/**
 * xsltICUSort.c: module provided by Richard Jinks to provide a
 *                sort function replacement using ICU, it is not
 *                included in standard due to the size of the ICU
 *                library
 *
 * See http://mail.gnome.org/archives/xslt/2002-November/msg00093.html
 *     http://oss.software.ibm.com/icu/index.html
 *
 * Copyright Richard Jinks
 */
#define IN_LIBXSLT
#include "libxslt.h"

#include <libxml/parserInternals.h>

#include "xsltconfig.h"
#include "xslt.h"
#include "xsltInternals.h"
#include "xsltutils.h"
#include "transform.h"
#include "templates.h"

#include <unicode/ucnv.h>
#include <unicode/ustring.h>
#include <unicode/utypes.h>
#include <unicode/uloc.h>
#include <unicode/ucol.h>

/**
 * xsltICUComputeSortResult:
 * @ctxt:  a XSLT process context
 * @sort:  node list
 *
 * reorder the current node list accordingly to the set of sorting
 * requirement provided by the array of nodes.
 *
 * Returns a ordered XPath nodeset or NULL in case of error.
 */
xmlXPathObjectPtr *
xsltICUComputeSortResult(xsltTransformContextPtr ctxt, xmlNodePtr sort) {
#ifdef XSLT_REFACTORED
    xsltStyleItemSortPtr comp;
#else
    xsltStylePreCompPtr comp;
#endif
    xmlXPathObjectPtr *results = NULL;
    xmlNodeSetPtr list = NULL;
    xmlXPathObjectPtr res;
    int len = 0;
    int i;
    xmlNodePtr oldNode;
    xmlNodePtr oldInst;
    int	oldPos, oldSize ;
    int oldNsNr;
    xmlNsPtr *oldNamespaces;

    comp = sort->psvi;
    if (comp == NULL) {
	xsltGenericError(xsltGenericErrorContext,
	     "xsl:sort : compilation failed\n");
	return(NULL);
    }

    if ((comp->select == NULL) || (comp->comp == NULL))
	return(NULL);

    list = ctxt->nodeList;
    if ((list == NULL) || (list->nodeNr <= 1))
	return(NULL);

    len = list->nodeNr;

    /* TODO: xsl:sort lang attribute */
    /* TODO: xsl:sort case-order attribute */


    results = xmlMalloc(len * sizeof(xmlXPathObjectPtr));
    if (results == NULL) {
	xsltGenericError(xsltGenericErrorContext,
	     "xsltICUComputeSortResult: memory allocation failure\n");
	return(NULL);
    }

    oldNode = ctxt->node;
    oldInst = ctxt->inst;
    oldPos = ctxt->xpathCtxt->proximityPosition;
    oldSize = ctxt->xpathCtxt->contextSize;
    oldNsNr = ctxt->xpathCtxt->nsNr;
    oldNamespaces = ctxt->xpathCtxt->namespaces;
    for (i = 0;i < len;i++) {
	ctxt->inst = sort;
	ctxt->xpathCtxt->contextSize = len;
	ctxt->xpathCtxt->proximityPosition = i + 1;
	ctxt->node = list->nodeTab[i];
	ctxt->xpathCtxt->node = ctxt->node;
#ifdef XSLT_REFACTORED
	if (comp->inScopeNs != NULL) {
	    ctxt->xpathCtxt->namespaces = comp->inScopeNs->list;
	    ctxt->xpathCtxt->nsNr = comp->inScopeNs->xpathNumber;
	} else {
	    ctxt->xpathCtxt->namespaces = NULL;
	    ctxt->xpathCtxt->nsNr = 0;
	}
#else
	ctxt->xpathCtxt->namespaces = comp->nsList;
	ctxt->xpathCtxt->nsNr = comp->nsNr;
#endif
	res = xmlXPathCompiledEval(comp->comp, ctxt->xpathCtxt);
	if (res != NULL) {
	    if (res->type != XPATH_STRING)
		res = xmlXPathConvertString(res);
	    if (comp->number)
		res = xmlXPathConvertNumber(res);
	    res->index = i;	/* Save original pos for dupl resolv */
	    if (comp->number) {
		if (res->type == XPATH_NUMBER) {
		    results[i] = res;
		} else {
#ifdef WITH_XSLT_DEBUG_PROCESS
		    xsltGenericDebug(xsltGenericDebugContext,
			"xsltICUComputeSortResult: select didn't evaluate to a number\n");
#endif
		    results[i] = NULL;
		}
	    } else {
		if (res->type == XPATH_STRING) {
		    results[i] = res;
		} else {
#ifdef WITH_XSLT_DEBUG_PROCESS
		    xsltGenericDebug(xsltGenericDebugContext,
			"xsltICUComputeSortResult: select didn't evaluate to a string\n");
#endif
		    results[i] = NULL;
		}
	    }
	} else {
	    ctxt->state = XSLT_STATE_STOPPED;
	    results[i] = NULL;
	}
    }
    ctxt->node = oldNode;
    ctxt->inst = oldInst;
    ctxt->xpathCtxt->contextSize = oldSize;
    ctxt->xpathCtxt->proximityPosition = oldPos;
    ctxt->xpathCtxt->nsNr = oldNsNr;
    ctxt->xpathCtxt->namespaces = oldNamespaces;

