<?php namespace MapGuesser\Repository;

use Generator;
use MapGuesser\Database\Query\Select;
use MapGuesser\PersistentData\Model\Map;
use MapGuesser\PersistentData\Model\Place;
use MapGuesser\PersistentData\PersistentDataManager;

class PlaceRepository
{
    private PersistentDataManager $pdm;

    public function __construct()
    {
        $this->pdm = new PersistentDataManager();
    }

    public function getById(int $placeId): ?Place
    {
        return $this->pdm->selectFromDbById($placeId, Place::class);
    }

    public function getAllForMap(Map $map): Generator
    {
        $select = new Select(\Container::$dbConnection);
        $select->where('map_id', '=', $map->getId());

        yield from $this->pdm->selectMultipleFromDb($select, Place::class);
    }

    //TODO: use Map instead of id
    public function getRandomNForMapWithValidPano(int $mapId, int $n, array $exclude = []): array
    {
        $places = [];

        for ($i = 1; $i <= $n; ++$i) {
            $place = $this->getRandomForMapWithValidPano($mapId, $exclude);

            $places[] = $place;
            $exclude[] = $place->getId();
        }

        return $places;
    }

    //TODO: use Map instead of id
    public function getRandomForMapWithValidPano(int $mapId, array $exclude = []): Place
    {
        do {
            $place = $this->selectRandomFromDbForMap($mapId, $exclude);

            $panoId = $place->getFreshPanoId();
            if ($panoId === null) {
                $exclude[] = $place->getId();
            }
        } while ($panoId === null);

        return $place;
    }

    private function selectRandomFromDbForMap(int $mapId, array $exclude): Place
    {
        //TODO: omit table name here
        $select = new Select(\Container::$dbConnection, 'places');
        $select->where('id', 'NOT IN', $exclude);
        $select->where('map_id', '=', $mapId);

        $numberOfPlaces = $select->count();

        //TODO: prevent this
        if ($numberOfPlaces === 0) {
            throw new \Exception('There is no selectable place (count was 0).');
        }

        $randomOffset = random_int(0, $numberOfPlaces - 1);

        $select->orderBy('id');
        $select->limit(1, $randomOffset);

        return $this->pdm->selectFromDb($select, Place::class);
    }
}