// Copyright 2023 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <Common/StringUtils/StringUtils.h>
#include <Common/escapeForFileName.h>
#include <Common/hex.h>
#include <common/StringRef.h>

namespace DB
{
std::string escapeForFileName(const StringRef & s)
{
    std::string res;
    const char * pos = s.data;
    const char * end = pos + s.size;

    while (pos != end)
    {
        unsigned char c = *pos;

        if (isWordCharASCII(c))
            res += c;
        else
        {
            res += '%';
            res += hexDigitUppercase(c / 16);
            res += hexDigitUppercase(c % 16);
        }

        ++pos;
    }

    return res;
}

std::string unescapeForFileName(const StringRef & s)
{
    std::string res;
    const char * pos = s.data;
    const char * end = pos + s.size;

    while (pos != end)
    {
        if (!(*pos == '%' && pos + 2 < end))
        {
            res += *pos;
            ++pos;
        }
        else
        {
            ++pos;
            res += unhex2(pos);
            pos += 2;
        }
    }
    return res;
}

} // namespace DB