#pragma once
/**
 *  @file exception.hpp
 *  @brief Defines exception's used by fc 
 */
#include <fc/log/log_message.hpp>
#include <fc/optional.hpp>
#include <exception>
#include <unordered_map>


namespace fc
{
   namespace detail { class exception_impl; }

   enum exception_code 
   {
       /** for exceptions we threw that don't have an assigned code */
       unspecified_exception_code        = 0, 
       unhandled_exception_code          = 1, ///< for unhandled 3rd party exceptions
       timeout_exception_code            = 2, ///< timeout exceptions
       file_not_found_exception_code     = 3,
       parse_error_exception_code        = 4,
       invalid_arg_exception_code        = 5,
       key_not_found_exception_code      = 6,
       bad_cast_exception_code           = 7,
       out_of_range_exception_code       = 8,
       canceled_exception_code           = 9,
       assert_exception_code             = 10,
       eof_exception_code                = 11,
       std_exception_code                = 13,
       invalid_operation_exception_code  = 14
   };

   /**
    *  @brief Used to generate a useful error report when an exception is thrown.
    *  @ingroup serializable
    *
    *  At each level in the stack where the exception is caught and rethrown a
    *  new log_message is added to the exception.
    *
    *  exception's are designed to be serialized to a variant and
    *  deserialized from an variant.  
    *
    *  @see FC_THROW_EXCEPTION
    *  @see FC_RETHROW_EXCEPTION
    *  @see FC_RETHROW_EXCEPTIONS
    */
   class exception 
   {
      public:
         enum code_enum 
         {
            code_value = unspecified_exception_code
         };

         exception( int64_t code = unspecified_exception_code, 
                    const std::string& name_value = "exception",
                    const std::string& what_value = "unspecified");
         exception( log_message&&, int64_t code = unspecified_exception_code,
                                   const std::string& name_value = "exception",
                                   const std::string& what_value = "unspecified");
         exception( log_messages&&, int64_t code = unspecified_exception_code,
                                    const std::string& name_value = "exception",
                                    const std::string& what_value = "unspecified");
         exception( const exception& e );
         exception( exception&& e );
         ~exception();

         const char*          name()const throw();
         int64_t              code()const throw();
         virtual const char*  what()const throw();

         /**
          *   @return a reference to log messages that have
          *   been added to this log.
          */
         const log_messages&  get_log()const;
         void                 append_log( log_message m );
         
         /**
          *   Generates a detailed string including file, line, method,
          *   and other information that is generally only useful for
          *   developers.
          */
         std::string to_detail_string( log_level ll = log_level::all )const;

         /**
          *   Generates a user-friendly error report.
          */
         std::string to_string( log_level ll = log_level::info  )const;

         /**
          *  Throw this exception as its most derived type. 
          *
          *  @note does not return.
          */
         virtual NO_RETURN void     dynamic_rethrow_exception()const;

         /**
          *  This is equivalent to:
          *  @code
          *   try { throwAsDynamic_exception(); } 
          *   catch( ... ) { return std::current_exception(); }
          *  @endcode
          */
          virtual std::shared_ptr<exception> dynamic_copy_exception()const;

         friend void to_variant( const exception& e, variant& v );
         friend void from_variant( const variant& e, exception& ll );
      protected:
         std::unique_ptr<detail::exception_impl> my;
   };

   void to_variant( const exception& e, variant& v );
   void from_variant( const variant& e, exception& ll );
   typedef std::shared_ptr<exception> exception_ptr;

   typedef optional<exception> oexception;


   /**
    *  @brief re-thrown whenever an unhandled exception is caught.
    *  @ingroup serializable
    *  Any exceptions thrown by 3rd party libraries that are not
    *  caught get wrapped in an unhandled_exception exception.  
    *
    *  The original exception is captured as a std::exception_ptr 
    *  which may be rethrown.  The std::exception_ptr does not
    *  propgate across process boundaries. 
    */
   class unhandled_exception : public exception 
   { 
      public: 
       enum code_enum { 
          code_value = unhandled_exception_code, 
       }; 
       unhandled_exception( log_message&& m, std::exception_ptr e = std::current_exception() ); 
       unhandled_exception( log_messages ); 
       unhandled_exception( const exception&  ); 

