/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 * DocumentFunctionCall
 * A representation of the XSLT additional function: document()
 */

#include "nsGkAtoms.h"
#include "txIXPathContext.h"
#include "txXSLTFunctions.h"
#include "txExecutionState.h"
#include "txURIUtils.h"

/*
 * Creates a new DocumentFunctionCall.
 */
DocumentFunctionCall::DocumentFunctionCall(const nsAString& aBaseURI)
    : mBaseURI(aBaseURI) {}

static void retrieveNode(txExecutionState* aExecutionState,
                         const nsAString& aUri, const nsAString& aBaseUri,
                         txNodeSet* aNodeSet) {
  nsAutoString absUrl;
  URIUtils::resolveHref(aUri, aBaseUri, absUrl);

  int32_t hash = absUrl.RFindChar(char16_t('#'));
  uint32_t urlEnd, fragStart, fragEnd;
  if (hash == kNotFound) {
    urlEnd = absUrl.Length();
    fragStart = 0;
    fragEnd = 0;
  } else {
    urlEnd = hash;
    fragStart = hash + 1;
    fragEnd = absUrl.Length();
  }

  nsDependentSubstring docUrl(absUrl, 0, urlEnd);
  nsDependentSubstring frag(absUrl, fragStart, fragEnd);

  const txXPathNode* loadNode = aExecutionState->retrieveDocument(docUrl);
  if (loadNode) {
    if (frag.IsEmpty()) {
      aNodeSet->add(*loadNode);
    } else {
      txXPathTreeWalker walker(*loadNode);
      if (walker.moveToElementById(frag)) {
        aNodeSet->add(walker.getCurrentPosition());
      }
    }
  }
}

/*
 * Evaluates this Expr based on the given context node and processor state
 * NOTE: the implementation is incomplete since it does not make use of the
 * second argument (base URI)
 * @param context the context node for evaluation of this Expr
 * @return the result of the evaluation
 */
nsresult DocumentFunctionCall::evaluate(txIEvalContext* aContext,
                                        txAExprResult** aResult) {
  *aResult = nullptr;
  txExecutionState* es =
      static_cast<txExecutionState*>(aContext->getPrivateContext());

  RefPtr<txNodeSet> nodeSet;
  nsresult rv = aContext->recycler()->getNodeSet(getter_AddRefs(nodeSet));
  NS_ENSURE_SUCCESS(rv, rv);

  // document(object, node-set?)
  if (!requireParams(1, 2, aContext)) {
    return NS_ERROR_XPATH_BAD_ARGUMENT_COUNT;
  }

  RefPtr<txAExprResult> exprResult1;
  rv = mParams[0]->evaluate(aContext, getter_AddRefs(exprResult1));
  NS_ENSURE_SUCCESS(rv, rv);

  nsAutoString baseURI;
  bool baseURISet = false;

  if (mParams.Length() == 2) {
    // We have 2 arguments, get baseURI from the first node
    // in the resulting nodeset
    RefPtr<txNodeSet> nodeSet2;
    rv = evaluateToNodeSet(mParams[1], aContext, getter_AddRefs(nodeSet2));
    NS_ENSURE_SUCCESS(rv, rv);

    // Make this true, even if nodeSet2 is empty. For relative URLs,
    // we'll fail to load the document with an empty base URI, and for
    // absolute URLs, the base URI doesn't matter
    baseURISet = true;

    if (!nodeSet2->isEmpty()) {
      rv = txXPathNodeUtils::getBaseURI(nodeSet2->get(0), baseURI);
      NS_ENSURE_SUCCESS(rv, rv);
    }
  }

  if (exprResult1->getResultType() == txAExprResult::NODESET) {
    // The first argument is a NodeSet, iterate on its nodes
    txNodeSet* nodeSet1 =
        static_cast<txNodeSet*>(static_cast<txAExprResult*>(exprResult1));
    int32_t i;
    for (i = 0; i < nodeSet1->size(); ++i) {
      const txXPathNode& node = nodeSet1->get(i);
      nsAutoString uriStr;
      txXPathNodeUtils::appendNodeValue(node, uriStr);
      if (!baseURISet) {
        // if the second argument wasn't specified, use
        // the baseUri of node itself
        rv = txXPathNodeUtils::getBaseURI(node, baseURI);
        NS_ENSURE_SUCCESS(rv, rv);
      }
      retrieveNode(es, uriStr, baseURI, nodeSet);
    }

    NS_ADDREF(*aResult = nodeSet);

    return NS_OK;
  }

  // The first argument is not a NodeSet
  nsAutoString uriStr;
  exprResult1->stringValue(uriStr);
  const nsAString* base = baseURISet ? &baseURI : &mBaseURI;
  retrieveNode(es, uriStr, *base, nodeSet);

  NS_ADDREF(*aResult = nodeSet);

  return NS_OK;
}

Expr::ResultType DocumentFunctionCall::getReturnType() {
  return NODESET_RESULT;
}

bool DocumentFunctionCall::isSensitiveTo(ContextSensitivity aContext) {
  return (aContext & PRIVATE_CONTEXT) || argsSensitiveTo(aContext);
}

#ifdef TX_TO_STRING
void DocumentFunctionCall::appendName(nsAString& aDest) {
  aDest.Append(nsGkAtoms::document->GetUTF16String());
}
#endif