.

src/main/java/core/basesyntax/WorkWithFile.java

@@ -1,7 +1,43 @@
 package core.basesyntax;
 
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
 public class WorkWithFile {
     public void getStatistic(String fromFileName, String toFileName) {
+        int supply = 0;
+        int buy = 0;
+
+        try (BufferedReader reader = Files.newBufferedReader(Paths.get(fromFileName))) {
+            String line = " ";
+            while ((line = reader.readLine()) != null){
+                String [] parts = line.split(",");
+                if (parts.length == 2) {
+                    String operation = parts[0].trim();
+                    int amount = Integer.parseInt(parts[1].trim());
+                    if ("supply".equalsIgnoreCase(operation)) {
+                        supply += amount;
+                    } else if ("buy".equalsIgnoreCase(operation)){
+                        buy += amount;
+                    }
+                }
+            }
+        } catch (IOException e) {
+            throw new RuntimeException(fromFileName, e);
+        }
+        int result = supply - buy;
 
+        try (BufferedWriter writer = Files.newBufferedWriter(Paths.get(toFileName))) {
+            writer.write("supply," + supply);
+            writer.newLine();
+            writer.write("buy," + buy);
+            writer.newLine();
+            writer.write("result," + result);
+        } catch (IOException e) {
+            System.err.println("Error writing to the file: " + e.getMessage());
+        }
     }
 }