import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.*;
import org.w3c.dom.*;
import java.io.ByteArrayInputStream;
import java.nio.charset.StandardCharsets;

// --- 1. Sample XML ---
xml =
"<library>" +
  "<section name='Fiction'>" +
    "<book id='b1' category='fantasy' rating='4.8'>" +
      "<title>Harry Potter and the Philosopher's Stone</title>" +
      "<author nationality='British'>J.K. Rowling</author>" +
      "<price currency='USD'>29.99</price>" +
    "</book>" +
    "<book id='b2' category='fantasy' rating='4.2'>" +
      "<title>The Hobbit</title>" +
      "<author nationality='British'>J.R.R. Tolkien</author>" +
      "<price currency='USD'>25.00</price>" +
    "</book>" +
  "</section>" +
  "<section name='Nonfiction'>" +
    "<book id='b3' category='history' rating='4.7'>" +
      "<title>Sapiens</title>" +
      "<author nationality='Israeli'>Yuval Noah Harari</author>" +
      "<price currency='USD'>35.00</price>" +
    "</book>" +
    "<book id='b4' category='science' rating='4.5'>" +
      "<title>Brief Answers to the Big Questions</title>" +
      "<author nationality='British'>Stephen Hawking</author>" +
      "<price currency='USD'>28.00</price>" +
    "</book>" +
  "</section>" +
"</library>";

// --- 2. Parse XML ---
factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(true);
builder = factory.newDocumentBuilder();
doc = builder.parse(new ByteArrayInputStream(xml.getBytes(StandardCharsets.UTF_8)));

// --- 3. Setup XPath ---
xpath = XPathFactory.newInstance().newXPath();
results = "";

// --- 4. Define helper function (as global) ---
void queryAndAppend(String label, String pattern, String type) throws Exception {
    expr = xpath.compile(pattern);
    results += "[" + label + "] " + pattern + "\n";

    if (type.equals("nodes")) {
        nodes = (NodeList) expr.evaluate(doc, XPathConstants.NODESET);
        if (nodes.getLength() == 0) {
            results += "(no match)\n\n";
            return;
        }
        for (i = 0; i < nodes.getLength(); i++) {
            val = nodes.item(i).getNodeValue();
            if (val == null) val = nodes.item(i).getTextContent();
            results += "- " + val + "\n";
        }
        results += "\n";
    } else if (type.equals("value")) {
        val = xpath.evaluate(pattern, doc);
        results += "→ " + val + "\n\n";
    }
}

// --- 5. Run multiple queries ---
queryAndAppend("A", "//book/title/text()", "nodes");
queryAndAppend("B", "//author[@nationality='British']/text()", "nodes");
queryAndAppend("C", "//book[number(price) > 28]/title/text()", "nodes");
queryAndAppend("D", "//book[number(@rating) >= 4.5]/title/text()", "nodes");
queryAndAppend("E", "count(//book)", "value");
queryAndAppend("F", "//section/@name", "nodes");

// --- 6. Return the full report ---
tasker.log("XPath Results:\n" + results);
return results.trim();