#include "string.h"

#include "core/math/math.h"
#include "error_macros.h"
#include <stdlib.h>
#include <cstdio>
#include <cstring>

static const int MAX_DECIMALS = 32;

void String::push_back(const char element) {
	ensure_capacity(_size + 1);

	_data[_size++] = element;
	_data[_size] = '\0';
}

void String::pop_back() {
	if (_size == 0) {
		return;
	}

	--_size;

	_data[_size] = '\0';
}

void String::remove(const int index) {
	_data[index] = _data[_size - 1];

	--_size;

	_data[_size] = '\0';
}

void String::erase(const char element) {
	int index = find(element);

	if (index != -1) {
		remove(index);
	}
}

void String::erase(const int start_index, const int length) {
	ERR_FAIL_INDEX(start_index, _size);

	int sil = start_index + length;

	if (sil > _size) {
		sil = _size;
	}

	for (int i = start_index; i < _size; ++i) {
		_data[i] = _data[sil + i];
	}

	_size -= length;

	_data[_size] = '\0';
}

void String::clear() {
	_size = 0;
}

bool String::empty() const {
	return _size == 0;
}

char String::get(const int index) {
	return _data[index];
}

const char String::get(const int index) const {
	return _data[index];
}

void String::set(const int index, const char value) {
	_data[index] = value;
}

int String::size() const {
	return _size;
}

int String::capacity() const {
	return _actual_size;
}

void String::ensure_capacity(const int capacity) {
	if (capacity < _actual_size) {
		return;
	}

	int tsize = capacity + _grow_by;

	char *nd = new char[tsize];

	if (_data) {
		for (int i = 0; i < _size; ++i) {
			nd[i] = _data[i];
		}

		delete[] _data;
	}

	_data = nd;
	_actual_size = tsize;
}

void String::resize(const int s) {
	ensure_capacity(s + 1); // +1 for the null terminator

	_size = s;

	_data[_size] = '\0';
}

int String::find(const char val, const int from) const {
	for (int i = from; i < _size; ++i) {
		if (_data[i] == val) {
			return i;
		}
	}

	return -1;
}

int String::find(const String &val, const int from) const {
	int ve = _size - val.size();

	for (int i = from; i < ve; ++i) {
		bool found = true;
		for (int j = 0; j < val.size(); ++j) {
			if (_data[i + j] != val[j]) {
				found = false;
				break;
			}
		}

		if (found) {
			return i;
		}
	}

	return -1;
}

void String::get_substr(char *into_buf, const int start_index, const int len) {
	ERR_FAIL_INDEX(start_index + len - 1, _size);

	int j = 0;
	for (int i = start_index; i < start_index + len; ++i) {
		into_buf[j++] = _data[i];
	}
}

void String::get_substr_nt(char *into_buf, const int start_index, const int len) {
	ERR_FAIL_INDEX(start_index + len - 1, _size);

	int j = 0;
	for (int i = start_index; i < start_index + len; ++i) {
		into_buf[j++] = _data[i];
	}

	into_buf[len + 1] = '\0';
}

String String::substr(const int start_index, const int len) {
	ERR_FAIL_INDEX_V(start_index, _size, String());

	int sil = start_index + len;

	ERR_FAIL_INDEX_V(sil, _size + 1, String());

	String str;
	str.ensure_capacity(len + 1);
	for (int i = start_index; i < sil; ++i) {
		str._data[str._size++] = _data[i];
	}

	str._data[str._size] = '\0';

	return str;
}

void String::replace_from(const int start_index, const int length, const String &with) {
	ERR_FAIL_INDEX(start_index, _size);

	int sil = start_index + length;

	ERR_FAIL_INDEX(sil, _size + 1);

	if (length < with.size()) {
		int loffs = with.size() - length;

		ensure_capacity(_size + loffs + 1);

		_size += loffs;
		_data[_size] = '\0';

		for (int i = _size - 1; i > start_index + loffs; --i) {
			_data[i] = _data[i - loffs];
		}
	} else if (length > with.size()) {
		int loffs = length - with.size();

		for (int i = start_index + with.size(); i < _size; ++i) {
			_data[i] = _data[i + loffs];
		}

