/*
 * 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_init_h__
#define _ttail_init_h__

#include <ctype.h>
#include <errno.h>
#include <getopt.h>
#include <regex.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>

#include "ttail.h"

/**@todo set logfiles as "leadings" option */
#define TTAIL_LONG_OPT {\
	{"date-min", required_argument, 0, 'd'},\
	{"date-max", required_argument, 0, 'm'},\
	{"date-format", required_argument, 0, 'f'},\
	{"prefix-len", required_argument, 0, 'p'},\
	{"re-prefix", required_argument, 0, 'r'},\
	{"re-extended", no_argument, 0, 'E'},\
	{"re-ignore-case", no_argument, 0, 'i'},\
	{"permissive", no_argument, 0, 'P'},\
	{"verbose", no_argument, 0, 'v'},\
	{"help", no_argument, 0, 'h'},\
	{0,	0,	0,	0 }\
}
#define TTAIL_SHORT_OPT "vr:Eip:f:d:l:m:Ph"

#define TTAIL_OPT_HELP {\
	{"Start to output loglines starting from this date","DATE"},\
	{"Stop to output loglines before this date","DATE"},\
	{"Set the date format (see man strptime for supported date formats"\
,"FORMAT"},\
	{"Indicate to strip a fixed len prefix","CHAR_COUNT"},\
	{"Matched part of logline will be stripped","REGEX"},\
	{"Interpret REGEX as an extended regular expression (specified by \
POSIX) ",NULL},\
	{"Ignore  case  distinctions (specified by POSIX)",NULL},\
	{"Tell ttail to not stop on loglines not formatted as expected",NULL},\
	{"Augment the verbosity level",NULL},\
	{"Print this help and exit",NULL},\
	{"",NULL}\
}

#define TTAIL_HELP_TEXT "\tLOGFILES\n\t\tLogfiles, can take '-' as value to \
tell ttail to read from stdin instead of files\n\n\
Date formats\n\n\
\tTwo date formats are allowed for dates arguments (-d , -m) :\n\
\t- the same than in the logfile\n\
\t- relative from now prefixing the argument with '#-' and given a unit\n\
\t\t- y : year\n\
\t\t- M : Month\n\
\t\t- d : day\n\
\t\t- h : hour\n\
\t\t- m : min\n\
\t\t- s : sec\n\
"

#define TTAIL_NORMDATE(ttail,tm,FIELD) {\
	if(ttail->flag & TTAIL_FLAG_DATE_MIN && (tm)->FIELD == -1)\
	{ ttail->date_min.FIELD = -1; }\
	if(ttail->flag & TTAIL_FLAG_DATE_MAX && (tm)->FIELD == -1)\
	{ ttail->date_max.FIELD = -1; }\
}

/**<! Print help & usage */
void usage();

/**@brief Parse cli arguments and return a ttail_t
 *@param int argc
 *@param char** argv
 *@return NULL on error
 */
ttail_t *ttail_init(int, char**);

/**@brief Checks that init returns a valid ttail_t runtime
 *@param ttail_t* t
 *@return 0 if no error -1 if fatal error
 */
int ttail_init_check(ttail_t*);

/**@brief Add a logfile
 *@param ttail_t*
 *@param const char * filename
 *@return 0 if no errors 1 if unable to open file -1 if fatal error
 */
int ttail_add_logfile(ttail_t*, const char*);

/**@brief Set a date prefix regex
 *@param ttail_t*
 *@param const char * regex
 *@return 0 if no errors 1 if allready set -1 if compilation fails
 */
int ttail_set_prefix(ttail_t*, const char*);

