class PrrByKey2CsvConverter {

    static convertPrrByKey2Csv(
        {
            heading,
            columns: { keyColumn, prrColumn },
            prrByKey
        }
    ) {
        return heading + '\n\n' +
            PrrByKey2CsvConverter.#convert2Csv(
                {
                    prrByKey: PrrByKey2CsvConverter.#quoteKeys(prrByKey),
                    keyColumn: PrrByKey2CsvConverter.#quote(keyColumn),
                    prrColumn: PrrByKey2CsvConverter.#quote(prrColumn)
                });
    }

    static #quoteKeys(prrByKey) {
        return Object.fromEntries(
            Object
                .entries(prrByKey)
                .map(([key, prr]) => [PrrByKey2CsvConverter.#quote(key), prr]))
    }

    static #quote(str) {
        return '"' + str + '"';
    }

    static #convert2Csv({ prrByKey, keyColumn, prrColumn }) {
        const header = `${keyColumn},${prrColumn}`;
        return `${header}\n${PrrByKey2CsvConverter.#convertDict2Csv(prrByKey)}`;
    }

    static #convertDict2Csv(dict) {
        return Object
            .entries(dict)
            .map(([key, value]) => `${key},${value}`)
            .join('\n');
    }
}