#include "global.h"

#include <cstdio>

dynbuf::dynbuf (int initial, int extend)
{
  ext = extend;
  _size = 0;

  first = last = (chunk *)salloc<char> (sizeof (chunk) + initial);
  first->alloc = sizeof (chunk) + initial;
  first->next = 0;

  ptr = first->data;
  end = ptr + initial;
}

dynbuf::~dynbuf ()
{
  _clear ();
}

void
dynbuf::_clear ()
{
  while (first)
    {
      chunk *next = first->next;

      sfree<char> ((char *)first, first->alloc);
      first = next;
    }
}

void
dynbuf::clear ()
{
  _clear ();
  _size = 0;

  first = last = (chunk *)salloc<char> (sizeof (chunk) + ext);
  first->alloc = sizeof (chunk) + ext;
  first->next = 0;

  ptr = first->data;
  end = ptr + ext;
}

void
dynbuf::finish ()
{
  // finalise current chunk
  _size += last->size = ptr - last->data;
}

void
dynbuf::_reserve (int size)
{
  finish ();

  do
    {
      ext += ext >> 1;
      ext = (ext + 15) & ~15;
    }
  while (ext < size);

  chunk *add = (chunk *) salloc<char> (sizeof (chunk) + ext);
  add->alloc = sizeof (chunk) + ext;
  add->next = 0;

  last->next = add;
  last = add;

  ptr = last->data;
  end = ptr + ext;
}

void
dynbuf::linearise (void *data)
{
  last->size = ptr - last->data;

  for (chunk *c = first; c; c = c->next)
    {
      memcpy (data, c->data, c->size);
      data = (void *)(((char *)data) + c->size);
    }
}

char *
dynbuf::linearise ()
{
  if (first->next)
    {
      finish ();

      chunk *add = (chunk *) salloc<char> (sizeof (chunk) + _size);
      add->alloc = sizeof (chunk) + _size;
      add->next = 0;

      linearise ((void *)add->data);
      _clear ();

      first = last = add;
      ptr = last->data + _size;
      end = ptr;
      _size = 0;
    }

  return first->data;
}

dynbuf::operator std::string ()
{
  // could optimise
  return std::string (linearise (), size ());
}

void
dynbuf_text::printf (const char *format, ...)
{
  int len;

  {
    force (128);

    va_list ap;
    va_start (ap, format);
    len = vsnprintf (ptr, end - ptr, format, ap);
    va_end (ap);

    assert (len >= 0); // shield against broken vsnprintf's

    // was enough room available
    if (ptr + len < end)
      {
        alloc (len);
        return;
      }
  }

  // longer, try harder
  va_list ap;
  va_start (ap, format);
  vsnprintf (force (len + 1), len + 1, format, ap);
  va_end (ap);

  alloc (len);
}

void
dynbuf_text::add (sint32 i)
{
  char buf[max_sint32_size];
  char *p = buf + sizeof (buf);
  char neg;

  uint32 val;

  if (i < 0)
    {
      neg = '-';
      val = -i;
    }
  else
    {
      neg = 0;
      val = i;
    }

  do
    {
      uint32 div = val / 10;
      *--p = '0' + char (val - div * 10);

      val = div;
    }
  while (val);

  if (neg)
    *--p = neg;

  add ((void *) p, buf + sizeof (buf) - p);
}

void
dynbuf_text::add (sint64 i)
{
  if (i > -10000000 && i < 10000000)
    {
      add (sint32 (i));
      return;
    }

  char buf[max_sint64_size];
  char *p = buf + sizeof (buf);
  char neg;

  uint64 val;

  if (i < 0)
    {
      neg = '-';
      val = -i;
    }
  else
    {
      neg = 0;
      val = i;
    }

  do
    {
      uint64 div = val / 10;
      *--p = '0' + char (val - div * 10);

      val = div;
    }
  while (val);

  if (neg)
    *--p = neg;

  add ((void *) p, buf + sizeof (buf) - p);
}