chore: SP-2487 add extractFilePathFromWFP() utils function

Author: isasmendiagus

src/main/java/com/scanoss/utils/WinnowingUtils.java

@@ -22,6 +22,8 @@
  */
 package com.scanoss.utils;
 
+import org.jetbrains.annotations.NotNull;
+
 /**
  * SCANOSS Winnowing Utils Class
  * <p>
@@ -47,4 +49,31 @@ public static char normalize(char c) {
             return 0;
         }
     }
+    
+    /**
+     * Extract the file path from a WFP.
+     * The format of the input string is as follows:
+     *   file=e8585d8740d6664fda9e242a1d68b0f0,1815,demo.ts
+     *   4=30777ca8,e9227657,81c8e7e1
+     *   9=831bd2c5,701a2c74
+     * This method extracts and returns the `demo.ts` part.
+     *
+     * @param wfpEntry the WFP entry as a string
+     * @return the extracted file path, or null if not found
+     */
+    public static String extractFilePathFromWFP(@NotNull String wfpEntry) {
+        if (wfpEntry.isEmpty()) {
+            return null;
+        }
+        for (String line : wfpEntry.split("\n")) {
+            if (line.startsWith("file=")) {
+                String[] parts = line.split(",");
+                if (parts.length == 3) {
+                    return parts[2]; // The file path is the 3rd element
+                }
+            }
+        }
+        return null;
+    }
+    
 }

src/test/java/com/scanoss/utils/WinnowingUtilsTest.java

@@ -0,0 +1,56 @@
+package com.scanoss.utils;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+public class WinnowingUtilsTest {
+
+    @Test
+    public void testExtractFilePathFromWFP_ValidEntry_ReturnsFilePath() {
+        String wfpEntry = "file=sha1,md5,/path/to/file\nanother=line";
+        String result = WinnowingUtils.extractFilePathFromWFP(wfpEntry);
+        assertEquals("/path/to/file", result);
+    }
+
+    @Test
+    public void testExtractFilePathFromWFP_EmptyString_ReturnsNull() {
+        String wfpEntry = "";
+        String result = WinnowingUtils.extractFilePathFromWFP(wfpEntry);
+        assertNull(result);
+    }
+
+    @Test
+    public void testExtractFilePathFromWFP_NoFileLine_ReturnsNull() {
+        String wfpEntry = "another=line\nsomething=else";
+        String result = WinnowingUtils.extractFilePathFromWFP(wfpEntry);
+        assertNull(result);
+    }
+
+    @Test
+    public void testExtractFilePathFromWFP_InvalidFileLineFormat_ReturnsNull() {
+        String wfpEntry = "file=sha1,md5\nfile=incorrect,format";
+        String result = WinnowingUtils.extractFilePathFromWFP(wfpEntry);
+        assertNull(result);
+    }
+
+    @Test
+    public void testExtractFilePathFromWFP_MultipleLinesWithValidFileLine_ReturnsFilePath() {
+        String wfpEntry = "something=else\nfile=sha1,md5,/valid/path\nanother=line";
+        String result = WinnowingUtils.extractFilePathFromWFP(wfpEntry);
+        assertEquals("/valid/path", result);
+    }
+
+    @Test
+    public void testExtractFilePathFromWFP_FileLineWithExtraCommas_ReturnsNull() {
+        String wfpEntry = "file=sha1,md5,/path,with,comma";
+        String result = WinnowingUtils.extractFilePathFromWFP(wfpEntry);
+        assertNull(result);
+    }
+
+    @Test(expected = NullPointerException.class)
+    public void testExtractFilePathFromWFP_NullInput_ThrowsNullPointerException() {
+        String wfpEntry = null;
+        WinnowingUtils.extractFilePathFromWFP(wfpEntry);
+    }
+}