#include "log.h"

log_stream log_cout;

log_stream::log_stream(): m_active(false), m_buffer(), m_log_lines() {}

void log_stream::log_lines(int n) {
  m_log_lines = n;
}

std::string log_stream::get_log() {
  return m_buffer.str();
}

// log to buffer
void log_stream::activate()
{
  m_active = true;
}

// log to plain console
void log_stream::deactivate()
{
  m_active = false;
}

log_stream& log_stream::operator<<(
  std::basic_ostream<char>& (*func)
      (std::basic_ostream<char>&) ) {
  if (m_active) {
    m_buffer << *func;
    trim_buffer();
  }
  else
  {
    std::cout << *func;
  }
  return *this;
}

void log_stream::trim_buffer()
{
  std::string s = m_buffer.str();

  size_t pos = s.npos;
  for (int i = 0; i <= m_log_lines; ++i) {
    pos = s.rfind("\n", pos);
    if (pos == s.npos) {
      // too few lines
      return;
    }
    if (pos > 0) {
      --pos;
    }
  }

  m_buffer.str(s.substr((pos <= (s.size() - 2)) ? pos + 2 : pos));
  m_buffer.seekp(0, std::ios_base::end);
}