ExchangeRates.php

<?php
namespace App\Services;

use Carbon\Carbon;
use Illuminate\Support\Facades\Http;

/**
 * ExchangeRates is a wrapper class for the Exchange Retes API at https://api.exchangerate.host
 */
class ExchangeRates
{
    public function __construct()
    {
        $this->baseUrl = 'https://api.exchangerate.host';
    }

    /**
     * This method gets currency conversation data base on the given country codes
     * If an amount is provided it will also provide the amount after conversion.
     *
     * @param $from the three letter currency code to convert from e.g. USD.
     * @param $to the three letter currency code to convert to e.g. GBP
     * @param $date the date to use when looking up the exchange rate.
     * @param $amount the amount to convert. Note this is optional
     * @param $placs how many decimals to round the conversion rate to
     *
     */
    public function convertCurrency(string $from, string $to, Carbon $date = null, string $amount = null, $places = 5)
    {
        $url = '/convert';

        $response = Http::get($this->baseUrl . $url, [
            'base' => $from,
            'from' => $from,
            'to' => $to,
            'date' => $date ? $date->format('Y-m-d') : now()->format('Y-m-d'),
            'amount' => $amount,
            'places' => $places
        ]);

        return $response->json();
    }

    /**
     * This function retrieves historical currency rates based on a given date.
     *
     * @param Carbon $date a Carbon instance representing a date.
     * @param $placs how many decimals to round the conversion rate to
     */
    public function exchangeRateAtDate(Carbon $date = null, $places = 5, $symbols = null, string $base = 'GBP')
    {
        $symbols = is_array($symbols) ? implode(',', $symbols) : null;

        $url = $date ? '/' . $date->format('Y-m-d') : '/latest';

        $response = Http::get($this->baseUrl . $url, [
            'base' => $base,
            'places' => $places,
            'symbols' => $symbols
        ]);

        return $response->json();
    }

    /**
     * This function retrieves a list of all available currencies.
     * This could be used to simply check or even build a validation rule to ensure inputs will return data.
     * Returned data contains a symbols array.
     */
    public function currencies()
    {
        $url = '/symbols';

        $response = Http::get($this->baseUrl . $url);

        return $response->json();
    }
}