/*
 * Copyright (C) 2007, 2008 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "XSLTUnicodeSort.h"

#if ENABLE(XSLT)

#include <libxslt/templates.h>
#include <libxslt/xsltutils.h>

#if USE(ICU_UNICODE)
#include <unicode/ucnv.h>
#include <unicode/ucol.h>
#include <unicode/ustring.h>
#define WTF_USE_ICU_COLLATION !UCONFIG_NO_COLLATION
#endif

#if PLATFORM(MAC)
#include "SoftLinking.h"
#endif

#if PLATFORM(MAC)
SOFT_LINK_LIBRARY(libxslt)
SOFT_LINK(libxslt, xsltComputeSortResult, xmlXPathObjectPtr*, (xsltTransformContextPtr ctxt, xmlNodePtr sort), (ctxt, sort))
SOFT_LINK(libxslt, xsltEvalAttrValueTemplate, xmlChar*, (xsltTransformContextPtr ctxt, xmlNodePtr node, const xmlChar *name, const xmlChar *ns), (ctxt, node, name, ns))

static void init_xsltTransformError(xsltTransformContextPtr ctxt, xsltStylesheetPtr style, xmlNodePtr node, const char *, ...) WTF_ATTRIBUTE_PRINTF(4, 5);
static void (*softLink_xsltTransformError)(xsltTransformContextPtr ctxt, xsltStylesheetPtr style, xmlNodePtr node, const char *, ...) WTF_ATTRIBUTE_PRINTF(4, 5) = init_xsltTransformError;

static void init_xsltTransformError(xsltTransformContextPtr ctxt, xsltStylesheetPtr style, xmlNodePtr node, const char* msg, ...)
{
    softLink_xsltTransformError = (void (*) (xsltTransformContextPtr ctxt, xsltStylesheetPtr style, xmlNodePtr node, const char *, ...))dlsym(libxsltLibrary(), "xsltTransformError");
    ASSERT(softLink_xsltTransformError);

    va_list args;
    va_start(args, msg);
#if PLATFORM(WIN_OS)
    char str[1024];
    vsnprintf(str, sizeof(str) - 1, msg, args);
#else
    char* str;
    vasprintf(&str, msg, args);
#endif
    va_end(args);

    softLink_xsltTransformError(ctxt, style, node, "%s", str);

#if !PLATFORM(WIN_OS)
    free(str);
#endif
}

inline void xsltTransformError(xsltTransformContextPtr ctxt, xsltStylesheetPtr style, xmlNodePtr node, const char* msg, ...) WTF_ATTRIBUTE_PRINTF(4, 5);

inline void xsltTransformError(xsltTransformContextPtr ctxt, xsltStylesheetPtr style, xmlNodePtr node, const char* msg, ...)
{
    va_list args;
    va_start(args, msg);
#if PLATFORM(WIN_OS)
    char str[1024];
    vsnprintf(str, sizeof(str) - 1, msg, args);
#else
    char* str;
    vasprintf(&str, msg, args);
#endif
    va_end(args);

    softLink_xsltTransformError(ctxt, style, node, "%s", str);

#if !PLATFORM(WIN_OS)
    free(str);
#endif
}

#endif

namespace WebCore {

// Based on default implementation from libxslt 1.1.22 and xsltICUSort.c example.
void xsltUnicodeSortFunction(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];

#if USE(ICU_COLLATION)
    UCollator *coll = 0;
    UConverter *conv;
    UErrorCode status;
    UChar *target,*target2;
    int targetlen, target2len;
#endif

    if ((ctxt == NULL) || (sorts == NULL) || (nbsorts <= 0) ||
        (nbsorts >= XSLT_MAX_SORT))
        return;
    if (sorts[0] == NULL)
        return;
    comp = static_cast<xsltStylePreComp*>(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 = static_cast<xsltStylePreComp*>(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] = xsltComputeSortResult(ctxt, sorts[0]);
    for (i = 1;i < XSLT_MAX_SORT;i++)
        resultsTab[i] = NULL;

    results = resultsTab[0];

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

#if USE(ICU_COLLATION)
    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((const char*)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");
#endif

    /* 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 {
#if USE(ICU_COLLATION)
                        targetlen = xmlStrlen(results[j]->stringval) + 1;
                        target2len = xmlStrlen(results[j + incr]->stringval) + 1;
                        target = (UChar*)xmlMalloc(targetlen * sizeof(UChar));
                        target2 = (UChar*)xmlMalloc(target2len * sizeof(UChar));
                        targetlen = ucnv_toUChars(conv, target, targetlen, (const char*)results[j]->stringval, -1, &status);
                        target2len = ucnv_toUChars(conv, target2, target2len, (const char*)results[j+incr]->stringval, -1, &status);
                        tst = ucol_strcoll(coll, target, u_strlen(target), target2, u_strlen(target2));
                        xmlFree(target);
                        xmlFree(target2);
#else
                        tst = xmlStrcmp(results[j]->stringval,
                            results[j + incr]->stringval); 
#endif
                    }
                    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 = static_cast<xsltStylePreComp*>(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] = xsltComputeSortResult(ctxt,
                                                        sorts[depth]);
                        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 {
#if USE(ICU_COLLATION)
                                targetlen = xmlStrlen(res[j]->stringval) + 1;
                                target2len = xmlStrlen(res[j + incr]->stringval) + 1;
                                target = (UChar*)xmlMalloc(targetlen * sizeof(UChar));
                                target2 = (UChar*)xmlMalloc(target2len * sizeof(UChar));
                                targetlen = ucnv_toUChars(conv, target, targetlen, (const char*)res[j]->stringval, -1, &status);
                                target2len = ucnv_toUChars(conv, target2, target2len, (const char*)res[j+incr]->stringval, -1, &status);
                                tst = ucol_strcoll(coll, target, u_strlen(target), target2, u_strlen(target2));
                                xmlFree(target);
                                xmlFree(target2);
#else
                                tst = xmlStrcmp(res[j]->stringval,
                                    res[j + incr]->stringval); 
#endif
                            }
                            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;
            }
        }
    }

#if USE(ICU_COLLATION)
    ucol_close(coll);
    ucnv_close(conv);
#endif

    for (j = 0; j < nbsorts; j++) {
        comp = static_cast<xsltStylePreComp*>(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]);
        }
    }
}

}

#endif