Rewrite include code support using a IncludeCodeBlockMacroProcessor

The original `IncludeCodeBlockMacroProcessor` unfortunately didn't
support [tag=] attributes. This commit rewrites it using a
`IncludeCodeIncludeProcessor` instead.

Closes gh-56

Author: philwebb

README.adoc

@@ -484,7 +484,7 @@ For example, the following `.adoc` file will try to import the Java file `{docs-
 ....
 [[my.example-project]]
 == My Example Project
-import-code::SomeCode[]
+import::code:SomeCode[]
 ....
 
 The following languages are supported by convention based imports:

src/main/java/io/spring/asciidoctor/backend/SpringBackendsExtensionRegistry.java

@@ -17,7 +17,7 @@
 package io.spring.asciidoctor.backend;
 
 import io.spring.asciidoctor.backend.anchorrewrite.AnchorRewriteDocinfoProcessor;
-import io.spring.asciidoctor.backend.includecode.IncludeCodeBlockMacroProcessor;
+import io.spring.asciidoctor.backend.includecode.IncludeCodeIncludeProcessor;
 import org.asciidoctor.Asciidoctor;
 import org.asciidoctor.jruby.extension.spi.ExtensionRegistry;
 
@@ -32,7 +32,9 @@ public class SpringBackendsExtensionRegistry implements ExtensionRegistry {
 	public void register(Asciidoctor asciidoctor) {
 		asciidoctor.requireLibrary("spring-asciidoctor-backends");
 		asciidoctor.javaExtensionRegistry().docinfoProcessor(new AnchorRewriteDocinfoProcessor());
-		asciidoctor.javaExtensionRegistry().blockMacro(new IncludeCodeBlockMacroProcessor());
+		// asciidoctor.javaExtensionRegistry().blockMacro(new
+		// IncludeCodeBlockMacroProcessor());
+		asciidoctor.javaExtensionRegistry().includeProcessor(new IncludeCodeIncludeProcessor());
 	}
 
 }

src/main/java/io/spring/asciidoctor/backend/includecode/IncludeCodeBlockMacroProcessor.java

