<?php

/**
 * Chill is a software for social workers
 *
 * For the full copyright and license information, please view
 * the LICENSE file that was distributed with this source code.
 */

declare(strict_types=1);

namespace Chill\MainBundle\Service\Import;

use Doctrine\DBAL\Connection;
use Doctrine\DBAL\Statement;
use Exception;
use function array_key_exists;
use function count;

/**
 * Optimized way to load postal code into database.
 */
class PostalCodeBaseImporter
{
    private const QUERY = <<<'SQL'
        WITH g AS (
            SELECT DISTINCT
                country.id AS country_id,
                g.*
            FROM (VALUES
                      {{ values }}
                 ) AS g (countrycode, label, code, refpostalcodeid, postalcodeSource, lon, lat, srid)
            JOIN country ON country.countrycode = g.countrycode
        )
        INSERT INTO chill_main_postal_code (id, country_id, label, code, origin, refpostalcodeid, postalcodeSource, center, createdAt, updatedAt)
               SELECT
                   nextval('chill_main_postal_code_id_seq'),
                   g.country_id,
                   g.label AS glabel,
                   g.code,
                   0,
                   g.refpostalcodeid,
                   g.postalcodeSource,
                   CASE WHEN (g.lon::float != 0.0 AND g.lat::float != 0.0) THEN ST_Transform(ST_setSrid(ST_point(g.lon::float, g.lat::float), g.srid::int), 4326) ELSE NULL END,
                   NOW(),
                   NOW()
               FROM g
        ON CONFLICT (code, refpostalcodeid, postalcodeSource) WHERE refpostalcodeid IS NOT NULL DO UPDATE SET label = excluded.label, center = excluded.center, updatedAt = NOW()
        SQL;

    private const VALUE = '(?, ?, ?, ?, ?, ?, ?, ?)';

    /**
     * @var array<int, Statement>
     */
    private array $cachingStatements = [];

    private Connection $defaultConnection;

    private array $waitingForInsert = [];

    public function __construct(
        Connection $defaultConnection
    ) {
        $this->defaultConnection = $defaultConnection;
    }

    public function finalize(): void
    {
        $this->doInsertPending();
    }

    public function importCode(
        string $countryCode,
        string $label,
        string $code,
        string $refPostalCodeId,
        string $refPostalCodeSource,
        float $centerLat,
        float $centerLon,
        int $centerSRID
    ): void {
        $this->waitingForInsert[] = [
            $countryCode,
            $label,
            $code,
            $refPostalCodeId,
            $refPostalCodeSource,
            $centerLon,
            $centerLat,
            $centerSRID,
        ];

        if (100 <= count($this->waitingForInsert)) {
            $this->doInsertPending();
        }
    }

    private function doInsertPending(): void
    {
        if (!array_key_exists($forNumber = count($this->waitingForInsert), $this->cachingStatements)) {
            $sql = strtr(self::QUERY, [
                '{{ values }}' => implode(
                    ', ',
                    array_fill(0, $forNumber, self::VALUE)
                ),
            ]);

            $this->cachingStatements[$forNumber] = $this->defaultConnection->prepare($sql);
        }

        $statement = $this->cachingStatements[$forNumber];

        try {
            $statement->executeStatement(array_merge(...$this->waitingForInsert));
        } catch (Exception $e) {
            // in some case, we can add debug code here
            //dump($this->waitingForInsert);
            throw $e;
        } finally {
            $this->waitingForInsert = [];
        }
    }
}