Improved organisation of Services

src/Services/Parts/PricedetailHelper.php

@@ -0,0 +1,218 @@
+<?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/>.
+ */
+
+declare(strict_types=1);
+
+namespace App\Services\Parts;
+
+use App\Entity\Parts\Part;
+use App\Entity\PriceInformations\Currency;
+use App\Entity\PriceInformations\Pricedetail;
+use Brick\Math\BigDecimal;
+use Brick\Math\RoundingMode;
+use Doctrine\ORM\PersistentCollection;
+use Locale;
+
+use function count;
+
+class PricedetailHelper
+{
+    protected string $base_currency;
+    protected string $locale;
+
+    public function __construct(string $base_currency)
+    {
+        $this->base_currency = $base_currency;
+        $this->locale = Locale::getDefault();
+    }
+
+    /**
+     * Determines the highest amount, for which you get additional discount.
+     * This function determines the highest min_discount_quantity for the given part.
+     */
+    public function getMaxDiscountAmount(Part $part): ?float
+    {
+        $orderdetails = $part->getOrderdetails(true);
+
+        $max = 0;
+
+        foreach ($orderdetails as $orderdetail) {
+            $pricedetails = $orderdetail->getPricedetails();
+            //The orderdetail must have pricedetails, otherwise this will not work!
+            if (0 === count($pricedetails)) {
+                continue;
+            }
+
+            if ($pricedetails instanceof PersistentCollection) {
+                /* Pricedetails in orderdetails are ordered by min discount quantity,
+                    so our first object is our min order amount for the current orderdetail */
+                $max_amount = $pricedetails->last()->getMinDiscountQuantity();
+            } else {
+                // We have to sort the pricedetails manually
+                $array = $pricedetails->map(
+                    static function (Pricedetail $pricedetail) {
+                        return $pricedetail->getMinDiscountQuantity();
+                    }
+                )->toArray();
+                sort($array);
+                $max_amount = end($array);
+            }
+
+            if ($max_amount > $max) {
+                $max = $max_amount;
+            }
+        }
+
+        if ($max > 0.0) {
+            return $max;
+        }
+
+        return null;
+    }
+
+    /**
+     * Determines the minimum amount of the part that can be ordered.
+     *
+     * @param Part $part the part for which the minimum order amount should be determined
+     *
+     * @return float
+     */
+    public function getMinOrderAmount(Part $part): ?float
+    {
+        $orderdetails = $part->getOrderdetails(true);
+
+        $min = INF;
+
+        foreach ($orderdetails as $orderdetail) {
+            $pricedetails = $orderdetail->getPricedetails();
+            //The orderdetail must have pricedetails, otherwise this will not work!
+            if (0 === count($pricedetails)) {
+                continue;
+            }
+
+            /* Pricedetails in orderdetails are ordered by min discount quantity,
+                so our first object is our min order amount for the current orderdetail */
+            $min_amount = $pricedetails[0]->getMinDiscountQuantity();
+
+            if ($min_amount < $min) {
+                $min = $min_amount;
+            }
+        }
+
+        if ($min < INF) {
+            return $min;
+        }
+
+        return null;
+    }
+
+    /**
+     * Calculates the average price of a part, when ordering the amount $amount.
+     *
+     * @param  Part  $part  the part for which the average price should be calculated
+     * @param  float|null  $amount  The order amount for which the average price should be calculated.
+     *                                If set to null, the mininmum order amount for the part is used.
+     * @param  Currency|null  $currency  The currency in which the average price should be calculated
+     *
+     * @return BigDecimal|null The Average price as bcmath string. Returns null, if it was not possible to calculate the
+     *                         price for the given
+     */
+    public function calculateAvgPrice(Part $part, ?float $amount = null, ?Currency $currency = null): ?BigDecimal
+    {
+        if (null === $amount) {
+            $amount = $this->getMinOrderAmount($part);
+        }
+
+        if (null === $amount) {
+            return null;
+        }
+
+        $orderdetails = $part->getOrderdetails(true);
+
+        $avg = BigDecimal::zero();
+        $count = 0;
+
+        //Find the price for the amount, for the given
+        foreach ($orderdetails as $orderdetail) {
+            $pricedetail = $orderdetail->findPriceForQty($amount);
+
+            //When we dont have informations about this amount, ignore it
+            if (null === $pricedetail) {
+                continue;
+            }
+
+            $converted = $this->convertMoneyToCurrency($pricedetail->getPricePerUnit(), $pricedetail->getCurrency(), $currency);
+            //Ignore price informations that can not be converted to base currency.
+            if (null !== $converted) {
+                $avg = $avg->plus($converted);
+                ++$count;
+            }
+        }
+
+        if (0 === $count) {
+            return null;
+        }
+
+        return $avg->dividedBy($count)->toScale(Pricedetail::PRICE_PRECISION, RoundingMode::HALF_UP);
+    }
+
+    /**
+     * Converts the given value in origin currency to the choosen target currency.
+     *
+     * @param Currency|null $originCurrency The currency the $value is given in.
+     *                                      Set to null, to use global base currency.
+     * @param Currency|null $targetCurrency The target currency, to which $value should be converted.
+     *                                      Set to null, to use global base currency.
+     *
+     * @return BigDecimal|null The value in $targetCurrency given as bcmath string.
+     *                         Returns null, if it was not possible to convert between both values (e.g. when the exchange rates are missing)
+     */
+    public function convertMoneyToCurrency(BigDecimal $value, ?Currency $originCurrency = null, ?Currency $targetCurrency = null): ?BigDecimal
+    {
+        //Skip conversion, if both currencies are same
+        if ($originCurrency === $targetCurrency) {
+            return $value;
+        }
+
+        $val_base = $value;
+        //Convert value to base currency
+        if (null !== $originCurrency) {
+            //Without an exchange rate we can not calculate the exchange rate
+            if (null === $originCurrency->getExchangeRate() || $originCurrency->getExchangeRate()->isZero()) {
+                return null;
+            }
+
+            $val_base = $value->multipliedBy($originCurrency->getExchangeRate());
+        }
+
+        $val_target = $val_base;
+        //Convert value in base currency to target currency
+        if (null !== $targetCurrency) {
+            //Without an exchange rate we can not calculate the exchange rate
+            if (null === $targetCurrency->getExchangeRate()) {
+                return null;
+            }
+
+            $val_target = $val_base->multipliedBy($targetCurrency->getInverseExchangeRate());
+        }
+
+        return $val_target->toScale(Pricedetail::PRICE_PRECISION, RoundingMode::HALF_UP);
+    }
+}