//=============================================================================
// drt/sys/itime1.cpp
//	DRT primitive date and time classes.
//	This contains the O/S-dependent implementation code for class DrtTime.
//
// History
//	0.01, 1999-02-27, David R Tribble.
//	First cut.
//
// Copyright ©1999, by David R. Tribble, all rights reserved.
// See "drt/sys/copyr.txt" for more information.
//-----------------------------------------------------------------------------


// Identification

static const char	id[] =
    "@(#)drt/sys/itime1.cpp 0.01";


// System includes

#include <assert.h>
#define drt_std_assert_h	1

#include <time.h>
#define drt_std_time_h		1


// Special includes

#include "sdefs.hpp"


// System-specific includes

#if DRT_OS_UNIX
 #ifndef drt_std_sys_time_h
  #include <sys/time.h>
  #define drt_std_sys_time_h	1
 #endif
#elif DRT_OS_WIN32
 #ifndef drt_std_windows_h
  #define WIN32_LEAN_AND_MEAN	1
  #include <windows.h>
  #define drt_std_windows_h	1
 #endif
#endif


// Local includes

#include "sdebug.hpp"

#include "stime.hpp"


// Local wrappers

drt_namespace_begin


//-----------------------------------------------------------------------------
// Shared class functions
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// DrtTime::now()
//	Determine the current date and time, and set 'r' to this value.
//
// Returns
//	True if successful, otherwise false.
//-----------------------------------------------------------------------------

/*static*/
DrtTime DrtTime::now()
{
#if DrtTime_VS/100 != 1
#error DrtTime_VS has changed
#endif

    DrtTrace	dbg(s_grp, "now");
    DrtTime	t;

#if DRT_OS_UNIX
    //---------------------------------------------------------------------
    // The BSD gettimeofday() function fills a 'timeval' structure with the
    // current time_t value (which is the number of seconds since
    // AD1970-01-01 00:00:00 Z) and a microsecond count.  These time values
    // are directly convertible into DrtTime epoch tick counts.
    //
    // If the gettimeofday() function is not available, we can use the
    // POSIX.4 clock_gettime() function instead.
    //---------------------------------------------------------------------

    // Retrieve the current (system) date
    struct timeval	tv;

    // Get the current system time (secs & usecs)
    #if DRT_USE_POSIX_GETTIMEOFDAY
        clock_gettimeofday(&tv, null);
    #else
        gettimeofday(&tv, null);
    #endif

    // Convert to DrtTime form
    t.m_ticks =  AD1970;
    t.m_ticks += tv.tv_sec  * (drt_int64_t)TICKS_PER_SEC;
    t.m_ticks += tv.tv_usec * (drt_int64_t)(TICKS_PER_SEC/1000000);

    return (t);

#elif DRT_OS_WIN32
    //-------------------------------------------------------------------------
    // The Microsoft Win32 API can return the current system time in "file
    // timestamp" format, which is a 64-bit value representing the number of
    // 100-nanosecond ticks since AD1601-01-01 00:00:00 Z.  This time value is
    // directly convertible into a DrtTime epoch tick count.
    //-------------------------------------------------------------------------

    // Retrieve the current (system) date
    FILETIME	ft;

    // Get the current system time
    GetSystemTimeAsFileTime(&ft);	// Not GetSystemTime(&st)

    // Convert to DrtTime form
    drt_int64_t		x;

    x = ((drt_int64_t)ft.dwHighDateTime << 32) + ft.dwLowDateTime;
    t.m_ticks =  AD1601;
    t.m_ticks += x;

    return (t);

#elif DRT_OS_ISO
    //-------------------------------------------------------------------------
    // If all else fails, we can use the ISO C/C++ time() function to get the
    // current system time.
    //
    // Unfortunately, the only thing we know (portably) about the value is that
    // the time_t type is arithmetic.  This isn't much help for converting the
    // value into DrtTime epoch tick counts.
    //
    // We can, however, convert the time_t value into a broken-down 'tm'
    // structure, and then convert that back into a DrtTime value.  What a
    // pain.
    //-------------------------------------------------------------------------

    // Retrieve the current (system) date
    time_t	t;
    struct tm	st;

    // Get the current system time (secs & usecs)
    time(&t);

REDO
    // Convert to broken-down (expanded) form
    st = *gmtime(&t);

REDO
    r->m_year = st.tm_year+1900;
    r->m_mon =  st.tm_mon;
    r->m_mday = st.tm_mday;
    r->m_hour = st.tm_hour;
    r->m_min =  st.tm_min;
    r->m_sec =  st.tm_sec;
    r->m_usec = 0;

    return (true);

#else
    #error Unknown O/S

    return (0);

#endif
}


drt_namespace_end


//=============================================================================
// Test code
//-----------------------------------------------------------------------------

#if TEST


//-----------------------------------------------------------------------------
// ::main()
//	Test driver.
//-----------------------------------------------------------------------------

int main(int argc, char **argv)
{
    printf("Create a DrtTime object...\n");

    drt_namespace::DrtTime	t;

    printf("Get the current time and time...\n");
    t = t.now();

    {
        union /*anonymous*/
        {
            drt_int64_t		t;
            unsigned char	b[sizeof(drt_int64_t)];
        }	u;

        u.t = t.ticks();

    #if DRT_BYTE_HL
        for (int i = 0;  i < sizeof(u.t);  i++)
            printf(" %02X", u.b[i]);
    #else
        for (int i = sizeof(u.t)-1;  i >= 0;  i--)
            printf(" %02X", u.b[i]);
    #endif
        printf("\n");
    }

    return (0);
}


#endif // TEST

// End itime1.cpp