fix: internalized relative links fix

src/main/java/ch/sbb/polarion/extension/pdf_exporter/util/html/ExternalCssInternalizer.java

@@ -1,12 +1,17 @@
 package ch.sbb.polarion.extension.pdf_exporter.util.html;
 
+import ch.sbb.polarion.extension.generic.regex.RegexMatcher;
 import ch.sbb.polarion.extension.pdf_exporter.util.FileResourceProvider;
+import com.polarion.core.util.StringUtils;
 
 import java.util.Map;
 import java.util.Optional;
 
 public class ExternalCssInternalizer implements LinkInternalizer {
+
+    private static final String URL_REGEX = "url\\(\\s*([\"'])?(?<url>.*?)\\1?\\s*\\)";
     private static final String DATA_PRECEDENCE = "data-precedence";
+    private static final String HREF = "href";
     private final FileResourceProvider fileResourceProvider;
 
     public ExternalCssInternalizer(FileResourceProvider fileResourceProvider) {
@@ -15,8 +20,9 @@ public ExternalCssInternalizer(FileResourceProvider fileResourceProvider) {
 
     @Override
     public Optional<String> inline(Map<String, String> attributes) {
+        String url = attributes.get(HREF);
         if (!"stylesheet".equals(attributes.get("rel"))
-                || !attributes.containsKey("href")) {
+                || StringUtils.isEmptyTrimmed(url)) {
             return Optional.empty();
         }
         StringBuilder inlinedContent = new StringBuilder("<style");
@@ -28,10 +34,25 @@ public Optional<String> inline(Map<String, String> attributes) {
                     .append("\"");
         }
         inlinedContent.append(">");
-        String url = attributes.get("href");
-        inlinedContent.append(new String(fileResourceProvider.getResourceAsBytes(url)));
+
+        String cssContent = new String(fileResourceProvider.getResourceAsBytes(url));
+        cssContent = processRelativeUrls(url, cssContent);
+        inlinedContent.append(cssContent);
         inlinedContent.append("</style>");
 
         return Optional.of(inlinedContent.toString());
     }
+
+    private String processRelativeUrls(String resourceUrl, String cssContent) {
+        int lastSlashPosition = resourceUrl.lastIndexOf('/');
+        if (lastSlashPosition == -1) {
+            return cssContent;
+        }
+        String resourcePath = resourceUrl.substring(0, lastSlashPosition + 1);
+        return RegexMatcher.get(URL_REGEX).useJavaUtil().replace(cssContent, engine -> {
+            String url = engine.group("url");
+            return url.startsWith("/") || url.toLowerCase().startsWith("http:") || url.toLowerCase().startsWith("https:") ? null :
+                    "url(%s%s)".formatted(resourcePath, url);
+        });
+    }
 }

src/main/java/ch/sbb/polarion/extension/pdf_exporter/util/html/HtmlLinksHelper.java

@@ -31,7 +31,7 @@ public static Map<String, String> parseLinkTagAttributes(String linkTag) {
         RegexMatcher.get(ATTRIBUTE_REGEX).useJavaUtil().processEntry(linkTag, regexEngine -> {
             String attributeName = regexEngine.group(1);
             String attributeValue = regexEngine.group(3);
-            attributes.put(attributeName, attributeValue);
+            attributes.put(attributeName.toLowerCase(), attributeValue);
         });
 
         return attributes;

src/test/java/ch/sbb/polarion/extension/pdf_exporter/util/html/ExternalCssInternalizerTest.java

@@ -50,4 +50,30 @@ void shouldConvertStylesheetLinkAndTransferDataPrecedence() {
         assertThat(result.get()).isEqualTo("""
                 <style data-precedence="test-data-precedence">test-stylesheet</style>""");
     }
+
+    @Test
+    void shouldConvertStylesheetLinkAndProcessRelativeLinks() {
+        when(fileResourceProvider.getResourceAsBytes("/some/location/file.css")).thenReturn("""
+                @font-face {
+                  src: url('../fonts/some-font.woff');
+                }
+                @font-face {
+                  src: url('relative2/some-font2.woff');
+                }
+                @font-face {
+                  src: url('/non-relative/fonts/some-font3.woff');
+                }
+                """.getBytes());
+        Optional<String> result = cssLinkInliner.inline(Map.of(
+                "rel", "stylesheet",
+                "href", "/some/location/file.css",
+                "data-precedence", "test-data-precedence"));
+
+        assertThat(result).isNotEmpty();
+        assertThat(result.get()).contains(
+                "src: url(/some/location/../fonts/some-font.woff)",
+                "src: url(/some/location/relative2/some-font2.woff)",
+                "src: url('/non-relative/fonts/some-font3.woff')"
+        );
+    }
 }

src/test/java/ch/sbb/polarion/extension/pdf_exporter/util/html/HtmlLinksHelperTest.java

@@ -56,14 +56,14 @@ void shouldCallInlinersForLinkTags() {
     void shouldParseAttributesAndReplaceLinkTags() {
         when(linkInternalizer1.inline(anyMap())).thenReturn(Optional.of("<style>replacement</style>"));
         String resultHtml = htmlLinksHelper.internalizeLinks("""
-                <html lang='en'><head><link attr1="value1" attr2="value2">some content</head>""");
+                <html lang='en'><head><link attr1="value1" ATTR2="value2">some content</head>""");
 
         assertThat(resultHtml).isEqualTo("""
                 <html lang='en'><head><style>replacement</style>some content</head>""");
         @SuppressWarnings("unchecked")
         ArgumentCaptor<Map<String, String>> captor = ArgumentCaptor.forClass(Map.class);
         verify(linkInternalizer1).inline(captor.capture());
-        assertThat(captor.getValue()).containsExactly(Map.entry("attr1", "value1"), Map.entry("attr2", "value2"));
+        assertThat(captor.getValue()).containsExactly(Map.entry("attr1", "value1"), Map.entry("attr2", "value2")); // also it must lowercase attributes
     }
 
     @Test