#ifndef ERMYTH_EXCEPTION_H
#define ERMYTH_EXCEPTION_H

#include <cstdarg>
#include <cstdio>
#include <algorithm>
#include <exception>

#ifdef __GNUC__
# define CURFUNC       __PRETTY_FUNCTION__
#elif defined(__BORLANDC__)
# define CURFUNC       __FUNC__
#else
# define CURFUNC       __FUNCTION__
#endif

#define SRCINF  srcinf (__FILE__, __LINE__, CURFUNC)

#define EBUFSIZE 1024

struct srcinf
{
  srcinf (char const *file, unsigned int line, char const *func)
  : m_info (info (file, line, func))
  {
  }

  unsigned int line() const throw() { return m_info.line; }
  char const *file() const throw()  { return m_info.file; }
  char const *func() const throw()  { return m_info.func; }
  
  srcinf &operator = (srcinf const &rhs)
  {
    if (this != &rhs)
      this->m_info = rhs.m_info;
    return *this;
  }

  srcinf (srcinf const &rhs)
  {
    this->m_info = rhs.m_info;
  }

private:
  struct info
  {
    char const *file;
    unsigned line;
    char const *func;

    info ()
    : file (0), line (0), func (0)
    {
    }

    info (char const *file, unsigned line, char const *func)
    : file (file ? file : "<anonymous file>"), line (line), func (func ? func : "<anonymous function> ()")
    {
    }
  };

  info m_info;
};

struct exception : std::exception
{
  virtual const char *what() const throw ()
  {
    return m_what ? m_what : "";
  }

protected:
  explicit exception (const char *fmt, ...)
  {
    va_list ap;
    va_start (ap, fmt);
    vsnprintf (m_what, EBUFSIZE - 1, fmt, ap);
    va_end (ap);
  }

  explicit exception (srcinf const &si, char const *fmt, ...)
  {
    va_list ap;
    va_start (ap, fmt);
    what (si, fmt, ap);
    va_end (ap);
  }

  void what (srcinf const &si, char const *fmt, va_list ap) throw ()
  {
    char buf[EBUFSIZE];
    char *bufptr = buf;
    int l = snprintf (bufptr, EBUFSIZE - 1, "%s(#%d): %s: ", si.file (), si.line (), si.func ());
    vsnprintf (bufptr + l, EBUFSIZE - 1, fmt, ap);
    what (buf);
  }

  void what (char const *fmt, va_list ap) throw ()
  {
    char buf[EBUFSIZE];
    vsnprintf (buf, EBUFSIZE - 1, fmt, ap);
    what (buf);
  }

  void what (char const *w) throw ()
  {
    std::copy (w, w + EBUFSIZE, m_what);
  }

  exception ()
  {
  }

private:
  char m_what[EBUFSIZE];
};

struct nullpointer_exception : exception
{
  explicit nullpointer_exception ()
  {
  }
  
  explicit nullpointer_exception (char const *fmt, ...)
  {
    va_list ap;
    va_start (ap, fmt);
    what (fmt, ap);
    va_end (ap);
  }

  explicit nullpointer_exception (srcinf const &si, char const *fmt, ...)
  {
    va_list ap;
    va_start (ap, fmt);
    what (si, fmt, ap);
    va_end (ap);
  }
};

#endif // ERMYTH_EXCEPTION_H