#pragma once

class wxString;

#if defined(_MSC_VER) && _MSC_VER <= 1800
#define snprintf _snprintf
#endif

namespace fmt
{
	//struct empty_t{};

	//extern const std::string placeholder;

	template <typename T>
	std::string AfterLast(const std::string& source, T searchstr)
	{
		size_t search_pos = source.rfind(searchstr);
		search_pos = search_pos == std::string::npos ? 0 : search_pos;
		return source.substr(search_pos);
	}

	template <typename T>
	std::string BeforeLast(const std::string& source, T searchstr)
	{
		size_t search_pos = source.rfind(searchstr);
		search_pos = search_pos == std::string::npos ? 0 : search_pos;
		return source.substr(0, search_pos);
	}

	template <typename T>
	std::string AfterFirst(const std::string& source, T searchstr)
	{
		size_t search_pos = source.find(searchstr);
		search_pos = search_pos == std::string::npos ? 0 : search_pos;
		return source.substr(search_pos);
	}

	template <typename T>
	std::string BeforeFirst(const std::string& source, T searchstr)
	{
		size_t search_pos = source.find(searchstr);
		search_pos = search_pos == std::string::npos ? 0 : search_pos;
		return source.substr(0, search_pos);
	}

	// write `fmt` from `pos` to the first occurence of `fmt::placeholder` to
	// the stream `os`. Then write `arg` to to the stream. If there's no
	// `fmt::placeholder` after `pos` everything in `fmt` after pos is written
	// to `os`. Then `arg` is written to `os` after appending a space character
	//template<typename T>
	//empty_t write(const std::string &fmt, std::ostream &os, std::string::size_type &pos, T &&arg)
	//{
	//	std::string::size_type ins = fmt.find(placeholder, pos);

	//	if (ins == std::string::npos)
	//	{
	//		os.write(fmt.data() + pos, fmt.size() - pos);
	//		os << ' ' << arg;

	//		pos = fmt.size();
	//	}
	//	else
	//	{
	//		os.write(fmt.data() + pos, ins - pos);
	//		os << arg;

	//		pos = ins + placeholder.size();
	//	}
	//	return{};
	//}

	// typesafe version of a sprintf-like function. Returns the printed to
	// string. To mark positions where the arguments are supposed to be
	// inserted use `fmt::placeholder`. If there's not enough placeholders
	// the rest of the arguments are appended at the end, seperated by spaces
	//template<typename  ... Args>
	//std::string SFormat(const std::string &fmt, Args&& ... parameters)
	//{
	//	std::ostringstream os;
	//	std::string::size_type pos = 0;
	//	std::initializer_list<empty_t> { write(fmt, os, pos, parameters)... };

	//	if (!fmt.empty())
	//	{
	//		os.write(fmt.data() + pos, fmt.size() - pos);
	//	}

	//	std::string result = os.str();
	//	return result;
	//}

	std::string replace_first(const std::string& src, const std::string& from, const std::string& to);
	std::string replace_all(const std::string &src, const std::string& from, const std::string& to);

	template<size_t list_size>
	std::string replace_all(std::string src, const std::pair<std::string, std::string>(&list)[list_size])
	{
		for (size_t pos = 0; pos < src.length(); ++pos)
		{
			for (size_t i = 0; i < list_size; ++i)
			{
				const size_t comp_length = list[i].first.length();

				if (src.length() - pos < comp_length)
					continue;

				if (src.substr(pos, comp_length) == list[i].first)
				{
					src = (pos ? src.substr(0, pos) + list[i].second : list[i].second) + src.substr(pos + comp_length);
					pos += list[i].second.length() - 1;
					break;
				}
			}
		}

		return src;
	}

	template<size_t list_size>
	std::string replace_all(std::string src, const std::pair<std::string, std::function<std::string()>>(&list)[list_size])
	{
		for (size_t pos = 0; pos < src.length(); ++pos)
		{
			for (size_t i = 0; i < list_size; ++i)
			{
				const size_t comp_length = list[i].first.length();

				if (src.length() - pos < comp_length)
					continue;

				if (src.substr(pos, comp_length) == list[i].first)
				{
					src = (pos ? src.substr(0, pos) + list[i].second() : list[i].second()) + src.substr(pos + comp_length);
					pos += list[i].second().length() - 1;
					break;
				}
			}
		}

		return src;
	}

	std::string to_hex(u64 value, size_t count = 1);
	std::string to_udec(u64 value);
	std::string to_sdec(s64 value);

	template<typename T, bool is_enum = std::is_enum<T>::value> struct unveil
	{
		using result_type = T;

		force_inline static result_type get_value(const T& arg)
		{
			return arg;
		}
	};

	template<> struct unveil<char*, false>
	{
		using result_type = const char*;

		force_inline static result_type get_value(const char* arg)
		{
			return arg;
		}
	};

