/*
 * 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/>.
 */
#include "ttail_search_std.h"

int TTAIL_STDIN_FD = 0;
FILE *TTAIL_STDIN = NULL;

int ttail_search_std_init(ttail_t* t)
{
	if(!TTAIL_STDIN_FD)
	{
		TTAIL_STDIN = stdin;
	}
	else
	{
		TTAIL_STDIN = fdopen(TTAIL_STDIN_FD, "r");
		if(!TTAIL_STDIN)
		{
			perror("Fail to open stdin");
			return -1;
		}
	}

	t->session = (ttail_search_t*)malloc(sizeof(ttail_search_stdin_t));
	if(!t->session)
	{
		perror("Unable to allocate memory for search session");
		return -1;
	}
	t->session->std.buff = NULL;
	t->session->std.buff_sz = 0;
	if(_ttail_search_std_fmt_init(t) < 0)
	{
		return -1;
	}
	return 0;
}

int _ttail_search_std_fmt_init(ttail_t* t)
{
	ssize_t rd_sz;
	const char *buff;
	int fmt_id, max_lines, i;
	const char *fmt[] = TTAIL_DEFAULT_FORMATS;

	if(t->flag & TTAIL_FLAG_FORMAT)
	{
		return 1;
	}

	max_lines = 10;
	
	for(i=0; i<max_lines; i++)
	{
		if((rd_sz = ttail_std_getline(t)) < 0)
		{
			fprintf(stderr, "Unable to detect date from stdin\n");
			return -1;
		}

		buff = ttail_logline_subst(t, ttail_std_getline_buff(t));
		if(!buff)
		{
			if(ttail_permissive(t))
			{
				continue;
			}

			fprintf(stderr, "Unable to find prefix in logline");
			if(t->verbose > 0)
			{
				fprintf(stderr, " : '%s'",
					ttail_std_getline_buff(t));
			}
			fprintf(stderr, "\n");
			return -1;
		}
		fmt_id = ttail_format_guess(buff, NULL);
		if(fmt_id >= 0)
		{
			break;
		}
		if(!ttail_permissive(t))
		{
			ttail_strict_msg();
			break;
		}
	}
	if(fmt_id < 0)
	{
		fprintf(stderr, "Unable to detect date format from stdin\
after %d lines were readed\n", max_lines);
		return -1;
	}
	buff = fmt[fmt_id];
	t->fmt = malloc(sizeof(char) *  (strlen(buff)+1));
	if(!t->fmt)
	{
		perror("Unable to allocate memory for date format");
		return -1;
	}
	strcpy(t->fmt, buff);
	t->flag |= TTAIL_FLAG_FORMAT;
	return 0;
}

int _ttail_search_closest_stdin(ttail_t* t)
{
	struct tm tm;
	ssize_t rd_sz;
	int ret, tmp;
	if(!(t->flag & TTAIL_FLAG_DATE_MIN))
	{
		return 0;
	}
	if(! t->session->std.buff)
	{
		if((rd_sz = ttail_std_getline(t)) < 0)
		{
			perror("Unable to read stdin");
			return -1;
		}
	}
	else
	{
		/*first line allready in the buffer thank's to format
		 *detection*/
		rd_sz = strlen(ttail_std_getline_buff(t)) + 1;
	}
	while(rd_sz > 0)
	{
		ttail_tm_init(&tm);
		ret = ttail_logline2date(t, ttail_std_getline_buff(t), &tm);
		if(ret < 0)
		{
			return -1;
		}
		else if(ret > 0)
		{
			if(!ttail_permissive(t))
			{
				fprintf(stderr,
					"Unable to find the %s in logline",
					ret==1?"prefix":"date");
				if(t->verbose > 0)
				{
					fprintf(stderr, " : '%s'\n",
						ttail_file_getline_buf(t));
				}
				else
				{
					fprintf(stderr, "\n");
				}
				ttail_strict_msg();
				return -1;
			}
			rd_sz = ttail_std_getline(t);
			continue;
		}
		ret = ttail_tm_cmp(&tm, &(t->date_min));
		if(ret >= 0)
		{
			//buffer contains the first line to print
			return 0;
		}
		rd_sz = ttail_std_getline(t);
	}
	if(rd_sz < 0)
	{
		tmp = errno;
		ret = feof(TTAIL_STDIN);
		if(ret <= 0)
		{
			errno = tmp;
			perror("Error while reading loglines from stdin");
			return -1;
		}
	}
	return 1;
}

void _ttail_search_print_stdin(ttail_t* t, int fd)
{
	struct tm tm;
	ssize_t rd_sz;
	int ret, tmp;
	
	rd_sz = strlen(ttail_std_getline_buff(t));
	if(!(t->flag & TTAIL_FLAG_DATE_MAX))
	{
		do
		{
			ret = write(1, ttail_std_getline_buff(t),
				sizeof(char)*rd_sz);
			if(ret < 0)
			{
				perror("Unable to write to stdout");
				return;
			}
		}
		while((rd_sz = ttail_std_getline(t)) > 0);
	}
	else
	{
		do
		{
			ttail_tm_init(&tm);
			ret = ttail_logline2date(t, ttail_std_getline_buff(t),
				&tm);
			//dropping errors
			if(ret == 0)
			{
				ret = ttail_tm_cmp(&tm, &(t->date_max));
				if(ret > 0)
				{
					return;
				}
			}
			ret = write(1, ttail_std_getline_buff(t),
				sizeof(char)*rd_sz);
			if(ret < 0)
			{
				perror("Unable to write to stdout");
				return;
			}
		}
		while((rd_sz = ttail_std_getline(t)) > 0);
	}
	if(rd_sz < 0)
	{
		tmp = errno;
		ret = feof(TTAIL_STDIN);
		if(ret <= 0)
		{
			errno = tmp;
			perror("Error while reading loglines from stdin");
		}
	}
	return;
}

void _ttail_search_stdin_free(ttail_t* t)
{
	if(TTAIL_STDIN)
	{
		fclose(TTAIL_STDIN);
	}
	if(t->session->std.buff)
	{
		free(t->session->std.buff);
	}
}

void _ttail_set_stdin(int std)
{
	TTAIL_STDIN_FD = std;
	TTAIL_STDIN = NULL;
}