// Copyright 2013 Facebook, Inc. Licensed under Apache License 2.0

#pragma once

#include <algorithm>
#include <cctype>
#include <cstdarg>
#include <cstdint>
#include <cstdio>
#include <cstring>
#include <format>
#include <iostream>
#include <sstream>
#include <string>
#include <tuple>
#include <vector>

// String formatting with variable arguments - creates formatted string from format specifier and arguments
const std::string vStringFormat(const char* format, va_list args)
{
	std::string output;
	va_list tmpargs;

	va_copy(tmpargs, args);
	int characters_used = vsnprintf(nullptr, 0, format, tmpargs);
	va_end(tmpargs);

	// Looks like we have a valid format string
	if (characters_used > 0) {
		output.resize(characters_used + 1);

		va_copy(tmpargs, args);
		characters_used = vsnprintf(&output[0], output.capacity(), format, tmpargs);
		va_end(tmpargs);

		output.resize(characters_used);

		// Format error handling - return empty string if error occurred
		if (characters_used < 0)
			output.clear();
	}
	return output;
}

// Convert string to lowercase - returns new lowercase string
const std::string str_tolower(std::string s)
{
	std::transform(
		s.begin(), s.end(), s.begin(),
		[](unsigned char c) { return ::tolower(c); }
	);
	return s;
}

// Split string by delimiter - returns vector of substrings
std::vector<std::string> split(std::string str_to_split, char delimiter)
{
	std::stringstream ss(str_to_split);
	std::string item;
	std::vector<std::string> exploded_values;
	while (std::getline(ss, item, delimiter)) {
		exploded_values.push_back(item);
	}

	return exploded_values;
}

// Convert string to uppercase - returns new uppercase string
const std::string str_toupper(std::string s)
{
	std::transform(
		s.begin(), s.end(), s.begin(),
		[](unsigned char c) { return ::toupper(c); }
	);
	return s;
}

// Capitalize first character - returns string with first character uppercase
const std::string ucfirst(std::string s)
{
	std::string output = s;
	if (!s.empty())
		output[0] = static_cast<char>(::toupper(s[0]));

	return output;
}

// Format string with printf-style arguments - creates formatted string
const std::string StringFormat(const char *format, ...)
{
	va_list args;
	va_start(args, format);
	std::string output = vStringFormat(format, args);
	va_end(args);
	return output;
}

// Split string by delimiter - alternative implementation returning vector of substrings
std::vector<std::string> SplitString(const std::string &str, char delim)
{
	std::vector<std::string> ret;
	std::stringstream ss(str);
	std::string item;

	while(std::getline(ss, item, delim)) {
		ret.push_back(item);
	}

	return ret;
}

// Join vector of strings with glue string - concatenates strings with separator
std::string implode(std::string glue, std::vector<std::string> src)
{
	if (src.empty()) {
		return {};
	}

	std::ostringstream output;
	std::vector<std::string>::iterator src_iter;

	for (src_iter = src.begin(); src_iter != src.end(); src_iter++) {
		output << *src_iter << glue;
	}

	std::string final_output = output.str();
	final_output.resize(output.str().size() - glue.size());

	return final_output;
}

// Escape special characters in string - adds backslash escapes for special characters
std::string EscapeString(const std::string &s)
{
	std::string ret;

	size_t sz = s.length();
	for(size_t i = 0; i < sz; ++i) {
		char c = s[i];
		switch(c) {
		case '\x00':
			ret += "\\x00";
			break;
		case '\n':
			ret += "\\n";
			break;
		case '\r':
			ret += "\\r";
			break;
		case '\\':
			ret += "\\\\";
			break;
		case '\'':
			ret += "\\'";
			break;
		case '\"':
			ret += "\\\"";
			break;
		case '\x1a':
			ret += "\\x1a";
			break;
		default:
			ret.push_back(c);
			break;
		}
	}

	return ret;
}

// Escape special characters in C string - adds backslash escapes for special characters
std::string EscapeString(const char *src, size_t sz)
{
	std::string ret;

	for(size_t i = 0; i < sz; ++i) {
		char c = src[i];
		switch(c) {
		case '\x00':
			ret += "\\x00";
			break;
		case '\n':
			ret += "\\n";
			break;
		case '\r':
			ret += "\\r";
			break;
		case '\\':
			ret += "\\\\";
			break;
		case '\'':
			ret += "\\'";
			break;
		case '\"':
			ret += "\\\"";
			break;
		case '\x1a':
			ret += "\\x1a";
			break;
		default:
			ret.push_back(c);
			break;
		}
	}

	return ret;
}

// Check if string represents a number - returns true if string can be converted to double
bool StringIsNumber(const std::string &s)
{
	try {
		auto r = stod(s);
		return true;
	}
	catch (std::exception &) {
		return false;
	}
}

