package com.example.statemachinedemo;
import org.eclipse.jdt.core.dom.*;
import java.io.*;
import java.nio.file.*;
import java.util.*;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class AstFileFinder {

    public static List<Path> findJavaFiles(Path startDir, String extension) throws IOException {
        try (Stream<Path> paths = Files.walk(startDir)) {
            return paths
                    .filter(p -> Files.isRegularFile(p) && p.toString().endsWith(extension))
                    .collect(Collectors.toList());
        }
    }

    public static boolean hasClassWithAnnotation(String source, String annotationName) {
        ASTParser parser = ASTParser.newParser(AST.JLS17);
        parser.setSource(source.toCharArray());
        parser.setKind(ASTParser.K_COMPILATION_UNIT);
        parser.setResolveBindings(false);

        CompilationUnit cu = (CompilationUnit) parser.createAST(null);

        final boolean[] found = {false};

        cu.accept(new ASTVisitor() {
            @Override
            public boolean visit(TypeDeclaration node) {
                if (node.isInterface()) return true;

                for (Object modifier : node.modifiers()) {
                    if (modifier instanceof Annotation) {
                        Annotation annotation = (Annotation) modifier;
                        String name = annotation.getTypeName().getFullyQualifiedName();
                        if (name.equals(annotationName)) {
                            found[0] = true;
                            return false;
                        }
                    }
                }
                return true;
            }
        });

        return found[0];
    }
}