/* -*- 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"

#include "txSingleNodeContext.h"

#include "txXMLUtils.h"

#include "txXPathTreeWalker.h"

  //------------/

 //- PathExpr -/

//------------/

/**

 * Adds the Expr to this PathExpr

 * @param expr the Expr to add to this PathExpr

**/

nsresult

PathExpr::addExpr(Expr* aExpr, PathOperator aPathOp)

{

    NS_ASSERTION(!mItems.IsEmpty() || aPathOp == RELATIVE_OP,

                 "First step has to be relative in PathExpr");

    PathExprItem* pxi = mItems.AppendElement();

    if (!pxi) {

        return NS_ERROR_OUT_OF_MEMORY;

    }

    pxi->expr = aExpr;

    pxi->pathOp = aPathOp;

    return NS_OK;

}

    //-----------------------------/

  //- Virtual methods from Expr -/

//-----------------------------/

/**

 * 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

**/

nsresult

PathExpr::evaluate(txIEvalContext* aContext, txAExprResult** aResult)

{

    *aResult = nullptr;

    // We need to evaluate the first step with the current context since it

    // can depend on the context size and position. For example:

    // key('books', concat('book', position()))

    RefPtr<txAExprResult> res;

    nsresult rv = mItems[0].expr->evaluate(aContext, getter_AddRefs(res));

    NS_ENSURE_SUCCESS(rv, rv);

    NS_ENSURE_TRUE(res->getResultType() == txAExprResult::NODESET,

                   NS_ERROR_XSLT_NODESET_EXPECTED);

    RefPtr<txNodeSet> nodes = static_cast<txNodeSet*>

                                           (static_cast<txAExprResult*>

                                                       (res));

    if (nodes->isEmpty()) {

        res.forget(aResult);

        return NS_OK;

    }

    res = nullptr; // To allow recycling

    // Evaluate remaining steps

    uint32_t i, len = mItems.Length();

    for (i = 1; i < len; ++i) {

        PathExprItem& pxi = mItems[i];

        RefPtr<txNodeSet> tmpNodes;

        txNodeSetContext eContext(nodes, aContext);

        while (eContext.hasNext()) {

            eContext.next();

            RefPtr<txNodeSet> resNodes;

            if (pxi.pathOp == DESCENDANT_OP) {

                rv = aContext->recycler()->getNodeSet(getter_AddRefs(resNodes));

                NS_ENSURE_SUCCESS(rv, rv);

                rv = evalDescendants(pxi.expr, eContext.getContextNode(),

                                     &eContext, resNodes);

                NS_ENSURE_SUCCESS(rv, rv);

            }

            else {

                RefPtr<txAExprResult> res;

                rv = pxi.expr->evaluate(&eContext, getter_AddRefs(res));

                NS_ENSURE_SUCCESS(rv, rv);

                if (res->getResultType() != txAExprResult::NODESET) {

                    //XXX ErrorReport: report nonnodeset error

                    return NS_ERROR_XSLT_NODESET_EXPECTED;

                }

                resNodes = static_cast<txNodeSet*>

                                      (static_cast<txAExprResult*>

                                                  (res));

            }

            if (tmpNodes) {

                if (!resNodes->isEmpty()) {

                    RefPtr<txNodeSet> oldSet;

                    oldSet.swap(tmpNodes);

                    rv = aContext->recycler()->

                        getNonSharedNodeSet(oldSet, getter_AddRefs(tmpNodes));

                    NS_ENSURE_SUCCESS(rv, rv);

                    oldSet.swap(resNodes);

                    rv = aContext->recycler()->

                        getNonSharedNodeSet(oldSet, getter_AddRefs(resNodes));

                    NS_ENSURE_SUCCESS(rv, rv);

                    tmpNodes->addAndTransfer(resNodes);

                }

            }

            else {

                tmpNodes = resNodes;

            }

        }

        nodes = tmpNodes;

        if (nodes->isEmpty()) {

            break;

        }

    }

    *aResult = nodes;

    NS_ADDREF(*aResult);

    return NS_OK;

} //-- evaluate

/**

 * Selects from the descendants of the context node

 * all nodes that match the Expr

**/

nsresult

PathExpr::evalDescendants(Expr* aStep, const txXPathNode& aNode,

                          txIMatchContext* aContext, txNodeSet* resNodes)

{

    txSingleNodeContext eContext(aNode, aContext);

    RefPtr<txAExprResult> res;

    nsresult rv = aStep->evaluate(&eContext, getter_AddRefs(res));

    NS_ENSURE_SUCCESS(rv, rv);

    if (res->getResultType() != txAExprResult::NODESET) {

        //XXX ErrorReport: report nonnodeset error

        return NS_ERROR_XSLT_NODESET_EXPECTED;

    }

    txNodeSet* oldSet = static_cast<txNodeSet*>

                                   (static_cast<txAExprResult*>(res));

    RefPtr<txNodeSet> newSet;

    rv = aContext->recycler()->getNonSharedNodeSet(oldSet,

                                                   getter_AddRefs(newSet));

    NS_ENSURE_SUCCESS(rv, rv);

    resNodes->addAndTransfer(newSet);

    bool filterWS;

    rv = aContext->isStripSpaceAllowed(aNode, filterWS);

    NS_ENSURE_SUCCESS(rv, rv);

    txXPathTreeWalker walker(aNode);

    if (!walker.moveToFirstChild()) {

        return NS_OK;

    }

    do {

        const txXPathNode& node = walker.getCurrentPosition();

        if (!(filterWS && txXPathNodeUtils::isText(node) &&

              txXPathNodeUtils::isWhitespace(node))) {

            rv = evalDescendants(aStep, node, aContext, resNodes);

            NS_ENSURE_SUCCESS(rv, rv);

        }

    } while (walker.moveToNextSibling());

    return NS_OK;

} //-- evalDescendants

Expr::ExprType

PathExpr::getType()

{

  return PATH_EXPR;

}

TX_IMPL_EXPR_STUBS_BASE(PathExpr, NODESET_RESULT)

Expr*

PathExpr::getSubExprAt(uint32_t aPos)

{

    return aPos < mItems.Length() ? mItems[aPos].expr.get() : nullptr;

}

void

PathExpr::setSubExprAt(uint32_t aPos, Expr* aExpr)

{

    NS_ASSERTION(aPos < mItems.Length(), "setting bad subexpression index");

    mItems[aPos].expr.forget();

    mItems[aPos].expr = aExpr;

}

bool

PathExpr::isSensitiveTo(ContextSensitivity aContext)

{

    if (mItems[0].expr->isSensitiveTo(aContext)) {

        return true;

    }

    // 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 == NO_CONTEXT) {

        return false;

    }

    uint32_t i, len = mItems.Length();

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

        NS_ASSERTION(!mItems[i].expr->isSensitiveTo(Expr::NODESET_CONTEXT),

                     "Step cannot depend on nodeset-context");

        if (mItems[i].expr->isSensitiveTo(context)) {

            return true;

        }

    }

    return false;

}

#ifdef TX_TO_STRING

void

PathExpr::toString(nsAString& dest)

{

    if (!mItems.IsEmpty()) {

        NS_ASSERTION(mItems[0].pathOp == RELATIVE_OP,

                     "First step should be relative");

        mItems[0].expr->toString(dest);

    }

    uint32_t i, len = mItems.Length();

    for (i = 1; i < len; ++i) {

        switch (mItems[i].pathOp) {

            case DESCENDANT_OP:

                dest.AppendLiteral("//");

                break;

            case RELATIVE_OP:

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

                break;

        }

        mItems[i].expr->toString(dest);

    }

}

#endif