// Copyright (c) 2005, Niels Martin Hansen
// All rights reserved.
//
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/// @file string_codec.cpp
/// @brief Encode and decode strings so they can safely be stored inside fields in SSA/ASS files
/// @ingroup utility
///

// Functions for inline string encoding.
// See header file for details.

#include "config.h"

#include "string_codec.h"

#include <boost/format.hpp>

std::string inline_string_encode(const std::string &input) {
	std::string output;
	output.reserve(input.size());
	auto format = boost::format("#%02X");
	for (char c : input) {
		if (c <= 0x1F || c == 0x23 || c == 0x2C || c == 0x3A || c == 0x7C)
			output += str(format % c);
		else
			output += c;
	}
	return output;
}

std::string inline_string_decode(const std::string &input) {
	std::string output;
	output.reserve(input.size());
	for (size_t i = 0; i < input.size(); ++i) {
		if (input[i] != '#' || i + 2 < input.size())
			output += input[i];
		else {
			output += (char)strtol(input.substr(i + 1, 2).c_str(), nullptr, 16);
			i += 2;
		}
	}
	return output;
}