/**
 * @file kassert.h
 * @author Travis Vroman (travis@kohiengine.com)
 * @brief This file contains assertion functions to be used throughout
 * the codebase.
 * @version 1.0
 * @date 2022-01-10
 *
 * @copyright Kohi Game Engine is Copyright (c) Travis Vroman 2021-2022
 *
 */

#pragma once

#include "defines.h"

// Disable assertions by commenting out the below line.
#define KASSERTIONS_ENABLED

// Always define kdebug_break in case it is ever needed outside assertions (i.e fatal log errors)
// Try via __has_builtin first.
#if defined(__has_builtin) && !defined(__ibmxl__)
#	if __has_builtin(__builtin_debugtrap)
#		define kdebug_break() __builtin_debugtrap()
#	elif __has_builtin(__debugbreak)
#		define kdebug_break() __debugbreak()
#	endif
#endif

// If not setup, try the old way.
#if !defined(kdebug_break)
#	if defined(__clang__) || defined(__gcc__)
/** @brief Causes a debug breakpoint to be hit. */
#		define kdebug_break() __builtin_trap()
#	elif defined(_MSC_VER)
#		include <intrin.h>
/** @brief Causes a debug breakpoint to be hit. */
#		define kdebug_break() __debugbreak()
#	else
// Fall back to x86/x86_64
#		define kdebug_break() asm { int 3 }
#	endif
#endif

#ifdef KASSERTIONS_ENABLED
/**
 * @brief Reports an assertion failure. Note that this is not the assertion itself,
 * just a reporting of an assertion failure that has already occurred.
 * @param expression The expression to be reported.
 * @param message A custom message to be reported, if provided.
 * @param file The path and name of the file containing the expression.
 * @param line The line number in the file where the assertion failure occurred.
 */
KAPI void report_assertion_failure (const char *expression, const char *message, const char *file, i32 line);

/**
 * @brief Asserts the provided expression to be true, and logs a failure if not.
 * Also triggers a breakpoint if debugging.
 * @param expr The expression to be evaluated.
 */
#	define KASSERT(expr)                                                \
		{                                                                \
			if (expr) {                                                  \
			} else {                                                     \
				report_assertion_failure(#expr, "", __FILE__, __LINE__); \
				kdebug_break();                                          \
			}                                                            \
		}

/**
 * @brief Asserts the provided expression to be true, and logs a failure if not.
 * Allows the user to specify a message to accompany the failure.
 * Also triggers a breakpoint if debugging.
 * @param expr The expression to be evaluated.
 * @param message The message to be reported along with the assertion failure.
 */
#	define KASSERT_MSG(expr, message)                                        \
		{                                                                     \
			if (expr) {                                                       \
			} else {                                                          \
				report_assertion_failure(#expr, message, __FILE__, __LINE__); \
				kdebug_break();                                               \
			}                                                                 \
		}

#	if KOHI_DEBUG
/**
 * @brief Asserts the provided expression to be true, and logs a failure if not.
 * Also triggers a breakpoint if debugging.
 * NOTE: Only included in debug builds; otherwise this is preprocessed out.
 * @param expr The expression to be evaluated.
 */
#		define KASSERT_DEBUG(expr)                                          \
			{                                                                \
				if (expr) {                                                  \
				} else {                                                     \
					report_assertion_failure(#expr, "", __FILE__, __LINE__); \
					kdebug_break();                                          \
				}                                                            \
			}

/**
 * @brief Asserts the provided expression to be true, and logs a failure if not.
 * Allows the user to specify a message to accompany the failure.
 * Also triggers a breakpoint if debugging.
 * NOTE: Only included in debug builds; otherwise this is preprocessed out.
 * @param expr The expression to be evaluated.
 * @param message The message to be reported along with the assertion failure.
 */
#		define KASSERT_DEBUG_MSG(expr, message)                                  \
			{                                                                     \
				if (expr) {                                                       \
				} else {                                                          \
					report_assertion_failure(#expr, message, __FILE__, __LINE__); \
					kdebug_break();                                               \
				}                                                                 \
			}
#	else
#		define KASSERT_DEBUG(expr)				 // Does nothing at all
#		define KASSERT_DEBUG_MSG(expr, message) // Does nothing at all
#	endif

#else
#	define KASSERT(expr)					 // Does nothing at all
#	define KASSERT_MSG(expr, message)		 // Does nothing at all
#	define KASSERT_DEBUG(expr)				 // Does nothing at all
#	define KASSERT_DEBUG_MSG(expr, message) // Does nothing at all
#endif