Improved organisation of Services

src/Services/Tools/ExchangeRateUpdater.php

@@ -0,0 +1,56 @@
+<?php
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2022 Jan Böhmer (https://github.com/jbtronics)
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published
+ *  by the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+namespace App\Services\Tools;
+
+use App\Entity\PriceInformations\Currency;
+use Brick\Math\BigDecimal;
+use Brick\Math\RoundingMode;
+use Swap\Swap;
+
+class ExchangeRateUpdater
+{
+    private string $base_currency;
+    private Swap $swap;
+
+    public function __construct(string $base_currency, Swap $swap)
+    {
+        $this->base_currency = $base_currency;
+        $this->swap = $swap;
+    }
+
+    /**
+     * Updates the exchange rate of the given currency using the globally configured providers.
+     */
+    public function update(Currency $currency): Currency
+    {
+        //Currency pairs are always in the format "BASE/QUOTE"
+        $rate = $this->swap->latest($this->base_currency.'/'.$currency->getIsoCode());
+        //The rate says how many quote units are worth one base unit
+        //So we need to invert it to get the exchange rate
+
+        $rate_bd = BigDecimal::of($rate->getValue());
+        $rate_inverted = BigDecimal::one()->dividedBy($rate_bd, Currency::PRICE_SCALE, RoundingMode::HALF_UP);
+
+        $currency->setExchangeRate($rate_inverted);
+
+        return $currency;
+    }
+}