/*
 * Error.h
 *
 * This source file is part of the FoundationDB open source project
 *
 * Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef FLOW_ERROR_H
#define FLOW_ERROR_H
#pragma once

#include <exception>
#include <map>
#include <boost/preprocessor/assert_msg.hpp>
#include <boost/preprocessor/facilities/is_empty.hpp>
#include <boost/preprocessor/control/if.hpp>
#include "flow/Platform.h"
#include "flow/Knobs.h"
#include "flow/FileIdentifier.h"
#include "flow/ObjectSerializerTraits.h"

enum { invalid_error_code = 0xffff };

class ErrorCodeTable : public std::map<int, std::pair<const char*, const char*>> {
public:
	ErrorCodeTable();
	void addCode(int code, const char *name, const char *description);
};

class Error {
public:
	constexpr static FileIdentifier file_identifier = 14065384;
	int code() const { return error_code; }
	const char* name() const;
	const char* what() const;
	bool isInjectedFault() const { return flags & FLAG_INJECTED_FAULT; }  // Use as little as possible, so injected faults effectively test real faults!
	bool isValid() const { return error_code != invalid_error_code; }

	template <class Ar>
	void serialize( Ar& ar ) {
		serializer(ar, error_code);
	}

	Error() : error_code(invalid_error_code), flags(0) {}
	explicit Error(int error_code);

	static void init();
	static ErrorCodeTable& errorCodeTable();
	static Error fromCode(int error_code) {
		Error e;
		e.error_code = error_code;
		return e;
	}
	static Error fromUnvalidatedCode(int error_code);  // Converts codes that are outside the legal range (but not necessarily individually unknown error codes) to unknown_error()

	Error asInjectedFault() const;  // Returns an error with the same code() as this but isInjectedFault() is true
private:
	uint16_t error_code;
	uint16_t flags;

	enum Flags { FLAG_INJECTED_FAULT=1 };
};

Error systemErrorCodeToError();

#undef ERROR
#define ERROR(name, number, description) inline Error name() { return Error( number ); }; enum { error_code_##name = number };

#include "error_definitions.h"

//actor_cancelled has been renamed
inline Error actor_cancelled() { return Error( error_code_operation_cancelled ); }
enum { error_code_actor_cancelled = error_code_operation_cancelled };

extern Error internal_error_impl(const char* file, int line);
extern Error internal_error_impl(const char* msg, const char* file, int line);
extern Error internal_error_impl(const char * a_nm, long long a, const char * op_nm, const char * b_nm, long long b, const char * file, int line);

#define internal_error() internal_error_impl(__FILE__, __LINE__)
#define internal_error_msg(msg) internal_error_impl(msg, __FILE__, __LINE__)

extern bool isAssertDisabled( int line );
//#define ASSERT( condition ) ((void)0)
#define ASSERT(condition)                                                                                              \
	do {                                                                                                               \
		if (!((condition) || isAssertDisabled(__LINE__))) {                                                            \
			throw internal_error_impl(#condition, __FILE__, __LINE__);                                                 \
		}                                                                                                              \
	} while (false)
#define ASSERT_ABORT(condition)                                                                                        \
	do {                                                                                                               \
		if (!((condition) || isAssertDisabled(__LINE__))) {                                                            \
			internal_error_impl(#condition, __FILE__, __LINE__);                                                       \
			abort();                                                                                                   \
		}                                                                                                              \
	} while (false) // For use in destructors, where throwing exceptions is extremely dangerous
#define UNSTOPPABLE_ASSERT(condition)                                                                                  \
	do {                                                                                                               \
		if (!(condition)) {                                                                                            \
			throw internal_error_impl(#condition, __FILE__, __LINE__);                                                 \
		}                                                                                                              \
	} while (false)
#define UNREACHABLE()                                                                                                  \
	{ throw internal_error_impl("unreachable", __FILE__, __LINE__); }

enum assert_op { EQ, NE, LT, GT, LE, GE };

