/*
// Copyright (c) 2018 Intel 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.
*/

#pragma once

#include "app.hpp"
#include "dbus_utility.hpp"
#include "generated/enums/resource.hpp"
#include "query.hpp"
#include "registries/privilege_registry.hpp"
#include "utils/collection.hpp"
#include "utils/dbus_utils.hpp"
#include "utils/pcie_util.hpp"

#include <boost/system/linux_error.hpp>
#include <boost/url/format.hpp>
#include <sdbusplus/asio/property.hpp>
#include <sdbusplus/unpack_properties.hpp>

#include <limits>

namespace redfish
{

static constexpr const char* inventoryPath = "/xyz/openbmc_project/inventory";
static constexpr std::array<std::string_view, 1> pcieDeviceInterface = {
    "xyz.openbmc_project.Inventory.Item.PCIeDevice"};
static constexpr std::array<std::string_view, 1> pcieSlotInterface = {
    "xyz.openbmc_project.Inventory.Item.PCIeSlot"};

static inline void handlePCIeDevicePath(
    const std::string& pcieDeviceId,
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const dbus::utility::MapperGetSubTreePathsResponse& pcieDevicePaths,
    const std::function<void(const std::string& pcieDevicePath,
                             const std::string& service)>& callback)

{
    for (const std::string& pcieDevicePath : pcieDevicePaths)
    {
        std::string pciecDeviceName =
            sdbusplus::message::object_path(pcieDevicePath).filename();
        if (pciecDeviceName.empty() || pciecDeviceName != pcieDeviceId)
        {
            continue;
        }

        dbus::utility::getDbusObject(
            pcieDevicePath, {},
            [pcieDevicePath, asyncResp,
             callback](const boost::system::error_code& ec,
                       const dbus::utility::MapperGetObject& object) {
                if (ec || object.empty())
                {
                    BMCWEB_LOG_ERROR("DBUS response error {}", ec);
                    messages::internalError(asyncResp->res);
                    return;
                }
                callback(pcieDevicePath, object.begin()->first);
            });
        return;
    }

    BMCWEB_LOG_WARNING("PCIe Device not found");
    messages::resourceNotFound(asyncResp->res, "PCIeDevice", pcieDeviceId);
}

static inline void getValidPCIeDevicePath(
    const std::string& pcieDeviceId,
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const std::function<void(const std::string& pcieDevicePath,
                             const std::string& service)>& callback)
{
    dbus::utility::getSubTreePaths(
        inventoryPath, 0, pcieDeviceInterface,
        [pcieDeviceId, asyncResp,
         callback](const boost::system::error_code& ec,
                   const dbus::utility::MapperGetSubTreePathsResponse&
                       pcieDevicePaths) {
            if (ec)
            {
                BMCWEB_LOG_ERROR("D-Bus response error on GetSubTree {}", ec);
                messages::internalError(asyncResp->res);
                return;
            }
            handlePCIeDevicePath(pcieDeviceId, asyncResp, pcieDevicePaths,
                                 callback);
            return;
        });
}

static inline void handlePCIeDeviceCollectionGet(
    crow::App& app, const crow::Request& req,
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const std::string& systemName)
{
    if (!redfish::setUpRedfishRoute(app, req, asyncResp))
    {
        return;
    }
    if constexpr (BMCWEB_EXPERIMENTAL_REDFISH_MULTI_COMPUTER_SYSTEM)
    {
        // Option currently returns no systems.  TBD
        messages::resourceNotFound(asyncResp->res, "ComputerSystem",
                                   systemName);
        return;
    }
    if (systemName != BMCWEB_REDFISH_SYSTEM_URI_NAME)
    {
        messages::resourceNotFound(asyncResp->res, "ComputerSystem",
                                   systemName);
        return;
    }

