/*
 * File      : rtc.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006 - 2012, RT-Thread Development Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rt-thread.org/license/LICENSE
 *
 * Change Logs:
 * Date           Author       Notes
 * 2012-01-29     aozima       first version.
 * 2012-04-12     aozima       optimization: find rtc device only first.
 * 2012-04-16     aozima       add scheduler lock for set_date and set_time.
 */

#include <time.h>
#include <string.h>
#include <rtthread.h>

/** \brief returns the current time.
 *
 * \param time_t * t the timestamp pointer, if not used, keep NULL.
 * \return time_t return timestamp current.
 *
 */
/* for IAR 6.2 later Compiler */
#if defined (__IAR_SYSTEMS_ICC__) &&  (__VER__) >= 6020000
#pragma module_name = "?time"
time_t (__time32)(time_t *t) /* Only supports 32-bit timestamp */
#else
time_t time(time_t* t)
#endif
{
    static rt_device_t device = RT_NULL;
    time_t time_now = 0;

    /* optimization: find rtc device only first. */
    if (device == RT_NULL)
    {
        device = rt_device_find("rtc");
    }

    /* read timestamp from RTC device. */
    if (device != RT_NULL)
    {
        rt_device_control(device, RT_DEVICE_CTRL_RTC_GET_TIME, &time_now);
    }

    /* if t is not NULL, write timestamp to *t */
    if (t != RT_NULL)
    {
        *t = time_now;
    }

    return time_now;
}

/** \brief set system date(time not modify).
 *
 * \param rt_uint32_t year  e.g: 2012.
 * \param rt_uint32_t month e.g: 12 (1~12).
 * \param rt_uint32_t day   e.g: e.g: 31.
 * \return rt_err_t if set success, return RT_EOK.
 *
 */
rt_err_t set_date(rt_uint32_t year, rt_uint32_t month, rt_uint32_t day)
{
    time_t now;
    struct tm * p_tm;
    struct tm tm_new;
    rt_device_t device;

    /* get current time */
    now = time(RT_NULL);

    /* lock scheduler. */
    rt_enter_critical();
    /* converts calendar time time into local time. */
    p_tm = localtime(&now);
    /* copy the statically located variable */
    memcpy(&tm_new, p_tm, sizeof(struct tm));
    /* unlock scheduler. */
    rt_exit_critical();

    /* update date. */
    tm_new.tm_year = year - 1900;
    tm_new.tm_mon  = month - 1; /* tm_mon: 0~11 */
    tm_new.tm_mday = day;

    /* converts the local time in time to calendar time. */
    now = mktime(&tm_new);

    device = rt_device_find("rtc");
    if (device == RT_NULL)
    {
        return -RT_ERROR;
    }

    /* update to RTC device. */
    return rt_device_control(device, RT_DEVICE_CTRL_RTC_SET_TIME, &now);
}

/** \brief set system time(date not modify).
 *
 * \param rt_uint32_t hour   e.g: 0~23.
 * \param rt_uint32_t minute e.g: 0~59.
 * \param rt_uint32_t second e.g: 0~59.
 * \return rt_err_t if set success, return RT_EOK.
 *
 */
rt_err_t set_time(rt_uint32_t hour, rt_uint32_t minute, rt_uint32_t second)
{
    time_t now;
    struct tm * p_tm;
    struct tm tm_new;
    rt_device_t device;

    /* get current time */
    now = time(RT_NULL);

    /* lock scheduler. */
    rt_enter_critical();
    /* converts calendar time time into local time. */
    p_tm = localtime(&now);
    /* copy the statically located variable */
    memcpy(&tm_new, p_tm, sizeof(struct tm));
    /* unlock scheduler. */
    rt_exit_critical();

    /* update time. */
    tm_new.tm_hour = hour;
    tm_new.tm_min  = minute;
    tm_new.tm_sec  = second;

    /* converts the local time in time to calendar time. */
    now = mktime(&tm_new);

    device = rt_device_find("rtc");
    if (device == RT_NULL)
    {
        return RT_ERROR;
    }

    /* update to RTC device. */
    return rt_device_control(device, RT_DEVICE_CTRL_RTC_SET_TIME, &now);
}

#ifdef RT_USING_FINSH
#include <finsh.h>

void list_date(void)
{
    time_t now;

    now = time(RT_NULL);
    rt_kprintf("%s\n", ctime(&now));
}
FINSH_FUNCTION_EXPORT(list_date, show date and time.)

FINSH_FUNCTION_EXPORT(set_date, set date. e.g: set_date(2010,2,28))
FINSH_FUNCTION_EXPORT(set_time, set time. e.g: set_time(23,59,59))
#endif