#ifndef TMP_DEBUG_H
#define TMP_DEBUG_H

/**
 * @file tmp/debug.h
 * @brief compile-time typename to string resolution
 *
 * see: https://stackoverflow.com/questions/81870/is-it-possible-to-print-a-variables-type-in-standard-c
 * see: https://stackoverflow.com/a/20170989
 *
 * Adapted, minimal C++ version supported is C++14
 */

#include <cstdio>
#include "stringview.h"

namespace tmp {

namespace detail {

constexpr unsigned strlen(char const*str) {
	unsigned l = 0;
	while(*str++) ++l;
	return l;
}

}

/**
 * @brief compile-time typename to string resolution
 *
 * @param[in] T type to resolve
 *
 * @return constexpr string_view containing the typename
 *
 * TODO this function has not been tested for Windows
 */
template<typename T>
constexpr string_view typeName() {
#if defined(__clang__)
	string_view p = __PRETTY_FUNCTION__;
	constexpr auto leftDummy = detail::strlen("tmp::string_view tmp::typeName() [T = ");
	constexpr auto rightDummy = detail::strlen("]");
#elif defined(__GNUC__)
	string_view p = __PRETTY_FUNCTION__;
	constexpr auto leftDummy = detail::strlen("constexpr tmp::string_view tmp::typeName() [with T = ");
	constexpr auto rightDummy = detail::strlen("]");
#elif defined(_MSC_VER)
	string_view p = __FUNCSIG__;
	constexpr auto leftDummy = detail::strlen("");
	constexpr auto rightDummy = detail::strlen("");
#else
	return {"[err: tmp::typeNameF is not implemented for your compiler]"};
#endif

#if defined(__clang__) || defined(__GNUC__) || defined(__MSC_VER)
	return string_view(p.data() + leftDummy, p.size() - leftDummy - rightDummy);
#endif
}

template<typename... As, typename... Ts>
std::string strTypes(Ts...) {
	using Fold = int[];
	std::string result;
	static_cast<void>(Fold{(result += std::string{typeName<As>()} + ", ", 0)...});
	static_cast<void>(Fold{(result += std::string{typeName<Ts>()} + ", ", 0)...});
	if(result.empty())  return "";
	else                return result.substr(0, result.size()-2);
}

template<typename... As, typename... Ts>
void printTypes(Ts...) {
	std::puts(strTypes<As..., Ts...>().c_str());
}

}

#endif