    asyncResp->res.addHeader(boost::beast::http::field::link,
                             "</redfish/v1/JsonSchemas/PCIeDeviceCollection/"
                             "PCIeDeviceCollection.json>; rel=describedby");
    asyncResp->res.jsonValue["@odata.type"] =
        "#PCIeDeviceCollection.PCIeDeviceCollection";
    asyncResp->res.jsonValue["@odata.id"] = std::format(
        "/redfish/v1/Systems/{}/PCIeDevices", BMCWEB_REDFISH_SYSTEM_URI_NAME);
    asyncResp->res.jsonValue["Name"] = "PCIe Device Collection";
    asyncResp->res.jsonValue["Description"] = "Collection of PCIe Devices";

    pcie_util::getPCIeDeviceList(asyncResp,
                                 nlohmann::json::json_pointer("/Members"));
}

inline void requestRoutesSystemPCIeDeviceCollection(App& app)
{
    /**
     * Functions triggers appropriate requests on DBus
     */
    BMCWEB_ROUTE(app, "/redfish/v1/Systems/<str>/PCIeDevices/")
        .privileges(redfish::privileges::getPCIeDeviceCollection)
        .methods(boost::beast::http::verb::get)(
            std::bind_front(handlePCIeDeviceCollectionGet, std::ref(app)));
}

inline void addPCIeSlotProperties(
    crow::Response& res, const boost::system::error_code& ec,
    const dbus::utility::DBusPropertiesMap& pcieSlotProperties)
{
    if (ec)
    {
        BMCWEB_LOG_ERROR("DBUS response error for getAllProperties{}",
                         ec.value());
        messages::internalError(res);
        return;
    }
    std::string generation;
    size_t lanes = 0;
    std::string slotType;

    bool success = sdbusplus::unpackPropertiesNoThrow(
        dbus_utils::UnpackErrorPrinter(), pcieSlotProperties, "Generation",
        generation, "Lanes", lanes, "SlotType", slotType);

    if (!success)
    {
        messages::internalError(res);
        return;
    }

    std::optional<pcie_device::PCIeTypes> pcieType =
        pcie_util::redfishPcieGenerationFromDbus(generation);
    if (!pcieType)
    {
        BMCWEB_LOG_WARNING("Unknown PCIeType: {}", generation);
    }
    else
    {
        if (*pcieType == pcie_device::PCIeTypes::Invalid)
        {
            BMCWEB_LOG_ERROR("Invalid PCIeType: {}", generation);
            messages::internalError(res);
            return;
        }
        res.jsonValue["Slot"]["PCIeType"] = *pcieType;
    }

    if (lanes != 0)
    {
        res.jsonValue["Slot"]["Lanes"] = lanes;
    }

    std::optional<pcie_slots::SlotTypes> redfishSlotType =
        pcie_util::dbusSlotTypeToRf(slotType);
    if (!redfishSlotType)
    {
        BMCWEB_LOG_WARNING("Unknown PCIeSlot Type: {}", slotType);
    }
    else
    {
        if (*redfishSlotType == pcie_slots::SlotTypes::Invalid)
        {
            BMCWEB_LOG_ERROR("Invalid PCIeSlot type: {}", slotType);
            messages::internalError(res);
            return;
        }
        res.jsonValue["Slot"]["SlotType"] = *redfishSlotType;
    }
}

inline void getPCIeDeviceSlotPath(
    const std::string& pcieDevicePath,
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    std::function<void(const std::string& pcieDeviceSlot)>&& callback)
{
    std::string associationPath = pcieDevicePath + "/contained_by";
    dbus::utility::getAssociatedSubTreePaths(
        associationPath, sdbusplus::message::object_path(inventoryPath), 0,
        pcieSlotInterface,
        [callback = std::move(callback), asyncResp, pcieDevicePath](
            const boost::system::error_code& ec,
            const dbus::utility::MapperGetSubTreePathsResponse& endpoints) {
            if (ec)
            {
                if (ec.value() == EBADR)
                {
                    // Missing association is not an error
                    return;
                }
                BMCWEB_LOG_ERROR(
                    "DBUS response error for getAssociatedSubTreePaths {}",
                    ec.value());
                messages::internalError(asyncResp->res);
                return;
            }
            if (endpoints.size() > 1)
            {
                BMCWEB_LOG_ERROR(
                    "PCIeDevice is associated with more than one PCIeSlot: {}",
                    endpoints.size());
                messages::internalError(asyncResp->res);
                return;
            }
            if (endpoints.empty())
            {
                // If the device doesn't have an association, return without
                // PCIe Slot properties
                BMCWEB_LOG_DEBUG("PCIeDevice is not associated with PCIeSlot");
                return;
            }
            callback(endpoints[0]);
        });
}

