/******************************************************************************
 * $Id$
 *
 * Project:  MapServer
 * Purpose:  Implementation of debug/logging, msDebug() and related functions.
 * Author:   Daniel Morissette
 *
 ******************************************************************************
 * Copyright (c) 1996-2007 Regents of the University of Minnesota.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in 
 * all copies of this Software or works derived from this Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ****************************************************************************/


#include "mapserver.h"
#include "maperror.h"
#include "mapthread.h"
#include "maptime.h"

#include <time.h>
#ifndef _WIN32
#include <sys/time.h>
#include <unistd.h>
#endif
#include <stdarg.h>

#ifdef NEED_NONBLOCKING_STDERR
#include <fcntl.h>
#endif

#ifdef _WIN32
#include <windows.h> /* OutputDebugStringA() */
#endif

#if defined(_WIN32) && !defined(__CYGWIN__)
/* Need to use _vsnprintf() with VS2003 */
#define vsnprintf _vsnprintf
#endif 

MS_CVSID("$Id$")


#ifndef USE_THREAD

debugInfoObj *msGetDebugInfoObj()
{
    static debugInfoObj debuginfo = {MS_DEBUGLEVEL_ERRORSONLY,
                                     MS_DEBUGMODE_OFF, NULL, NULL };
    return &debuginfo;
}

#else

static debugInfoObj *debuginfo_list = NULL;

debugInfoObj *msGetDebugInfoObj()
{
    debugInfoObj *link;
    int          thread_id;
    debugInfoObj *ret_obj;
    
    msAcquireLock( TLOCK_DEBUGOBJ );
    
    thread_id = msGetThreadId();

    /* find link for this thread */
    
    for( link = debuginfo_list; 
         link != NULL && link->thread_id != thread_id
             && link->next != NULL && link->next->thread_id != thread_id;
         link = link->next ) {}

    /* If the target thread link is already at the head of the list were ok */
    if( debuginfo_list != NULL && debuginfo_list->thread_id == thread_id )
    {
    }

    /* We don't have one ... initialize one. */
    else if( link == NULL || link->next == NULL )
    {
        debugInfoObj *new_link;

        new_link = (debugInfoObj *) malloc(sizeof(debugInfoObj));
        new_link->next = debuginfo_list;
        new_link->thread_id = thread_id;
        new_link->global_debug_level = MS_DEBUGLEVEL_ERRORSONLY;
        new_link->debug_mode = MS_DEBUGMODE_OFF;
        new_link->errorfile = NULL;
        new_link->fp = NULL;

        debuginfo_list = new_link;
    }

    /* If the link is not already at the head of the list, promote it */
    else if( link != NULL && link->next != NULL )
    {
        debugInfoObj *target = link->next;

        link->next = link->next->next;
        target->next = debuginfo_list;
        debuginfo_list = target;
    }

    ret_obj = debuginfo_list;

    msReleaseLock( TLOCK_DEBUGOBJ ); 

    return ret_obj;
}
#endif


/* msSetErrorFile()
**
** Set output target, ready to write to it, open file if necessary
**
** Returns MS_SUCCESS/MS_FAILURE
*/
int msSetErrorFile(const char *pszErrorFile)
{
    debugInfoObj *debuginfo = msGetDebugInfoObj();

    if (debuginfo->errorfile && pszErrorFile &&
        strcmp(debuginfo->errorfile, pszErrorFile) == 0)
    {
        /* Nothing to do, already writing to the right place */
        return MS_SUCCESS;
    }

    /* Close current output file if any */
    msCloseErrorFile();

    /* NULL or empty target will just close current output and return */
    if (pszErrorFile == NULL || *pszErrorFile == '\0')
        return MS_SUCCESS;  

    if (strcmp(pszErrorFile, "stderr") == 0)
    {
        debuginfo->fp = stderr;
        debuginfo->errorfile = strdup(pszErrorFile);
        debuginfo->debug_mode = MS_DEBUGMODE_STDERR;
#if defined(NEED_NONBLOCKING_STDERR) && !defined(USE_MAPIO) && !defined(_WIN32)
        fcntl(fileno(stderr), F_SETFL, O_NONBLOCK);
        nonblocking_set = 1;
#endif
    }
    else if (strcmp(pszErrorFile, "stdout") == 0)
    {
        debuginfo->fp = stdout;
        debuginfo->errorfile = strdup(pszErrorFile);
        debuginfo->debug_mode = MS_DEBUGMODE_STDOUT;
    }
    else if (strcmp(pszErrorFile, "windowsdebug") == 0)
    {
#ifdef _WIN32
        debuginfo->errorfile = strdup(pszErrorFile);
        debuginfo->fp = NULL;
        debuginfo->debug_mode = MS_DEBUGMODE_WINDOWSDEBUG;
#else
        msSetError(MS_MISCERR, "'MS_ERRORFILE windowsdebug' is available only on Windows platforms.", "msSetErrorFile()");
        return MS_FAILURE;
#endif
    }
    else 
    {
        debuginfo->fp = fopen(pszErrorFile, "a");
        if (debuginfo->fp == NULL)
        {
            msSetError(MS_MISCERR, "Failed to open MS_ERRORFILE %s", "msSetErrorFile()", pszErrorFile);
            return MS_FAILURE;
        }
        debuginfo->errorfile = strdup(pszErrorFile);
        debuginfo->debug_mode = MS_DEBUGMODE_FILE;
    }