       std::exception_ptr get_inner_exception()const;

       virtual NO_RETURN void               dynamic_rethrow_exception()const;
       virtual std::shared_ptr<exception>   dynamic_copy_exception()const;
      private:
       std::exception_ptr _inner;
   };

   template<typename T>
   fc::exception_ptr copy_exception( T&& e )
   {
#if defined(_MSC_VER) && (_MSC_VER < 1700)
     return std::make_shared<unhandled_exception>( log_message(), 
                                                   std::copy_exception(fc::forward<T>(e)) );
#else
     return std::make_shared<unhandled_exception>( log_message(), 
                                                   std::make_exception_ptr(fc::forward<T>(e)) );
#endif
   }


   class exception_factory
   {
      public:
        struct base_exception_builder
        {
           virtual NO_RETURN void rethrow( const exception& e )const = 0;
        };

        template<typename T> 
        struct exception_builder : public base_exception_builder
        {
           virtual NO_RETURN void rethrow( const exception& e )const override
           {
              throw T( e );
           }
        };

        template<typename T>
        void register_exception()
        {
           static exception_builder<T> builder;
           auto itr = _registered_exceptions.find( T::code_value );
           assert( itr == _registered_exceptions.end() );
           (void)itr; // in release builds this hides warnings
           _registered_exceptions[T::code_value] = &builder;
        }
        
        void NO_RETURN rethrow( const exception& e )const;

        static exception_factory& instance()
        {
           static exception_factory once;
           return once;
        }

      private:
        std::unordered_map<int64_t,base_exception_builder*> _registered_exceptions;
   };
#define FC_REGISTER_EXCEPTION(r, unused, base) \
   fc::exception_factory::instance().register_exception<base>();

#define FC_REGISTER_EXCEPTIONS( SEQ )\
     \
   static bool exception_init = []()->bool{ \
    BOOST_PP_SEQ_FOR_EACH( FC_REGISTER_EXCEPTION, v, SEQ )  \
      return true; \
   }();  \


#define FC_DECLARE_EXCEPTION( TYPE, CODE, WHAT ) \
   class TYPE : public fc::exception \
   { \
      public: \
       enum code_enum { \
          code_value = CODE, \
       }; \
       TYPE( fc::log_message&& m ) \
       :exception( fc::move(m), CODE, BOOST_PP_STRINGIZE(TYPE), WHAT ){}\
       TYPE( fc::log_messages msgs ) \
       :exception( fc::move( msgs ), CODE, BOOST_PP_STRINGIZE(TYPE), WHAT ) {} \
       TYPE( const TYPE& c ) \
       :exception(c){} \
       TYPE( const exception& c ) \
       :exception(c){} \
       TYPE():exception(){}\
       \
       virtual std::shared_ptr<exception> dynamic_copy_exception()const\
       { return std::make_shared<TYPE>( *this ); } \
       virtual NO_RETURN void     dynamic_rethrow_exception()const \
       { if( code() == CODE ) throw *this;\
         else fc::exception::dynamic_rethrow_exception(); \
       } \
   };
   

  FC_DECLARE_EXCEPTION( timeout_exception, timeout_exception_code, "Timeout" );
  FC_DECLARE_EXCEPTION( file_not_found_exception, file_not_found_exception_code, "File Not Found" );
  /**
   * @brief report's parse errors
   */
  FC_DECLARE_EXCEPTION( parse_error_exception, parse_error_exception_code, "Parse Error" );
  FC_DECLARE_EXCEPTION( invalid_arg_exception, invalid_arg_exception_code, "Invalid Argument" );
  /**
   * @brief reports when a key, guid, or other item is not found.
   */
  FC_DECLARE_EXCEPTION( key_not_found_exception, key_not_found_exception_code, "Key Not Found" );
  FC_DECLARE_EXCEPTION( bad_cast_exception, bad_cast_exception_code, "Bad Cast" );
  FC_DECLARE_EXCEPTION( out_of_range_exception, out_of_range_exception_code, "Out of Range" );

  /** @brief if an operation is unsupported or not valid this may be thrown */
  FC_DECLARE_EXCEPTION( invalid_operation_exception, 
                        invalid_operation_exception_code, 
                        "Invalid Operation" );

