#include "nvparse_errors.h"
#include "nvparse_externs.h"
#include <string.h>
#include <string>
#include <ctype.h>

#if defined(__APPLE__) && defined(__GNUC__)
#include <OpenGL/glu.h>
#else
#include <GL/glu.h>
#endif

#include <OgreGLPrerequisites.h>

using namespace std;

namespace
{
	void LoadProgram( GLenum target, GLuint id, char *instring );
	void StrToUpper(char * string);
	GLint vpid;
}


bool is_avp10(const char * s)
{
	return ! strncmp(s, "!!ARBvp1.0", 10);
}

bool avp10_init(char * s)
{
	static bool avpinit = false;
	if (avpinit == false )
	{
      /*
		if(! glh_init_extensions("GL_ARB_vertex_program"))
		{
			errors.set("unable to initialize GL_ARB_vertex_program");
			return false;
		}
		else
		{
        */
			avpinit = true;
            /*
		}
        */
	}
	
	errors.reset();
	line_number = 1;
	myin = s;

    glGetProgramivARB(GL_VERTEX_PROGRAM_ARB, GL_PROGRAM_BINDING_ARB, &vpid);
        
    if ( vpid == 0 )
    {
        char str[128];
        sprintf( str, "No vertex program id bound for nvparse() invocation.  Bound id = %d\n", (int)vpid );
        errors.set( str );
		return false;
    }
	
	return true;	
}

int avp10_parse()
{
    LoadProgram( GL_VERTEX_PROGRAM_ARB, vpid, myin );
	return 0;
}

namespace
{
	//.----------------------------------------------------------------------------.
	//|   Function   : LoadProgram                                                 |
	//|   Description: Load a program into GL, and report any errors encountered.  |
	//.----------------------------------------------------------------------------.
	void LoadProgram( GLenum target, GLuint id, char *instring )
	{
        GLint  errPos;
        GLenum errCode;
        const GLubyte *errString;
        int len = strlen(instring);

        glBindProgramARB(target, id);
        errCode = glGetError();
        if (errCode == GL_INVALID_OPERATION)
                errString = gluErrorString(errCode);

        glProgramStringARB(target, 
                           GL_PROGRAM_FORMAT_ASCII_ARB, 
                           len,
                           instring);

		if ((errCode = glGetError()) != GL_NO_ERROR)
		{
			errString = gluErrorString(errCode);
			
			glGetIntegerv(GL_PROGRAM_ERROR_POSITION_ARB, &errPos);
            if (errPos == -1)
                return;
			
			int nlines = 1;
			int nchar  = 1;
			int i;
			for (i = 0; i < errPos; i++)
			{
				if (instring[i] == '\n')
				{
					nlines++;
					nchar = 1;
				}
				else
				{
					nchar++;
				}
			}
			int start;
			int end;
			int flag = ((instring[errPos]==';') | (instring[errPos-1]==';')) ? 1 : 0;
			for (i = errPos; i >= 0; i--)
			{
				start = i;
				if (flag && (start >= errPos-1))
					continue;
				if (instring[i] == ';')
				{
					if (!flag)
					{
						start = i+1;
						if (instring[start] == '\n')
							start++;
					}
					break;
				}
			}
			for (i = errPos; i < len; i++)
			{
				end = i;
				if (instring[i] == ';' && end > start)
				{
					break;
				}
			}
			if (errPos - start > 30)
			{
				start = errPos - 30;
			}
			if (end - errPos > 30)
			{
				end = errPos + 30;
			}
			
			char substring[96];
			memset( substring, 0, 96 );
			strncpy( substring, &(instring[start]), end-start+1 );

            char str[256];
			sprintf(str, "error at line %d character %d\n\"%s\"\n", nlines, nchar, substring);
			int width = errPos-start;

			for (i = 0; i < width; i++)
			{
				strcat(str, " ");
			}

			strcat(str, "|\n");
			for (i = 0; i < width; i++)
			{
				strcat(str, " ");
			}
			strcat(str, "^\n");
			
			errors.set(str);
		}
	}
	
	
	//.----------------------------------------------------------------------------.
	//|   Function   : StrToUpper                                                  |
	//|   Description: Converts all lowercase chars in a string to uppercase.      |
	//.----------------------------------------------------------------------------.
	void StrToUpper(char *string)
	{
		for (unsigned int i = 0; i < strlen(string); i++)
			string[i] = toupper(string[i]);
	}
	
}