    return(results);
}

/**
 * xsltICUSortFunction:
 * @ctxt:  a XSLT process context
 * @sorts:  array of sort nodes
 * @nbsorts:  the number of sorts in the array
 *
 * reorder the current node list accordingly to the set of sorting
 * requirement provided by the arry of nodes.
 * uses the ICU library
 */
void
xsltICUSortFunction(xsltTransformContextPtr ctxt, xmlNodePtr *sorts,
	           int nbsorts) {
#ifdef XSLT_REFACTORED
    xsltStyleItemSortPtr comp;
#else
    xsltStylePreCompPtr comp;
#endif
    xmlXPathObjectPtr *resultsTab[XSLT_MAX_SORT];
    xmlXPathObjectPtr *results = NULL, *res;
    xmlNodeSetPtr list = NULL;
    int descending, number, desc, numb;
    int len = 0;
    int i, j, incr;
    int tst;
    int depth;
    xmlNodePtr node;
    xmlXPathObjectPtr tmp;
    int tempstype[XSLT_MAX_SORT], temporder[XSLT_MAX_SORT];

    /* Start ICU change */
    UCollator *coll = 0;
    UConverter *conv;
    UErrorCode status;
    UChar *target,*target2;
    int targetlen, target2len;
    /* End ICU change */

    if ((ctxt == NULL) || (sorts == NULL) || (nbsorts <= 0) ||
	(nbsorts >= XSLT_MAX_SORT))
	return;
    if (sorts[0] == NULL)
	return;
    comp = sorts[0]->psvi;
    if (comp == NULL)
	return;

    list = ctxt->nodeList;
    if ((list == NULL) || (list->nodeNr <= 1))
	return; /* nothing to do */

    for (j = 0; j < nbsorts; j++) {
	comp = sorts[j]->psvi;
	tempstype[j] = 0;
	if ((comp->stype == NULL) && (comp->has_stype != 0)) {
	    comp->stype =
		xsltEvalAttrValueTemplate(ctxt, sorts[j],
					  (const xmlChar *) "data-type",
					  XSLT_NAMESPACE);
	    if (comp->stype != NULL) {
		tempstype[j] = 1;
		if (xmlStrEqual(comp->stype, (const xmlChar *) "text"))
		    comp->number = 0;
		else if (xmlStrEqual(comp->stype, (const xmlChar *) "number"))
		    comp->number = 1;
		else {
		    xsltTransformError(ctxt, NULL, sorts[j],
			  "xsltDoSortFunction: no support for data-type = %s\n",
				     comp->stype);
		    comp->number = 0; /* use default */
		}
	    }
	}
	temporder[j] = 0;
	if ((comp->order == NULL) && (comp->has_order != 0)) {
	    comp->order = xsltEvalAttrValueTemplate(ctxt, sorts[j],
						    (const xmlChar *) "order",
						    XSLT_NAMESPACE);
	    if (comp->order != NULL) {
		temporder[j] = 1;
		if (xmlStrEqual(comp->order, (const xmlChar *) "ascending"))
		    comp->descending = 0;
		else if (xmlStrEqual(comp->order,
				     (const xmlChar *) "descending"))
		    comp->descending = 1;
		else {
		    xsltTransformError(ctxt, NULL, sorts[j],
			     "xsltDoSortFunction: invalid value %s for order\n",
				     comp->order);
		    comp->descending = 0; /* use default */
		}
	    }
	}
    }

