/**
* Relational pipes
* Copyright © 2022 František Kučera (Frantovo.cz, GlobalCode.info)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <iomanip>
#include <iostream>
#include <sstream>
#include <vector>
#include <stdexcept>
namespace relpipe {
namespace out {
namespace mqtt {
class Hex {
private:
Hex() {
}
static char fromHex(wchar_t ch) {
if (L'0' <= ch && ch <= L'9') return ch - L'0';
else if (L'a' <= ch && ch <= L'f') return ch - L'a' + 10;
else throw std::invalid_argument("Unable to decode hexadeximal string.");
}
public:
static std::stringstream fromHex(const std::wstring& hex) {
std::stringstream octets;
char octet = 0;
for (size_t i = 0, limit = hex.size(); i < limit; i++) {
if (i % 2 == 0) {
octet = fromHex(hex[i]) << 4;
} else {
octet += fromHex(hex[i]);
octets.put(octet);
}
}
return octets;
}
static std::wstring toHex(const std::string& octets) {
std::wstring_convert < codecvt_utf8<wchar_t>> convertor; // TODO: do not create converter each time
std::stringstream hex;
hex << std::hex << std::setfill('0') << std::hex;
for (size_t i = 0, size = octets.size(); i < size; i++) hex << std::setw(2) << (0xff & octets[i]);
return convertor.from_bytes(hex.str());
}
static std::wstring toTxt(const std::string& octets, bool* validEncoding = nullptr) {
std::wstring_convert < codecvt_utf8<wchar_t>> convertor; // TODO: do not create converter each time
try {
if (validEncoding) *validEncoding = true;
// TODO: use encoding from the HTTP response headers instead of the constant one?
return convertor.from_bytes(octets);
} catch (...) {
if (validEncoding) *validEncoding = false;
std::stringstream filtered;
for (char ch : octets) filtered << (ch >= ' ' && ch < 127 ? ch : '.');
return convertor.from_bytes(filtered.str());
}
}
};
}
}
}