// Convert string to lowercase in-place - modifies original string
void ToLowerString(std::string &s)
{
	std::transform(s.begin(), s.end(), s.begin(), ::tolower);
}

// Convert string to uppercase in-place - modifies original string
void ToUpperString(std::string &s)
{
	std::transform(s.begin(), s.end(), s.begin(), ::toupper);
}

// Join vector of strings with delimiter - concatenates strings with separator
std::string JoinString(const std::vector<std::string>& ar, const std::string &delim)
{
	std::string ret;
	for (size_t i = 0; i < ar.size(); ++i) {
		if (i != 0) {
			ret += delim;
		}

		ret += ar[i];
	}

	return ret;
}

// Find and replace all occurrences in string - replaces search string with replacement string
void find_replace(std::string &string_subject, const std::string &search_string, const std::string &replace_string)
{
	if (string_subject.find(search_string) == std::string::npos) {
		return;
	}

	size_t start_pos = 0;
	while((start_pos = string_subject.find(search_string, start_pos)) != std::string::npos) {
		string_subject.replace(start_pos, search_string.length(), replace_string);
		start_pos += replace_string.length();
	}
}

// Parse account string format - extracts account and login server from colon-separated string
void ParseAccountString(const std::string &s, std::string &account, std::string &loginserver)
{
	auto split = SplitString(s, ':');
	if (split.size() == 2) {
		loginserver = split[0];
		account = split[1];
	}
	else if(split.size() == 1) {
		account = split[0];
	}
}

// String copy with null termination - copies string ensuring null termination
char* strn0cpy(char* dest, const char* source, std::uint32_t size)
{
	if (!dest)
		return 0;
	if (size == 0 || source == 0) {
		dest[0] = 0;
		return dest;
	}
	strncpy(dest, source, size);
	dest[size - 1] = 0;
	return dest;
}

// String copy with truncation check - copies string and returns whether it was truncated
bool strn0cpyt(char* dest, const char* source, std::uint32_t size)
{
	if (!dest)
		return 0;
	if (size == 0 || source == 0) {
		dest[0] = 0;
		return false;
	}
	strncpy(dest, source, size);
	dest[size - 1] = 0;
	return (bool)(source[strlen(dest)] == 0);
}

// Convert string to lowercase using static buffer - returns pointer to lowercase string
const char *MakeLowerString(const char *source)
{
	static char str[128];
	if (!source)
		return nullptr;
	MakeLowerString(source, str);
	return str;
}

// Convert string to lowercase into target buffer - writes lowercase string to target
void MakeLowerString(const char *source, char *target)
{
	if (!source || !target) {
		*target = 0;
		return;
	}
	while (*source) {
		*target = tolower(*source);
		target++; source++;
	}
	*target = 0;
}

// Allocate and format string of any length - dynamically allocates buffer for formatted string
int MakeAnyLenString(char** ret, const char* format, ...)
{
	int buf_len = 128;
	int chars = -1;
	va_list argptr, tmpargptr;
	va_start(argptr, format);
	while (chars == -1 || chars >= buf_len) {
		delete[] *ret;
		if (chars == -1)
			buf_len *= 2;
		else
			buf_len = chars + 1;
		*ret = new char[buf_len];
		va_copy(tmpargptr, argptr);
		chars = vsnprintf(*ret, buf_len, format, tmpargptr);
	}
	va_end(argptr);
	return chars;
}

