/*
 * Copyright 2017 Yann Weber
 * 
 * This file is part of Ttail.
 * 
 * Ttail 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 3 of the License, or
 * any later version.
 * 
 * Ttail 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 Ttail.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef _ttail_search_h__
#define _ttail_search_h__

#include <errno.h>
#include <string.h>
#include <time.h>
#include <regex.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

typedef union _ttail_search_u ttail_search_t;

#include "ttail.h"

typedef char* (*ttail_search_subst_f)(ttail_t*, const char*);

/**@brief Comparison results
 *
 * -1 if a < b, 1 if a > b, 0 if a == b, -2 if exception
 *
 * If an exception occur, exception flags are set with | on the result.
 * Exceptions flags are : TTAIL_NODATE_A and TTAIL_NODATE_B
 */
typedef int ttail_cmp_res;

#include "config.h"
#include "ttail_search_files.h"
#include "ttail_search_std.h"

/**@brief Search session is an union depending in the search method
 * employed
 */
union _ttail_search_u
{
	ttail_search_file_t file;
	ttail_search_stdin_t std;
};


/**@brief Init ttail search session
 *
 *If logfiles given as argument start a files session. Else a stdin session
 *is started
 *@param ttail_t* t
 *@return 0 on success -1 on error
 */
int ttail_search_init_session(ttail_t*);

/**@brief Begin a search session placing it in a ready to print situation
 *@param ttail_t*
 *@param struct tm* tmin
 *@return 0 if ok -1 if fatal error 1 if not found
 */
int ttail_search_closest(ttail_t*);

/**@brief Print search result on t->out_fd
 *@param ttail_t*
 */
void ttail_search_print_res(ttail_t*);

/**@brief Loglines comparison function
 *@param ttail_t* ttail
 *@param const char* logline a
 *@param const char* logline b
 *@return @ref ttail_cmp_res
 */
ttail_cmp_res ttail_cmp_loglines(ttail_t*, const char*, const char*);

/**@brief Fetch a date from a logline
 *@param ttail_t* ttail
 *@param const char* logline
 *@param struct tm* tm will be set to extracted date if not NULL
 *@return 0 if ok, -1 if error 1 if no prefix found 2 if no date found
 */
int ttail_logline2date(ttail_t*, const char*, struct tm*);

/**@brief Apply the choosen substitution to the logline
 *@param ttail_t* ttail
 *@param const char* logline
 *@return a pointer on the end of the subst string or NULL if subst fails
 */
const char* ttail_logline_subst(ttail_t*, const char*);

/**@brief Compare two struct tm
 *@param a struct tm*
 *@param b struct tm*
 *@return <0 if a<b, >0 if a>b and 0 if a == b
 */
int ttail_tm_cmp(const struct tm*, const struct tm*);

/**<! Set all fields to -1 */
void ttail_tm_init(struct tm* tm);

/**@brief Print a struct tm on stdout
 *@param struct tm *
 */
void ttail_tm_print(const struct tm*);
void ttail_tm_fprint(FILE*, const struct tm*);

#endif