = [];

        foreach ($lexvoidsMap as $lexvoid => $lexvoidSource) {

            $cachedValue = Cache::get("lexvo:$lexvoid");

            if(is_null($cachedValue)) {

                array_push($missingLexvoids, $lexvoid);

            } else {

                $results[$lexvoidSource] = $cachedValue;

            }

        }

        if(count($missingLexvoids) == 0) {

            return $results;

        }

        $query = "SELECT ?s ?o WHERE {";

        foreach ($missingLexvoids as $index => $lid) {

            if($index > 0) {

                $query .= " UNION ";

            }

            $query .= "{<$lid> rdfs:label ?o. ?s rdfs:label ?o FILTER(?s = <$lid> && (lang(?o) = \"fr\" || lang(?o) = \"en\"))}";

        }

        $query .= "}";

        $docs = $this->sparqlClient->query($query);

        $resultsRaw = [];

        foreach ($docs as $doc) {

            $lexvoid = $doc->s->getUri();

            $lexvoname = $doc->o;

            $lang = $lexvoname->getLang();

            $value = $lexvoname->getValue();

            if(!array_key_exists($lexvoid, $resultsRaw) ||

            ($lang == "fr" && ($resultsRaw[$lexvoid]->getLang() == "en" || mb_strlen($resultsRaw[$lexvoid]->getValue()) > mb_strlen($value))) ||

            ($lang == "en" && $resultsRaw[$lexvoid]->getLang() == "en" && mb_strlen($resultsRaw[$lexvoid]->getValue()) > mb_strlen($value)) ) {

                $resultsRaw[$lexvoid] = $lexvoname;

            }

        }

        foreach ($missingLexvoids as $lexvoid) {

            $lexvoidSource = $lexvoidsMap[$lexvoid];

            $missingValue = array_key_exists($lexvoid,$resultsRaw) && $resultsRaw[$lexvoid]?mb_strtolower($resultsRaw[$lexvoid]->getValue()):"";

            Cache::put("lexvo:$lexvoid", $missingValue, config('corpusparole.lexvo_cache_expiration'));

            $results[$lexvoidSource] = mb_strlen($missingValue)>0?$missingValue:null;

        }

        return $results;

    }

}