// Copyright 2022 Google LLC
//
// 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 <flashupdate/version.hpp>

#include <charconv>
#include <format>
#include <span>

namespace flashupdate
{
namespace version
{

std::string Version::format()
{
    return std::format("{}.{}.{}.{}", major, minor, point, subpoint);
}

uint32_t Version::splitVersionChunk(std::string_view& version)
{
    if (version.empty())
    {
        throw std::runtime_error(
            std::format("Empty version string, got {}.{}.{}.{} so far.", major,
                        minor, point, subpoint));
    }

    auto index = version.find('.');
    auto sub = version.substr(0, index);
    uint32_t num;
    auto [ptr, ec]{std::from_chars(version.begin(), version.end(), num)};
    if (ec != std::errc())
    {
        throw std::runtime_error(
            std::format("failed to convert string `{}` to uint32_t: {}", sub,
                        std::make_error_code(ec).message()));
    }
    if (ptr != version.begin() + sub.size())
    {
        throw std::runtime_error(
            std::format("converted invalid characters: {}", sub));
    }

    version = ptr + (index == std::string::npos ? 0 : 1);
    return num;
}

Version::Version(std::string_view version) :
    major(splitVersionChunk(version)), minor(splitVersionChunk(version)),
    point(splitVersionChunk(version)), subpoint(splitVersionChunk(version))
{}

} // namespace version
} // namespace flashupdate