// TODO: magic so this works even if const-ness doesn not match.
template<typename T, typename U>
void assert_num_impl(char const * a_nm,
					T const & a,
					assert_op op,
					char const * b_nm,
					U const & b,
					char const * file,
					int line) {
  bool success;
  char const * op_name;
  switch (op) {
    case EQ:
      success = a == b;
      op_name = "==";
      break;
    case NE:
      success = a != b;
      op_name = "!=";
      break;
    case LT:
      success = a < b;
      op_name = "<";
      break;
    case GT:
      success = a > b;
      op_name = ">";
      break;
    case LE:
      success = a <= b;
      op_name = "<=";
      break;
    case GE:
      success = a >= b;
      op_name = ">=";
      break;
    default:
      success = false;
      op_name = "UNKNOWN OP";
  }

  if (!success) {
	  throw internal_error_impl(a_nm, (long long)a, op_name, b_nm, (long long)b, file, line);
  }
}

#define ASSERT_EQ(a, b)                                                        \
  do {                                                                         \
    assert_num_impl((#a), (a), assert_op::EQ, (#b), (b), __FILE__, __LINE__);  \
  } while (0)
#define ASSERT_NE(a, b)                                                        \
  do {                                                                         \
    assert_num_impl((#a), (a), assert_op::NE, (#b), (b), __FILE__, __LINE__);  \
  } while (0)
#define ASSERT_LT(a, b)                                                        \
  do {                                                                         \
    assert_num_impl((#a), (a), assert_op::LT, (#b), (b), __FILE__, __LINE__);  \
  } while (0)
#define ASSERT_LE(a, b)                                                        \
  do {                                                                         \
    assert_num_impl((#a), (a), assert_op::LE, (#b), (b), __FILE__, __LINE__);  \
  } while (0)
#define ASSERT_GT(a, b)                                                        \
  do {                                                                         \
    assert_num_impl((#a), (a), assert_op::GT, (#b), (b), __FILE__, __LINE__);  \
  } while (0)
#define ASSERT_GE(a, b)                                                        \
  do {                                                                         \
    assert_num_impl((#a), (a), assert_op::GE, (#b), (b), __FILE__, __LINE__);  \
  } while (0)

// ASSERT_WE_THINK() is to be used for assertions that we want to validate in testing, but which are judged too
// risky to evaluate at runtime, because the code should work even if they are false and throwing internal_error() would
// result in a bug.  Don't use it for assertions that are *expensive*; look at EXPENSIVE_VALIDATION.
#define ASSERT_WE_THINK( condition ) ASSERT( !g_network->isSimulated() || (condition) )

#define ABORT_ON_ERROR( code_to_run ) \
	try { code_to_run; } \
	catch(Error &e) { criticalError(FDB_EXIT_ABORT, "AbortOnError", e.what()); } \
	catch(...) { criticalError(FDB_EXIT_ABORT, "AbortOnError", "Aborted due to unknown error"); }

EXTERNC void breakpoint_me();

#ifdef FDB_CLEAN_BUILD
#  define NOT_IN_CLEAN BOOST_STATIC_ASSERT_MSG(0, "This code can not be enabled in a clean build.");
#else
#  define NOT_IN_CLEAN
#endif

#define FDB_EXPAND(...) __VA_ARGS__
#define FDB_STRINGIZE(...) BOOST_PP_IIF(BOOST_PP_IS_EMPTY(FDB_EXPAND(__VA_ARGS__)), "", #__VA_ARGS__)
#define ENABLED(...) BOOST_PP_IIF(BOOST_PP_IS_EMPTY(FDB_EXPAND(__VA_ARGS__)), 1, BOOST_PP_ASSERT_MSG(0, FDB_STRINGIZE(__VA_ARGS__)))
#define DISABLED(...) BOOST_PP_IIF(BOOST_PP_NOT(BOOST_PP_IS_EMPTY(FDB_EXPAND(__VA_ARGS__))), 1, BOOST_PP_ASSERT_MSG(0, FDB_STRINGIZE(__VA_ARGS__)))

/* Windows compilers won't allow the syntax of:
	 #if 0 && ENABLED(x)
   So these macros replicate that, you instead do:
	 #if CENABLED(0, x)
 */
#define CENABLED(x,y) BOOST_PP_IF(x, ENABLED(y), 0)
#define CDISABLED(x,y) BOOST_PP_IF(x, DISABLED(y), 0)

#endif