/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "XalanEXSLTDateTime.hpp"
#include "XalanEXSLTDateTimeImpl.hpp"


#include <cstdio>
#include <ctime>


#include <xalanc/PlatformSupport/XalanMessageLoader.hpp>


#include <xalanc/XPath/XObjectFactory.hpp>


namespace XALAN_CPP_NAMESPACE {


static const XalanEXSLTFunctionDateTime         s_dateTimeFunction;


static const XalanDOMChar   s_dateTimeFunctionName[] =
{
    XalanUnicode::charLetter_d,
    XalanUnicode::charLetter_a,
    XalanUnicode::charLetter_t,
    XalanUnicode::charLetter_e,
    XalanUnicode::charHyphenMinus,
    XalanUnicode::charLetter_t,
    XalanUnicode::charLetter_i,
    XalanUnicode::charLetter_m,
    XalanUnicode::charLetter_e,
    0
};

static const XalanEXSLTDateTimeFunctionsInstaller::FunctionTableEntry   theFunctionTable[] =
{
    { s_dateTimeFunctionName, &s_dateTimeFunction },
    { 0, 0 }
};

static const XalanDOMChar   s_dateTimeNamespace[] =
{
    XalanUnicode::charLetter_h,
    XalanUnicode::charLetter_t,
    XalanUnicode::charLetter_t,
    XalanUnicode::charLetter_p,
    XalanUnicode::charColon,
    XalanUnicode::charSolidus,
    XalanUnicode::charSolidus,
    XalanUnicode::charLetter_e,
    XalanUnicode::charLetter_x,
    XalanUnicode::charLetter_s,
    XalanUnicode::charLetter_l,
    XalanUnicode::charLetter_t,
    XalanUnicode::charFullStop,
    XalanUnicode::charLetter_o,
    XalanUnicode::charLetter_r,
    XalanUnicode::charLetter_g,
    XalanUnicode::charSolidus,
    XalanUnicode::charLetter_d,
    XalanUnicode::charLetter_a,
    XalanUnicode::charLetter_t,
    XalanUnicode::charLetter_e,
    XalanUnicode::charLetter_s,
    XalanUnicode::charHyphenMinus,
    XalanUnicode::charLetter_a,
    XalanUnicode::charLetter_n,
    XalanUnicode::charLetter_d,
    XalanUnicode::charHyphenMinus,
    XalanUnicode::charLetter_t,
    XalanUnicode::charLetter_i,
    XalanUnicode::charLetter_m,
    XalanUnicode::charLetter_e,
    XalanUnicode::charLetter_s,
    0
};


using std::sprintf;
using std::time;
using std::time_t;
using std::tm;


#if defined(XALAN_NO_REENTRANT_TIME_FUNCTIONS)

namespace
{
    using std::gmtime;
    using std::localtime;

    static struct tm*
    localtime_r(const time_t *clock, struct tm *res)
    {
        assert( res != 0 );

        struct tm * tmpTime = localtime(clock);

        if (tmpTime == 0 )
        {
            return 0;
        }
        else
        {
            *res = *tmpTime;

            return res;
        }
    }

    static struct tm *
    gmtime_r(const time_t *clock, struct tm *res)
    {
        assert( res != 0 );

        struct tm * tmpTime = gmtime(clock);

        if (tmpTime == 0 )
        {
            return 0;
        }
        else
        {
            *res = *tmpTime;

            return res;
        }
    }
}
#endif


XObjectPtr
XalanEXSLTFunctionDateTime::execute(
            XPathExecutionContext&          executionContext,
            XalanNode*                      context,
            const XObjectArgVectorType&     args,
            const Locator*                  locator) const
{
    if (args.size() != 0)
    {
        generalError(
            executionContext,
            context,
            locator);
    }

    const GetCachedString   theGuard(executionContext);

    XalanDOMString&     theResult = theGuard.get();
    
    theResult.clear();

    time_t long_time;

    time( &long_time );

    struct tm localTime;

    const struct tm*    ptrStrctTime = localtime_r(&long_time, &localTime);

    if (ptrStrctTime != 0 )
    {
        struct tm gmtTime;

        ptrStrctTime = gmtime_r(&long_time, &gmtTime);

        if(ptrStrctTime != 0 )
        {

            const size_t    MAX_DATE_TIME_LEN = 1000;
            char stringTime[MAX_DATE_TIME_LEN + 1];

            const size_t    result = strftime(stringTime, MAX_DATE_TIME_LEN, "%Y-%m-%dT%H:%M:%S", ptrStrctTime);

            if (result != 0)
            {
                theResult.assign(stringTime);
                
                long localData = localTime.tm_year * 10000 + localTime.tm_mon * 100 + localTime.tm_mday;
                long gmtData = gmtTime.tm_year * 10000 + gmtTime.tm_mon * 100 + gmtTime.tm_mday;

                char timeZone[MAX_DATE_TIME_LEN+1];
                
                int offset = 0; 

                if( localData == gmtData )
                {
                    if(localTime.tm_hour == gmtTime.tm_hour)
                    {
                        offset = 100; //  much bigger then any legal offset
                    }
                    else
                    {
                        offset = localTime.tm_hour - gmtTime.tm_hour;
                    }
                }
                else if(localData < gmtData)
                {
                    offset = localTime.tm_hour - gmtTime.tm_hour - 24;
                }
                else
                {
                    offset = localTime.tm_hour - gmtTime.tm_hour + 24;
                }

                if(offset == 100)
                {
                    sprintf(timeZone, "%s", "Z");
                }
                else
                {
                    if(offset < 0)
                    {
                        sprintf(timeZone, "%2.2d:00", offset);
                    }
                    else
                        sprintf(timeZone, "+%2.2d:00", offset);
                    
                }

                theResult.append(timeZone);
            }
        }
    }

    return executionContext.getXObjectFactory().createString(theResult);
}


const XalanDOMString&
XalanEXSLTFunctionDateTime::getError(XalanDOMString&    theResult) const
{
    return XalanMessageLoader::getMessage(
                theResult,
                XalanMessages::EXSLTFunctionAcceptsOneArgument_1Param,
                s_dateTimeFunctionName);
}


void
XalanEXSLTDateTimeFunctionsInstaller::installLocal(XPathEnvSupportDefault&      theSupport)
{
    doInstallLocal(s_dateTimeNamespace, theFunctionTable, theSupport);
}


void
XalanEXSLTDateTimeFunctionsInstaller::installGlobal(MemoryManager& theManager)
{
    doInstallGlobal(theManager, s_dateTimeNamespace, theFunctionTable);
}


void
XalanEXSLTDateTimeFunctionsInstaller::uninstallLocal(XPathEnvSupportDefault&    theSupport)
{
    doUninstallLocal(s_dateTimeNamespace, theFunctionTable, theSupport);
}


void
XalanEXSLTDateTimeFunctionsInstaller::uninstallGlobal(MemoryManager& theManager)
{
    doUninstallGlobal(theManager, s_dateTimeNamespace, theFunctionTable);
}


}