		_size -= loffs;
	}

	for (int i = 0; i < length; ++i) {
		_data[i + start_index] = with._data[i];
	}
}

void String::replace(const String &find_str, const String &with) {
	if (empty()) {
		return;
	}

	if (find_str.empty())
		return;

	int start_pos = 0;
	while ((start_pos = find(find_str, start_pos)) != -1) {
		replace_from(start_pos, find_str.size(), with);
		start_pos += with.size();
	}
}

int String::compare(const String &other) const {
	if (size() < other.size()) {
		return 1;
	} else if (size() > other.size()) {
		return 2;
	} else {
		for (int i = 0; i < _size; ++i) {
			if (_data[i] < other._data[i]) {
				return 1;
			} else if (_data[i] > other._data[i]) {
				return 2;
			}
		}

		return 0;
	}
}

uint8_t String::read_uint8_bytes_at(int &index, bool advance_index) {
	ERR_FAIL_INDEX_V(index, _size, 0);

	if (advance_index) {
		return static_cast<uint8_t>(_data[index++]);
	} else {
		return static_cast<uint8_t>(_data[index]);
	}
}
uint16_t String::read_uint16_bytes_at(int &index, bool advance_index) {
	ERR_FAIL_INDEX_V(index + 1, _size, 0);

	char carr[3];
	char *p = carr;

	//printf("%u %u\n", static_cast<uint8_t>(p[0]),  static_cast<uint8_t>(p[1]));

	get_substr_nt(p, index, 2);

	const uint16_t *vp = static_cast<const uint16_t *>((void *)p);

	if (advance_index) {
		index += 2;
	}

	return *vp;
}
uint32_t String::read_uint32_bytes_at(int &index, bool advance_index) {
	ERR_FAIL_INDEX_V(index + 3, _size, 0);

	char carr[5];
	char *p = carr;

	get_substr_nt(p, index, 4);

	const uint32_t *vp = static_cast<const uint32_t *>((void *)p);

	if (advance_index) {
		index += 4;
	}

	return *vp;
}
uint64_t String::read_uint64_bytes_at(int &index, bool advance_index) {
	ERR_FAIL_INDEX_V(index + 7, _size, 0);

	char carr[9];
	char *p = carr;

	get_substr_nt(p, index, 8);

	const uint64_t *vp = static_cast<const uint64_t *>((void *)p);

	if (advance_index) {
		index += 8;
	}

	return *vp;
}

int8_t String::read_int8_bytes_at(int &index, bool advance_index) {
	ERR_FAIL_INDEX_V(index, _size, 0);

	if (advance_index) {
		return static_cast<int8_t>(_data[index++]);
	} else {
		return static_cast<int8_t>(_data[index]);
	}
}
int16_t String::read_int16_bytes_at(int &index, bool advance_index) {
	ERR_FAIL_INDEX_V(index + 1, _size, 0);

	char carr[3];
	char *p = carr;

	//printf("%u %u\n", static_cast<uint8_t>(p[0]),  static_cast<uint8_t>(p[1]));

	get_substr_nt(p, index, 2);

	const int16_t *vp = static_cast<const int16_t *>((void *)p);

	if (advance_index) {
		index += 2;
	}

	return *vp;
}
int32_t String::read_int32_bytes_at(int &index, bool advance_index) {
	ERR_FAIL_INDEX_V(index + 3, _size, 0);

	char carr[5];
	char *p = carr;

	get_substr_nt(p, index, 4);

	const int32_t *vp = static_cast<const int32_t *>((void *)p);

	if (advance_index) {
		index += 4;
	}

	return *vp;
}
int64_t String::read_int64_bytes_at(int &index, bool advance_index) {
	ERR_FAIL_INDEX_V(index + 7, _size, 0);

	char carr[9];
	char *p = carr;

	get_substr_nt(p, index, 8);

	const int64_t *vp = static_cast<const int64_t *>((void *)p);

	if (advance_index) {
		index += 8;
	}

	return *vp;
}

void String::append_uint8_bytes(const uint8_t val) {
	ensure_capacity(_size + 1);

	_data[_size++] = val;
	_data[_size] = '\0';
}
void String::append_uint16_bytes(const uint16_t val) {
	ensure_capacity(_size + 2);

	const char *vp = static_cast<const char *>((void *)&val);

	//printf("a %u %u\n", static_cast<uint8_t>(vp[0]),  static_cast<uint8_t>(vp[1]));

	memcpy(&_data[_size], vp, 2);

	_size += 2;

	_data[_size] = '\0';
}
void String::append_uint32_bytes(const uint32_t val) {
	ensure_capacity(_size + 4);

	const char *vp = static_cast<const char *>((void *)&val);

	memcpy(&_data[_size], vp, 4);

	_size += 4;

	_data[_size] = '\0';
}
void String::append_uint64_bytes(const uint64_t val) {
	ensure_capacity(_size + 8);

	const char *vp = static_cast<const char *>((void *)&val);

	memcpy(&_data[_size], vp, 8);

