/*
  duration.cc -- implement Duration

  source file of the LilyPond music typesetter

  (c) 1997--2004 Jan Nieuwenhuizen <janneke@gnu.org>
                 Han-Wen Nienhuys <hanwen@cs.uu.nl>

*/

#include <assert.h>

#include "misc.hh"
#include "lily-proto.hh"
#include "string.hh"
#include "moment.hh"
#include "duration.hh"
#include "ly-smobs.icc"


int
Duration::compare (Duration const &left, Duration const &right)
{
  return Rational::compare (left.get_length (), right.get_length ());
}

Duration::Duration ()
{
  durlog_ = 0;
  dots_ = 0;
  factor_ = Rational (1, 1);
}

Duration::Duration (int log, int d)
{
  durlog_ = log;
  dots_ = d;
  factor_ = Rational (1, 1);
}

Duration
Duration::compressed (Rational m) const
{
  Duration d (*this);
  d.factor_ *= m;
  return d;
}

Rational
Duration::get_length () const
{
  Rational mom (1 << abs (durlog_));

  if (durlog_> 0)
    mom = Rational (1) / mom;

  Rational delta = mom;
  for (int i = 0; i < dots_; i++)
    {
      delta /= Rational (2);
      mom += delta;
    }

  return mom * factor_;
}

String
Duration::to_string () const
{
  String s;

  if (durlog_ < 0  )
    s = "log = "  + ::to_string (durlog_);
  else
    s = ::to_string (1 << durlog_);

  s += ::to_string ('.', dots_);
  if (factor_ != Moment (Rational (1, 1)))
    s += "*" + factor_.to_string ();
  return s;
}


IMPLEMENT_TYPE_P (Duration, "ly:duration?");

SCM
Duration::mark_smob (SCM)
{
  return SCM_EOL;
}

IMPLEMENT_SIMPLE_SMOBS (Duration);
int
Duration::print_smob (SCM s, SCM port, scm_print_state *)
{
  Duration  *r = (Duration *) ly_cdr (s);

  scm_puts ("#<Duration ", port);
  scm_display (scm_makfrom0str (r->to_string ().to_str0 ()), port);
  scm_puts (" >", port);

  return 1;
}

SCM
Duration::equal_p (SCM a , SCM b)
{
  Duration  *p = (Duration *) ly_cdr (a);
  Duration  *q = (Duration *) ly_cdr (b);

  bool eq = p->dots_ == q->dots_
    && p->durlog_ == q->durlog_
    && p->factor_ == q->factor_;

  return eq ? SCM_BOOL_T : SCM_BOOL_F;
}

MAKE_SCHEME_CALLBACK (Duration, less_p, 2);
SCM
Duration::less_p (SCM p1, SCM p2)
{
  Duration *a = unsmob_duration (p1);
  Duration *b = unsmob_duration (p2);

  if (compare (*a, *b) < 0)
    return SCM_BOOL_T;
  else
    return SCM_BOOL_F;
}

LY_DEFINE (ly_duration_less_p, "ly:duration<?",
	   2, 0, 0, (SCM p1, SCM p2),
	  "Is @var{p1} shorter than @var{p2}?")
{
  Duration *a = unsmob_duration (p1);
  Duration *b = unsmob_duration (p2);

  SCM_ASSERT_TYPE (a, p1, SCM_ARG1, __FUNCTION__, "Duration");
  SCM_ASSERT_TYPE (b, p2, SCM_ARG2, __FUNCTION__, "Duration");

  if (Duration::compare (*a, *b) < 0)
    return SCM_BOOL_T;
  else
    return SCM_BOOL_F;
}

LY_DEFINE (ly_make_duration, "ly:make-duration",
	   1, 3, 0, (SCM length, SCM dotcount, SCM num, SCM den),
	   "@var{length} is the negative logarithm (base 2) of the duration:\n"
	   "1 is a half note, 2 is a quarter note, 3 is an eighth\n"
	   "note, etc.  The number of dots after the note is given by\n"
	   "the optional argument @var{dotcount}.\n"
	   "\n"
	   "The duration factor is optionally given by @var{num}\n"
	   "and @var{den}.\n\n"
	   "A duration is a musical duration, "
	   "i.e. a length of time described by a power of two "
	   "(whole, half, quarter, etc.) and a number of augmentation\n"
	   "dots. \n")
{
  SCM_ASSERT_TYPE (scm_integer_p (length) == SCM_BOOL_T,
		   length, SCM_ARG1, __FUNCTION__, "integer");

  int dots = 0;
  if (dotcount != SCM_UNDEFINED)
    {
      SCM_ASSERT_TYPE (scm_integer_p (dotcount) == SCM_BOOL_T,
		       dotcount, SCM_ARG2, __FUNCTION__, "integer");
      dots = scm_to_int (dotcount);
    }

  bool compress = false;
  if (num != SCM_UNDEFINED)
    {
      SCM_ASSERT_TYPE (scm_is_number (num), length, SCM_ARG3, __FUNCTION__, "integer");
      compress = true;
    }
  else
    num = scm_int2num (1);

  if (den != SCM_UNDEFINED)
    {
      SCM_ASSERT_TYPE (scm_is_number (den), length, SCM_ARG4, __FUNCTION__, "integer");
      compress = true;
    }
  else
    den = scm_int2num (1);

  Duration p (scm_to_int (length), dots);
  if (compress)
    p = p.compressed (Rational (scm_to_int (num), scm_to_int (den)));

  return p.smobbed_copy ();
}

LY_DEFINE (ly_duration_log, "ly:duration-log",
	   1, 0, 0, (SCM dur),
	  "Extract the duration log from @var{dur}")
{
  SCM_ASSERT_TYPE (unsmob_duration (dur), dur, SCM_ARG1, __FUNCTION__, "duration");
  return scm_int2num (unsmob_duration (dur)->duration_log ());
}

LY_DEFINE (ly_duration_dot_count, "ly:duration-dot-count",
	   1, 0, 0, (SCM dur),
	  "Extract the dot count from @var{dur}")
{
  SCM_ASSERT_TYPE (unsmob_duration (dur), dur, SCM_ARG1, __FUNCTION__, "duration");
  return scm_int2num (unsmob_duration (dur)->dot_count ());
}

LY_DEFINE (ly_intlog2, "ly:intlog2",
	   1, 0, 0, (SCM d),
	  "The 2-logarithm of 1/@var{d}.")
{
  SCM_ASSERT_TYPE (scm_is_number (d), d, SCM_ARG1, __FUNCTION__, "integer");
  int log = intlog2 (scm_to_int (d));
  return scm_int2num (log);
}

LY_DEFINE (ly_duration_factor, "ly:duration-factor",
	   1, 0, 0, (SCM dur),
	  "Extract the compression factor from @var{dur}. Return as a pair.")
{
  SCM_ASSERT_TYPE (unsmob_duration (dur), dur, SCM_ARG1, __FUNCTION__, "duration");
  Rational r = unsmob_duration (dur)->factor ();
  return scm_cons (scm_int2num (r.num ()), scm_int2num (r.den ()));
}

int
Duration::duration_log () const
{
  return durlog_;
}

int
Duration::dot_count () const
{
  return dots_;
}
