/*
 * (C) Copyright 2001
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

/*
 * RTC, Date & Time support: get and set date & time
 */
#include <common.h>
#include <string.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>


static const char * const weekdays[] = {
	"Sun", "Mon", "Tues", "Wednes", "Thurs", "Fri", "Satur",
};

int mk_date (const char *, struct rtc_time *);

command_ret_t do_date(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	struct rtc_time tm;
	int rcode = CMD_RET_SUCCESS;
	
	(void) cmdtp; (void) flag;

	switch (argc) {
	case 2:			/* set date & time */
		/* initialize tm with current time */
		rcode = rtc_get (&tm);

		if(!rcode) {
			/* insert new date & time */
			if (mk_date (argv[1], &tm) != 0) {
				my_puts_P(PSTR("## Bad date format\n"));
				break;
			}
			/* and write to RTC */
			rcode = rtc_set (&tm);
			if(rcode)
				my_puts_P(PSTR("## Set date failed\n"));
		} else {
			my_puts_P(PSTR("## Get date failed\n"));
		}
		/* FALL TROUGH */
	case 1:			/* get date & time */
		rcode = rtc_get (&tm);

		if (rcode) {
			my_puts_P(PSTR("## Get date failed\n"));
			break;
		}
		/* TODO: put weekdays[] in flash */
		printf_P(PSTR("Date: %4d-%02d-%02d (%sday)    Time: %2d:%02d:%02d\n"),
			tm.tm_year, tm.tm_mon, tm.tm_mday,
			(tm.tm_wday<0 || tm.tm_wday>6) ?
				"unknown " : weekdays[tm.tm_wday],
			tm.tm_hour, tm.tm_min, tm.tm_sec);

		break;
	default:
		rcode = CMD_RET_USAGE;
	}

	return rcode;
}

/*
 * simple conversion of two-digit string with error checking
 */
static int cnvrt2 (const char *str, int *valp)
{
	int val;

	if ((*str < '0') || (*str > '9'))
		return (-1);

	val = *str - '0';

	++str;

	if ((*str < '0') || (*str > '9'))
		return (-1);

	*valp = 10 * val + (*str - '0');

	return (0);
}

/*
 * Convert date string: MMDDhhmm[[CC]YY][.ss]
 *
 * Some basic checking for valid values is done, but this will not catch
 * all possible error conditions.
 */
int mk_date (const char *datestr, struct rtc_time *tmp)
{
	int len, val;
	char *ptr;

	ptr = strchr (datestr,'.');
	len = strlen (datestr);

	/* Set seconds */
	if (ptr) {
		int sec;

		*ptr++ = '\0';
		if ((len - (ptr - datestr)) != 2)
			return (-1);

		len = strlen (datestr);

		if (cnvrt2 (ptr, &sec))
			return (-1);

		tmp->tm_sec = sec;
	} else {
		tmp->tm_sec = 0;
	}

	if (len == 12) {		/* MMDDhhmmCCYY	*/
		int year, century;

		if (cnvrt2 (datestr+ 8, &century) ||
		    cnvrt2 (datestr+10, &year) ) {
			return (-1);
		}
		tmp->tm_year = 100 * century + year;
	} else if (len == 10) {		/* MMDDhhmmYY	*/
		int year, century;

		century = tmp->tm_year / 100;
		if (cnvrt2 (datestr+ 8, &year))
			return (-1);
		tmp->tm_year = 100 * century + year;
	}

	switch (len) {
	case 8:			/* MMDDhhmm	*/
		/* fall thru */
	case 10:		/* MMDDhhmmYY	*/
		/* fall thru */
	case 12:		/* MMDDhhmmCCYY	*/
		if (cnvrt2 (datestr+0, &val) ||
		    val > 12) {
			break;
		}
		tmp->tm_mon  = val;
		if (cnvrt2 (datestr+2, &val) ||
		    val > ((tmp->tm_mon==2) ? 29 : 31)) {
			break;
		}
		tmp->tm_mday = val;

		if (cnvrt2 (datestr+4, &val) ||
		    val > 23) {
			break;
		}
		tmp->tm_hour = val;

		if (cnvrt2 (datestr+6, &val) ||
		    val > 59) {
			break;
		}
		tmp->tm_min  = val;

		/* calculate day of week */
		GregorianDay (tmp);

		return (0);
	default:
		break;
	}

	return (-1);
}