Serializing metrics to InfluxDB line format

InfluxdbLine.php

<?php

class InfluxdbLine
{
    // https://docs.influxdata.com/influxdb/v2.0/reference/syntax/line-protocol/
    public function format(string $measurement, array $tags, array $fields, string $timestampNanoSeconds): string
    {
        $measurementEscaped = $this->escapeMeasurement($measurement);
        $tagsFlat = $this->flattenTags($tags);
        $fieldsFlat = $this->flattenFields($fields);

        return "{$measurementEscaped}{$tagsFlat} {$fieldsFlat} {$timestampNanoSeconds}";
    }

    private function escapeMeasurement(string $measurement): string
    {
        return $this->escapeComma($this->escapeSpace($measurement));
    }

    private function escapeKey(string $key): string
    {
        return $this->escapeComma($this->escapeEqual($this->escapeSpace($key)));
    }

    private function escapeTagValue(string $value): string
    {
        return $this->escapeComma($this->escapeEqual($this->escapeSpace($value)));
    }

    private function escapeFieldValue($value): string
    {
        if (is_string($value)) {
            return '"' . $this->escapeDoubleQuote($this->escapeBackslash($value)) . '"';
        }

        if (is_int($value)) {
            return ((string)$value) . 'i';
        }

        if (is_float($value)) {
            return (string)$value;
        }

        if (is_bool($value)) {
            return $value ? 'true' : 'false';
        }

        throw new \LogicException('Неподдерживаемый тип значения для метрики');
    }

    private function flattenTags(array $tags): string
    {
        if (count($tags) === 0) {
            return '';
        }

        return ',' . implode(',', $this->valuePairs($tags, false));
    }

    private function flattenFields(array $fields): string
    {
        if (count($fields) === 0) {
            throw new \LogicException('Не указаны поля для метрик');
        }

        return implode(',', $this->valuePairs($fields, true));
    }

    private function valuePairs(array $items, bool $isFields): array
    {
        if (count($items) === 0) {
            return [];
        }

        $result = [];

        foreach ($items as $key => $value) {
            $result[] = $this->escapeKey($key) . '=' . ($isFields ? $this->escapeFieldValue($value) : $this->escapeTagValue($value));
        }

        return $result;
    }

    private function escapeSpace(string $value): string
    {
        return str_replace(' ', '\ ', $value);
    }

    private function escapeComma(string $value): string
    {
        return str_replace(',', '\,', $value);
    }

    private function escapeEqual(string $value): string
    {
        return str_replace('=', '\=', $value);
    }

    private function escapeDoubleQuote(string $value): string
    {
        return str_replace('"', '\"', $value);
    }

    private function escapeBackslash(string $value): string
    {
        return str_replace('\\', '\\\\', $value);
    }
}