writing codes in reportGenerator file

src/main/java/Main.java

@@ -24,6 +24,22 @@ public class Main {
 
         // NOTE
         // - The data in products.csv is guaranteed to be valid.
+        while (scanner.hasNextLine()) {
+
+            String line = scanner.nextLine();
+
+            String[] parts = line.split(",");
+
+            int productId = Integer.parseInt(parts[0]);
+            String name = parts[1];
+            double price = Double.parseDouble(parts[2]);
+
+            Product product = new Product(productId, name, price);
+
+            productCatalog.add(product);
+        }
+
+        scanner.close();
     }
 
     public static void main(String[] args)

src/main/java/ReportGenerator.java

@@ -55,6 +55,75 @@ public class ReportGenerator {
         //      - increment totalInvalidLines
         //      - skip the line and continue processing the next line
         // 12. Close all file resources
+        try {
+
+            java.io.File file = new java.io.File(ordersFilePath);
+
+            java.util.Scanner scanner = new java.util.Scanner(file);
+
+            while (scanner.hasNextLine()) {
+
+                String line = scanner.nextLine();
+
+                try {
+
+                    String[] parts = line.split(",");
+
+                    int productId = Integer.parseInt(parts[0]);
+                    int quantity = Integer.parseInt(parts[1]);
+                    int discountPercent = Integer.parseInt(parts[2]);
+
+                    if (productId <= 0 ||
+                            quantity <= 0 ||
+                            discountPercent < 0 ||
+                            discountPercent > 99) {
+
+                        totalInvalidLines++;
+                        continue;
+                    }
+
+                    Product foundProduct = null;
+
+                    for (Product product : productList) {
+
+                        if (product.getProductID() == productId) {
+                            foundProduct = product;
+                            break;
+                        }
+                    }
+
+                    if (foundProduct == null) {
+                        totalInvalidLines++;
+                        continue;
+                    }
+
+                    double subtotal =
+                            quantity * foundProduct.getPrice();
+
+                    double discountValue =
+                            subtotal * discountPercent / 100.0;
+
+                    double finalCost =
+                            subtotal - discountValue;
+
+                    totalQuantity += quantity;
+                    totalFinalCost += finalCost;
+                    totalDiscountValue += discountValue;
+
+                }
+                catch (NumberFormatException e) {
+
+                    totalInvalidLines++;
+                }
+            }
+
+            scanner.close();
+
+        }
+        catch (java.io.IOException e) {
+
+            System.out.println("Error reading order file.");
+        }
     }
 
     public void saveReport()
@@ -79,5 +148,29 @@ public class ReportGenerator {
         Invalid Rows: 3
         ================================
         */
+        try {
+
+            java.io.FileWriter writer =
+                    new java.io.FileWriter("report.txt");
+
+            String report =
+                    "========= SALES REPORT =========\n" +
+                            "Total Quantity Sold: " + totalQuantity + "\n" +
+                            "Total Final Cost: $" +
+                            String.format("%.2f", totalFinalCost) + "\n" +
+                            "Total Discount Value: $" +
+                            String.format("%.2f", totalDiscountValue) + "\n" +
+                            "Invalid Rows: " + totalInvalidLines + "\n" +
+                            "================================";
+
+            writer.write(report);
+
+            writer.close();
+
+        }
+        catch (java.io.IOException e) {
+
+            System.out.println("Error writing report file.");
+        }
     }
 }