src/main/java/Main.java

@@ -15,15 +15,15 @@ public class Main {
         }
         Scanner scanner = new Scanner(input);
 
-        // TODO:
-        // - Read each line from products.csv
-        // - For each line, parse productId, name, and price
-        // - The format of the file is like this:
-        //      [productId],[name],[price]
-        // - Store Product objects in the productCatalog ArrayList
-
-        // NOTE
-        // - The data in products.csv is guaranteed to be valid.
+        //reading file line by line and then parsing their values
+        while (scanner.hasNextLine()) {
+            String line = scanner.nextLine();
+            String[] cells = line.split(",");
+            int productID = Integer.parseInt(cells[0]);
+            String productName = cells[1];
+            double price = Double.parseDouble(cells[2]);
+            productCatalog.add(new Product(productID, productName, price));
+        }
     }
 
     public static void main(String[] args)

src/main/java/ReportGenerator.java

@@ -1,4 +1,7 @@
+import java.io.*;
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Scanner;
 
 public class ReportGenerator {
 
@@ -17,67 +20,68 @@ public class ReportGenerator {
 
     public void processFile()
     {
-        // TODO:
-        // 1. Open the order details CSV file
-        // 2. Read the file line by line
-        // 3. Split each line using comma delimiter
-        //      (each line is guaranteed to contain exactly two commas)
-        // 4. Each line contains exactly 3 values in the format:
-        //      [productId],[quantity],[discountPercent]
-        // 5. Attempt to convert values:
-        //      - productId -> int
-        //      - quantity -> int
-        //      - discountPercent -> int
-        //    NOTE:
-        //      - quantity and discountPercent may contain invalid characters
-        //        (e.g., letters instead of numbers).
-        //      - If parsing any value fails (NumberFormatException),
-        //        the entire line must be considered invalid.
-        //      - Use try-catch blocks and exception handling to safely
-        //        handle parsing and validation errors without stopping
-        //        the processing of the remaining lines.
-        // 6. Validate parsed values:
-        //      - productId must be greater than 0
-        //      - quantity must be greater than 0
-        //      - discountPercent must be between 0 and 99 inclusive
-        // 7. Look for a Product in productList that matches productId
-        // 8. If no Product with that ID exists in the catalog,
-        //      the entire line is considered invalid
-        // 9. If all values are valid and the product exists, calculate:
-        //      subtotal = quantity * product price
-        //      discountValue = subtotal * discountPercent / 100
-        //      finalCost = subtotal - discountValue
-        // 10. Update report totals:
-        //      - totalQuantity += quantity
-        //      - totalFinalCost += finalCost
-        //      - totalDiscountValue += discountValue
-        // 11. If any parsing error, validation failure, or missing product occurs:
-        //      - increment totalInvalidLines
-        //      - skip the line and continue processing the next line
-        // 12. Close all file resources
+        // use try-catch to check is file available
+        try {
+            File file = new File(ordersFilePath);
+            Scanner input = new Scanner(file);
+            // counter for better reporting invalid lines
+            int lineNumber = 0;
+            while (input.hasNextLine()) {
+                lineNumber++;
+                // use try-catch to validate the lines
+                try {
+                    String line = input.nextLine();
+                    String[] fields = line.split(",");
+                    int productID = Integer.parseInt(fields[0]);
+                    int quantity = Integer.parseInt(fields[1]);
+                    int discountPercent = Integer.parseInt(fields[2]);
+                    // check if any field has wrong amounts
+                    if ((discountPercent < 0 || discountPercent > 99) || (quantity <= 0) ||
+                            (productList.stream().noneMatch(product -> product.getProductID() == productID)))
+                    { throw  new IllegalArgumentException(); }
+
+                    Product p = productList.stream().filter(product -> product.getProductID() == productID).findFirst().get();
+                    double subtotal = quantity * p.getPrice();
+                    double discountValue = subtotal * discountPercent / 100;
+                    double finalCost = subtotal - discountValue;
+
+                    //updating report attributes
+                    totalQuantity += quantity;
+                    totalFinalCost += finalCost;
+                    totalDiscountValue += discountValue;
+                }
+                catch (IllegalArgumentException e) {
+                    totalInvalidLines++;
+                    System.out.println("Inavalid line: " + lineNumber);
+                }
+            }
+            input.close();
+
+        }
+
+        catch (IOException e) {
+            System.out.println("Orders file not found");
+        }
+
     }
 
     public void saveReport()
     {
-        // TODO:
-        // 1. Build a formatted report string
-        // 2. Include:
-        //      - total quantity
-        //      - total final cost
-        //      - total discount value
-        //      - total invalid lines
-        // 3. Create/open output report file (name it report.txt)
-        // 4. Write report string into file
-        // 5. Handle file writing exceptions
-        // 6. Close writer resources
 
-        /* Example Structure
-        ========= SALES REPORT =========
-        Total Quantity Sold: 42
-        Total Final Cost: $1520.75
-        Total Discount Value: $230.50
-        Invalid Rows: 3
-        ================================
-        */
+        String report = "========= SALES REPORT =========\n" +
+                "Total Quantity Sold: " + totalQuantity + "\n" +
+                "Total Final Cost: " + totalFinalCost + "\n" +
+                "Total Discount Value: " + totalDiscountValue + "\n" +
+                "Total Invalid Rows: " + totalInvalidLines + "\n" +
+                "=======================================";
+
+        try {
+            PrintWriter output = new PrintWriter("report.txt");
+            output.println(report);
+            output.close();
+        }
+        catch (FileNotFoundException e) {
+            System.out.println("Error writing report file!");
+        }
     }
 }