@@ -0,0 +1,190 @@
+/*
+ * Copyright 2021-2022 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.asciidoctor.backend.includecode;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import io.spring.asciidoctor.backend.language.Language;
+import org.asciidoctor.ast.Document;
+import org.asciidoctor.extension.IncludeProcessor;
+import org.asciidoctor.extension.PreprocessorReader;
+
+/**
+ * {@link IncludeProcessor} to deal with convention based code imports.
+ *
+ * @author Phillip Webb
+ */
+public class IncludeCodeIncludeProcessor extends IncludeProcessor {
+
+	private static final String PREFIX = "code:";
+
+	private final Map<String, AsciidoctorFile> files = new LinkedHashMap<String, AsciidoctorFile>() {
+
+		@Override
+		protected boolean removeEldestEntry(Map.Entry<String, AsciidoctorFile> eldest) {
+			return size() > 10;
+		};
+
+	};
+
+	@Override
+	public boolean handles(String target) {
+		return target.startsWith(PREFIX);
+	}
+
+	@Override
+	public void process(Document document, PreprocessorReader reader, String target, Map<String, Object> attributes) {
+		target = target.substring(PREFIX.length());
+		String includeAttributes = getIncludeAttributes(attributes);
+		AsciidoctorFile asciidoctorFile = this.files.computeIfAbsent(reader.getFile(), AsciidoctorFile::new);
+		String sectionId = asciidoctorFile.getSectionId(reader.getLineNumber() - 2);
+		try {
+			String packagePath = getPackagePath(sectionId);
+			List<Include> includes = new ArrayList<>();
+			for (Language language : Language.values()) {
+				Include include = Include.load(document, language, includeAttributes, packagePath, target);
+				if (include != null) {
+					includes.add(include);
+				}
+			}
+			reader.push_include(getIncludeData(includes), null, null, 0, Collections.emptyMap());
+		}
+		catch (Exception ex) {
+			throw new IllegalStateException(
+					"Error processing code include " + target + " in " + sectionId + " : " + ex.getMessage(), ex);
+		}
+	}
+
+	private String getIncludeAttributes(Map<String, Object> attributes) {
+		StringBuilder markup = new StringBuilder();
+		markup.append("[");
+		attributes.forEach((key, value) -> markup.append(key + "=" + value));
+		markup.append("]");
+		return markup.toString();
+	}
+
+	private String getIncludeData(List<Include> includes) {
+		if (includes.isEmpty()) {
+			throw new IllegalStateException("Unable to find code");
+		}
+		StringBuilder data = new StringBuilder();
+		for (int i = 0; i < includes.size(); i++) {
+			String role = (includes.size() == 1) ? null : (i == 0) ? "primary" : "secondary";
+			includes.get(i).append(role, data);
+		}
+		return data.toString();
+	}
+
+	private String getPackagePath(String sectionId) {
+		return sectionId.replace('.', '/').replace("-", "");
+	}
+
+	static class AsciidoctorFile {
+
+		private final List<String> lines;
+
+		AsciidoctorFile(String filename) {
+			try {
+				this.lines = Files.readAllLines(Paths.get(filename));
+			}
+			catch (IOException ex) {
+				throw new IllegalStateException(ex);
+			}
+		}
+
+		String getSectionId(int lineNumber) {
+			while (lineNumber >= 0) {
+				String line = this.lines.get(lineNumber).trim();
+				if (line.startsWith("[[") && line.endsWith("]]")) {
+					return line.substring(2, line.length() - 2);
+				}
+				lineNumber--;
+			}
+			throw new IllegalStateException("Cannot find anchor");
+
+		}
+
+	}
+
+	static class Include {
+
+		private final Language language;
+
+		private final String includeAttributes;
+
+		private Path source;
+
+		Include(Language language, String includeAttributes, Path source) throws IOException {
+			this.language = language;
+			this.includeAttributes = includeAttributes;
+			this.source = source;
+		}
+
+		void append(String role, StringBuilder data) {
+			data.append("[source," + this.language.getId() + ",indent=0,subs=\"verbatim\"");
+			if (role != null) {
+				data.append("role=" + role);
+			}
+			data.append("]\n");
+			if (role != null) {
+				data.append("." + this.language.getTitle() + "\n");
+			}
+			data.append("----\n");
+			data.append("include::" + this.source.toAbsolutePath().toString() + this.includeAttributes + "\n");
+			data.append("----\n");
+		}
+
+		static Include load(Document document, Language language, String includeAttributes, String packagePath,
+				String target) throws IOException {
+			String path = (String) document.getAttribute(language.getPathAttribute());
+			if (path != null) {
+				Path source = cleanPath(path + "/" + packagePath + "/" + target + "." + language.GetExtension());
+				if (Files.isRegularFile(source)) {
+					return new Include(language, includeAttributes, source);
+				}
+			}
+			return null;
+		}
+
+		private static Path cleanPath(String path) {
+			path = path.replace("//", "/");
+			List<String> elements = new ArrayList<>();
+			for (String element : path.split("\\/")) {
+				if ("..".equals(element) && !elements.isEmpty()) {
+					elements.remove(elements.size() - 1);
+				}
+				else {
+					elements.add(element);
+				}
+			}
+			String cleanPath = elements.stream().collect(Collectors.joining("/"));
+			cleanPath = (path.startsWith("/")) ? "/" + cleanPath : cleanPath;
+			return Paths.get(cleanPath);
+		}
+
+	}
+
+}

src/main/java/io/spring/asciidoctor/backend/includecode/IncludeCodeIncludeProcessor.java

@@ -27,18 +27,23 @@
 import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
- * Tests for {@link IncludeCodeBlockMacroProcessor}.
+ * Tests for {@link IncludeCodeIncludeProcessor}.
  *
  * @author Phillip Webb
  */
 @ExtendWith(AsciidoctorExtension.class)
-class IncludeCodeBlockMacroProcessorTests {
+class IncludeCodeIncludeProcessorTests {
 
 	@Test
 	void includeOnlyJava(ConvertedHtml html, ExpectedHtml expected) {
 		assertThat(html.getElementByClass("sectionbody")).satisfies(expected.whenIgnoringTrailingWhitespace());
 	}
 
+	@Test
+	void includeOnlyJavaWithTag(ConvertedHtml html, ExpectedHtml expected) {
+		assertThat(html.getElementByClass("sectionbody")).satisfies(expected.whenIgnoringTrailingWhitespace());
+	}
+
 	@Test
 	void includeJavaAndKotlin(ConvertedHtml html, ExpectedHtml expected) {
 		assertThat(html.getElementByClass("sectionbody")).satisfies(expected.whenIgnoringTrailingWhitespace());