/**

 * $Id$

 *

 * gendec action file parser. 

 *

 * Copyright (c) 2005 Nathan Keynes.

 *

 * 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.

 */

#include <errno.h>

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <ctype.h>

#include <sys/stat.h>

#include <glib/gstrfuncs.h>

#include "tools/gendec.h"

static int add_action( struct action *actions, struct ruleset *rules, char *operation, const char *file, int line, char *action )

{

    char *act = g_strchomp(action);

    char opclean[strlen(operation)+1];

    char *p = operation, *q = opclean;

    int i;

    // Strip c-style comments 

    while( *p ) {

        if( *p == '/' && *(p+1) == '*' ) {

            p+=2;

            while( *p ) {

                if( *p == '*' && *(p+1) == '/' ) {

                    p+=2;

                    break;

                }

                p++;

            }

        } else if( *p == '/' && *(p+1) == '/' ) {

            p+=2;

            while( *p && *p != '\n' ) {

                p++;

            }

        } else {

            *q++ = *p++;

        }

    }

    *q = '\0';

    /* Drop any leading blank lines from the start of the action (and add them

     * to the line number ) */ 

    for( p=act; isspace(*p); p++ ) {

        if( *p == '\n' ) {

            act = p+1;

            line++;

        }

    }

    strcpy( operation, g_strstrip(opclean) );

    for( i=0; i<rules->rule_count; i++ ) {

        if( strcasecmp(rules->rules[i]->format, operation) == 0 ) {

            if( actions[i].text != NULL ) {

                fprintf( stderr, "gendec:%d: Duplicate actions for operation '%s' (previous action on line %d)\n", line, operation,

                         actions[i].lineno );

                return -1;

            }

            actions[i].filename = file;

            actions[i].lineno = line;

            actions[i].text = act;

            return 0;

        }

    }

    fprintf(stderr, "gendec:%d: No operation found matching '%s'\n", line, operation );

    return -1;

}

struct actionfile {

    FILE *f;

    const char *filename;

    char *text;

    int length;

    int yyposn;

    int yyline;

    struct ruleset *rules;

    struct actiontoken token;

};

actionfile_t action_file_open( const char *filename, struct ruleset *rules )

{

    struct stat st;

    FILE *f = fopen( filename, "ro" );

    if( f == NULL ) 

        return NULL;

    fstat( fileno(f), &st );

    actionfile_t af = malloc( sizeof(struct actionfile) );

    af->f = f;

    af->filename = filename;

    af->length = st.st_size+1;

    af->text = malloc( st.st_size+1 );

    if( fread( af->text, st.st_size, 1, f ) != 1 ) {

        fprintf( stderr, "Error: unable to read from file '%s' (%s)\n", filename, strerror(errno));

        free(af);

        fclose(f);

        return NULL;

    }

    af->text[st.st_size] = '\0';

    af->yyline = 1;

    af->yyposn = 0;

    af->rules = rules;

    af->token.symbol = NONE;

    af->token.lineno = 1;

    af->token.filename = filename;

    return af;

}

actiontoken_t action_file_next( actionfile_t af )

{

    af->token.lineno = af->yyline;

    if( af->yyposn == af->length ) {

        af->token.symbol = END;

    } else if( af->token.symbol == TEXT || /* ACTIONS must follow TEXT */ 

            (af->token.symbol == NONE && af->text[af->yyposn] == '%' && af->text[af->yyposn+1] == '%') ) {

        /* Begin action block */

        af->token.symbol = ACTIONS;

        memset( af->token.actions, 0, sizeof(af->token.actions) );

        char *operation = &af->text[af->yyposn];

        while( af->yyposn < af->length ) {

            if( af->text[af->yyposn] == '\n' ) {

                af->yyline++;

                if( af->text[af->yyposn+1] == '%' && af->text[af->yyposn+2] == '%' ) {

                    af->yyposn += 3;

                    break;

                }

            }

            if( af->text[af->yyposn] == '{' && af->text[af->yyposn+1] == ':' ) {

                af->text[af->yyposn] = '\0';

                int line = af->yyline;

                af->yyposn+=2;

                char *action = &af->text[af->yyposn];

                while( af->yyposn < af->length ) {

                    if( af->text[af->yyposn] == ':' && af->text[af->yyposn+1] == '}' ) {

                        af->text[af->yyposn] = '\0';

                        af->yyposn++;

                        if( add_action( af->token.actions, af->rules, operation, af->filename, line, action ) != 0 ) {

                            af->token.symbol = ERROR;

                            return &af->token;

                        }

                        operation = &af->text[af->yyposn+1];

                        break;

                    } else if( af->text[af->yyposn] == '\n' ) {

                        af->yyline++;

                    }

                    af->yyposn++;

                }

            }

            af->yyposn++;

        }

    } else {

        /* Text block */

        af->token.symbol = TEXT;

        af->token.text = &af->text[af->yyposn]; 

        while( af->yyposn < af->length ) {

            af->yyposn++;

            if( af->text[af->yyposn-1] == '\n' ) {

                af->yyline++;

                if( af->text[af->yyposn] == '%' && af->text[af->yyposn+1] == '%' ) {

                    af->text[af->yyposn] = '\0';

                    af->yyposn += 2;

                    break;

                }

            }

        }

    }

    return &af->token;

}

void action_file_close( actionfile_t af )

{

    free( af->text );

    fclose( af->f );

    free( af );

}