/*
 * Copyright (c) 2011-2012 - Mauro Carvalho Chehab
 * Copyright (c) 2012-2014 - Andre Roth <neolynx@gmail.com>
 *
 * 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 version 2
 * of the License.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 * Or, point your browser to http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 *
 */

#include <libdvbv5/pat.h>
#include <libdvbv5/descriptors.h>
#include <libdvbv5/dvb-fe.h>

ssize_t dvb_table_pat_init(struct dvb_v5_fe_parms *parms, const uint8_t *buf,
			ssize_t buflen, struct dvb_table_pat **table)
{
	const uint8_t *p = buf, *endbuf = buf + buflen;
	struct dvb_table_pat *pat;
	struct dvb_table_pat_program **head;
	size_t size;

	size = offsetof(struct dvb_table_pat, programs);
	if (p + size > endbuf) {
		dvb_logerr("%s: short read %zd/%zd bytes", __func__,
			   endbuf - p, size);
		return -1;
	}

	if (buf[0] != DVB_TABLE_PAT) {
		dvb_logerr("%s: invalid marker 0x%02x, sould be 0x%02x",
				__func__, buf[0], DVB_TABLE_PAT);
		return -2;
	}

	if (!*table) {
		*table = calloc(sizeof(struct dvb_table_pat), 1);
		if (!*table) {
			dvb_logerr("%s: out of memory", __func__);
			return -3;
		}
	}
	pat = *table;
	memcpy(pat, buf, size);
	p += size;
	dvb_table_header_init(&pat->header);

	/* find end of current list */
	head = &pat->program;
	while (*head != NULL)
		head = &(*head)->next;

	size = pat->header.section_length + 3 - DVB_CRC_SIZE; /* plus header, minus CRC */
	if (buf + size > endbuf) {
		dvb_logerr("%s: short read %zd/%zd bytes", __func__,
			   endbuf - buf, size);
		return -4;
	}
	endbuf = buf + size;

	size = offsetof(struct dvb_table_pat_program, next);
	while (p + size <= endbuf) {
		struct dvb_table_pat_program *prog;

		prog = malloc(sizeof(struct dvb_table_pat_program));
		if (!prog) {
			dvb_logerr("%s: out of memory", __func__);
			return -5;
		}

		memcpy(prog, p, size);
		p += size;

		bswap16(prog->service_id);

		if (prog->pid == 0x1fff) { /* ignore null packets */
			free(prog);
			break;
		}
		bswap16(prog->bitfield);
		pat->programs++;

		prog->next = NULL;

		*head = prog;
		head = &(*head)->next;
	}
	if (endbuf - p)
		dvb_logwarn("%s: %zu spurious bytes at the end",
			   __func__, endbuf - p);
	return p - buf;
}

void dvb_table_pat_free(struct dvb_table_pat *pat)
{
	struct dvb_table_pat_program *prog = pat->program;

	while (prog) {
		struct dvb_table_pat_program *tmp = prog;
		prog = prog->next;
		free(tmp);
	}
	free(pat);
}

void dvb_table_pat_print(struct dvb_v5_fe_parms *parms, struct dvb_table_pat *pat)
{
	struct dvb_table_pat_program *prog = pat->program;

	dvb_loginfo("PAT");
	dvb_table_header_print(parms, &pat->header);
	dvb_loginfo("|\\ %d program pid%s", pat->programs, pat->programs != 1 ? "s" : "");

	while (prog) {
		dvb_loginfo("|  pid 0x%04x: service 0x%04x", prog->pid, prog->service_id);
		prog = prog->next;
	}
}