// Append formatted string to existing buffer - extends buffer and appends formatted text
std::uint32_t AppendAnyLenString(char** ret, std::uint32_t* bufsize, std::uint32_t* strlen, const char* format, ...)
{
	if (*bufsize == 0)
		*bufsize = 256;
	if (*ret == 0)
		*strlen = 0;
	int chars = -1;
	char* oldret = 0;
	va_list argptr, tmpargptr;
	va_start(argptr, format);
	while (chars == -1 || chars >= (int32_t)(*bufsize - *strlen)) {
		if (chars == -1)
			*bufsize += 256;
		else
			*bufsize += chars + 25;
		oldret = *ret;
		*ret = new char[*bufsize];
		if (oldret) {
			if (*strlen)
				memcpy(*ret, oldret, *strlen);
			delete[] oldret;
		}
		va_copy(tmpargptr, argptr);
		chars = vsnprintf(&(*ret)[*strlen], (*bufsize - *strlen), format, tmpargptr);
	}
	va_end(argptr);
	*strlen += chars;
	return *strlen;
}

// Convert hexadecimal string to integer - parses hex string to 32-bit unsigned integer
std::uint32_t hextoi(const char* num)
{
	if (num == nullptr)
		return 0;

	int len = strlen(num);
	if (len < 3)
		return 0;

	if (num[0] != '0' || (num[1] != 'x' && num[1] != 'X'))
		return 0;

	std::uint32_t ret = 0;
	int mul = 1;
	for (int i = len - 1; i >= 2; i--) {
		if (num[i] >= 'A' && num[i] <= 'F')
			ret += ((num[i] - 'A') + 10) * mul;
		else if (num[i] >= 'a' && num[i] <= 'f')
			ret += ((num[i] - 'a') + 10) * mul;
		else if (num[i] >= '0' && num[i] <= '9')
			ret += (num[i] - '0') * mul;
		else
			return 0;
		mul *= 16;
	}
	return ret;
}

// Convert hexadecimal string to 64-bit integer - parses hex string to 64-bit unsigned integer
std::uint64_t hextoi64(const char* num)
{
	if (num == nullptr)
		return 0;

	int len = strlen(num);
	if (len < 3)
		return 0;

	if (num[0] != '0' || (num[1] != 'x' && num[1] != 'X'))
		return 0;

	std::uint64_t ret = 0;
	int mul = 1;
	for (int i = len - 1; i >= 2; i--) {
		if (num[i] >= 'A' && num[i] <= 'F')
			ret += ((num[i] - 'A') + 10) * mul;
		else if (num[i] >= 'a' && num[i] <= 'f')
			ret += ((num[i] - 'a') + 10) * mul;
		else if (num[i] >= '0' && num[i] <= '9')
			ret += (num[i] - '0') * mul;
		else
			return 0;
		mul *= 16;
	}
	return ret;
}

// Convert string to boolean - parses various boolean representations to bool
bool atobool(const char* iBool)
{
	if (iBool == nullptr)
		return false;
	if (!strcasecmp(iBool, "true"))
		return true;
	if (!strcasecmp(iBool, "false"))
		return false;
	if (!strcasecmp(iBool, "yes"))
		return true;
	if (!strcasecmp(iBool, "no"))
		return false;
	if (!strcasecmp(iBool, "on"))
		return true;
	if (!strcasecmp(iBool, "off"))
		return false;
	if (!strcasecmp(iBool, "enable"))
		return true;
	if (!strcasecmp(iBool, "disable"))
		return false;
	if (!strcasecmp(iBool, "enabled"))
		return true;
	if (!strcasecmp(iBool, "disabled"))
		return false;
	if (!strcasecmp(iBool, "y"))
		return true;
	if (!strcasecmp(iBool, "n"))
		return false;
	if (atoi(iBool))
		return true;
	return false;
}

// Clean mob name for display - removes non-alphabetic characters and converts underscores to spaces
char *CleanMobName(const char *in, char *out)
{
	unsigned i, j;

	for (i = j = 0; i < strlen(in); i++) {
		// Convert _ to space - other conversions may be added here
		if (in[i] == '_') {
			out[j++] = ' ';
		}
		else {
			// Only keep alphabetic characters and backticks - skip numbers and other characters
			if (isalpha(in[i]) || (in[i] == '`'))
				out[j++] = in[i];
		}
	}
	out[j] = 0;	// Terminate the string before returning
	return out;
}

// Remove apostrophes from string in-place - replaces apostrophes with underscores
void RemoveApostrophes(std::string &s)
{
	for (unsigned int i = 0; i < s.length(); ++i)
		if (s[i] == '\'')
			s[i] = '_';
}