	_size += 8;

	_data[_size] = '\0';
}

void String::append_int8_bytes(const int8_t val) {
	ensure_capacity(_size + 1);

	_data[_size++] = val;
	_data[_size] = '\0';
}
void String::append_int16_bytes(const int16_t val) {
	ensure_capacity(_size + 2);

	const char *vp = static_cast<const char *>((void *)&val);

	//printf("a %u %u\n", static_cast<uint8_t>(vp[0]),  static_cast<uint8_t>(vp[1]));

	memcpy(&_data[_size], vp, 2);

	_size += 2;

	_data[_size] = '\0';
}
void String::append_int32_bytes(const int32_t val) {
	ensure_capacity(_size + 4);

	const char *vp = static_cast<const char *>((void *)&val);

	memcpy(&_data[_size], vp, 4);

	_size += 4;

	_data[_size] = '\0';
}
void String::append_int64_bytes(const int64_t val) {
	ensure_capacity(_size + 8);

	const char *vp = static_cast<const char *>((void *)&val);

	memcpy(&_data[_size], vp, 8);

	_size += 8;

	_data[_size] = '\0';
}

float String::read_float_bytes_at(int &index, bool advance_index) {
	ERR_FAIL_INDEX_V(index + 3, _size, 0);

	char carr[5];
	char *p = carr;

	get_substr_nt(p, index, 4);

	const float *vp = static_cast<const float *>((void *)p);

	if (advance_index) {
		index += 4;
	}

	return *vp;
}
void String::append_float_bytes(const float val) {
	ensure_capacity(_size + 4);

	const char *vp = static_cast<const char *>((void *)&val);

	memcpy(&_data[_size], vp, 4);

	_size += 4;

	_data[_size] = '\0';
}

double String::read_double_bytes_at(int &index, bool advance_index) {
	ERR_FAIL_INDEX_V(index + 7, _size, 0);

	char carr[9];
	char *p = carr;

	get_substr_nt(p, index, 8);

	const double *vp = static_cast<const double *>((void *)p);

	if (advance_index) {
		index += 8;
	}

	return *vp;
}
void String::append_double_bytes(const double val) {
	ensure_capacity(_size + 8);

	const char *vp = static_cast<const char *>((void *)&val);

	memcpy(&_data[_size], vp, 8);

	_size += 8;

	_data[_size] = '\0';
}

void String::append_str(const char *str) {
	if (str == nullptr) {
		return;
	}

	int i = 0;

	while (str[i] != '\0') {
		push_back(str[i++]);
	}
}

void String::append_str(const String &other) {
	ensure_capacity(_size + other._size + 1); // +1 for the null terminator

	for (int i = 0; i < other._size; ++i) {
		_data[_size++] = other._data[i];
	}

	_data[_size] = '\0';
}

void String::append_str(const std::string &str) {
	ensure_capacity(_size + str.size() + 1); // +1 for the null terminator

	for (int i = 0; i < str.size(); ++i) {
		_data[_size++] = str[i];
	}

	_data[_size] = '\0';
}

float String::to_float() const {
	return atof(c_str());
}

double String::to_double() const {
	return atof(c_str());
}

int String::to_int() const {
	return atoi(c_str());
}

bool String::is_numeric() const {
	if (_size == 0) {
		return false;
	}

	int starti = 0;

	if (_data[0] == '-') {
		starti += 1;
	}

	bool had_dot = false;
	for (int i = starti; i < _size; ++i) {
		if (_data[i] == '.') {
			if (!had_dot) {
				had_dot = true;
				continue;
			} else {
				return false;
			}
		}

		char c = _data[i];

		if (c < '0' || c > '9') {
			return false;
		}
	}

	return true;
}

bool String::is_int() const {
	if (_size == 0) {
		return false;
	}

	int starti = 0;

	if (_data[0] == '-') {
		starti += 1;
	}

	for (int i = starti; i < _size; ++i) {
		char c = _data[i];

		if (c < '0' || c > '9') {
			return false;
		}
	}

	return true;
}

bool String::is_uint() const {
	if (_size == 0) {
		return false;
	}

	for (int i = 0; i < _size; ++i) {
		char c = _data[i];

		if (c < '0' || c > '9') {
			return false;
		}
	}

	return true;
}

bool String::is_zero() const {
	if (_size == 0) {
		return false;
	}

	int starti = 0;

	if (_data[0] == '-') {
		starti += 1;
	}

	bool had_dot = false;
	for (int i = starti; i < _size; ++i) {
		if (_data[i] == '.') {
			if (!had_dot) {
				had_dot = true;
				continue;
			} else {
				return false;
			}
		}

