/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/* 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 "txExpr.h"

#include "txNodeSet.h"

#include "txNodeSetContext.h"

/*

 * Represents an ordered list of Predicates,

 * for use with Step and Filter Expressions

 */

nsresult

PredicateList::evaluatePredicates(txNodeSet* nodes,

                                  txIMatchContext* aContext)

{

    NS_ASSERTION(nodes, "called evaluatePredicates with nullptr NodeSet");

    nsresult rv = NS_OK;

    uint32_t i, len = mPredicates.Length();

    for (i = 0; i < len && !nodes->isEmpty(); ++i) {

        txNodeSetContext predContext(nodes, aContext);

        /*

         * add nodes to newNodes that match the expression

         * or, if the result is a number, add the node with the right

         * position

         */

        int32_t index = 0;

        while (predContext.hasNext()) {

            predContext.next();

            RefPtr<txAExprResult> exprResult;

            rv = mPredicates[i]->evaluate(&predContext,

                                          getter_AddRefs(exprResult));

            NS_ENSURE_SUCCESS(rv, rv);

            // handle default, [position() == numberValue()]

            if (exprResult->getResultType() == txAExprResult::NUMBER) {

                if ((double)predContext.position() == exprResult->numberValue()) {

                    nodes->mark(index);

                }

            }

            else if (exprResult->booleanValue()) {

                nodes->mark(index);

            }

            ++index;

        }

        // sweep the non-marked nodes

        nodes->sweep();

    }

    return NS_OK;

}

bool

PredicateList::isSensitiveTo(Expr::ContextSensitivity aContext)

{

    // We're creating a new node/nodeset so we can ignore those bits.

    Expr::ContextSensitivity context =

        aContext & ~(Expr::NODE_CONTEXT | Expr::NODESET_CONTEXT);

    if (context == Expr::NO_CONTEXT) {

        return false;

    }

    uint32_t i, len = mPredicates.Length();

    for (i = 0; i < len; ++i) {

        if (mPredicates[i]->isSensitiveTo(context)) {

            return true;

        }

    }

    return false;

}

#ifdef TX_TO_STRING

void PredicateList::toString(nsAString& dest)

{

    for (uint32_t i = 0; i < mPredicates.Length(); ++i) {

        dest.Append(char16_t('['));

        mPredicates[i]->toString(dest);

        dest.Append(char16_t(']'));

    }

}

#endif