/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2014-2015 Mario Luzeiro <mrluzeiro@gmail.com>
 * Copyright (C) 1992-2015 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you may find one here:
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * or you may search the http://www.gnu.org website for the version 2 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */

/**
 * @file vrml_aux.cpp
 * @brief implements auxiliar functions to parse VRML files
 */

#include "vrml_aux.h"


bool GetString( FILE* File, char* aDstString, size_t maxDstLen )
{

    if( (!aDstString) || (maxDstLen == 0) )
        return false;

    int c;
    
    while( ( c = fgetc( File ) ) != EOF )
    {
        if( c == '\"' )
        {
            break;
        }
    }

    if( c != '\"' )
    {
        return false;
    }

    while( (( c = fgetc( File ) ) != EOF) && (maxDstLen > 0) )
    {
        if( c == '\"' )
        {
            break;
        }

        maxDstLen--;

        *aDstString = c;
        aDstString++;

    }

    *aDstString = 0;

    if( c == '\"' )
    {
        return true;
    }

    return false;
}


static int SkipGetChar ( FILE* File );


static int SkipGetChar( FILE* File )
{
    int    c;
    bool    re_parse;

    if( ( c = fgetc( File ) ) == EOF )
    {
        // DBG( printf( "EOF\n" ) );
        return EOF;
    }

    // DBG( printf( "c %c 0x%02X\n", c, c ) );

    do
    {
        re_parse = false;

        if( (c == ' ') || (c == '\t') || (c == '{') || (c == '[') )
        {
            // DBG( printf( "Skipping space \\t or { or [\n" ) );
            do
            {
                if( ( c = fgetc( File ) ) == EOF )
                {
                    // DBG( printf( "EOF\n" ) );

                    return EOF;
                }
            } while( (c == ' ') || (c == '\t') || (c == '{') || (c == '[') );
        }

        if( (c == '#') || (c == '\n') ||  (c == '\r') || (c == 0) || (c == ',') )
        {
            if( c == '#' )
            {
                // DBG( printf( "Skipping # \\n or \\r or 0, 0x%02X\n", c ) );
                do
                {
                    if( ( c = fgetc( File ) ) == EOF )
                    {
                        // DBG( printf( "EOF\n" ) );
                        return EOF;
                    }
                } while( (c != '\n') &&  (c != '\r') && (c != 0) && (c != ',') );
            }
            else
            {
                if( ( c = fgetc( File ) ) == EOF )
                {
                    // DBG( printf( "EOF\n" ) );
                    return EOF;
                }
            }

            re_parse = true;
        }
    } while( re_parse == true );

    return c;
}


bool GetNextTag( FILE* File, char* tag, size_t len )
{
    int c = SkipGetChar( File );

    if( c == EOF )
    {
        return false;
    }

    tag[0]  = c;
    tag[1]  = 0;

    // DBG( printf( "tag[0] %c\n", tag[0] ) );
    if( (c != '}') && (c != ']') )
    {
        len--;
        char* dst = &tag[1];

        while( fscanf( File, "%c", dst ) && len > 0 )
        {
            if( (*dst == ' ') || (*dst == '[') || (*dst == '{')
                || (*dst == '\t') || (*dst == '\n')|| (*dst == '\r') )
            {
                *dst = 0;
                break;
            }

            dst++;
            len--;
        }


        // DBG( printf( "tag %s\n", tag ) );
        c = SkipGetChar( File );

        if( c != EOF )
        {
            // Puts again the read char in the buffer
            ungetc( c, File );
        }
    }

    return true;
}


int Read_NotImplemented( FILE* File, char closeChar )
{
    int c;

    // DBG( printf( "look for %c\n", closeChar) );
    while( ( c = fgetc( File ) ) != EOF )
    {
        if( c == '{' )
        {
            // DBG( printf( "{\n") );
            Read_NotImplemented( File, '}' );
        }
        else if( c == '[' )
        {
            // DBG( printf( "[\n") );
            Read_NotImplemented( File, ']' );
        }
        else if( c == closeChar )
        {
            // DBG( printf( "%c\n", closeChar) );
            return 0;
        }
    }

    // DBG( printf( "  NotImplemented failed\n" ) );
    return -1;
}


int ParseVertexList( FILE* File, std::vector<glm::vec3>& dst_vector )
{
    // DBG( printf( "      ParseVertexList\n" ) );

    dst_vector.clear();

    glm::vec3 vertex;

    while( ParseVertex( File, vertex ) == 3 )
    {
        dst_vector.push_back( vertex );
    }

    return 0;
}


int ParseVertex( FILE* File, glm::vec3& dst_vertex )
{
    float   a, b, c;
    int     ret = fscanf( File, "%e %e %e", &a, &b, &c );

    dst_vertex.x    = a;
    dst_vertex.y    = b;
    dst_vertex.z    = c;

    int s = SkipGetChar( File );

    if( s != EOF )
    {
        // Puts again the read char in the buffer
        ungetc( s, File );
    }

    // DBG( printf( "ret%d(%.9f,%.9f,%.9f)", ret, a,b,c) );

    return ret;
}


int ParseFloat( FILE* File, float* dst_float )
{
    float   value;
    int     ret = fscanf( File, "%e", &value );

    *dst_float = value;

    return ret;
}