AsciiDoctor to JSON AST Java Converter hack

Converter.java

import java.io.File;
import java.util.HashMap;
import java.util.Map;
import java.util.stream.Collectors;

import org.asciidoctor.Asciidoctor;
import org.asciidoctor.Options;
import org.asciidoctor.ast.ContentNode;
import org.asciidoctor.ast.Cursor;
import org.asciidoctor.ast.List;
import org.asciidoctor.ast.ListItem;
import org.asciidoctor.ast.PhraseNode;
import org.asciidoctor.ast.StructuralNode;
import org.asciidoctor.converter.ConverterFor;
import org.asciidoctor.converter.StringConverter;

import com.google.gson.Gson;

@ConverterFor("ast")
public class Converter extends StringConverter {
	
	public Converter(String backend, Map<String, Object> opts) {
		super(backend, opts);
	}

	public String convert(ContentNode node, String transform, Map<Object, Object> opts) {
		if(node instanceof List) {
			return convertList((List) node, transform, opts);
		}
		if(node instanceof PhraseNode) {
			return convertPhraseNode((PhraseNode) node, transform, opts);
		}
		if(node instanceof StructuralNode) {
			return convertStructuralNode((StructuralNode) node, transform, opts);
		}
		throw new RuntimeException(node.getClass().toString());
	}

	public String convertStructuralNode(StructuralNode structuralNode, String transform, Map<Object, Object> ops) {
		Map<String, Object> json = new HashMap<>();
		json.put("content", getJsonContent(structuralNode));
		json.put("title", structuralNode.getTitle());
		json.put("position", getJson(structuralNode.getSourceLocation()));
		return new Gson().toJson(json);
	}

	protected Object getJsonContent(StructuralNode structuralNode) {
		if(structuralNode.getContentModel().equals("simple") || structuralNode.getContentModel().equals("verbatim")) {
			return Map.of("text", structuralNode.getContent(), "position", getJson(structuralNode.getSourceLocation()));
		}
		else if(structuralNode.getContentModel().equals("compound")) {
			return structuralNode.getBlocks().stream().map(sn -> convert(sn, null, null)).map(s -> new Gson().fromJson(s, Object.class)).collect(Collectors.toList());
		}
		else {
			Object content = structuralNode.getContent();
			if(content == null) {
				return "null";
			}
			return new Gson().fromJson(content.toString(), Object.class);
		}
	}

	protected Map<String, String> getJson(Cursor sourceLocation) {
		return Map.of("lineNumber", Integer.toString(sourceLocation.getLineNumber()));
	}

	public String convertList(List list, String transform, Map<Object, Object> ops) {
		java.util.List<Map<String, String>> itemsJson = list.getItems().stream().map(ListItem.class::cast).map(this::convertListItem).collect(Collectors.toList());
		return new Gson().toJson(Map.ofEntries(Map.entry("items", itemsJson)));
	}

	public Map<String, String> convertListItem(ListItem listItem) {
		return Map.ofEntries(Map.entry("text", listItem.getText()));
	}
	
	
	public String convertPhraseNode(PhraseNode phraseNode, String transform, Map<Object, Object> ops) {
		return new Gson().toJson(Map.ofEntries(Map.entry("text", phraseNode.getText())));
	}		
	
	public static void main(String[] args) {
		Asciidoctor asciidoctor = Asciidoctor.Factory.create();
		asciidoctor.javaConverterRegistry().register(Converter.class); 
		System.out.println(asciidoctor.convertFile(new File(args[0]), Options.builder().sourcemap(true).backend("ast").toFile(false).build()));
	}

}