<?php

namespace Toalett\Redis\Timeseries;

use Predis\Client;
use Toalett\Redis\Timeseries\Exception\DatabaseException;
use Toalett\Redis\Timeseries\Model\Range;
use Toalett\Redis\Timeseries\Model\Value;
use Toalett\Redis\Timeseries\Protocol\Query\AbstractMRangeQuery;
use Toalett\Redis\Timeseries\Protocol\Query\AbstractRangeQuery;
use Toalett\Redis\Timeseries\Protocol\Query\GetQuery;
use Toalett\Redis\Timeseries\Protocol\Query\MGetQuery;
use Toalett\Redis\Timeseries\Protocol\Query\Query;

final class QueryService
{
    private Client $client;

    public function __construct(Client $client)
    {
        $this->client = $client;
    }

    public function exists(string $key): bool
    {
        return 1 === $this->client->exists($key);
    }

    /**
     * @param AbstractRangeQuery $rangeQuery
     * @return Value[]
     */
    public function range(AbstractRangeQuery $rangeQuery): array
    {
        $response = $this->send($rangeQuery);
        return array_map([$this, 'extractValue'], $response);
    }

    /**
     * @param AbstractMRangeQuery $mRangeQuery
     * @return Range[]
     */
    public function mrange(AbstractMRangeQuery $mRangeQuery): array
    {
        $response = $this->send($mRangeQuery);
        return array_map([$this, 'extractRange'], $response);
    }

    public function get(GetQuery $query): ?Value
    {
        $response = $this->send($query);
        return empty($response) ? null : $this->extractValue($response);
    }

    /**
     * @param MGetQuery $query
     * @return Range[]
     */
    public function mget(MGetQuery $query): array
    {
        $response = $this->send($query);
        return array_map([$this, 'extractRange'], $response);
    }

    private function extractValue(array $row): Value
    {
        return new Value((int)$row[0], (float)$row[1]->getPayload());
    }

    private function extractRange(array $row): Range
    {
        $labels = [];
        foreach ($row[1] as $labelRow) {
            $labels[$labelRow[0]] = $labelRow[1];
        }

        // Difference between mrange and range
        if (empty($row[2])) {
            $values = [];
        } else if (is_object(@$row[2][1])) {
            $values = [$this->extractValue($row[2])];
        } else {
            $values = array_map([$this, 'extractValue'], $row[2]);
        }

        return new Range($row[0], $labels, $values);
    }

    /**
     * @param Query $command
     * @return array|int
     */
    protected function send(Query $command)
    {
        $response = $this->client->executeRaw($command->toRawCommand());
        if (is_string($response) && 0 !== strpos($response, 'OK')) {
            throw new DatabaseException($response);
        }
        return $response;
    }
}