/*
 * This is the main module for the basic fcup-smsend utility.
 */

#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include "../../rvinterf/include/exitcodes.h"

#define	MAX_MSG_CHARS	(153*255)

int sms_write_mode, text_mode, utf8_input, concat_enable;
u_char dest_addr[12];
char msgtext[MAX_MSG_CHARS*2+2];
u_char msgtext_gsm7[MAX_MSG_CHARS];
unsigned msgtext_gsmlen;
u_char concat_refno;

process_cmdline(argc, argv)
	char **argv;
{
	int c;
	extern int optind;
	extern char *optarg;

	while ((c = getopt(argc, argv, "B:C:np:RtuwWX:")) != EOF) {
		if (atinterf_cmdline_opt(c))
			continue;
		switch (c) {
		case 'C':
			concat_enable = 1;
			concat_refno = strtoul(optarg, 0, 0);
			continue;
		case 't':
			text_mode = 1;
			continue;
		case 'u':
			utf8_input = 1;
			continue;
		case 'w':
			sms_write_mode = 1;
			continue;
		case 'W':
			sms_write_mode = 2;
			continue;
		default:
			/* error msg already printed */
			exit(ERROR_USAGE);
		}
	}
	if (concat_enable && text_mode) {
		fprintf(stderr,
			"%s error: cannot send concat SMS in text mode\n",
			argv[0]);
		exit(ERROR_USAGE);
	}
	if (argc > optind + 2) {
		fprintf(stderr, "usage: %s [options] dest-addr [message]\n",
			argv[0]);
		exit(ERROR_USAGE);
	}
	if (!argv[optind] || !argv[optind][0]) {
		if (sms_write_mode == 2) {
			dest_addr[0] = 0;
			dest_addr[1] = 0x80;
		} else {
			fprintf(stderr,
			"error: destination address must be specified\n");
			exit(ERROR_USAGE);
		}
	} else if (parse_and_encode_dest_addr(argv[optind], dest_addr) < 0) {
		fprintf(stderr,
			"error: destination address argument is invalid\n");
		exit(ERROR_USAGE);
	}
	if (!argv[optind+1])
		return(0);
	if (strlen(argv[optind+1]) > MAX_MSG_CHARS*2) {
		fprintf(stderr, "error: message argument is too long\n");
		exit(ERROR_USAGE);
	}
	strcpy(msgtext, argv[optind+1]);
	return(1);
}

read_msgtext_from_stdin()
{
	unsigned pos, remain;
	int cc;

	pos = 0;
	remain = sizeof(msgtext);
	for (;;) {
		if (!remain) {
			fprintf(stderr,
				"error: message on stdin is too long\n");
			exit(ERROR_USAGE);
		}
		cc = read(0, msgtext + pos, remain);
		if (cc < 0) {
			fprintf(stderr, "error reading message from stdin\n");
			exit(ERROR_USAGE);
		}
		if (cc == 0)
			break;
		pos += cc;
		remain -= cc;
	}
	msgtext[pos] = '\0';
}

trim_trailing_newlines()
{
	char *cp;

	cp = index(msgtext, '\0');
	while (cp > msgtext && cp[-1] == '\n')
		cp--;
	*cp = '\0';
}

common_init()
{
	atinterf_init();
	/* enable verbose error messages */
	atinterf_exec_cmd_needok("AT+CMEE=2", 0, 0);
}

main(argc, argv)
	char **argv;
{
	int rc;
	unsigned nparts, n;
	u_char udh[5];
	unsigned pos, remain, chunk;

	if (!process_cmdline(argc, argv))
		read_msgtext_from_stdin();
	if (utf8_input && utf8_to_latin1(msgtext) < 0) {
		fprintf(stderr, "error: invalid UTF-8 message\n");
		exit(ERROR_USAGE);
	}
	trim_trailing_newlines();
	if (text_mode) {
		if (index(msgtext, '\n')) {
			fprintf(stderr,
		"error: multiline messages not supported in text mode\n");
			exit(ERROR_USAGE);
		}
		if (strlen(msgtext) > 160) {
too_long_for_one_sms:	fprintf(stderr, "error: message exceeds 160 chars\n");
			exit(ERROR_USAGE);
		}
		common_init();
		prep_for_text_mode();
		send_in_text_mode(dest_addr, msgtext);
		if (sms_write_mode == 1)
			sendafterwr_process();
		exit(0);
	}
	rc = latin1_to_gsm7(msgtext, msgtext_gsm7, MAX_MSG_CHARS,
				&msgtext_gsmlen);
	if (rc == -1) {
		fprintf(stderr, "error: message not valid for GSM7 charset\n");
		exit(ERROR_USAGE);
	}
	if (rc == -2) {
		fprintf(stderr, "error: message too long for max concat SMS\n");
		exit(ERROR_USAGE);
	}
	if (msgtext_gsmlen <= 160) {
		common_init();
		prep_for_pdu_mode();
		send_in_pdu_mode(dest_addr, msgtext_gsm7, msgtext_gsmlen, 0, 0);
		if (sms_write_mode == 1)
			sendafterwr_process();
		if (concat_enable)
			printf("Message sent as single SMS\n");
		exit(0);
	}
	if (!concat_enable)
		goto too_long_for_one_sms;
	nparts = (msgtext_gsmlen + 152) / 153;
	udh[0] = 0x00;
	udh[1] = 0x03;
	udh[2] = concat_refno;
	udh[3] = nparts;
	common_init();
	prep_for_pdu_mode();
	if (sms_write_mode == 0)
		atinterf_exec_cmd_needok("AT+CMMS=1", 0, 0);
	pos = 0;
	remain = msgtext_gsmlen;
	for (n = 1; n <= nparts; n++) {
		udh[4] = n;
		chunk = 153;
		if (chunk > remain)
			chunk = remain;
		send_in_pdu_mode(dest_addr, msgtext_gsm7 + pos, chunk, udh, 5);
		pos += chunk;
		remain -= chunk;
	}
	if (sms_write_mode == 0)
		atinterf_exec_cmd_needok("AT+CMMS=0", 0, 0);
	if (sms_write_mode == 1)
		sendafterwr_process();
	printf("Message sent as %u SMS segments\n", nparts);
	exit(0);
}