		char c = _data[i];

		if (c != '0') {
			return false;
		}
	}

	return true;
}

uint32_t String::to_uint() const {
	return static_cast<uint32_t>(atoll(c_str()));
}

std::string String::to_string() const {
	return std::string(c_str());
}

void String::print() const {
	::printf("%s\n", c_str());
}

String String::bool_num(bool val) {
	if (val) {
		return String("1", 2);
	} else {
		return String("0", 2);
	}
}
String String::bool_str(bool val) {
	if (val) {
		return String("true", 5);
	} else {
		return String("false", 6);
	}
}

//Taken from the Godot Engine (MIT License)
//Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.
//Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).
String String::num(double p_num, int p_decimals) {
	if (Math::is_nan(p_num)) {
		return "nan";
	}

	if (Math::is_inf(p_num)) {
		if (signbit(p_num)) {
			return "-inf";
		} else {
			return "inf";
		}
	}

	if (p_decimals < 0) {
		p_decimals = 14;
		const double abs_num = Math::absd(p_num);
		if (abs_num > 10) {
			// We want to align the digits to the above sane default, so we only
			// need to subtract log10 for numbers with a positive power of ten.
			p_decimals -= (int)floor(log10(abs_num));
		}
	}
	if (p_decimals > MAX_DECIMALS) {
		p_decimals = MAX_DECIMALS;
	}

	char fmt[7];
	fmt[0] = '%';
	fmt[1] = '.';

	if (p_decimals < 0) {
		fmt[1] = 'l';
		fmt[2] = 'f';
		fmt[3] = 0;
	} else if (p_decimals < 10) {
		fmt[2] = '0' + p_decimals;
		fmt[3] = 'l';
		fmt[4] = 'f';
		fmt[5] = 0;
	} else {
		fmt[2] = '0' + (p_decimals / 10);
		fmt[3] = '0' + (p_decimals % 10);
		fmt[4] = 'l';
		fmt[5] = 'f';
		fmt[6] = 0;
	}
	char buf[256];

#if defined(__GNUC__) || defined(_MSC_VER)
	snprintf(buf, 256, fmt, p_num);
#else
	sprintf(buf, fmt, p_num);
#endif

	buf[255] = 0;
	//destroy trailing zeroes
	{
		bool period = false;
		int z = 0;
		while (buf[z]) {
			if (buf[z] == '.') {
				period = true;
			}
			z++;
		}

		if (period) {
			z--;
			while (z > 0) {
				if (buf[z] == '0') {
					buf[z] = 0;
				} else if (buf[z] == '.') {
					buf[z] = 0;
					break;
				} else {
					break;
				}

				z--;
			}
		}
	}

	return buf;
}

//Taken from the Godot Engine (MIT License)
//Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.
//Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).
String String::num_int64(int64_t p_num, int base, bool capitalize_hex) {
	bool sign = p_num < 0;

	int64_t n = p_num;

	int chars = 0;
	do {
		n /= base;
		chars++;
	} while (n);

	if (sign) {
		chars++;
	}

	String s;
	s.resize(chars + 1);
	char *c = s.dataw();
	c[chars] = 0;
	n = p_num;
	do {
		int mod = Math::absi(n % base);
		if (mod >= 10) {
			char a = (capitalize_hex ? 'A' : 'a');
			c[--chars] = a + (mod - 10);
		} else {
			c[--chars] = '0' + mod;
		}

		n /= base;
	} while (n);

	if (sign) {
		c[0] = '-';
	}

	return s;
}

//Taken from the Godot Engine (MIT License)
//Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.
//Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).
String String::num_uint64(uint64_t p_num, int base, bool capitalize_hex) {
	uint64_t n = p_num;

	int chars = 0;
	do {
		n /= base;
		chars++;
	} while (n);

	String s;
	s.resize(chars + 1);
	char *c = s.dataw();
	c[chars] = 0;
	n = p_num;
	do {
		int mod = n % base;
		if (mod >= 10) {
			char a = (capitalize_hex ? 'A' : 'a');
			c[--chars] = a + (mod - 10);
		} else {
			c[--chars] = '0' + mod;
		}

		n /= base;
	} while (n);

	return s;
}

//Taken from the Godot Engine (MIT License)
//Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.
//Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).
String String::num_real(double p_num, bool p_trailing) {
	if (Math::is_nan(p_num)) {
		return "nan";
	}

	if (Math::is_inf(p_num)) {
		if (signbit(p_num)) {
			return "-inf";
		} else {
			return "inf";
		}
	}

