/* -*- C++ -*-
 * src/lemon/error.h - Part of LEMON, a generic C++ optimization library
 *
 * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
 * (Egervary Combinatorial Optimization Research Group, EGRES).
 *
 * Permission to use, modify and distribute this software is granted
 * provided that this copyright notice appears in all copies. For
 * precise terms see the accompanying LICENSE file.
 *
 * This software is provided "AS IS" with no warranty of any kind,
 * express or implied, and with no claim as to its suitability for any
 * purpose.
 *
 */

#ifndef LEMON_ERROR_H
#define LEMON_ERROR_H

//! \ingroup misc
//! \file
//! \brief Basic exception classes and error handling.

#include <exception>
#include <string>
#include <sstream>
#include <iostream>
#include <cstdlib>

#include <boost/shared_ptr.hpp>

namespace lemon {

  /// Exception-safe convenient "error message" class.

  /// Helper class which provides a convenient ostream-like (operator <<
  /// based) interface to create a string message. Mostly useful in
  /// exception classes (therefore the name).
  class ErrorMessage {
  protected:
    ///\e 
    boost::shared_ptr<std::ostringstream> buf;
    
    ///\e 
    bool init() throw() {
      try {
	buf.reset(new std::ostringstream);
      }
      catch(...) {
	buf.reset();
      }
      return buf;
    }

  public:

    ///\e 
    ErrorMessage() throw() { init(); }

    ///\e 
    ErrorMessage(const char *message) throw() {
      init();
      *this << message;
    }

    ///\e 
    ErrorMessage(const std::string &message) throw() {
      init();
      *this << message;
    }

    ///\e 
    template <typename T>
    ErrorMessage& operator<<(const T &t) throw() {
      if( !buf ) return *this;

      try {
	*buf << t;
      }
      catch(...) {
	buf.reset();
      }
    }

    ///\e 
    const char* message() throw() {
      if( !buf ) return 0;

      const char* mes = 0;
      try {
	mes = buf->str().c_str();
      }
      catch(...) {}
      return mes;
    }
    
  };

  /**
   * \brief Generic exception class.
   *
   * Base class for exceptions used in LEMON.
   */
  class Exception : public std::exception {
  protected:
    ///\e
    const char *message;

  public:
    ///\e 
    Exception() throw() : message(0) {}
    ///\e 
    explicit Exception(const char *msg) throw()
      : message(msg) {}
    ///\e 
    virtual ~Exception() throw() {}
    
    ///\e 
    virtual const char* what() const throw() {
      if( message ) return message;
      return "lemon::Exception";
    }
  };

  ///\e 
  class LogicError : public Exception {
  public:
    ///\e 
    explicit LogicError() {}
    ///\e 
    explicit LogicError(const char *s)
      : Exception(s) {}
  };

  ///\e 
  class RuntimeError : public Exception {
  public:
    ///\e
    explicit RuntimeError() {}
    ///\e
    explicit RuntimeError(const char *s)
      : Exception(s) {}
  };

  ///\e
  class RangeError : public RuntimeError {
  public:
    ///\e 
    explicit RangeError(const char *s)
      : RuntimeError(s) {}
  };

  ///\e 
  class IOError : public RuntimeError {
  public:
    ///\e 
    explicit IOError(const char *s)
      : RuntimeError(s) {}
  };

  ///\e 
  class DataFormatError : public IOError {
  protected:
    int line;
    boost::shared_ptr<std::string> file;

  public:
    ///\e 
    explicit DataFormatError(const char *message)
      : IOError(message), line(0) {}
    ///\e 
    DataFormatError(const std::string &file_name, int line_num,
		    const char *message)
      : IOError(message), line(line_num) { set_file(file_name); }

    ///\e 
    void set_line(int line_num) { line=line_num; }
    ///\e 
    void set_file(const std::string &file_name) {
      try {
	file.reset(new std::string);
	*file = file_name;
      }
      catch(...) {
	file.reset();
      }
    }

    ///\e
    int get_line() const { return line; }

    /// \brief Returns the filename.
    ///
    /// Returns \e "(unknown)" if the filename was not specified.
    const char* get_file() const {
      if( file )
	return file->c_str();
      else
	return "(unknown)";
    }

