/**
 * Copyright © 2015  Mattias Andrée <maandree@member.fsf.org>
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */
#include "daemon.h"
#include <sys/file.h>
#include <sys/stat.h>



/**
 * Subroutine to the sat daemon: add job.
 * 
 * @param   argc  Should be 3.
 * @param   argv  The name of the process, the pathname of the socket,
 *                and the pathname to the state file.
 * @return  0     The process was successful.
 * @return  1     The process failed queuing the job.
 */
int
main(int argc, char *argv[])
{
	size_t n = 0, elements = 0, i;
	ssize_t r;
	char *message = NULL;
	int msg_argc;
	int rc = 0;
	struct job *job = NULL;
	struct stat attr;

	assert(argc == 3);
	t (reopen(STATE_FILENO, O_RDWR));

	/* Receive and validate message. */
	t (readall(SOCK_FILENO, &message, &n));
	shutdown(SOCK_FILENO, SHUT_RD);
	t (n < sizeof(int) + sizeof(clockid_t) + sizeof(struct timespec));
	n -= sizeof(int) + sizeof(clockid_t) + sizeof(struct timespec);
	msg_argc = *(int *)(message + n);
	t ((msg_argc < 1) || !n || message[n - 1]);
	for (i = n; i--; elements += !message[i]);
	t (elements < (size_t)msg_argc);

	/* Parse message. */
	t (!(job = malloc(sizeof(*job) + n)));
	job->argc = msg_argc;
	job->clk = *(clockid_t *)(message + n + sizeof(int));
	job->ts = *(struct timespec *)(message + n + sizeof(int) + sizeof(clockid_t));
	job->n = n;
	memcpy(job->payload, message, n);

	/* Update state file. */
	t (flock(STATE_FILENO, LOCK_EX));
	t (fstat(STATE_FILENO, &attr));
	r = preadn(STATE_FILENO, &(job->no), sizeof(job->no), 0);
	t (r < 0);
	if (r < (ssize_t)sizeof(job->no))
		job->no = 0;
	else
		job->no += 1;
	t (pwriten(STATE_FILENO, &(job->no), sizeof(job->no), 0) < (ssize_t)sizeof(job->no));
	if (attr.st_size < (off_t)sizeof(job->no))
		attr.st_size = (off_t)sizeof(job->no);
	n += sizeof(*job);
	t (pwriten(STATE_FILENO, job, n, attr.st_size) < (ssize_t)n);
	fsync(STATE_FILENO);
	t (flock(STATE_FILENO, LOCK_UN));

done:
	/* Cleanup. */
	shutdown(SOCK_FILENO, SHUT_WR);
	close(SOCK_FILENO);
	close(STATE_FILENO);
	free(message);
	free(job);
	return rc;
fail:
	if (send_string(SOCK_FILENO, STDERR_FILENO, argv[0], ": ", strerror(errno), "\n", NULL))
		perror(argv[0]);
	rc = 1;
	goto done;

	(void) argc;
}