/* time.c
 *
 * $Id$
 *
 * Copyright 1990, 1991, 1992, 1993, 1994, 1995, Oliver Laumann, Berlin
 * Copyright 2002, 2003 Sam Hocevar <sam@hocevar.net>, Paris
 *
 * This software was derived from Elk 1.2, which was Copyright 1987, 1988,
 * 1989, Nixdorf Computer AG and TELES GmbH, Berlin (Elk 1.2 has been written
 * by Oliver Laumann for TELES Telematic Services, Berlin, in a joint project
 * between TELES and Nixdorf Microprocessor Engineering, Berlin).
 *
 * Oliver Laumann, TELES GmbH, Nixdorf Computer AG and Sam Hocevar, as co-
 * owners or individual owners of copyright in this software, grant to any
 * person or company a worldwide, royalty free, license to
 *
 *    i) copy this software,
 *   ii) prepare derivative works based on this software,
 *  iii) distribute copies of this software or derivative works,
 *   iv) perform this software, or
 *    v) display this software,
 *
 * provided that this notice is not removed and that neither Oliver Laumann
 * nor Teles nor Nixdorf are deemed to have made any representations as to
 * the suitability of this software for any purpose nor are held responsible
 * for any defects of this software.
 *
 * THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE.
 */

#include "unix.h"

#include <string.h>

#if !defined(HAVE_GETTIMEOFDAY) && defined(HAVE_FTIME)
#  include <sys/timeb.h>
#endif

#ifdef HAVE_GETTIMEOFDAY
#  include <sys/time.h>
#endif

extern time_t time();

static Object P_Decode_Time(Object t, Object ret, Object utc) {
    time_t tt;
    struct tm *tp;
    Object *op;

    Check_Result_Vector(ret, 9);
    Check_Type(utc, T_Boolean);
    tt = (time_t)Get_Unsigned_Long(t);
    tp = Truep(utc) ? gmtime(&tt) : localtime(&tt);
    op = VECTOR(ret)->data;
    *op++ = Make_Integer(tp->tm_sec);
    *op++ = Make_Integer(tp->tm_min);
    *op++ = Make_Integer(tp->tm_hour);
    *op++ = Make_Integer(tp->tm_mday);
    *op++ = Make_Integer(tp->tm_mon);
    *op++ = Make_Integer(tp->tm_year);
    *op++ = Make_Integer(tp->tm_wday);
    *op++ = Make_Integer(tp->tm_yday);
    *op++ = Make_Integer(tp->tm_isdst);
    return Void;
}

static Object P_Nanotime(Object ret) {
    Object x, y;
#ifdef HAVE_GETTIMEOFDAY
    struct timeval tv;
    struct timezone tz;
#else
#ifdef HAVE_FTIME
    struct timeb tb;
#else
    time_t now;
    int i;
#endif
#endif
    GC_Node2;

    x = Null;
    Check_Result_Vector(ret, 3);
    GC_Link2(ret, x);
#ifdef HAVE_GETTIMEOFDAY
    (void)gettimeofday(&tv, &tz);
    x = Cons(Null, Make_Unsigned_Long((unsigned long)tv.tv_usec * 1000));
    y = Make_Unsigned_Long((unsigned long)tv.tv_sec);
    Car(x) = y;
    VECTOR(ret)->data[0] = x;
    VECTOR(ret)->data[1] = Make_Integer(tz.tz_minuteswest);
    VECTOR(ret)->data[2] = Make_Integer(tz.tz_dsttime);
#else
#ifdef HAVE_FTIME
    (void)ftime(&tb);
    x = Cons(Null, Make_Unsigned_Long((unsigned long)tb.millitm * 1000000));
    y = Make_Unsigned_Long((unsigned long)tb.time);
    Car(x) = y;
    VECTOR(ret)->data[0] = x;
    VECTOR(ret)->data[1] = Make_Integer(tb.timezone);
    VECTOR(ret)->data[2] = Make_Integer(tb.dstflag);
#else
    (void)time(&now);
    x = Cons(Make_Unsigned_Long((unsigned long)now), Make_Integer(0));
    VECTOR(ret)->data[0] = x;
    VECTOR(ret)->data[1] = Make_Integer(0);
    VECTOR(ret)->data[2] = Make_Integer(0);
#endif
#endif
    GC_Unlink;
    return Void;
}

static Object P_Time() {
    time_t t = time((time_t *)0);
    return Make_Unsigned_Long((unsigned long)t);
}

static struct tm *Get_Tm(Object v) {
    static struct tm tm;
    int i, n;
    Object *op;
    static struct { int min, max; } bounds[] = {
        { 0, 61 },       /* sec */
        { 0, 59 },       /* min */
        { 0, 23 },       /* hour */
        { 1, 31 },       /* mday */
        { 0, 11 },       /* mon */
        { 0, 65535 },  /* year */
        { 0, 7 },        /* wday */
        { 0, 365 }       /* yday */
    };

    Check_Result_Vector(v, 9);
    for (op = VECTOR(v)->data, i = 0; i < 7; i++, op++)
        if ((n = Get_Integer(*op)) < bounds[i].min || n > bounds[i].max)
            Range_Error(*op);
    op = VECTOR(v)->data;
    tm.tm_sec   = Get_Integer(*op++);
    tm.tm_min   = Get_Integer(*op++);
    tm.tm_hour  = Get_Integer(*op++);
    tm.tm_mday  = Get_Integer(*op++);
    tm.tm_mon   = Get_Integer(*op++);
    tm.tm_year  = Get_Integer(*op++);
    tm.tm_wday  = Get_Integer(*op++);
    tm.tm_yday  = Get_Integer(*op++);
    tm.tm_isdst = Get_Integer(*op);
    return &tm;
}

static Object P_Time_To_String(Object t) {
    time_t tt;
    char *ret;

    switch (TYPE(t)) {
    case T_Fixnum: case T_Bignum:
        tt = (time_t)Get_Unsigned_Long(t);
        ret = ctime(&tt);
        break;
    case T_Vector:
        ret = asctime(Get_Tm(t));
        break;
    default:
        Wrong_Type_Combination(t, "integer or vector");
        /*NOTREACHED*/
    }
    return Make_String(ret, strlen(ret));
}

void elk_init_unix_time() {
    Def_Prim(P_Time,            "unix-time",                     0, 0, EVAL);
    Def_Prim(P_Decode_Time,     "unix-decode-time-vector-fill!", 3, 3, EVAL);
    Def_Prim(P_Time_To_String,  "unix-time->string-internal",    1, 1, EVAL);
    Def_Prim(P_Nanotime,        "unix-nanotime-vector-fill!",    1, 1, EVAL);
}