#include <util/buffer.h>
#include <util/endian.hpp>

#include <stdarg.h>
#include <stdio.h>

size_t
llarp_buffer_size_left(const llarp_buffer_t& buff)
{
  size_t diff = buff.cur - buff.base;
  if(diff > buff.sz)
    return 0;
  else
    return buff.sz - diff;
}

bool
llarp_buffer_writef(llarp_buffer_t* buff, const char* fmt, ...)
{
  int written;
  ssize_t sz = llarp_buffer_size_left(*buff);
  va_list args;
  va_start(args, fmt);
  written = vsnprintf((char*)buff->cur, sz, fmt, args);
  va_end(args);
  if(written <= 0)
    return false;
  if(sz < written)
    return false;
  buff->cur += written;
  return true;
}

bool
llarp_buffer_write(llarp_buffer_t* buff, const void* data, size_t sz)
{
  size_t left = llarp_buffer_size_left(*buff);
  if(left >= sz)
  {
    memcpy(buff->cur, data, sz);
    buff->cur += sz;
    return true;
  }
  return false;
}

size_t
llarp_buffer_read_until(llarp_buffer_t* buff, char delim, byte_t* result,
                        size_t resultsize)
{
  size_t read = 0;

  // do the bound check first, to avoid over running
  while((buff->cur != buff->base + buff->sz) && *buff->cur != delim
        && resultsize)
  {
    *result = *buff->cur;
    buff->cur++;
    result++;
    resultsize--;
    read++;
  }

  if(llarp_buffer_size_left(*buff))
    return read;
  else
    return 0;
}

bool
llarp_buffer_eq(const llarp_buffer_t& buf, const char* str)
{
  llarp_buffer_t copy = buf.clone();
  while(*str && copy.cur != (copy.base + copy.sz))
  {
    if(*copy.cur != *str)
      return false;
    copy.cur++;
    str++;
  }
  return *str == 0;
}

bool
llarp_buffer_put_uint16(llarp_buffer_t* buf, uint16_t i)
{
  if(llarp_buffer_size_left(*buf) < sizeof(uint16_t))
    return false;
  htobe16buf(buf->cur, i);
  buf->cur += sizeof(uint16_t);
  return true;
}

bool
llarp_buffer_put_uint32(llarp_buffer_t* buf, uint32_t i)
{
  if(llarp_buffer_size_left(*buf) < sizeof(uint32_t))
    return false;
  htobe32buf(buf->cur, i);
  buf->cur += sizeof(uint32_t);
  return true;
}

bool
llarp_buffer_read_uint16(llarp_buffer_t* buf, uint16_t* i)
{
  if(llarp_buffer_size_left(*buf) < sizeof(uint16_t))
    return false;
  *i = bufbe16toh(buf->cur);
  buf->cur += sizeof(uint16_t);
  return true;
}

bool
llarp_buffer_read_uint32(llarp_buffer_t* buf, uint32_t* i)
{
  if(llarp_buffer_size_left(*buf) < sizeof(uint32_t))
    return false;
  *i = bufbe32toh(buf->cur);
  buf->cur += sizeof(uint32_t);
  return true;
}