/**
 * Copyright (c) 2021-2022 Huawei Device Co., Ltd.
 * 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.
 */

#ifndef LIBPANDABASE_UTILS_UTILS_H
#define LIBPANDABASE_UTILS_UTILS_H

#include <exception>
#include <string>

namespace panda {
// ----------------------------------------------------------------------------
// General helper functions

// Returns the value (0 .. 15) of a hexadecimal character c.
// If c is not a legal hexadecimal character, returns a value < 0.
inline uint32_t HexValue(uint32_t c)
{
    constexpr uint32_t BASE16 = 16;
    constexpr uint32_t BASE10 = 10;
    constexpr uint32_t MASK = 0x20;

    c -= '0';
    if (static_cast<unsigned>(c) < BASE10) {
        return c;
    }
    // NOLINTNEXTLINE(hicpp-signed-bitwise)
    c = (c | MASK) - ('a' - '0');
    if (static_cast<unsigned>(c) < (BASE16 - BASE10)) {
        return c + BASE10;
    }
    return -1;
}

// General helper class
class UnreachableException : public std::exception {
public:
    explicit UnreachableException(const char *msg) : msg_(msg) {}
    explicit UnreachableException(const std::string_view &msg) : msg_(msg) {}
    const char *what() const noexcept override
    {
        return msg_.c_str();
    }

private:
    std::string msg_;
};

}  // namespace panda

#endif  // LIBPANDABASE_UTILS_UTILS_H