/*
    Library for inifile like data files.
    
    Copyright (C) 2006 Olaf Klein, o.b.klein@gpsbabel.org

    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 USA
*/

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "defs.h"
#include "inifile.h"

#define MYNAME "inifile"

typedef struct inifile_entry_s
{
	queue Q;
	char *key;
	char *val;
} inifile_entry_t;

typedef struct inifile_section_s
{
	queue Q;
	char *name;
	int ientries;
	queue entries;
} inifile_section_t;

/* internal procedures */

#define START_BUFSIZE 257
#define DELTA_BUFSIZE 128

#define GPSBABEL_INIFILE "gpsbabel.ini"

/* Remember the filename we used so we can include it in errors. */
char *gbinipathname;

static char *
find_gpsbabel_inifile(const char *path)		/* can be empty or NULL */
{
	FILE *test;
	char *buff;
	int len;

	if (path == NULL) return NULL;
		
	len = strlen(path);
	buff = xmalloc(len + 1 + strlen(GPSBABEL_INIFILE) + 1);
	strcpy(buff, path);
	if (len > 0) {
		char test = buff[len - 1];
#ifdef __WIN32__
		if ((test != '\\') && (test != ':'))
			strcat(buff, "\\");
#else
		if (test != '/')
			strcat(buff, "/");
#endif
	}
	strcat(buff, GPSBABEL_INIFILE);
	test = fopen(buff, "rb");
	if (test) {
		fclose(test);
		return buff;
	}
	xfree(buff);
	return NULL;
}

static gbfile *
open_gpsbabel_inifile(void)
{
	char *name;
	char *envstr;
	gbfile *res = NULL;
	
	envstr = getenv("GPSBABELINI");
	if (envstr != NULL) {
		FILE *test;
		
		test = fopen(envstr, "r");
		if (test != NULL) {
			fclose(test);
			return gbfopen(envstr, "r", "GPSBabel");
		}
		warning("WARNING: GPSBabel-inifile, defined in environment, NOT found!\n");
		return NULL;
	}
	name = find_gpsbabel_inifile("");	/* PWD */
	if (name == NULL) {
#ifdef __WIN32__
		name = find_gpsbabel_inifile(getenv("APPDATA"));
		if (name == NULL) name = find_gpsbabel_inifile(getenv("WINDIR"));
		if (name == NULL) name = find_gpsbabel_inifile(getenv("SYSTEMROOT"));
#else
		if ((envstr = getenv("HOME")) != NULL) {
			char *path;
			
			path = xmalloc(strlen(envstr) + 11);
			strcpy(path, envstr);
			strcat(path, "/.gpsbabel");
			name = find_gpsbabel_inifile(path);
			xfree(path);
		}
		if (name == NULL) name = find_gpsbabel_inifile("/usr/local/etc");
		if (name == NULL) name = find_gpsbabel_inifile("/etc");
#endif
	}
	if (name != NULL) {
		res = gbfopen(name, "r", "GPSBabel");
		if (gbinipathname) {
			xfree(gbinipathname);
		}
		gbinipathname = name;
	}
	return res;
}

static void
inifile_load_file(gbfile *fin, inifile_t *inifile, const char *myname)
{
	char *buf;
	inifile_section_t *sec = NULL;
	
	while ((buf = gbfgetstr(fin)))
	{
		char *cin = lrtrim(buf);
		
		if (*cin == '\0') continue;			/* skip empty lines */
		if ((*cin == '#') || (*cin == ';')) continue;	/* skip comments */
		
		if (*cin == '[')
		{
			
			char *cend = strchr(++cin, ']');

			if (cend != NULL)
			{
				*cend = '\0';
				cin = lrtrim(cin);
			}
			if ((*cin == '\0') || (cend == NULL))
				fatal("%s: invalid section header '%s' in '%s'.\n", myname, cin, gbinipathname);
				
			sec = xcalloc(1, sizeof(*sec));
			
			sec->name = xstrdup(cin);
			QUEUE_INIT(&sec->entries);
			ENQUEUE_TAIL(&inifile->secs, &sec->Q);
			inifile->isecs++;
		}
		else
		{
			char *cx;
			inifile_entry_t *entry;
			
			if (sec == NULL)
				fatal("%s: missing section header in '%s'.\n", myname,gbinipathname);
			
			entry = xcalloc(1, sizeof(*entry));
			ENQUEUE_TAIL(&sec->entries, &entry->Q);
			sec->ientries++;
			
			cx = strchr(cin, '=');
			if (cx != NULL)
			{
				*cx = '\0';
				cin = lrtrim(cin);
			}
			
			entry->key = xstrdup(cin);
			
			if (cx != NULL)
			{
				cx = lrtrim(++cx);
				entry->val = xstrdup(cx);
			}
			else
				entry->val = xstrdup("");
		}
	}
}

static char *
inifile_find_value(const inifile_t *inifile, const char *sec_name, const char *key)
{
	queue *elem, *tmp;
	
	if (inifile == NULL) return NULL;
	
