/*

 * dynamic.c: Implementation of the EXSLT -- Dynamic module

 *

 * References:

 *   http://www.exslt.org/dyn/dyn.html

 *

 * See Copyright for the status of this software.

 *

 * Authors:

 *   Mark Vakoc <mark_vakoc@jdedwards.com>

 *   Thomas Broyer <tbroyer@ltgt.net>

 *

 * TODO:

 * elements:

 * functions:

 *    min

 *    max

 *    sum

 *    map

 *    closure

 */

#define IN_LIBEXSLT

#include "libexslt/libexslt.h"

#include <libxml/tree.h>

#include <libxml/xpath.h>

#include <libxml/xpathInternals.h>

#include <libxslt/xsltutils.h>

#include <libxslt/xsltInternals.h>

#include <libxslt/extensions.h>

#include "exslt.h"

/**

 * exsltDynEvaluateFunction:

 * @ctxt:  an XPath parser context

 * @nargs:  the number of arguments

 *

 * Evaluates the string as an XPath expression and returns the result

 * value, which may be a boolean, number, string, node set, result tree

 * fragment or external object.

 */

static void

exsltDynEvaluateFunction(xmlXPathParserContextPtr ctxt, int nargs) {

  xmlChar *str = NULL;

  xmlXPathObjectPtr ret = NULL;

  if (ctxt == NULL)

    return;

  if (nargs != 1) {

    xsltPrintErrorContext(xsltXPathGetTransformContext(ctxt), NULL, NULL);

        xsltGenericError(xsltGenericErrorContext,

      "dyn:evalute() : invalid number of args %d\n", nargs);

    ctxt->error = XPATH_INVALID_ARITY;

    return;

  }

  str = xmlXPathPopString(ctxt);

  /* return an empty node-set if an empty string is passed in */

  if (!str||!xmlStrlen(str)) {

    if (str) xmlFree(str);

    valuePush(ctxt,xmlXPathNewNodeSet(NULL));

    return;

  }

#if LIBXML_VERSION >= 20911

        /*

         * Recursive evaluation can grow the call stack quickly.

         */

        ctxt->context->depth += 5;

#endif

  ret = xmlXPathEval(str,ctxt->context);

#if LIBXML_VERSION >= 20911

        ctxt->context->depth -= 5;

#endif

  if (ret)

    valuePush(ctxt,ret);

  else {

    xsltGenericError(xsltGenericErrorContext,

      "dyn:evaluate() : unable to evaluate expression '%s'\n",str);

    valuePush(ctxt,xmlXPathNewNodeSet(NULL));

  }

  xmlFree(str);

  return;

}

/**

 * exsltDynMapFunction:

 * @ctxt:  an XPath parser context

 * @nargs:  the number of arguments

 *

 * Evaluates the string as an XPath expression and returns the result

 * value, which may be a boolean, number, string, node set, result tree

 * fragment or external object.

 */

static void

exsltDynMapFunction(xmlXPathParserContextPtr ctxt, int nargs)

{

    xmlChar *str = NULL;

    xmlNodeSetPtr nodeset = NULL;

    xsltTransformContextPtr tctxt;

    xmlXPathCompExprPtr comp = NULL;

    xmlXPathObjectPtr ret = NULL;

    xmlDocPtr oldDoc, container = NULL;

    xmlNodePtr oldNode;

    int oldContextSize;

    int oldProximityPosition;

    int i, j;

    if (nargs != 2) {

        xmlXPathSetArityError(ctxt);

        return;

    }

    str = xmlXPathPopString(ctxt);

    if (xmlXPathCheckError(ctxt))

        goto cleanup;

    nodeset = xmlXPathPopNodeSet(ctxt);

    if (xmlXPathCheckError(ctxt))

        goto cleanup;

    ret = xmlXPathNewNodeSet(NULL);

    if (ret == NULL) {

        xsltGenericError(xsltGenericErrorContext,

                         "exsltDynMapFunction: ret == NULL\n");

        goto cleanup;

    }

    tctxt = xsltXPathGetTransformContext(ctxt);

    if (tctxt == NULL) {

  xsltTransformError(xsltXPathGetTransformContext(ctxt), NULL, NULL,

        "dyn:map : internal error tctxt == NULL\n");

  goto cleanup;

    }

    if (str == NULL || !xmlStrlen(str) ||

        !(comp = xmlXPathCtxtCompile(tctxt->xpathCtxt, str)))

        goto cleanup;

    oldDoc = ctxt->context->doc;

    oldNode = ctxt->context->node;

    oldContextSize = ctxt->context->contextSize;

    oldProximityPosition = ctxt->context->proximityPosition;

        /**

   * since we really don't know we're going to be adding node(s)

   * down the road we create the RVT regardless

   */

    container = xsltCreateRVT(tctxt);

    if (container == NULL) {

  xsltTransformError(tctxt, NULL, NULL,

        "dyn:map : internal error container == NULL\n");

  goto cleanup;