	String s;
	String sd;

	// Integer part.

	bool neg = p_num < 0;
	p_num = Math::absd(p_num);
	int64_t intn = (int64_t)p_num;

	// Decimal part.

	if (intn != p_num) {
		double dec = p_num - (double)intn;

		int digit = 0;

#ifdef REAL_T_IS_DOUBLE
		int decimals = 14;
		double tolerance = 1e-14;
#else
		int decimals = 6;
		double tolerance = 1e-6;
#endif
		// We want to align the digits to the above sane default, so we only
		// need to subtract log10 for numbers with a positive power of ten.
		if (p_num > 10) {
			decimals -= (int)floor(log10(p_num));
		}

		if (decimals > MAX_DECIMALS) {
			decimals = MAX_DECIMALS;
		}

		// In case the value ends up ending in "99999", we want to add a
		// tiny bit to the value we're checking when deciding when to stop,
		// so we multiply by slightly above 1 (1 + 1e-7 or 1e-15).
		double check_multiplier = 1 + tolerance / 10;

		int64_t dec_int = 0;
		int64_t dec_max = 0;

		while (true) {
			dec *= 10.0;
			dec_int = dec_int * 10 + (int64_t)dec % 10;
			dec_max = dec_max * 10 + 9;
			digit++;

			if ((dec - (double)(int64_t)(dec * check_multiplier)) < tolerance) {
				break;
			}

			if (digit == decimals) {
				break;
			}
		}

		dec *= 10;
		int last = (int64_t)dec % 10;

		if (last > 5) {
			if (dec_int == dec_max) {
				dec_int = 0;
				intn++;
			} else {
				dec_int++;
			}
		}

		String decimal;
		for (int i = 0; i < digit; i++) {
			char num[2] = { 0, 0 };
			num[0] = '0' + dec_int % 10;
			decimal = num + decimal;
			dec_int /= 10;
		}
		sd = '.' + decimal;
	} else if (p_trailing) {
		sd = ".0";
	} else {
		sd = "";
	}

	if (intn == 0) {
		s = "0";
	} else {
		while (intn) {
			char32_t num = '0' + (intn % 10);
			intn /= 10;
			s = num + s;
		}
	}

	s = s + sd;
	if (neg) {
		s = "-" + s;
	}
	return s;
}

//Taken from the Godot Engine (MIT License)
//Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.
//Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).
String String::num_scientific(double p_num) {
	if (Math::is_nan(p_num)) {
		return "nan";
	}

	if (Math::is_inf(p_num)) {
		if (signbit(p_num)) {
			return "-inf";
		} else {
			return "inf";
		}
	}

	char buf[256];

#if defined(__GNUC__) || defined(_MSC_VER)

#if defined(__MINGW32__) && defined(_TWO_DIGIT_EXPONENT) && !defined(_UCRT)
	// MinGW requires _set_output_format() to conform to C99 output for printf
	unsigned int old_exponent_format = _set_output_format(_TWO_DIGIT_EXPONENT);
#endif
	snprintf(buf, 256, "%lg", p_num);

#if defined(__MINGW32__) && defined(_TWO_DIGIT_EXPONENT) && !defined(_UCRT)
	_set_output_format(old_exponent_format);
#endif

#else
	sprintf(buf, "%.16lg", p_num);
#endif

	buf[255] = 0;

	return buf;
}

//Taken from the Godot Engine (MIT License)
//Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.
//Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).
String String::ascii(bool p_allow_extended) const {
	if (!size()) {
		return String();
	}

	String cs;
	cs.resize(size());

	for (int i = 0; i < size(); i++) {
		cs[i] = operator[](i);
	}

	return cs;
}

//Taken from the Godot Engine (MIT License)
//Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.
//Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).
String String::utf8(const char *p_utf8, int p_len) {
	String ret;
	ret.parse_utf8(p_utf8, p_len);

	return ret;
};

//Taken from the Godot Engine (MIT License)
//Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.
//Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).
bool String::parse_utf8(const char *p_utf8, int p_len) {
	//#define _UNICERROR(m_err) print_line("Unicode error: " + String(m_err));

	if (!p_utf8) {
		return true;
	}

	String aux;

	int cstr_size = 0;
	int str_size = 0;

	/* HANDLE BOM (Byte Order Mark) */
	if (p_len < 0 || p_len >= 3) {
		bool has_bom = uint8_t(p_utf8[0]) == 0xEF && uint8_t(p_utf8[1]) == 0xBB && uint8_t(p_utf8[2]) == 0xBF;
		if (has_bom) {
			//just skip it
			if (p_len >= 0) {
				p_len -= 3;
			}
			p_utf8 += 3;
		}
	}

