/**
 * \file errors.c
 * Mesa debugging and error handling functions.
 */

/*
 * Mesa 3-D graphics library
 * Version:  7.1
 *
 * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
 *
 * 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 or substantial portions of the 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
 * BRIAN PAUL 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 "errors.h"

#include "imports.h"
#include "context.h"
#include "mtypes.h"
#include "version.h"


#define MAXSTRING 4000  /* for _mesa_vsnprintf() */

/**********************************************************************/
/** \name Diagnostics */
/*@{*/

static void
output_if_debug(const char *prefixString, const char *outputString,
                GLboolean newline)
{
   static int debug = -1;

   /* Check the MESA_DEBUG environment variable if it hasn't
    * been checked yet.  We only have to check it once...
    */
   if (debug == -1) {
      char *env = _mesa_getenv("MESA_DEBUG");

      /* In a debug build, we print warning messages *unless*
       * MESA_DEBUG is 0.  In a non-debug build, we don't
       * print warning messages *unless* MESA_DEBUG is
       * set *to any value*.
       */
#ifdef DEBUG
      debug = (env != NULL && atoi(env) == 0) ? 0 : 1;
#else
      debug = (env != NULL) ? 1 : 0;
#endif
   }

   /* Now only print the string if we're required to do so. */
   if (debug) {
      fprintf(stderr, "%s: %s", prefixString, outputString);
      if (newline)
         fprintf(stderr, "\n");

#if defined(_WIN32) && !defined(_WIN32_WCE)
      /* stderr from windows applications without console is not usually 
       * visible, so communicate with the debugger instead */ 
      {
         char buf[4096];
         _mesa_snprintf(buf, sizeof(buf), "%s: %s%s", prefixString, outputString, newline ? "\n" : "");
         OutputDebugStringA(buf);
      }
#endif
   }
}


/**
 * Return string version of GL error code.
 */
static const char *
error_string( GLenum error )
{
   switch (error) {
   case GL_NO_ERROR:
      return "GL_NO_ERROR";
   case GL_INVALID_VALUE:
      return "GL_INVALID_VALUE";
   case GL_INVALID_ENUM:
      return "GL_INVALID_ENUM";
   case GL_INVALID_OPERATION:
      return "GL_INVALID_OPERATION";
   case GL_STACK_OVERFLOW:
      return "GL_STACK_OVERFLOW";
   case GL_STACK_UNDERFLOW:
      return "GL_STACK_UNDERFLOW";
   case GL_OUT_OF_MEMORY:
      return "GL_OUT_OF_MEMORY";
   case GL_TABLE_TOO_LARGE:
      return "GL_TABLE_TOO_LARGE";
   case GL_INVALID_FRAMEBUFFER_OPERATION_EXT:
      return "GL_INVALID_FRAMEBUFFER_OPERATION";
   default:
      return "unknown";
   }
}


/**
 * When a new type of error is recorded, print a message describing
 * previous errors which were accumulated.
 */
static void
flush_delayed_errors( struct gl_context *ctx )
{
   char s[MAXSTRING];

   if (ctx->ErrorDebugCount) {
      _mesa_snprintf(s, MAXSTRING, "%d similar %s errors", 
                     ctx->ErrorDebugCount,
                     error_string(ctx->ErrorValue));

      output_if_debug("Mesa", s, GL_TRUE);

      ctx->ErrorDebugCount = 0;
   }
}


/**
 * Report a warning (a recoverable error condition) to stderr if
 * either DEBUG is defined or the MESA_DEBUG env var is set.
 *
 * \param ctx GL context.
 * \param fmtString printf()-like format string.
 */
void
_mesa_warning( struct gl_context *ctx, const char *fmtString, ... )
{
   char str[MAXSTRING];
   va_list args;
   va_start( args, fmtString );  
   (void) _mesa_vsnprintf( str, MAXSTRING, fmtString, args );
   va_end( args );
   
   if (ctx)
      flush_delayed_errors( ctx );

   output_if_debug("Mesa warning", str, GL_TRUE);
}


/**
 * Report an internal implementation problem.
 * Prints the message to stderr via fprintf().
 *
 * \param ctx GL context.
 * \param fmtString problem description string.
 */
void
_mesa_problem( const struct gl_context *ctx, const char *fmtString, ... )
{
   va_list args;
   char str[MAXSTRING];
   static int numCalls = 0;

   (void) ctx;

   if (numCalls < 50) {
      numCalls++;

      va_start( args, fmtString );  
      _mesa_vsnprintf( str, MAXSTRING, fmtString, args );
      va_end( args );
      fprintf(stderr, "Mesa %s implementation error: %s\n",
              MESA_VERSION_STRING, str);
      fprintf(stderr, "Please report at bugs.freedesktop.org\n");
   }
}


/**
 * Record an OpenGL state error.  These usually occur when the user
 * passes invalid parameters to a GL function.
 *
 * If debugging is enabled (either at compile-time via the DEBUG macro, or
 * run-time via the MESA_DEBUG environment variable), report the error with
 * _mesa_debug().
 * 
 * \param ctx the GL context.
 * \param error the error value.
 * \param fmtString printf() style format string, followed by optional args
 */
void
_mesa_error( struct gl_context *ctx, GLenum error, const char *fmtString, ... )
{
   static GLint debug = -1;

   /* Check debug environment variable only once:
    */
   if (debug == -1) {
      const char *debugEnv = _mesa_getenv("MESA_DEBUG");

#ifdef DEBUG
      if (debugEnv && strstr(debugEnv, "silent"))
         debug = GL_FALSE;
      else
         debug = GL_TRUE;
#else
      if (debugEnv)
         debug = GL_TRUE;
      else
         debug = GL_FALSE;
#endif
   }

   if (debug) {      
      if (ctx->ErrorValue == error &&
          ctx->ErrorDebugFmtString == fmtString) {
         ctx->ErrorDebugCount++;
      }
      else {
         char s[MAXSTRING], s2[MAXSTRING];
         va_list args;

         flush_delayed_errors( ctx );
         
         va_start(args, fmtString);
         _mesa_vsnprintf(s, MAXSTRING, fmtString, args);
         va_end(args);

         _mesa_snprintf(s2, MAXSTRING, "%s in %s", error_string(error), s);
         output_if_debug("Mesa: User error", s2, GL_TRUE);
         
         ctx->ErrorDebugFmtString = fmtString;
         ctx->ErrorDebugCount = 0;
      }
   }

   _mesa_record_error(ctx, error);
}


/**
 * Report debug information.  Print error message to stderr via fprintf().
 * No-op if DEBUG mode not enabled.
 * 
 * \param ctx GL context.
 * \param fmtString printf()-style format string, followed by optional args.
 */
void
_mesa_debug( const struct gl_context *ctx, const char *fmtString, ... )
{
#ifdef DEBUG
   char s[MAXSTRING];
   va_list args;
   va_start(args, fmtString);
   _mesa_vsnprintf(s, MAXSTRING, fmtString, args);
   va_end(args);
   output_if_debug("Mesa", s, GL_FALSE);
#endif /* DEBUG */
   (void) ctx;
   (void) fmtString;
}

/*@}*/