    len = list->nodeNr;

    resultsTab[0] = xsltICUComputeSortResult(ctxt, sorts[0]);
    for (i = 1;i < XSLT_MAX_SORT;i++)
	resultsTab[i] = NULL;

    results = resultsTab[0];

    comp = sorts[0]->psvi;
    descending = comp->descending;
    number = comp->number;
    if (results == NULL)
	return;

    /* Start ICU change */
    status = U_ZERO_ERROR;
    conv = ucnv_open("UTF8", &status);
    if(U_FAILURE(status)) {
	xsltTransformError(ctxt, NULL, NULL, "xsltICUSortFunction: Error opening converter\n");
    }
    if(comp->has_lang)
	coll = ucol_open(comp->lang, &status);
    if(U_FAILURE(status) || !comp->has_lang) {
	status = U_ZERO_ERROR;
	coll = ucol_open("en", &status);
    }
    if(U_FAILURE(status)) {
	xsltTransformError(ctxt, NULL, NULL, "xsltICUSortFunction: Error opening collator\n");
    }
    if(comp->lower_first)
	ucol_setAttribute(coll,UCOL_CASE_FIRST,UCOL_LOWER_FIRST,&status);
    else
	ucol_setAttribute(coll,UCOL_CASE_FIRST,UCOL_UPPER_FIRST,&status);
    if(U_FAILURE(status)) {
	xsltTransformError(ctxt, NULL, NULL, "xsltICUSortFunction: Error setting collator attribute\n");
    }
    /* End ICU change */

    /* Shell's sort of node-set */
    for (incr = len / 2; incr > 0; incr /= 2) {
	for (i = incr; i < len; i++) {
	    j = i - incr;
	    if (results[i] == NULL)
		continue;

	    while (j >= 0) {
		if (results[j] == NULL)
		    tst = 1;
		else {
		    if (number) {
			/* We make NaN smaller than number in accordance
			   with XSLT spec */
			if (xmlXPathIsNaN(results[j]->floatval)) {
			    if (xmlXPathIsNaN(results[j + incr]->floatval))
				tst = 0;
			    else
				tst = -1;
			} else if (xmlXPathIsNaN(results[j + incr]->floatval))
			    tst = 1;
			else if (results[j]->floatval ==
				results[j + incr]->floatval)
			    tst = 0;
			else if (results[j]->floatval >
				results[j + incr]->floatval)
			    tst = 1;
			else tst = -1;
		    } else {
/*			tst = xmlStrcmp(results[j]->stringval,
				     results[j + incr]->stringval); */
			/* Start ICU change */
			targetlen = xmlStrlen(results[j]->stringval) * 2;
			target2len = xmlStrlen(results[j + incr]->stringval) * 2;
			target = xmlMalloc(targetlen * sizeof(UChar));
			target2 = xmlMalloc(target2len * sizeof(UChar));
			targetlen = ucnv_toUChars(conv, target, targetlen, results[j]->stringval, -1, &status);
			target2len = ucnv_toUChars(conv, target2, target2len, results[j+incr]->stringval, -1, &status);
			tst = ucol_strcoll(coll, target, u_strlen(target), target2, u_strlen(target2));
			xmlFree(target);
			xmlFree(target2);
			/* End ICU change */
		    }
		    if (descending)
			tst = -tst;
		}
		if (tst == 0) {
		    /*
		     * Okay we need to use multi level sorts
		     */
		    depth = 1;
		    while (depth < nbsorts) {
			if (sorts[depth] == NULL)
			    break;
			comp = sorts[depth]->psvi;
			if (comp == NULL)
			    break;
			desc = comp->descending;
			numb = comp->number;

