/* -*- 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/. */

#include "nsGkAtoms.h"
#include "txIXPathContext.h"
#include "txNodeSet.h"
#include "txXPathTreeWalker.h"
#include "txXSLTFunctions.h"
#include "txExecutionState.h"

/*
  Implementation of XSLT 1.0 extension function: generate-id
*/

/**
 * Creates a new generate-id function call
 **/
GenerateIdFunctionCall::GenerateIdFunctionCall() = default;

/**
 * Evaluates this Expr based on the given context node and processor state
 * @param context the context node for evaluation of this Expr
 * @param ps the ContextState containing the stack information needed
 * for evaluation
 * @return the result of the evaluation
 * @see FunctionCall.h
 **/
nsresult GenerateIdFunctionCall::evaluate(txIEvalContext* aContext,
                                          txAExprResult** aResult) {
  *aResult = nullptr;
  if (!requireParams(0, 1, aContext)) return NS_ERROR_XPATH_BAD_ARGUMENT_COUNT;

  txExecutionState* es =
      static_cast<txExecutionState*>(aContext->getPrivateContext());
  if (!es) {
    NS_ERROR(
        "called xslt extension function \"generate-id\" with wrong context");
    return NS_ERROR_UNEXPECTED;
  }

  nsresult rv = NS_OK;
  if (mParams.IsEmpty()) {
    StringResult* strRes;
    rv = aContext->recycler()->getStringResult(&strRes);
    NS_ENSURE_SUCCESS(rv, rv);

    txXPathNodeUtils::getXSLTId(aContext->getContextNode(),
                                es->getSourceDocument(), strRes->mValue);

    *aResult = strRes;

    return NS_OK;
  }

  RefPtr<txNodeSet> nodes;
  rv = evaluateToNodeSet(mParams[0], aContext, getter_AddRefs(nodes));
  NS_ENSURE_SUCCESS(rv, rv);

  if (nodes->isEmpty()) {
    aContext->recycler()->getEmptyStringResult(aResult);

    return NS_OK;
  }

  StringResult* strRes;
  rv = aContext->recycler()->getStringResult(&strRes);
  NS_ENSURE_SUCCESS(rv, rv);

  txXPathNodeUtils::getXSLTId(nodes->get(0), es->getSourceDocument(),
                              strRes->mValue);

  *aResult = strRes;

  return NS_OK;
}

Expr::ResultType GenerateIdFunctionCall::getReturnType() {
  return STRING_RESULT;
}

bool GenerateIdFunctionCall::isSensitiveTo(ContextSensitivity aContext) {
  if (aContext & PRIVATE_CONTEXT) {
    return true;
  }

  if (mParams.IsEmpty()) {
    return !!(aContext & NODE_CONTEXT);
  }

  return argsSensitiveTo(aContext);
}

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