/*
 This file is part of pybliographer
 
 Copyright (C) 1998-1999 Frederic GOBRY
 Email : gobry@idiap.ch
 	   
 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, write to the Free Software
 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 
 $Id: source.c,v 1.2 1999/11/23 16:24:43 fredgo Exp $
*/


#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <errno.h>
#include "bibtex.h"

BibtexSource * 
bibtex_source_new (void) {
    BibtexSource * new;

    new = g_new (BibtexSource, 1);

    new->name  = NULL;
    new->type  = BIBTEX_SOURCE_NONE;
    new->table = g_hash_table_new (g_str_hash, g_str_equal);
    new->debug = FALSE;
    new->buffer = NULL;
    new->strict = TRUE;

    return new;
}

static void
reset_source (BibtexSource * source) {

    bibtex_analyzer_finish (source);

    if (source->name) {
	g_free (source->name);
    }
    
    switch (source->type) {
    case BIBTEX_SOURCE_NONE:
	break;

    case BIBTEX_SOURCE_FILE:
	fclose (source->source.file);
	break;

    case BIBTEX_SOURCE_STRING:
	g_free (source->source.string);
	break;

    default:
	g_assert_not_reached ();
    }

    source->offset = 0;
    source->line   = 1;
    source->eof    = FALSE;
    source->error  = FALSE;
}

static void
freedata (gpointer key, 
	   gpointer value, 
	   gpointer user) {

    g_free (key);

    if ((gboolean) user) {
	bibtex_struct_destroy ((BibtexStruct *) value, TRUE);
    }
}

BibtexStruct * 
bibtex_source_get_string (BibtexSource * source,
			  gchar * key) {
    g_return_val_if_fail (source != NULL, NULL);
    g_return_val_if_fail (key != NULL, NULL);

    return g_hash_table_lookup (source->table, key);
}

void
bibtex_source_set_string (BibtexSource * source,
			  gchar * key,
			  BibtexStruct * value) {
    gchar * inskey = key;
    BibtexStruct * oldstruct = NULL;

    g_return_if_fail (source != NULL);
    g_return_if_fail (key != NULL);

    if ((oldstruct = g_hash_table_lookup (source->table, inskey)) == NULL) {
	inskey = g_strdup (key);
	g_strdown (inskey);
    }
    else {
	bibtex_struct_destroy (oldstruct, TRUE);
    }

    g_hash_table_insert (source->table, inskey, value);
}

void           
bibtex_source_destroy (BibtexSource * source,
		       gboolean free_data) {
    g_return_if_fail (source != NULL);

    g_hash_table_foreach (source->table, freedata, (gpointer) free_data);
    g_hash_table_destroy (source->table);

    reset_source (source);

    g_free (source);
}


gboolean
bibtex_source_file (BibtexSource * source, 
		    gchar * filename) {
    FILE * fh = NULL;

    g_return_val_if_fail (source != NULL, FALSE);
    g_return_val_if_fail (filename != NULL, FALSE);
    
    fh = fopen (filename, "r");
    if (fh == NULL) {
	bibtex_error ("can't open file `%s': %s",
		      filename,
		      g_strerror (errno));
	return FALSE;
    }

    reset_source (source);

    source->type = BIBTEX_SOURCE_FILE;
    source->name = g_strdup (filename);
    source->source.file = fh;
    
    bibtex_analyzer_initialize (source);

    return TRUE;
}


gboolean
bibtex_source_string (BibtexSource * source, 
		      gchar * name,
		      gchar * string) {
    g_return_val_if_fail (source != NULL, FALSE);
    g_return_val_if_fail (string != NULL, FALSE);

    reset_source (source);

    source->type = BIBTEX_SOURCE_STRING;

    if (name) {
	source->name = g_strdup (name);
    }
    else {
	source->name = g_strdup ("<string>");
    }

    source->source.string = g_strdup (string);
    
    bibtex_analyzer_initialize (source);

    return TRUE;
}

void 
bibtex_source_rewind (BibtexSource * file) {

    bibtex_source_set_offset (file, 0);
}

gint 
bibtex_source_get_offset (BibtexSource * file) {
    g_return_val_if_fail (file != NULL, -1);

    return file->offset;
}
    
void
bibtex_source_set_offset (BibtexSource * file, 
			  gint offset) {
    g_return_if_fail (file != NULL);

    bibtex_analyzer_finish (file);

    switch (file->type) {
    case BIBTEX_SOURCE_FILE:
	if (fseek (file->source.file, offset, SEEK_SET) == -1) {
	    bibtex_error ("%s: can't jump to offset %d: %s", 
			  file->name,
			  offset, g_strerror (errno));
	    file->error = TRUE;
	    return;
	}
	break;

    case BIBTEX_SOURCE_STRING:
	break;

    case BIBTEX_SOURCE_NONE:
	g_warning ("no source to set offset");
	break;
    }

    file->offset = offset;
    file->eof    = file->error = FALSE;

    bibtex_analyzer_initialize (file);
}