			/*
			 * Compute the result of the next level for the
			 * full set, this might be optimized ... or not
			 */
			if (resultsTab[depth] == NULL) {
			    resultsTab[depth] = xsltICUComputeSortResult(ctxt,
				                        sorts[depth]); //requires libxslt to be built without locale support
			}
			res = resultsTab[depth];
			if (res == NULL)
			    break;
			if (res[j] == NULL) {
			    if (res[j+incr] != NULL)
				tst = 1;
			} else {
			    if (numb) {
				/* We make NaN smaller than number in
				   accordance with XSLT spec */
				if (xmlXPathIsNaN(res[j]->floatval)) {
				    if (xmlXPathIsNaN(res[j +
						incr]->floatval))
					tst = 0;
				    else
				        tst = -1;
				} else if (xmlXPathIsNaN(res[j + incr]->
						floatval))
				    tst = 1;
				else if (res[j]->floatval == res[j + incr]->
						floatval)
				    tst = 0;
				else if (res[j]->floatval >
					res[j + incr]->floatval)
				    tst = 1;
				else tst = -1;
			    } else {
/*				tst = xmlStrcmp(res[j]->stringval,
					     res[j + incr]->stringval); */
				/* Start ICU change */
				targetlen = xmlStrlen(res[j]->stringval) * 2;
				target2len = xmlStrlen(res[j + incr]->stringval) * 2;
				target = xmlMalloc(targetlen * sizeof(UChar));
				target2 = xmlMalloc(target2len * sizeof(UChar));
				targetlen = ucnv_toUChars(conv, target, targetlen, res[j]->stringval, -1, &status);
				target2len = ucnv_toUChars(conv, target2, target2len, res[j+incr]->stringval, -1, &status);
				tst = ucol_strcoll(coll, target, u_strlen(target), target2, u_strlen(target2));
				xmlFree(target);
				xmlFree(target2);
				/* End ICU change */
			    }
			    if (desc)
				tst = -tst;
			}

			/*
			 * if we still can't differenciate at this level
			 * try one level deeper.
			 */
			if (tst != 0)
			    break;
			depth++;
		    }
		}
		if (tst == 0) {
		    tst = results[j]->index > results[j + incr]->index;
		}
		if (tst > 0) {
		    tmp = results[j];
		    results[j] = results[j + incr];
		    results[j + incr] = tmp;
		    node = list->nodeTab[j];
		    list->nodeTab[j] = list->nodeTab[j + incr];
		    list->nodeTab[j + incr] = node;
		    depth = 1;
		    while (depth < nbsorts) {
			if (sorts[depth] == NULL)
			    break;
			if (resultsTab[depth] == NULL)
			    break;
			res = resultsTab[depth];
			tmp = res[j];
			res[j] = res[j + incr];
			res[j + incr] = tmp;
			depth++;
		    }
		    j -= incr;
		} else
		    break;
	    }
	}
    }

    /* Start ICU change */
    ucol_close(coll);
    ucnv_close(conv);
    /* End ICU change */

    for (j = 0; j < nbsorts; j++) {
	comp = sorts[j]->psvi;
	if (tempstype[j] == 1) {
	    /* The data-type needs to be recomputed each time */
	    xmlFree((void *)(comp->stype));
	    comp->stype = NULL;
	}
	if (temporder[j] == 1) {
	    /* The order needs to be recomputed each time */
	    xmlFree((void *)(comp->order));
	    comp->order = NULL;
	}
	if (resultsTab[j] != NULL) {
	    for (i = 0;i < len;i++)
		xmlXPathFreeObject(resultsTab[j][i]);
	    xmlFree(resultsTab[j]);
	}
    }
}