	{
		const char *ptrtmp = p_utf8;
		const char *ptrtmp_limit = &p_utf8[p_len];
		int skip = 0;
		while (ptrtmp != ptrtmp_limit && *ptrtmp) {
			if (skip == 0) {
				uint8_t c = *ptrtmp >= 0 ? *ptrtmp : uint8_t(256 + *ptrtmp);

				/* Determine the number of characters in sequence */
				if ((c & 0x80) == 0) {
					skip = 0;
				} else if ((c & 0xE0) == 0xC0) {
					skip = 1;
				} else if ((c & 0xF0) == 0xE0) {
					skip = 2;
				} else if ((c & 0xF8) == 0xF0) {
					skip = 3;
				} else if ((c & 0xFC) == 0xF8) {
					skip = 4;
				} else if ((c & 0xFE) == 0xFC) {
					skip = 5;
				} else {
					RLOG_ERR("UNICODE_ERROR: invalid skip\n");
					return true; //invalid utf8
				}

				if (skip == 1 && (c & 0x1E) == 0) {
					//printf("overlong rejected\n");
					RLOG_ERR("UNICODE_ERROR: overlong rejected\n");
					return true; //reject overlong
				}

				str_size++;

			} else {
				--skip;
			}

			cstr_size++;
			ptrtmp++;
		}

		if (skip) {
			RLOG_ERR("UNICODE_ERROR: no space left\n");
			return true; //not enough spac
		}
	}

	if (str_size == 0) {
		clear();
		return false;
	}

	ensure_capacity(str_size + 1);
	_size = str_size;

	char *dst = dataw();
	dst[str_size] = 0;

	while (cstr_size) {
		int len = 0;

		/* Determine the number of characters in sequence */
		if ((*p_utf8 & 0x80) == 0) {
			len = 1;
		} else if ((*p_utf8 & 0xE0) == 0xC0) {
			len = 2;
		} else if ((*p_utf8 & 0xF0) == 0xE0) {
			len = 3;
		} else if ((*p_utf8 & 0xF8) == 0xF0) {
			len = 4;
		} else if ((*p_utf8 & 0xFC) == 0xF8) {
			len = 5;
		} else if ((*p_utf8 & 0xFE) == 0xFC) {
			len = 6;
		} else {
			RLOG_ERR("UNICODE_ERROR: invalid len\n");

			return true; //invalid UTF8
		}

		if (len > cstr_size) {
			RLOG_ERR("UNICODE_ERROR: no space left\n");
			return true; //not enough space
		}

		if (len == 2 && (*p_utf8 & 0x1E) == 0) {
			//printf("overlong rejected\n");
			RLOG_ERR("UNICODE_ERROR: no space left\n");
			return true; //reject overlong
		}

		/* Convert the first character */

		uint32_t unichar = 0;

		if (len == 1) {
			unichar = *p_utf8;
		} else {
			unichar = (0xFF >> (len + 1)) & *p_utf8;

			for (int i = 1; i < len; i++) {
				if ((p_utf8[i] & 0xC0) != 0x80) {
					RLOG_ERR("UNICODE_ERROR: invalid utf8\n");
					return true; //invalid utf8
				}
				if (unichar == 0 && i == 2 && ((p_utf8[i] & 0x7F) >> (7 - len)) == 0) {
					RLOG_ERR("UNICODE_ERROR: invalid utf8 overlong\n");
					return true; //no overlong
				}
				unichar = (unichar << 6) | (p_utf8[i] & 0x3F);
			}
		}

		//printf("char %i, len %i\n",unichar,len);
		if (sizeof(wchar_t) == 2 && unichar > 0xFFFF) {
			unichar = ' '; //too long for windows
		}

		*(dst++) = unichar;
		cstr_size -= len;
		p_utf8 += len;
	}

	return false;
}

String String::utf8() const {
	int l = size();
	if (!l) {
		return String();
	}

	const char *d = data();
	int fl = 0;
	for (int i = 0; i < l; i++) {
		uint32_t c = d[i];
		if (c <= 0x7f) { // 7 bits.
			fl += 1;
		} else if (c <= 0x7ff) { // 11 bits
			fl += 2;
		} else if (c <= 0xffff) { // 16 bits
			fl += 3;
		} else if (c <= 0x001fffff) { // 21 bits
			fl += 4;