    ///\e 
    virtual const char* what() const throw() {
      const char *mes = 0;
      try {
	std::ostringstream ostr;
	ostr << IOError::what();
	if( file || line ) {
	  ostr << " (";
	  if( file ) ostr << "in file '" << *file << "'";
	  if( file && line ) ostr << " ";
	  if( line ) ostr << "at line " << line;
	  ostr << ")";
	}
	mes = ostr.str().c_str();
      }
      catch(...) {}
      if( mes ) return mes;
      return "lemon::DataFormatError";
    }

    virtual ~DataFormatError() throw() {}
  };


  ///\e
  class AssertionFailedError : public LogicError {
  protected:
    const char *assertion;
    const char *file;
    int line;
    const char *function;
    const char *message;
  public:
    ///\e
    AssertionFailedError(const char *_file, int _line, const char *func,
			 const char *msg, const char *_assertion = 0) :
      assertion(_assertion), file(_file), line(_line), function(func),
      message(msg) {}

    ///\e
    const char* get_assertion() const { return assertion; }
    ///\e
    const char* get_message() const { return message; }
    ///\e
    const char* get_file() const { return file; }
    ///\e
    const char* get_function() const { return function; }
    ///\e
    int get_line() const { return line; }


    virtual const char* what() const throw() {
      const char *mes = 0;
      try {
	std::ostringstream ostr;
	ostr << file << ":" << line << ": ";
	if( function )
	  ostr << function << ": ";
	ostr << message;
	if( assertion )
	  ostr << " (assertion '" << assertion << "' failed)";
	mes = ostr.str().c_str();
      }
      catch(...) {}
      if( mes ) return mes;
      return "lemon::AssertionFailedError";
    }

    virtual ~AssertionFailedError() throw() {}
  };


  /****************  Macros  ****************/


  inline
  void assert_fail(const char *file, int line, const char *func,
		   const char *message, const char *assertion = 0,
		   bool do_abort=true)
  {
    using namespace std;
    cerr << file << ":" << line << ": ";
    if( func )
      cerr << func << ": ";
    cerr << message;
    if( assertion )
      cerr << " (assertion '" << assertion << "' failed)";
    cerr << endl;
    if(do_abort)
      abort();
  }

  inline
  void assert_fail_throw(const char *file, int line, const char *func,
		   const char *message, const char *assertion = 0,
		   bool = true)
  {
    throw AssertionFailedError(file, line, func, message, assertion);
  }


}
#endif // LEMON_ERROR_H

#undef LEMON_ASSERT
#undef LEMON_FIXME

#ifndef LEMON_ASSERT_ABORT
#  define LEMON_ASSERT_ABORT 1
#endif

#ifndef LEMON_ASSERT_HANDLER
#  define LEMON_ASSERT_HANDLER ::lemon::assert_fail
#endif

#if defined(NDEBUG) || defined(LEMON_DISABLE_ASSERTS)

#  define LEMON_ASSERT(exp, msg)  (static_cast<void> (0))

#else

/**
 * \brief Macro for assertions with customizable message
 *
 * \todo __PRETTY_FUNCTION__ should be replaced by something
 * compiler-independant, like BOOST_CURRENT_FUNCTION
 */

#  define LEMON_ASSERT(exp, msg)                 \
     (static_cast<void> (!!(exp) ? 0 : (         \
       LEMON_ASSERT_HANDLER(__FILE__, __LINE__,  \
                            __PRETTY_FUNCTION__, \
			    (msg), #exp, LEMON_ASSERT_ABORT), 0)))

# endif // NDEBUG

/**
 * \brief Macro for mark not yet implemented features.
 *
 * \todo Is this the right place for this? It should be used only in
 * modules under development.
 *
 * \todo __PRETTY_FUNCTION__ should be replaced by something
 * compiler-independant, like BOOST_CURRENT_FUNCTION
 */

# define LEMON_FIXME(msg) \
    (LEMON_ASSERT_HANDLER(__FILE__, __LINE__, __PRETTY_FUNCTION__, \
			  "FIXME: " msg))