/**
 * Copyright © 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 <map>
#include <memory>
#include <phosphor-logging/elog.hpp>
#include <phosphor-logging/log.hpp>
#include <elog-errors.hpp>
#include <xyz/openbmc_project/Sensor/Device/error.hpp>
#include <xyz/openbmc_project/Control/Device/error.hpp>
#include <xyz/openbmc_project/Power/Fault/error.hpp>
#include "names_values.hpp"
#include "ucd90160.hpp"

namespace witherspoon
{
namespace power
{

using namespace std::string_literals;

const auto CLEAR_LOGGED_FAULTS = "clear_logged_faults"s;
const auto MFR_STATUS = "mfr_status"s;

const auto DEVICE_NAME = "UCD90160"s;
const auto DRIVER_NAME = "ucd9000"s;
constexpr auto NUM_PAGES = 16;

namespace fs = std::experimental::filesystem;
using namespace gpio;
using namespace pmbus;
using namespace phosphor::logging;
using namespace sdbusplus::xyz::openbmc_project::Control::Device::Error;
using namespace sdbusplus::xyz::openbmc_project::Sensor::Device::Error;
using namespace sdbusplus::xyz::openbmc_project::Power::Fault::Error;

UCD90160::UCD90160(size_t instance) :
    Device(DEVICE_NAME, instance),
    interface(std::get<ucd90160::pathField>(
                      deviceMap.find(instance)->second),
              DRIVER_NAME,
              instance)
{
    findGPIODevice();
}

void UCD90160::onFailure()
{
    try
    {
        auto voutError = checkVOUTFaults();

        auto pgoodError = checkPGOODFaults(false);

        //Not a voltage or PGOOD fault, but we know something
        //failed so still create an error log.
        if (!voutError && !pgoodError)
        {
            createPowerFaultLog();
        }
    }
    catch (ReadFailure& e)
    {
        if (!accessError)
        {
            commit<ReadFailure>();
            accessError = true;
        }
    }
}

void UCD90160::analyze()
{
    try
    {
        //Note: Voltage faults are always fatal, so they just
        //need to be analyzed in onFailure().

        checkPGOODFaults(true);
    }
    catch (ReadFailure& e)
    {
        if (!accessError)
        {
            commit<ReadFailure>();
            accessError = true;
        }
    }
}

uint16_t UCD90160::readStatusWord()
{
    return interface.read(STATUS_WORD, Type::Debug);
}

uint32_t UCD90160::readMFRStatus()
{
    return interface.read(MFR_STATUS, Type::DeviceDebug);
}

void UCD90160::clearFaults()
{
    try
    {
        interface.write(CLEAR_LOGGED_FAULTS, 1, Type::Base);
    }
    catch (WriteFailure& e)
    {
        if (!accessError)
        {
            log<level::ERR>("UCD90160 clear logged faults command failed");
            commit<WriteFailure>();
            accessError = true;
        }
    }
}

bool UCD90160::checkVOUTFaults()
{
    bool errorCreated = false;
    auto statusWord = readStatusWord();

    //The status_word register has a summary bit to tell us
    //if each page even needs to be checked
    if (!(statusWord & status_word::VOUT_FAULT))
    {
        return errorCreated;
    }

    for (size_t page = 0; page < NUM_PAGES; page++)
    {
        if (isVoutFaultLogged(page))
        {
            continue;
        }

        auto statusVout = interface.insertPageNum(STATUS_VOUT, page);
        uint8_t vout = interface.read(statusVout, Type::Debug);

        //Any bit on is an error
        if (vout)
        {
            auto& railNames = std::get<ucd90160::railNamesField>(
                    deviceMap.find(getInstance())->second);
            auto railName = railNames.at(page);

            util::NamesValues nv;
            nv.add("STATUS_WORD", statusWord);
            nv.add("STATUS_VOUT", vout);
            nv.add("MFR_STATUS", readMFRStatus());

            using metadata = xyz::openbmc_project::Power::Fault::
                    PowerSequencerVoltageFault;

            report<PowerSequencerVoltageFault>(
                    metadata::RAIL(page),
                    metadata::RAIL_NAME(railName.c_str()),
                    metadata::RAW_STATUS(nv.get().c_str()));

            setVoutFaultLogged(page);
            errorCreated = true;
        }
    }

    return errorCreated;
}

bool UCD90160::checkPGOODFaults(bool polling)
{
    bool errorCreated = false;

