/**
 * Copyright (C) 2017 IBM Corporation
 *
 * 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 "targeting.hpp"

#include <endian.h>

#include <experimental/filesystem>
#include <phosphor-logging/elog-errors.hpp>
#include <phosphor-logging/elog.hpp>
#include <phosphor-logging/log.hpp>
#include <regex>
#include <xyz/openbmc_project/Common/File/error.hpp>

namespace openpower
{
namespace targeting
{

using namespace phosphor::logging;
namespace fs = std::experimental::filesystem;
namespace file_error = sdbusplus::xyz::openbmc_project::Common::File::Error;

int Target::getCFAMFD()
{
    if (cfamFD.get() == nullptr)
    {
        cfamFD =
            std::make_unique<openpower::util::FileDescriptor>(getCFAMPath());
    }

    return cfamFD->get();
}

std::unique_ptr<Target>& Targeting::getTarget(size_t pos)
{
    auto search = [pos](const auto& t) { return t->getPos() == pos; };

    auto target = find_if(targets.begin(), targets.end(), search);
    if (target == targets.end())
    {
        throw std::runtime_error("Target not found: " + std::to_string(pos));
    }
    else
    {
        return *target;
    }
}

static uint32_t noEndianSwap(uint32_t data)
{
    return data;
}

static uint32_t endianSwap(uint32_t data)
{
    return htobe32(data);
}

Targeting::Targeting(const std::string& fsiMasterDev,
                     const std::string& fsiSlaveDir) :
    fsiMasterPath(fsiMasterDev),
    fsiSlaveBasePath(fsiSlaveDir)
{
    swap_endian_t swapper = endianSwap;
    std::regex exp{"fsi1/slave@([0-9]{2}):00", std::regex::extended};

    if (!fs::exists(fsiMasterPath))
    {
        std::regex expOld{"hub@00/slave@([0-9]{2}):00", std::regex::extended};

        // Fall back to old (4.7) path
        exp = expOld;
        fsiMasterPath = fsiMasterDevPathOld;
        fsiSlaveBasePath = fsiSlaveBaseDirOld;

        // And don't swap the endianness of CFAM data
        swapper = noEndianSwap;
    }

    // Always create P0, the FSI master.
    targets.push_back(std::make_unique<Target>(0, fsiMasterPath, swapper));
    try
    {
        // Find the the remaining P9s dynamically based on which files show up
        for (auto& file : fs::directory_iterator(fsiSlaveBasePath))
        {
            std::smatch match;
            std::string path = file.path();
            if (std::regex_search(path, match, exp))
            {
                auto pos = atoi(match[1].str().c_str());
                if (pos == 0)
                {
                    log<level::ERR>("Unexpected FSI slave device name found",
                                    entry("DEVICE_NAME=%s", path.c_str()));
                    continue;
                }

                path += "/raw";

                targets.push_back(std::make_unique<Target>(pos, path, swapper));
            }
        }
    }
    catch (fs::filesystem_error& e)
    {
        using metadata = xyz::openbmc_project::Common::File::Open;

        elog<file_error::Open>(metadata::ERRNO(e.code().value()),
                               metadata::PATH(e.path1().c_str()));
    }

    auto sortTargets = [](const std::unique_ptr<Target>& left,
                          const std::unique_ptr<Target>& right) {
        return left->getPos() < right->getPos();
    };
    std::sort(targets.begin(), targets.end(), sortTargets);
}

} // namespace targeting
} // namespace openpower