		} else if (c <= 0x03ffffff) { // 26 bits
			fl += 5;
		} else if (c <= 0x7fffffff) { // 31 bits
			fl += 6;
		}
	}

	String utf8s;
	if (fl == 0) {
		return utf8s;
	}

	utf8s.ensure_capacity(fl + 1);
	utf8s._size = fl;
	uint8_t *cdst = (uint8_t *)utf8s.dataw();

#define APPEND_CHAR(m_c) *(cdst++) = m_c

	for (int i = 0; i < l; i++) {
		uint32_t c = d[i];

		if (c <= 0x7f) { // 7 bits.
			APPEND_CHAR(c);
		} else if (c <= 0x7ff) { // 11 bits

			APPEND_CHAR(uint32_t(0xc0 | ((c >> 6) & 0x1f))); // Top 5 bits.
			APPEND_CHAR(uint32_t(0x80 | (c & 0x3f))); // Bottom 6 bits.
		} else if (c <= 0xffff) { // 16 bits

			APPEND_CHAR(uint32_t(0xe0 | ((c >> 12) & 0x0f))); // Top 4 bits.
			APPEND_CHAR(uint32_t(0x80 | ((c >> 6) & 0x3f))); // Middle 6 bits.
			APPEND_CHAR(uint32_t(0x80 | (c & 0x3f))); // Bottom 6 bits.
		} else if (c <= 0x001fffff) { // 21 bits

			APPEND_CHAR(uint32_t(0xf0 | ((c >> 18) & 0x07))); // Top 3 bits.
			APPEND_CHAR(uint32_t(0x80 | ((c >> 12) & 0x3f))); // Upper middle 6 bits.
			APPEND_CHAR(uint32_t(0x80 | ((c >> 6) & 0x3f))); // Lower middle 6 bits.
			APPEND_CHAR(uint32_t(0x80 | (c & 0x3f))); // Bottom 6 bits.
		} else if (c <= 0x03ffffff) { // 26 bits

			APPEND_CHAR(uint32_t(0xf8 | ((c >> 24) & 0x03))); // Top 2 bits.
			APPEND_CHAR(uint32_t(0x80 | ((c >> 18) & 0x3f))); // Upper middle 6 bits.
			APPEND_CHAR(uint32_t(0x80 | ((c >> 12) & 0x3f))); // middle 6 bits.
			APPEND_CHAR(uint32_t(0x80 | ((c >> 6) & 0x3f))); // Lower middle 6 bits.
			APPEND_CHAR(uint32_t(0x80 | (c & 0x3f))); // Bottom 6 bits.
		} else if (c <= 0x7fffffff) { // 31 bits

			APPEND_CHAR(uint32_t(0xfc | ((c >> 30) & 0x01))); // Top 1 bit.
			APPEND_CHAR(uint32_t(0x80 | ((c >> 24) & 0x3f))); // Upper upper middle 6 bits.
			APPEND_CHAR(uint32_t(0x80 | ((c >> 18) & 0x3f))); // Lower upper middle 6 bits.
			APPEND_CHAR(uint32_t(0x80 | ((c >> 12) & 0x3f))); // Upper lower middle 6 bits.
			APPEND_CHAR(uint32_t(0x80 | ((c >> 6) & 0x3f))); // Lower lower middle 6 bits.
			APPEND_CHAR(uint32_t(0x80 | (c & 0x3f))); // Bottom 6 bits.
		}
	}
#undef APPEND_CHAR
	*cdst = 0; //trailing zero

	return utf8s;
}

char *String::c_str() {
	return _data;
}

const char *String::c_str() const {
	return _data;
}

char *String::dataw() {
	return _data;
}

const char *String::data() const {
	return _data;
}

const char String::operator[](const int index) const {
	return _data[index];
}

char &String::operator[](const int index) {
	return _data[index];
}

String &String::operator+=(const String &b) {
	ensure_capacity(_size + b._size + 1); // +1 for the null terminator

	for (int i = 0; i < b._size; ++i) {
		_data[_size++] = b._data[i];
	}

	_data[_size] = '\0';

	return *this;
}

String &String::operator+=(const char chr) {
	push_back(chr);

	return *this;
}

String &String::operator+=(const char *p_c_str) {
	int i = 0;
	while (p_c_str[i] != '\0') {
		push_back(p_c_str[i]);
		++i;
	}

	return *this;
}

String &String::operator+=(const std::string &b) {
	append_str(b);

	return *this;
}
String operator+(String lhs, const String &rhs) {
	lhs.append_str(rhs);

	return lhs;
}

String operator+(String lhs, const char *rhs) {
	lhs.append_str(rhs);