	QUEUE_FOR_EACH(&inifile->secs, elem, tmp)
	{
		inifile_section_t *sec = (inifile_section_t *) elem;
		
		if (case_ignore_strcmp(sec->name, sec_name) == 0)
		{
			queue *elem, *tmp;
			
			QUEUE_FOR_EACH(&sec->entries, elem, tmp)
			{
				inifile_entry_t *entry = (inifile_entry_t *) elem;
			
				if (case_ignore_strcmp(entry->key, key) == 0)
				{
					return entry->val;
				}
			}
		}
	}
	return NULL;
}

/* public procedures */

/*
	inifile_init:
	  reads inifile filename into memory
	  myname represents the calling module
	  
	  filename == NULL: try to open global gpsbabel.ini
 */
inifile_t *
inifile_init(const char *filename, const char *myname)
{
	inifile_t *result;
	gbfile *fin = NULL;
	
	if (filename == NULL) {
		fin = open_gpsbabel_inifile();
		if (fin == NULL) return NULL;
	}
	else fin = gbfopen(filename, "rb", myname);
	
	result = xcalloc(1, sizeof(*result));
	QUEUE_INIT(&result->secs);
	inifile_load_file(fin, result, myname);
	
	gbfclose(fin);
	return result;
}

void
inifile_done(inifile_t *inifile)
{
	if (inifile == NULL) return;
	
	if (inifile->isecs > 0) 
	{
		queue *elem, *tmp;
		
		QUEUE_FOR_EACH(&inifile->secs, elem, tmp) {
			inifile_section_t *sec = (inifile_section_t *) elem;
			
			if (sec->ientries > 0) {
				queue *elem, *tmp;
				
				QUEUE_FOR_EACH(&sec->entries, elem, tmp) {
					inifile_entry_t *entry = (inifile_entry_t *) elem;
					
					if (entry->key) xfree(entry->key);
					if (entry->val) xfree(entry->val);
					dequeue(elem);
					xfree(entry);
				}
			}
			dequeue(elem);
			if (sec->name) xfree(sec->name);
			xfree(sec);
		}
		xfree(inifile);
	}
	if (gbinipathname) {
		xfree(gbinipathname);
		gbinipathname = NULL;
	}
}

int 
inifile_has_section(const inifile_t *inifile, const char *section)
{
	queue *elem, *tmp;
	
	QUEUE_FOR_EACH(&inifile->secs, elem, tmp)
	{
		inifile_section_t *sec = (inifile_section_t *) elem;
		if (case_ignore_strcmp(sec->name, section) == 0)
			return 1;
	}
	return 0;
}

/* 
     inifile_readstr:
       returns NULL if not found, otherwise a pointer to the value of key ...
       all key values are valid entities until "inifile_done" 
 */

char *
inifile_readstr(const inifile_t *inifile, const char *section, const char *key)
{
	return inifile_find_value(inifile, section, key);
}

/* 
     inifile_readint:
       on success the value is stored into "*value" and "inifile_readint" returns 1,
       otherwise inifile_readint returns 0
 */
 
int 
inifile_readint(const inifile_t *inifile, const char *section, const char *key, int *value)
{
	char *str;
	
	str = inifile_find_value(inifile, section, key);
	
	if (str == NULL) {
		return 0;
	}
	
	if (value != NULL) {
		*value = atoi(str);
	}
	return 1;
}

/*
     inifile_readint_def:
       if found inifile_readint_def returns value of key, otherwise a default value "def"
 */

int 
inifile_readint_def(const inifile_t *inifile, const char *section, const char *key, const int def)
{
	int result;
	
	if (inifile_readint(inifile, section, key, &result) == 0) {
		return def;
	}
	else {
		return result;
	}
}