    //While PGOOD faults could show up in MFR_STATUS (and we could then
    //check the summary bit in STATUS_WORD first), they are edge triggered,
    //and as the device driver sends a clear faults command every time we
    //do a read, we will never see them.  So, we'll have to just read the
    //real time GPI status GPIO.

    //Check only the GPIs configured on this system.
    auto& gpiConfigs = std::get<ucd90160::gpiConfigField>(
            deviceMap.find(getInstance())->second);

    for (const auto& gpiConfig : gpiConfigs)
    {
        auto gpiNum = std::get<ucd90160::gpiNumField>(gpiConfig);
        auto doPoll = std::get<ucd90160::pollField>(gpiConfig);

        //Can skip this one if there is already an error on this input,
        //or we are polling and these inputs don't need to be polled
        //(because errors on them are fatal).
        if (isPGOODFaultLogged(gpiNum) || (polling && !doPoll))
        {
            continue;
        }

        //The real time status is read via the pin ID
        auto pinID = std::get<ucd90160::pinIDField>(gpiConfig);
        auto gpio = gpios.find(pinID);
        Value gpiStatus;

        try
        {
            //The first time through, create the GPIO objects
            if (gpio == gpios.end())
            {
                gpios.emplace(
                        pinID,
                        std::make_unique<GPIO>(
                                gpioDevice, pinID, Direction::input));
                gpio = gpios.find(pinID);
            }

            gpiStatus = gpio->second->read();
        }
        catch (std::exception& e)
        {
            if (!accessError)
            {
                log<level::ERR>(e.what());
                accessError = true;
            }
            continue;
        }

        if (gpiStatus == Value::low)
        {
            auto& gpiName = std::get<ucd90160::gpiNameField>(gpiConfig);
            auto status = (gpiStatus == Value::low) ? 0 : 1;

            util::NamesValues nv;
            nv.add("STATUS_WORD", readStatusWord());
            nv.add("MFR_STATUS", readMFRStatus());
            nv.add("INPUT_STATUS", status);

            using metadata =  xyz::openbmc_project::Power::Fault::
                    PowerSequencerPGOODFault;

            report<PowerSequencerPGOODFault>(
                    metadata::INPUT_NUM(gpiNum),
                    metadata::INPUT_NAME(gpiName.c_str()),
                    metadata::RAW_STATUS(nv.get().c_str()));

            setPGOODFaultLogged(gpiNum);
            errorCreated = true;
        }
    }

    return errorCreated;
}

void UCD90160::createPowerFaultLog()
{
    util::NamesValues nv;
    nv.add("STATUS_WORD", readStatusWord());
    nv.add("MFR_STATUS", readMFRStatus());

    using metadata = xyz::openbmc_project::Power::Fault::
        PowerSequencerFault;

    report<PowerSequencerFault>(
            metadata::RAW_STATUS(nv.get().c_str()));
}

void UCD90160::findGPIODevice()
{
    auto& path = interface.path();

    //In the driver directory, look for a subdirectory
    //named gpiochipX, where X is some number.  Then
    //we'll access the GPIO at /dev/gpiochipX.
    if (fs::is_directory(path))
    {
        for (auto& f : fs::directory_iterator(path))
        {
            if (f.path().filename().string().find("gpiochip") !=
                    std::string::npos)
            {
                gpioDevice = "/dev" / f.path().filename();
                break;
            }
        }
    }

    if (gpioDevice.empty())
    {
        log<level::ERR>("Could not find UCD90160 GPIO device path",
                entry("BASE_PATH=%s", path.c_str()));
    }
}

}
}