    }

    xsltRegisterLocalRVT(tctxt, container);

    if (nodeset && nodeset->nodeNr > 0) {

        xmlXPathNodeSetSort(nodeset);

        ctxt->context->contextSize = nodeset->nodeNr;

        ctxt->context->proximityPosition = 0;

        for (i = 0; i < nodeset->nodeNr; i++) {

            xmlXPathObjectPtr subResult = NULL;

            xmlNodePtr cur = nodeset->nodeTab[i];

            ctxt->context->proximityPosition++;

            ctxt->context->node = cur;

            if (cur->type == XML_NAMESPACE_DECL) {

                /*

                * The XPath module sets the owner element of a ns-node on

                * the ns->next field.

                */

                cur = (xmlNodePtr) ((xmlNsPtr) cur)->next;

                if ((cur == NULL) || (cur->type != XML_ELEMENT_NODE)) {

                    xsltGenericError(xsltGenericErrorContext,

                        "Internal error in exsltDynMapFunction: "

                        "Cannot retrieve the doc of a namespace node.\n");

                    continue;

                }

                ctxt->context->doc = cur->doc;

            } else {

                ctxt->context->doc = cur->doc;

            }

            subResult = xmlXPathCompiledEval(comp, ctxt->context);

            if (subResult != NULL) {

                switch (subResult->type) {

                    case XPATH_NODESET:

                        if (subResult->nodesetval != NULL)

                            for (j = 0; j < subResult->nodesetval->nodeNr;

                                 j++)

                                xmlXPathNodeSetAdd(ret->nodesetval,

                                                   subResult->nodesetval->

                                                   nodeTab[j]);

                        break;

                    case XPATH_BOOLEAN:

                        if (container != NULL) {

                            xmlNodePtr newChildNode =

                                xmlNewTextChild((xmlNodePtr) container, NULL,

                                                BAD_CAST "boolean",

                                                BAD_CAST (subResult->

                                                boolval ? "true" : ""));

                            if (newChildNode != NULL) {

                                newChildNode->ns =

                                    xmlNewNs(newChildNode,

                                             BAD_CAST

                                             "http://exslt.org/common",

                                             BAD_CAST "exsl");

                                xmlXPathNodeSetAddUnique(ret->nodesetval,

                                                         newChildNode);

                            }

                        }

                        break;

                    case XPATH_NUMBER:

                        if (container != NULL) {

                            xmlChar *val =

                                xmlXPathCastNumberToString(subResult->

                                                           floatval);

                            xmlNodePtr newChildNode =

                                xmlNewTextChild((xmlNodePtr) container, NULL,

                                                BAD_CAST "number", val);

                            if (val != NULL)

                                xmlFree(val);

                            if (newChildNode != NULL) {

                                newChildNode->ns =

                                    xmlNewNs(newChildNode,

                                             BAD_CAST

                                             "http://exslt.org/common",

                                             BAD_CAST "exsl");

                                xmlXPathNodeSetAddUnique(ret->nodesetval,

                                                         newChildNode);

                            }

                        }

                        break;

                    case XPATH_STRING:

                        if (container != NULL) {

                            xmlNodePtr newChildNode =

                                xmlNewTextChild((xmlNodePtr) container, NULL,

                                                BAD_CAST "string",

                                                subResult->stringval);

                            if (newChildNode != NULL) {

                                newChildNode->ns =

                                    xmlNewNs(newChildNode,

                                             BAD_CAST

                                             "http://exslt.org/common",

                                             BAD_CAST "exsl");

                                xmlXPathNodeSetAddUnique(ret->nodesetval,

                                                         newChildNode);

                            }

                        }

                        break;

        default:

                        break;

                }

                xmlXPathFreeObject(subResult);

            }

        }

    }

    ctxt->context->doc = oldDoc;

    ctxt->context->node = oldNode;

    ctxt->context->contextSize = oldContextSize;

    ctxt->context->proximityPosition = oldProximityPosition;

  cleanup:

    /* restore the xpath context */

    if (comp != NULL)

        xmlXPathFreeCompExpr(comp);

    if (nodeset != NULL)

        xmlXPathFreeNodeSet(nodeset);

    if (str != NULL)

        xmlFree(str);

    valuePush(ctxt, ret);

    return;

}

/**

 * exsltDynRegister:

 *

 * Registers the EXSLT - Dynamic module

 */

void

exsltDynRegister (void) {

    xsltRegisterExtModuleFunction ((const xmlChar *) "evaluate",

           EXSLT_DYNAMIC_NAMESPACE,

           exsltDynEvaluateFunction);

  xsltRegisterExtModuleFunction ((const xmlChar *) "map",

           EXSLT_DYNAMIC_NAMESPACE,

           exsltDynMapFunction);

}