/**@brief Set a date format
 *
 * The supported input field descriptors are listed below.  In case a text string (such as the name
 * of a day of the week or a month name) is to be matched, the comparison is case insensitive.   In
 * case a number is to be matched, leading zeros are permitted but not required.
 * 
 * \%%     The % character.
 * 
 * \%a or %A
 * The  name  of the day of the week according to the current locale, in abbreviated form or
 * the full name.
 * 
 * \%b or %B or %h
 * The month name according to the current locale, in abbreviated form or the full name.
 * 
 * \%c     The date and time representation for the current locale.
 * 
 * \%C     The century number (0-99).
 * 
 * \%d or %e
 * The day of month (1-31).
 * 
 * \%D     Equivalent to %m/%d/%y.  (This is the American style date, very confusing  to  non-Ameri‐
 * cans,  especially  since %d/%m/%y is widely used in Europe.  The ISO 8601 standard format
 * is %Y-%m-%d.)
 * 
 * \%H     The hour (0-23).
 * 
 * \%I     The hour on a 12-hour clock (1-12).
 * 
 * \%j     The day number in the year (1-366).
 * 
 * \%m     The month number (1-12).
 * 
 * \%M     The minute (0-59).
 * 
 * \%n     Arbitrary whitespace.
 * 
 * \%p     The locale's equivalent of AM or PM.  (Note: there may be none.)
 * 
 * \%r     The 12-hour clock time (using the locale's AM or PM).  In the POSIX locale equivalent  to
 * \%I:%M:%S  %p.  If t_fmt_ampm is empty in the LC_TIME part of the current locale, then the
 * behavior is undefined.
 * 
 * \%R     Equivalent to %H:%M.
 * 
 * \%S     The second (0-60; 60 may occur for leap seconds; earlier also 61 was allowed).
 * 
 * \%t     Arbitrary whitespace.
 * 
 * \%T     Equivalent to %H:%M:%S.
 * 
 * \%U     The week number with Sunday the first day of the week (0-53).  The first Sunday of  Janu‐
 * ary is the first day of week 1.
 * 
 * \%w     The ordinal number of the day of the week (0-6), with Sunday = 0.
 * 
 * \%W     The  week number with Monday the first day of the week (0-53).  The first Monday of Janu‐
 * ary is the first day of week 1.
 * 
 * \%x     The date, using the locale's date format.
 * 
 * \%X     The time, using the locale's time format.
 * 
 * \%y     The year within century (0-99).  When a century is not otherwise specified, values in the
 * range  69-99  refer  to  years  in the twentieth century (1969-1999); values in the range
 * 00-68 refer to years in the twenty-first century (2000-2068).
 * 
 * \%Y     The year, including century (for example, 1991).
 * 
 * Some field descriptors can be modified by the E or O modifier characters  to  indicate  that  an
 * alternative  format or specification should be used.  If the alternative format or specification
 * does not exist in the current locale, the unmodified field descriptor is used.
 * 
 * 
 * The E modifier specifies that the input string may contain alternative locale-dependent versions
 * of the date and time representation:
 * 
 * \%Ec    The locale's alternative date and time representation.
 * 
 * \%EC    The name of the base year (period) in the locale's alternative representation.
 * 
 * \%Ex    The locale's alternative date representation.
 * 
 * \%EX    The locale's alternative time representation.
 * 
 * \%Ey    The offset from %EC (year only) in the locale's alternative representation.
 * 
 * \%EY    The full alternative year representation.
 * 
 * The O modifier specifies that the numerical input may be in an alternative locale-dependent for‐
 * mat:
 * 
 * \%Od or %Oe
 * The day of the month using the locale's alternative numeric symbols;  leading  zeros  are
 * permitted but not required.
 * 
 * \%OH    The hour (24-hour clock) using the locale's alternative numeric symbols.
 * 
 * \%OI    The hour (12-hour clock) using the locale's alternative numeric symbols.
 * 
 * \%Om    The month using the locale's alternative numeric symbols.
 * 
 * \%OM    The minutes using the locale's alternative numeric symbols.
 * 
 * \%OS    The seconds using the locale's alternative numeric symbols.
 * 
 * \%OU    The  week  number  of  the  year (Sunday as the first day of the week) using the locale's
 * alternative numeric symbols.
 * 
 * \%Ow    The ordinal number of the day of the week (Sunday=0),
 * using the locale's alternative numeric symbols.
 * 
 * \%OW    The week number of the year (Monday as the first day of  the  week)  using  the  locale's
 * alternative numeric symbols.
 * 
 * \%Oy    The year (offset from %C) using the locale's alternative numeric symbols.
 *
 *
 *@param ttail_t*
 *@param const char * format
 *@return 0 if no errors 1 if allready set -1 if compilation fails
 */
int ttail_set_fmt(ttail_t*, const char*);

/**@brief Set the extended regex flag
 *@param ttail ttail_t*
 *@return -1 on error else 0
 */
int ttail_set_flag_re_ex(ttail_t*);

/**@brief Set the case insensitive regex flag
 *@param ttail ttail_t*
 *@return -1 on error else 0
 */
int ttail_set_flag_re_ci(ttail_t*);

/**@brief Set dates min/max
 *
 *After the call dates are free and set to NULL except if error
 *@param ttail_t ttail instance
 *@param char*[2] dates {min,max} both can be NULL
 *@return -1 if error 0 else
 */
int ttail_set_dates(ttail_t*, char*[2]);

/**@brief Set a date using format or format detection
 *
 *@param ttail_t ttail instance
 *@param char*[2] dates {min,max} both can be NULL
 *@param int c the date id to handle
 *@return -1 if error 0 else
 */
int _ttail_set_date_fmt(ttail_t*, char*, int);

/**@brief Set a ttail_t date in relative format
 *
 * The function will set values for date_min or date_max given a relative 
 * format (described bellow) from now (returned by localtime() )
 *
 *Relative date formats are "-#", an integer followed by a unit. Regcognized
 *units are :
 *- y[ear]
 *- M[onth]
 *- d[ay]
 *- h[our]
 *- m[in]
 *- s[ec]
 *
 *Examples :
 *- -#2s
 *- -#3Month
 *@param ttail_t ttail instance
 *@param char*[2] dates {min,max} both can be NULL
 *@param int c the date id to handle
 *@return -1 if error 0 else
 *@todo checks
 */
int _ttail_set_date_relative(ttail_t*, char*, int);

/**@brief Normalize dates using ttail.fmt
 *
 *When dates are relatives from now all the struct tm fields are set. In 
 *logfiles year or seconds can be missing from date format. In those case we 
 *have to set to -1 missing fields
 *@note must be called after arg parsing, ttail_set_dates() calls and
 *ttail_format_guess() calls
 *@param ttail_t* An initialized ttail_t
 *@return -1 if error 0 else
 */
int ttail_norm_dates(ttail_t*);

/**@brief Attempt to guess a dateformat
 *@param const char* date as a dtring
 *@param struct tm* if non NULL will be set to detected date
 *@return -1 if no guess else id in TTAIL_DEFAULT_FORMATS
 */
int ttail_format_guess(const char*, struct tm*);


void ttail_free(ttail_t*);


#endif