	template<std::size_t N> struct unveil<const char[N], false>
	{
		using result_type = const char*;

		force_inline static result_type get_value(const char(&arg)[N])
		{
			return arg;
		}
	};

	template<> struct unveil<std::string, false>
	{
		using result_type = const char*;

		force_inline static result_type get_value(const std::string& arg)
		{
			return arg.c_str();
		}
	};

	template<typename T> struct unveil<T, true>
	{
		using result_type = std::underlying_type_t<T>;

		force_inline static result_type get_value(const T& arg)
		{
			return static_cast<result_type>(arg);
		}
	};

	template<typename T, bool Se> struct unveil<se_t<T, Se>, false>
	{
		using result_type = typename unveil<T>::result_type;

		force_inline static result_type get_value(const se_t<T, Se>& arg)
		{
			return unveil<T>::get_value(arg);
		}
	};

	template<typename T>
	force_inline typename unveil<T>::result_type do_unveil(const T& arg)
	{
		return unveil<T>::get_value(arg);
	}

	// Formatting function with special functionality:
	//
	// std::string is forced to .c_str()
	// be_t<> is forced to .value() (fmt::do_unveil reverts byte order automatically)
	//
	// External specializations for fmt::do_unveil (can be found in another headers):
	// vm::ptr, vm::bptr, ... (fmt::do_unveil) (vm_ptr.h) (with appropriate address type, using .addr() can be avoided)
	// vm::ref, vm::bref, ... (fmt::do_unveil) (vm_ref.h)
	//
	template<typename... Args> safe_buffers std::string format(const char* fmt, Args... args)
	{
		// fixed stack buffer for the first attempt
		std::array<char, 4096> fixed_buf;

		// possibly dynamically allocated buffer for the second attempt
		std::unique_ptr<char[]> buf;

		// pointer to the current buffer
		char* buf_addr = fixed_buf.data();

		for (std::size_t buf_size = fixed_buf.size();;)
		{
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wformat-security"
			const std::size_t len = std::snprintf(buf_addr, buf_size, fmt, do_unveil(args)...);

#pragma GCC diagnostic pop

			if (len > INT_MAX)
			{
				throw std::runtime_error("std::snprintf() failed");
			}

			if (len < buf_size)
			{
				return{ buf_addr, len };
			}

			buf.reset(buf_addr = new char[buf_size = len + 1]);
		}
	}

	struct exception : public std::exception
	{
		std::unique_ptr<char[]> message;

		template<typename... Args> never_inline safe_buffers exception(const char* file, int line, const char* func, const char* text, Args... args) noexcept
		{
			const std::string data = format(text, args...) + format("\n(in file %s:%d, in function %s)", file, line, func);

			message.reset(new char[data.size() + 1]);

			std::memcpy(message.get(), data.c_str(), data.size() + 1);
		}

		exception(const exception& other) noexcept
		{
			const std::size_t size = std::strlen(other.message.get());

			message.reset(new char[size + 1]);

			std::memcpy(message.get(), other.message.get(), size + 1);
		}

		virtual const char* what() const noexcept override
		{
			return message.get();
		}
	};

	//convert a wxString to a std::string encoded in utf8
	//CAUTION, only use this to interface with wxWidgets classes
	std::string ToUTF8(const wxString& right);

	//convert a std::string encoded in utf8 to a wxString
	//CAUTION, only use this to interface with wxWidgets classes
	wxString FromUTF8(const std::string& right);

	//TODO: remove this after every snippet that uses it is gone
	//WARNING: not fully compatible with CmpNoCase from wxString
	int CmpNoCase(const std::string& a, const std::string& b);

	//TODO: remove this after every snippet that uses it is gone
	//WARNING: not fully compatible with Replace from wxString
	void Replace(std::string &str, const std::string &searchterm, const std::string& replaceterm);

	std::vector<std::string> rSplit(const std::string& source, const std::string& delim);

	std::vector<std::string> split(const std::string& source, std::initializer_list<std::string> separators, bool is_skip_empty = true);
	std::string trim(const std::string& source, const std::string& values = " \t");

	template<typename T>
	std::string merge(const T& source, const std::string& separator)
	{
		if (!source.size())
		{
			return{};
		}

		std::string result;

		auto it = source.begin();
		auto end = source.end();
		for (--end; it != end; ++it)
		{
			result += *it + separator;
		}

		return result + source.back();
	}

	template<typename T>
	std::string merge(std::initializer_list<T> sources, const std::string& separator)
	{
		if (!sources.size())
		{
			return{};
		}

		std::string result;
		bool first = true;

		for (auto &v : sources)
		{
			if (first)
			{
				result = fmt::merge(v, separator);
				first = false;
			}
			else
			{
				result += separator + fmt::merge(v, separator);
			}
		}

		return result;
	}

	std::string tolower(std::string source);
	std::string toupper(std::string source);
	std::string escape(std::string source);
}