#pragma once

#if !defined(MIJIN_DEBUG_ASSERT_HPP_INCLUDED)
#define MIJIN_DEBUG_ASSERT_HPP_INCLUDED 1

#include <cstdio>
#include <cstdlib>
#include <source_location>

#include "../internal/common.hpp"

#if MIJIN_THROWING_ASSERTS
#include <sstream>
#include <stdexcept> // I'd prefer mijin Exceptions here, but that would result in a circual include :/
#endif

#ifdef _WIN32
#pragma comment(lib, "kernel32")
extern "C" __declspec(dllimport) void __stdcall DebugBreak();
#define MIJIN_TRAP() DebugBreak()
#else // _WIN32
#include <unistd.h>
#define MIJIN_TRAP()                            \
{                                               \
    const pid_t tid = gettid();                 \
    const pid_t pid = getpid();                 \
    __asm__ __volatile__                        \
    (                                           \
        "syscall"                               \
        :                                       \
        : "D"(pid), "S"(tid), "d"(5), "a"(0xea) \
        : "rcx", "r11", "memory"                \
    );                                          \
}
#endif // !_WIN32

namespace mijin
{
//
// public defines
//

#if MIJIN_DEBUG

#define MIJIN_RAISE_ERROR(msg, source_loc)    \
switch (mijin::handleError(msg, source_loc))  \
{                                             \
    case mijin::ErrorHandling::CONTINUE:      \
        break;                                \
    case mijin::ErrorHandling::TRAP:          \
        MIJIN_TRAP();                         \
        break;                                \
    default: /* ABORT */                      \
        std::abort();                         \
}

#define MIJIN_ERROR(msg) \
MIJIN_RAISE_ERROR(msg, std::source_location::current())

#define MIJIN_FATAL(msg) \
MIJIN_ERROR(msg)         \
std::abort()

// TODO: make ignoreAll work (static variables cannot be used in constexpr functions)
#define MIJIN_ASSERT(condition, msg)                                                   \
do                                                                                     \
{                                                                                      \
    if (!static_cast<bool>(condition))                                                 \
    {                                                                                  \
        /* static bool ignoreAll = false; */                                           \
        if (true) /*!ignoreAll */                                                      \
        {                                                                              \
            const mijin::AssertionResult assertion_result__ = mijin::handleAssert(     \
                    #condition, msg, std::source_location::current());                 \
            switch (assertion_result__)                                                \
            {                                                                          \
            case mijin::AssertionResult::ABORT:                                        \
                std::abort();                                                          \
                break;                                                                 \
            case mijin::AssertionResult::IGNORE:                                       \
                /*break*/;                                                             \
            case mijin::AssertionResult::IGNORE_ALL:                                   \
                /* ignoreAll = true; */                                                \
                break;                                                                 \
            default: /* ERROR */                                                       \
                MIJIN_ERROR("Debug assertion failed: " #condition "\nMessage:  " msg); \
                break;                                                                 \
            }                                                                          \
        }                                                                              \
    }                                                                                  \
} while(false)

#define MIJIN_ASSERT_FATAL(condition, msg)                                  \
if (!static_cast<bool>(condition))                                          \
{                                                                           \
    MIJIN_FATAL("Debug assertion failed: " #condition "\nMessage: " msg);   \
}
#else // MIJIN_DEBUG
#define MIJIN_ERROR(...) ((void)0)
#define MIJIN_FATAL(...) std::abort()
#define MIJIN_ASSERT(...) ((void)0)
#define MIJIN_ASSERT_FATAL(...) ((void)0)
#endif // !MIJIN_DEBUG  

//
// public constants
//

//
// public types
//

#if defined(ERROR)
#error "Someone included windows.h! Include mijin/util/winundef.h."
#endif

enum class AssertionResult
{
    ABORT = -1,    // call std::abort()
    ERROR = 0,     // raise an error using MIJIN_ERROR() handling
    IGNORE = 1,    // do nothing
    IGNORE_ALL = 2 // do nothing and nevery halt again (not implemented yet)
};

enum class ErrorHandling
{
    TRAP = 0,
    CONTINUE = 1,
    ABORT = 2
};

#if MIJIN_THROWING_ASSERTS
namespace impl
{
inline std::string formatAssertionExceptionMessage(const char* condition, const char* message, const std::source_location& location)
{
    std::ostringstream oss;
    oss << "Assertion failed!\n"
        << "Condition: " << condition << "\n"
        << "Message:   " << message << "\n"
        << "Location:  " << location.file_name() << ":" << location.line() << ":" << location.column() << "\n"
        << "Function:  " << location.function_name();
    return oss.str();
}

inline std::string formatErrorExceptionMessage(const char* message, const std::source_location& location)
{
    std::ostringstream oss;
    oss << "Mijin error!\n"
        << "Message:   " << message << "\n"
        << "Location:  " << location.file_name() << ":" << location.line() << ":" << location.column() << "\n"
        << "Function:  " << location.function_name();
    return oss.str();
}
}
class AssertionException : public std::runtime_error
{
public:
    AssertionException(const char* condition, const char* message, const std::source_location& location)
        : std::runtime_error(impl::formatAssertionExceptionMessage(condition, message, location))
    {
    }
};

class ErrorException : public std::runtime_error
{
public:
    ErrorException(const char* message, const std::source_location& location)
        : std::runtime_error(impl::formatErrorExceptionMessage(message, location))
    {
    }
};
#endif

//
// public functions
//

#ifdef MIJIN_USE_CUSTOM_ASSERTION_HANDLER
AssertionResult handleAssert(const char* condition,
        const char* message, const std::source_location& location);
#elif MIJIN_THROWING_ASSERTS
inline AssertionResult handleAssert(const char* condition, const char* message, const std::source_location& location)
{
    throw AssertionException(condition, message, location);
}
#else
constexpr AssertionResult handleAssert(const char* /* condition */, const char* /* message */,
                                       const std::source_location& /* location */)
{
    return AssertionResult::ERROR;
}
#endif // MIJIN_USE_CUSTOM_ASSERTION_HANDLER

#ifdef MIJIN_USE_CUSTOM_ERROR_HANDLER
ErrorHandling handleError(const char* message, const std::source_location& location);
#else
inline ErrorHandling handleError(const char* message, const std::source_location& location) MIJIN_NOEXCEPT
{
#if MIJIN_THROWING_ASSERTS
    throw ErrorException(message, location);
#else
    std::puts(message);
    std::printf("Function: %s\n", location.function_name());
    std::printf("Location: %s:%d:%d\n", location.file_name(), location.line(), location.column());
    (void) std::fflush(stdout);
    return ErrorHandling::TRAP;
#endif
}
#endif

} // namespace mijin

#endif // !defined(MIJIN_DEBUG_ASSERT_HPP_INCLUDED)