Merge branch 'Funktion-zur-automatischen-Margenermittlung' into dev

src/main/java/de/rwu/easydrop/Main.java

@@ -12,6 +12,7 @@ import de.rwu.easydrop.api.client.DataSourceFactory;
 import de.rwu.easydrop.data.connector.AbstractProductPersistence;
 import de.rwu.easydrop.data.connector.SQLiteConnector;
 import de.rwu.easydrop.model.ProductCatalogue;
+import de.rwu.easydrop.service.processing.OrderManager;
 import de.rwu.easydrop.service.retriever.CatalogueRetriever;
 import de.rwu.easydrop.service.retriever.ProductRetriever;
 import de.rwu.easydrop.service.writer.CatalogueWriter;
@@ -58,5 +59,7 @@ public final class Main {
             String pCatStr = pCat.toString();
             LOGGER.info(pCatStr);
         }
+
+        OrderManager.createOrders(pCats);
     }
 }

src/main/java/de/rwu/easydrop/exception/InvalidCatalogueException.java

@@ -0,0 +1,27 @@
+package de.rwu.easydrop.exception;
+
+/**
+ * Exception that signifies the data of a Product are invalid.
+ *
+ * @since 0.3.0
+ */
+public class InvalidCatalogueException extends RuntimeException {
+    /**
+     * Throws an exception that signifies the data of a Product are invalid.
+     *
+     * @param message
+     */
+    public InvalidCatalogueException(final String message) {
+        super(message);
+    }
+
+    /**
+     * Throws an exception that signifies the data of a Product are invalid.
+     *
+     * @param message
+     * @param cause
+     */
+    public InvalidCatalogueException(final String message, final Throwable cause) {
+        super(message, cause);
+    }
+}

src/main/java/de/rwu/easydrop/model/ProductPair.java

@@ -0,0 +1,31 @@
+package de.rwu.easydrop.model;
+
+import lombok.Data;
+
+/**
+ * Associates two related Products to one another.
+ *
+ * @since 0.3.0
+ */
+@Data
+public class ProductPair {
+    /**
+     * The first product.
+     */
+    private final Product product1;
+    /**
+     * The second product.
+     */
+    private final Product product2;
+
+    /**
+     * Constructs a Product Pair.
+     *
+     * @param a First product
+     * @param b Second product
+     */
+    public ProductPair(final Product a, final Product b) {
+        this.product1 = a;
+        this.product2 = b;
+    }
+}

src/main/java/de/rwu/easydrop/service/processing/OrderManager.java

@@ -1,10 +1,87 @@
 package de.rwu.easydrop.service.processing;
 
-/**
- * Processes dropshipping orders.
- *
- * TODO implement
- */
-public class OrderManager {
+import java.util.List;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import de.rwu.easydrop.exception.InvalidCatalogueException;
+import de.rwu.easydrop.model.Product;
+import de.rwu.easydrop.model.ProductCatalogue;
+import de.rwu.easydrop.model.ProductPair;
+import de.rwu.easydrop.util.FormattingUtil;
+
+/**
+ * Creates dropshipping orders based on price margin.
+ *
+ * @since 0.3.0
+ */
+public final class OrderManager {
+
+    /**
+     * Temporary logging instance.
+     */
+    private static final Logger LOGGER = LoggerFactory.getLogger(OrderManager.class);
+
+    /**
+     * Private constructor to prevent unwanted instantiation.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    private OrderManager() throws UnsupportedOperationException {
+        throw new UnsupportedOperationException("This is a stateless class, don't instantiate it.");
+    }
+
+    /**
+     * Creates orders for products with sufficient margin.
+     *
+     * @param pCats Product Catalogues
+     */
+    public static void createOrders(final List<ProductCatalogue> pCats) {
+        for (ProductCatalogue pCat : pCats) {
+            ProductPair pair = getHighestMarginProducts(pCat);
+
+            // #12: Create actual orders/transactions, remove logger
+            double margin = pair.getProduct2().getCurrentPrice()
+                    - pair.getProduct1().getCurrentPrice();
+            String marginFormatted = FormattingUtil.formatEuro(margin);
+            LOGGER.info("{}: Margin {} ({} to {})",
+                    pCat.getProductName(),
+                    marginFormatted,
+                    pair.getProduct1().getDataOrigin(),
+                    pair.getProduct2().getDataOrigin());
+        }
+    }
+
+    /**
+     * Returns the cheapest and most expensive product of a catalogue to guarantee
+     * the biggest margin as a pair.
+     *
+     * @param pCat Product Catalogue
+     * @return Cheapest Product, Most Expensive Product as a Product Pair
+     */
+    public static ProductPair getHighestMarginProducts(final ProductCatalogue pCat) {
+        if (pCat.getProducts().size() < 2) {
+            throw new InvalidCatalogueException("Product Catalogue holds less than 2 products!");
+        }
+
+        // Initialize indexes
+        Product cheapestProduct = pCat.getProducts().get(0);
+        Product mostExpensiveProduct = pCat.getProducts().get(0);
+
+        for (Product product : pCat.getProducts()) {
+            if (product.getCurrentPrice() < cheapestProduct.getCurrentPrice()) {
+                cheapestProduct = product;
+            }
+            if (product.getCurrentPrice() > mostExpensiveProduct.getCurrentPrice()) {
+                mostExpensiveProduct = product;
+            }
+        }
+
+        if (cheapestProduct.getCurrentPrice() == mostExpensiveProduct.getCurrentPrice()) {
+            throw new InvalidCatalogueException("Price margin is zero!");
+        }
+
+        return new ProductPair(cheapestProduct, mostExpensiveProduct);
+    }
 }

src/main/java/de/rwu/easydrop/util/FormattingUtil.java

@@ -25,7 +25,7 @@ public final class FormattingUtil {
      * @return formatted price
      */
     public static String formatEuro(final double amount) {
-        return String.format(Locale.GERMAN, "%,.2f", amount) + " €";
+        return String.format(Locale.GERMAN, "%,.2f", amount) + " Euro";
     }
 
     /**