/**
 * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
 */

package net.sourceforge.pmd.lang.ast.xpath.saxon;

import net.sourceforge.pmd.lang.ast.xpath.Attribute;

import net.sf.saxon.om.NodeInfo;
import net.sf.saxon.om.SequenceIterator;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.Type;
import net.sf.saxon.value.BooleanValue;
import net.sf.saxon.value.EmptySequence;
import net.sf.saxon.value.Int64Value;
import net.sf.saxon.value.StringValue;
import net.sf.saxon.value.Value;

/**
 * A Saxon OM Attribute node for an AST Node Attribute.
 */
public class AttributeNode extends AbstractNodeInfo {
    protected final Attribute attribute;
    protected final int id;
    protected Value value;

    public AttributeNode(Attribute attribute, int id) {
        this.attribute = attribute;
        this.id = id;
    }

    @Override
    public int getNodeKind() {
        return Type.ATTRIBUTE;
    }

    @Override
    public String getLocalPart() {
        return attribute.getName();
    }

    @Override
    public String getURI() {
        return "";
    }

    @Override
    public Value atomize() throws XPathException {
        if (value == null) {
            Object v = attribute.getValue();
            // TODO Need to handle the full range of types, is there something
            // Saxon can do to help?
            if (v instanceof String) {
                value = new StringValue((String) v);
            } else if (v instanceof Boolean) {
                value = BooleanValue.get(((Boolean) v).booleanValue());
            } else if (v instanceof Integer) {
                value = Int64Value.makeIntegerValue((Integer) v);
            } else if (v == null) {
                value = EmptySequence.getInstance();
            } else {
                throw new RuntimeException(
                        "Unable to create ValueRepresentaton for attribute value: " + v + " of type " + v.getClass());
            }
        }
        return value;
    }

    @Override
    public CharSequence getStringValueCS() {
        return attribute.getStringValue();
    }

    @Override
    public SequenceIterator getTypedValue() throws XPathException {
        return atomize().iterate();
    }

    @Override
    public int compareOrder(NodeInfo other) {
        return Integer.signum(this.id - ((AttributeNode) other).id);
    }
}