package pmbauer;

import javax.tools.JavaCompiler;
import javax.tools.ToolProvider;
import java.io.File;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;

public class JavaIsKindaLight {
    public static void main(String[] args) throws IOException, ClassNotFoundException, InstantiationException, IllegalAccessException, NoSuchMethodException, InvocationTargetException {
        StringBuilder sb = new StringBuilder();
        sb.append("package test;");
        sb.append("import java.util.*;");
        sb.append("public class ParseSomeCode { ");
        sb.append("  public static Object data() {");
        sb.append("    Map m = new HashMap() {{");
        sb.append("      put(\"parse\", new HashMap() {{");
        sb.append("        put(\"some\", \"data\");");
        sb.append("      }});");
        sb.append("    }};");
        sb.append("    return ((Map)((Map)m.get(\"parse\"))).get(\"some\");");
        sb.append("  }");
        sb.append("}");

        // Save source in .java file.
        File root = new File("/tmp");
        File sourceFile = new File(root, "test/ParseSomeCode.java");
        sourceFile.getParentFile().mkdirs();
        Files.write(sourceFile.toPath(), sb.toString().getBytes(StandardCharsets.UTF_8));

        // compile
        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
        compiler.run(null, null, null, sourceFile.getPath());

        // load, run
        URLClassLoader classLoader = URLClassLoader.newInstance(new URL[] { root.toURI().toURL() });
        Class<?> cls = Class.forName("test.ParseSomeCode", true, classLoader);
        Method method = cls.getMethod("data");
        System.out.println(method.invoke(null));
    }
}