// Remove apostrophes from C string - creates new string with apostrophes replaced by underscores
char *RemoveApostrophes(const char *s)
{
	auto NewString = new char[strlen(s) + 1];

	strcpy(NewString, s);

	for (unsigned int i = 0; i < strlen(NewString); ++i)
		if (NewString[i] == '\'')
			NewString[i] = '_';

	return NewString;
}

// Convert integer to string - formats integer as string in provided buffer
const char *ConvertArray(int input, char *returnchar)
{
	sprintf(returnchar, "%i", input);
	return returnchar;
}

// Convert float to string - formats float as string with 2 decimal places in provided buffer
const char *ConvertArrayF(float input, char *returnchar)
{
	sprintf(returnchar, "%0.2f", input);
	return returnchar;
}

// Check if string contains only alphanumeric characters - returns true if all characters are letters or digits
bool isAlphaNumeric(const char *text)
{
	for (unsigned int charIndex = 0; charIndex < strlen(text); charIndex++) {
		if ((text[charIndex] < 'a' || text[charIndex] > 'z') &&
			(text[charIndex] < 'A' || text[charIndex] > 'Z') &&
			(text[charIndex] < '0' || text[charIndex] > '9'))
			return false;
	}

	return true;
}

// Inline utility functions for string trimming

// Trim whitespace from left side of string - removes leading whitespace characters
inline std::string &ltrim(std::string &str, const std::string &chars = "\t\n\v\f\r ")
{
	str.erase(0, str.find_first_not_of(chars));
	return str;
}

// Trim whitespace from right side of string - removes trailing whitespace characters
inline std::string &rtrim(std::string &str, const std::string &chars = "\t\n\v\f\r ")
{
	str.erase(str.find_last_not_of(chars) + 1);
	return str;
}

// Trim whitespace from both sides of string - removes leading and trailing whitespace
inline std::string &trim(std::string &str, const std::string &chars = "\t\n\v\f\r ")
{
	return ltrim(rtrim(str, chars), chars);
}

// Template function to join vector elements with encapsulation - joins elements with glue and wraps each in encapsulation characters
template <typename T>
std::string implode(const std::string &glue, const std::pair<char, char> &encapsulation, const std::vector<T> &src)
{
	if (src.empty()) {
		return {};
	}

	std::ostringstream oss;
	
	for (const T &src_iter : src) {
		oss << encapsulation.first << src_iter << encapsulation.second << glue;
	}

	std::string output(oss.str());
	output.resize(output.size() - glue.size());
	
	return output;
}

// Template function to join vector of pairs - formats pairs with encapsulation and glue
template <typename T1, typename T2>
std::vector<std::string> join_pair(const std::string &glue, const std::pair<char, char> &encapsulation, const std::vector<std::pair<T1, T2>> &src)
{
	if (src.empty()) {
		return {};
	}

	std::vector<std::string> output;

	for (const std::pair<T1, T2> &src_iter : src) {
		output.push_back(
			std::format(
				"{}{}{}{}{}{}{}",
				encapsulation.first,
				src_iter.first,
				encapsulation.second,
				glue,
				encapsulation.first,
				src_iter.second,
				encapsulation.second
			)
		);
	}

	return output;
}

// Template function to join vector of tuples - formats 4-tuples with encapsulation and glue
template <typename T1, typename T2, typename T3, typename T4>
std::vector<std::string> join_tuple(const std::string &glue, const std::pair<char, char> &encapsulation, const std::vector<std::tuple<T1, T2, T3, T4>> &src)
{
	if (src.empty()) {
		return {};
	}

	std::vector<std::string> output;

	for (const std::tuple<T1, T2, T3, T4> &src_iter : src) {
		output.push_back(
			std::format(
				"{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}",
				encapsulation.first,
				std::get<0>(src_iter),
				encapsulation.second,
				glue,
				encapsulation.first,
				std::get<1>(src_iter),
				encapsulation.second,
				glue,
				encapsulation.first,
				std::get<2>(src_iter),
				encapsulation.second,
				glue,
				encapsulation.first,
				std::get<3>(src_iter),
				encapsulation.second
			)
		);
	}

	return output;
}