  /**
   *  @brief used to report a canceled Operation
   */
  FC_DECLARE_EXCEPTION( canceled_exception, canceled_exception_code, "Canceled" );
  /**
   *  @brief used inplace of assert() to report violations of pre conditions.
   */
  FC_DECLARE_EXCEPTION( assert_exception, assert_exception_code, "Assert Exception" );
  FC_DECLARE_EXCEPTION( eof_exception, eof_exception_code, "End Of File" );

  std::string except_str();

} // namespace fc

/**
 *@brief: Workaround for varying preprocessing behavior between MSVC and gcc
 */
#define FC_EXPAND_MACRO( x ) x
/**
 *  @brief Checks a condition and throws an assert_exception if the test is FALSE
 */
#define FC_ASSERT( TEST, ... ) \
FC_EXPAND_MACRO( \
do { if( !(TEST) ) { FC_THROW_EXCEPTION( fc::assert_exception, #TEST ": "  __VA_ARGS__ ); } } while(0); \
)

#define FC_THROW( FORMAT, ... ) \
   do { \
   throw fc::exception( FC_LOG_MESSAGE( error, FORMAT, __VA_ARGS__ ) );  \
   } while(0)

#define FC_EXCEPTION( EXCEPTION_TYPE, FORMAT, ... ) \
    EXCEPTION_TYPE( FC_LOG_MESSAGE( error, FORMAT, __VA_ARGS__ ) )  
/**
 *  @def FC_THROW_EXCEPTION( EXCEPTION, FORMAT, ... )
 *  @param EXCEPTION a class in the Phoenix::Athena::API namespace that inherits
 *  @param format - a const char* string with "${keys}"
 */
#define FC_THROW_EXCEPTION( EXCEPTION, FORMAT, ... ) \
   do { \
   throw EXCEPTION( FC_LOG_MESSAGE( error, FORMAT, __VA_ARGS__ ) ); \
   } while(0)


/**
 *  @def FC_RETHROW_EXCEPTION(ER,LOG_LEVEL,FORMAT,...)
 *  @brief Appends a log_message to the exception ER and rethrows it.
 */
#define FC_RETHROW_EXCEPTION( ER, LOG_LEVEL, FORMAT, ... ) \
  do { \
     ER.append_log( FC_LOG_MESSAGE( LOG_LEVEL, FORMAT, __VA_ARGS__ ) ); \
     throw;\
  } while(false)

/**
 *  @def FC_RETHROW_EXCEPTIONS(LOG_LEVEL,FORMAT,...)
 *  @brief  Catchs all exception's, std::exceptions, and ... and rethrows them after
 *   appending the provided log message.
 */
#define FC_RETHROW_EXCEPTIONS( LOG_LEVEL, FORMAT, ... ) \
   catch( fc::exception& er ) { \
      FC_RETHROW_EXCEPTION( er, LOG_LEVEL, FORMAT, __VA_ARGS__ ); \
   } catch( const std::exception& e ) {  \
      fc::exception fce( \
                FC_LOG_MESSAGE( LOG_LEVEL, "${what}" FORMAT,__VA_ARGS__("what",e.what())), \
                fc::std_exception_code,\
                typeid(e).name(), \
                e.what() ) ; throw fce;\
   } catch( ... ) {  \
      throw fc::unhandled_exception( \
                FC_LOG_MESSAGE( LOG_LEVEL, FORMAT,__VA_ARGS__), \
                std::current_exception() ); \
   }

#define FC_CAPTURE_AND_RETHROW( ... ) \
   catch( fc::exception& er ) { \
      FC_RETHROW_EXCEPTION( er, warn, "", FC_FORMAT_ARG_PARAMS(__VA_ARGS__) ); \
   } catch( const std::exception& e ) {  \
      fc::exception fce( \
                FC_LOG_MESSAGE( warn, "${what}",FC_FORMAT_ARG_PARAMS(__VA_ARGS__)("what",e.what())), \
                fc::std_exception_code,\
                typeid(e).name(), \
                e.what() ) ; throw fce;\
   } catch( ... ) {  \
      throw fc::unhandled_exception( \
                FC_LOG_MESSAGE( warn, "",FC_FORMAT_ARG_PARAMS(__VA_ARGS__)), \
                std::current_exception() ); \
   }