    return MS_SUCCESS;
}

/* msCloseErrorFile()
**
** Close current output file (if one is open) and reset related members
*/
void msCloseErrorFile()
{
    debugInfoObj *debuginfo = msGetDebugInfoObj();

    if (debuginfo && debuginfo->debug_mode != MS_DEBUGMODE_OFF)
    {
        if (debuginfo->fp && debuginfo->debug_mode == MS_DEBUGMODE_FILE)
            fclose(debuginfo->fp);

        if (debuginfo->fp && (debuginfo->debug_mode == MS_DEBUGMODE_STDERR ||
                              debuginfo->debug_mode == MS_DEBUGMODE_STDOUT))
            fflush(debuginfo->fp); /* just flush stderr or stdout */

        debuginfo->fp = NULL;

        msFree(debuginfo->errorfile);
        debuginfo->errorfile = NULL;

        debuginfo->debug_mode = MS_DEBUGMODE_OFF;
    }
}



/* msGetErrorFile()
**
** Returns name of current error file
**
** Returns NULL if not set.
*/
const char *msGetErrorFile()
{
    debugInfoObj *debuginfo = msGetDebugInfoObj();

    if (debuginfo)
        return debuginfo->errorfile;
    
    return NULL;
}

/* Set/Get the current global debug level value, used as default value for
** new map and layer objects and to control msDebug() calls outside of 
** the context of mapObj or layerObj.
**
*/
void msSetGlobalDebugLevel(int level)
{
    debugInfoObj *debuginfo = msGetDebugInfoObj();

    if (debuginfo)
        debuginfo->global_debug_level = (debugLevel)level;
}

debugLevel msGetGlobalDebugLevel()
{
    debugInfoObj *debuginfo = msGetDebugInfoObj();

    if (debuginfo)
        return debuginfo->global_debug_level;

    return MS_DEBUGLEVEL_ERRORSONLY;
}


/* msDebugInitFromEnv()
**
** Init debug state from MS_ERRORFILE and MS_DEBUGLEVEL env vars if set
**
** Returns MS_SUCCESS/MS_FAILURE
*/
int msDebugInitFromEnv()
{
    const char *val;

    if( (val=getenv( "MS_ERRORFILE" )) != NULL )
    {
        if ( msSetErrorFile(val) != MS_SUCCESS )
            return MS_FAILURE;
    }
    
    if( (val=getenv( "MS_DEBUGLEVEL" )) != NULL )
        msSetGlobalDebugLevel(atoi(val));

    return MS_SUCCESS;
}


/* msDebugCleanup()
**
** Called by msCleanup to remove info related to this thread.
*/
void msDebugCleanup()
{
    /* make sure file is closed */
    msCloseErrorFile();

#ifdef USE_THREAD
  {
      int  thread_id = msGetThreadId();
      debugInfoObj *link;

      msAcquireLock( TLOCK_DEBUGOBJ );
      
      /* find link for this thread */
    
      for( link = debuginfo_list; 
           link != NULL && link->thread_id != thread_id
               && link->next != NULL && link->next->thread_id != thread_id;
           link = link->next ) {}
      
      if( link->thread_id == thread_id )
      { 
          /* presumably link is at head of list.  */
          if( debuginfo_list == link )
              debuginfo_list = link->next;

          free( link );
      }
      else if( link->next != NULL && link->next->thread_id == thread_id )
      {
          debugInfoObj *next_link = link->next;
          link->next = link->next->next;
          free( next_link );
      }
      msReleaseLock( TLOCK_DEBUGOBJ );
  }
#endif

}

/* msDebug()
**
** Outputs/logs messages to the MS_ERRORFILE if one is set 
** (see msSetErrorFile())
**
*/
void msDebug( const char * pszFormat, ... )
{
    va_list args;
    debugInfoObj *debuginfo = msGetDebugInfoObj();

    if (debuginfo == NULL || debuginfo->debug_mode == MS_DEBUGMODE_OFF)
        return;  /* Don't waste time here! */

    if (debuginfo->fp)
    {
        /* Writing to a stdio file handle */

#if defined(USE_FASTCGI)
        /* It seems the FastCGI stuff inserts a timestamp anyways, so  */
        /* we might as well skip this one if writing to stderr w/ FastCGI. */
        if (debuginfo->debug_mode != MS_DEBUGMODE_STDERR)
#endif
        {
            struct mstimeval tv;
            time_t t;
            msGettimeofday(&tv, NULL);
            t = tv.tv_sec;
            msIO_fprintf(debuginfo->fp, "[%s].%ld ", 
                         msStringChop(ctime(&t)), (long)tv.tv_usec);
        }

        va_start(args, pszFormat);
        msIO_vfprintf(debuginfo->fp, pszFormat, args);
        va_end(args);
    }
#ifdef _WIN32
    else if (debuginfo->debug_mode == MS_DEBUGMODE_WINDOWSDEBUG)
    {
        /* Writing to Windows Debug Console */

        char szMessage[MESSAGELENGTH];

        va_start(args, pszFormat);
        vsnprintf( szMessage, MESSAGELENGTH, pszFormat, args );
        va_end(args);

        szMessage[MESSAGELENGTH-1] = '\0';
        OutputDebugStringA(szMessage);
    }
#endif

}