package com.jclark.xsl.tr;

import com.jclark.xsl.om.*;
import com.jclark.xsl.expr.VariantExpr;
import com.jclark.xsl.expr.Variant;

class CopyOfAction implements Action {
  private final VariantExpr expr;

  CopyOfAction(VariantExpr expr) {
    this.expr = expr;
  }

  public void invoke(ProcessContext context, Node sourceNode, Result result) throws XSLException {
    Variant value = expr.eval(sourceNode, context);
    if (value instanceof ResultFragmentVariant)
      ((ResultFragmentVariant)value).append(result);
    else if (value.isNodeSet())
      copyNodes(context, value.convertToNodeSet(), result);
    else
      result.characters(value.convertToString());
  }

  private static void copyNodes(ProcessContext context, NodeIterator iter, Result result) throws XSLException {
    for (;;) {
      Node node = iter.next();
      if (node == null)
	break;
      switch (node.getType()) {
      case Node.ROOT:
	copyNodes(context, node.getChildren(), result);
	break;
      case Node.TEXT:
	result.characters(node.getData());
	break;
      case Node.ATTRIBUTE:
	result.attribute(node.getName(), node.getData());
	break;
      case Node.PROCESSING_INSTRUCTION:
	result.processingInstruction(node.getName().toString(),
				     node.getData());
	break;
      case Node.COMMENT:
	result.comment(node.getData());
	break;
      case Node.ELEMENT:
	result.startElement(node.getName(),
			    node.getNamespacePrefixMap());
	copyNodes(context, node.getAttributes(), result);
	copyNodes(context, node.getChildren(), result);
	result.endElement(node.getName());
	break;
      }
    }
  }
}