/**
 * Copyright 2017 Google 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 <cstring>
#include <iostream>
#include <libconfig.h++>
#include <map>
#include <memory>

/* Configuration. */
#include "conf.hpp"

#include "interfaces.hpp"
#include "manager.hpp"
#include "util.hpp"

#include "dbus/dbuspassive.hpp"
#include "notimpl/readonly.hpp"
#include "notimpl/writeonly.hpp"
#include "sysfs/sysfsread.hpp"
#include "sensors/manager.hpp"
#include "sensors/host.hpp"
#include "sensors/pluggable.hpp"
#include "sysfs/sysfswrite.hpp"


static constexpr bool deferSignals = true;

std::shared_ptr<SensorManager> BuildSensors(
    std::map<std::string, struct sensor>& Config)
{
    auto mgmr = std::make_shared<SensorManager>();
    auto& HostSensorBus = mgmr->getHostBus();
    auto& PassiveListeningBus = mgmr->getPassiveBus();

    for (auto& it : Config)
    {
        std::unique_ptr<ReadInterface> ri;
        std::unique_ptr<WriteInterface> wi;

        std::string name = it.first;
        struct sensor* info = &it.second;

        std::cerr << "Sensor: " << name << " " << info->type << " ";
        std::cerr << info->readpath << " " << info->writepath << "\n";

        IOInterfaceType rtype = GetReadInterfaceType(info->readpath);
        IOInterfaceType wtype = GetWriteInterfaceType(info->writepath);

        // fan sensors can be ready any way and written others.
        // fan sensors are the only sensors this is designed to write.
        // Nothing here should be write-only, although, in theory a fan could be.
        // I'm just not sure how that would fit together.
        // TODO(venture): It should check with the ObjectMapper to check if
        // that sensor exists on the Dbus.
        switch (rtype)
        {
            case IOInterfaceType::DBUSPASSIVE:
                ri = std::make_unique<DbusPassive>(
                         PassiveListeningBus,
                         info->type,
                         name);
                break;
            case IOInterfaceType::EXTERNAL:
                // These are a special case for read-only.
                break;
            case IOInterfaceType::SYSFS:
                ri = std::make_unique<SysFsRead>(info->readpath);
                break;
            default:
                ri = std::make_unique<WriteOnly>();
                break;
        }

        if (info->type == "fan")
        {
            switch (wtype)
            {
                case IOInterfaceType::SYSFS:
                    if (info->max > 0)
                    {
                        wi = std::make_unique<SysFsWritePercent>(
                                 info->writepath,
                                 info->min,
                                 info->max);
                    }
                    else
                    {
                        wi = std::make_unique<SysFsWrite>(
                                 info->writepath,
                                 info->min,
                                 info->max);
                    }

                    break;
                default:
                    wi = std::make_unique<ReadOnlyNoExcept>();
                    break;
            }

            auto sensor = std::make_unique<PluggableSensor>(
                              name,
                              info->timeout,
                              std::move(ri),
                              std::move(wi));
            mgmr->addSensor(info->type, name, std::move(sensor));
        }
        else if (info->type == "temp" || info->type == "margin")
        {
            // These sensors are read-only, but only for this application
            // which only writes to fan sensors.
            std::cerr << info->type << " readpath: " << info->readpath << "\n";

            if (IOInterfaceType::EXTERNAL == rtype)
            {
                std::cerr << "Creating HostSensor: " << name
                          << " path: " << info->readpath << "\n";

                /*
                 * The reason we handle this as a HostSensor is because it's
                 * not quite pluggable; but maybe it could be.
                 */
                auto sensor = HostSensor::CreateTemp(
                                  name,
                                  info->timeout,
                                  HostSensorBus,
                                  info->readpath.c_str(),
                                  deferSignals);
                mgmr->addSensor(info->type, name, std::move(sensor));
            }
            else
            {
                wi = std::make_unique<ReadOnlyNoExcept>();
                auto sensor = std::make_unique<PluggableSensor>(
                                  name,
                                  info->timeout,
                                  std::move(ri),
                                  std::move(wi));
                mgmr->addSensor(info->type, name, std::move(sensor));
            }
        }
    }

    return mgmr;
}

/*
 * If there's a configuration file, we build from that, and it requires special
 * parsing.  I should just ditch the compile-time version to reduce the
 * probability of sync bugs.
 */
std::shared_ptr<SensorManager> BuildSensorsFromConfig(std::string& path)
{
    using namespace libconfig;

    std::map<std::string, struct sensor> config;
    Config cfg;

    std::cerr << "entered BuildSensorsFromConfig\n";

    /* The load was modeled after the example source provided. */
    try
    {
        cfg.readFile(path.c_str());
    }
    catch (const FileIOException& fioex)
    {
        std::cerr << "I/O error while reading file: " << fioex.what() << std::endl;
        throw;
    }
    catch (const ParseException& pex)
    {
        std::cerr << "Parse error at " << pex.getFile() << ":" << pex.getLine()
                  << " - " << pex.getError() << std::endl;
        throw;
    }

    try
    {
        const Setting& root = cfg.getRoot();

        /* Grab the list of sensors and create them all */
        const Setting& sensors = root["sensors"];
        int count = sensors.getLength();

        for (int i = 0; i < count; ++i)
        {
            const Setting& sensor = sensors[i];

            std::string name;
            struct sensor thisOne;

            /* Not a super fan of using this library for run-time configuration. */
            name = sensor.lookup("name").c_str();
            thisOne.type = sensor.lookup("type").c_str();
            thisOne.readpath = sensor.lookup("readpath").c_str();
            thisOne.writepath = sensor.lookup("writepath").c_str();

            /* TODO: Document why this is wonky.  The library probably doesn't
             * like int64_t
             */
            int min = sensor.lookup("min");
            thisOne.min = static_cast<int64_t>(min);
            int max = sensor.lookup("max");
            thisOne.max = static_cast<int64_t>(max);
            int timeout = sensor.lookup("timeout");
            thisOne.timeout = static_cast<int64_t>(timeout);

            // leaving for verification for now.  and yea the above is
            // necessary.
            std::cerr << "min: " << min
                    << " max: " << max
                    << " savedmin: " << thisOne.min
                    << " savedmax: " << thisOne.max
                    << " timeout: " << thisOne.timeout
                    << std::endl;

            config[name] = thisOne;
        }
    }
    catch (const SettingTypeException &setex)
    {
        std::cerr << "Setting '" << setex.getPath()
                  << "' type exception!" << std::endl;
        throw;
    }
    catch (const SettingNotFoundException& snex)
    {
        std::cerr << "Setting not found!" << std::endl;
        throw;
    }

    return BuildSensors(config);
}