	return lhs;
}

String operator+(String lhs, const char rhs) {
	lhs.push_back(rhs);

	return lhs;
}

String operator+(String lhs, const std::string &rhs) {
	lhs.append_str(rhs);

	return lhs;
}

bool operator==(const String &a, const String &b) {
	if (a._size != b._size) {
		return false;
	}

	for (int i = 0; i < a._size; ++i) {
		if (a[i] != b[i]) {
			return false;
		}
	}

	return true;
}

bool operator!=(const String &a, const String &b) {
	return !(a == b);
}

bool operator==(const String &a, const char *b) {
	if (a._size == 0) {
		return b[0] == '\0';
	}

	int i = 0;
	while (i < a._size && b[i] != '\0') {
		if (a[i] != b[i]) {
			return false;
		}

		++i;
	}

	if (i != a._size) {
		return false;
	}

	return true;
}

bool operator!=(const String &a, const char *b) {
	return !(a == b);
}

bool operator==(const char *b, const String &a) {
	if (a._size == 0) {
		return b[0] == '\0';
	}

	int i = 0;
	while (i < a._size && b[i] != '\0') {
		if (a[i] != b[i]) {
			return false;
		}

		++i;
	}

	if (i != a._size) {
		return false;
	}

	return true;
}

bool operator!=(const char *b, const String &a) {
	return !(a == b);
}

bool operator==(const String &a, std::string &b) {
	if (a._size != b.size()) {
		return false;
	}

	char *bp = &b[0];

	for (int i = 0; i < a._size; ++i) {
		if (a[i] != bp[i]) {
			return false;
		}
	}

	return true;
}
bool operator!=(const String &a, std::string &b) {
	return !(a == b);
}

bool operator==(std::string &b, const String &a) {
	return (a == b);
}
bool operator!=(std::string &b, const String &a) {
	return !(a == b);
}

bool operator<(const String &a, const String &b) {
	return a.compare(b) == 1;
}
bool operator>(const String &a, const String &b) {
	return a.compare(b) == 2;
}
bool operator<=(const String &a, const String &b) {
	int c = a.compare(b);

	return c == 0 || c == 1;
}
bool operator>=(const String &a, const String &b) {
	int c = a.compare(b);

	return c == 0 || c == 2;
}

String &String::operator=(const String &other) {
	clear();

	append_str(other);

	return *this;
}

String &String::operator=(const std::string &other) {
	clear();

	append_str(other);

	return *this;
}

String &String::operator=(const char *other) {
	clear();

	append_str(other);

	return *this;
}

String::String() {
	_data = nullptr;
	_actual_size = 0;
	_size = 0;
	_grow_by = 100;

	ensure_capacity(100);

	_data[0] = '\0';
}

String::String(const String &other) {
	_data = nullptr;
	_actual_size = 0;
	_size = 0;
	_grow_by = 100;

	//+1 for the null terminator in case its needed
	ensure_capacity(other.size() + 1);

	for (int i = 0; i < other._size; ++i) {
		_data[i] = other._data[i];
	}
	_size = other._size;
	_data[other._size] = '\0';
}

String::String(const String &other, int grow_by) {
	_data = nullptr;
	_actual_size = 0;
	_size = 0;
	_grow_by = grow_by;

	//+1 for the null terminator in case its needed
	ensure_capacity(other.size() + 1);

	for (int i = 0; i < other._size; ++i) {
		_data[i] = other._data[i];
	}

	_size = other._size;

	_data[_size] = '\0';
}

String::String(const char *p_c_str) {
	_data = nullptr;
	_actual_size = 0;
	_size = 0;
	_grow_by = 100;

	append_str(p_c_str);
}

String::String(const char *p_c_str, const int grow_by) {
	_data = nullptr;
	_actual_size = 0;
	_size = 0;
	_grow_by = grow_by;

	append_str(p_c_str);
}

String::String(int prealloc) {
	_data = nullptr;
	_actual_size = 0;
	_size = 0;
	_grow_by = 100;

	ensure_capacity(prealloc);

	_data[0] = '\0';
}

String::String(int prealloc, int grow_by) {
	_data = nullptr;
	_actual_size = 0;
	_size = 0;
	_grow_by = grow_by;

	ensure_capacity(prealloc);

	_data[0] = '\0';
}

String::String(const std::string &str) {
	_data = nullptr;
	_actual_size = 0;
	_size = 0;
	_grow_by = 100;

	append_str(str);
}

String::~String() {
	if (_data) {
		delete[] _data;
		_data = nullptr;
	}
}