inline void afterGetDbusObject(
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const std::string& pcieDeviceSlot, const boost::system::error_code& ec,
    const dbus::utility::MapperGetObject& object)
{
    if (ec || object.empty())
    {
        BMCWEB_LOG_ERROR("DBUS response error for getDbusObject {}",
                         ec.value());
        messages::internalError(asyncResp->res);
        return;
    }
    sdbusplus::asio::getAllProperties(
        *crow::connections::systemBus, object.begin()->first, pcieDeviceSlot,
        "xyz.openbmc_project.Inventory.Item.PCIeSlot",
        [asyncResp](
            const boost::system::error_code& ec2,
            const dbus::utility::DBusPropertiesMap& pcieSlotProperties) {
            addPCIeSlotProperties(asyncResp->res, ec2, pcieSlotProperties);
        });
}

inline void afterGetPCIeDeviceSlotPath(
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const std::string& pcieDeviceSlot)
{
    dbus::utility::getDbusObject(
        pcieDeviceSlot, pcieSlotInterface,
        [asyncResp,
         pcieDeviceSlot](const boost::system::error_code& ec,
                         const dbus::utility::MapperGetObject& object) {
            afterGetDbusObject(asyncResp, pcieDeviceSlot, ec, object);
        });
}

inline void getPCIeDeviceHealth(
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const std::string& pcieDevicePath, const std::string& service)
{
    sdbusplus::asio::getProperty<bool>(
        *crow::connections::systemBus, service, pcieDevicePath,
        "xyz.openbmc_project.State.Decorator.OperationalStatus", "Functional",
        [asyncResp](const boost::system::error_code& ec, const bool value) {
            if (ec)
            {
                if (ec.value() != EBADR)
                {
                    BMCWEB_LOG_ERROR("DBUS response error for Health {}",
                                     ec.value());
                    messages::internalError(asyncResp->res);
                }
                return;
            }

            if (!value)
            {
                asyncResp->res.jsonValue["Status"]["Health"] =
                    resource::Health::Critical;
            }
        });
}

inline void getPCIeDeviceState(
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const std::string& pcieDevicePath, const std::string& service)
{
    sdbusplus::asio::getProperty<bool>(
        *crow::connections::systemBus, service, pcieDevicePath,
        "xyz.openbmc_project.Inventory.Item", "Present",
        [asyncResp](const boost::system::error_code& ec, bool value) {
            if (ec)
            {
                if (ec.value() != EBADR)
                {
                    BMCWEB_LOG_ERROR("DBUS response error for State");
                    messages::internalError(asyncResp->res);
                }
                return;
            }

            if (!value)
            {
                asyncResp->res.jsonValue["Status"]["State"] =
                    resource::State::Absent;
            }
        });
}

inline void getPCIeDeviceAsset(
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const std::string& pcieDevicePath, const std::string& service)
{
    sdbusplus::asio::getAllProperties(
        *crow::connections::systemBus, service, pcieDevicePath,
        "xyz.openbmc_project.Inventory.Decorator.Asset",
        [pcieDevicePath, asyncResp{asyncResp}](
            const boost::system::error_code& ec,
            const dbus::utility::DBusPropertiesMap& assetList) {
            if (ec)
            {
                if (ec.value() != EBADR)
                {
                    BMCWEB_LOG_ERROR("DBUS response error for Properties{}",
                                     ec.value());
                    messages::internalError(asyncResp->res);
                }
                return;
            }

            const std::string* manufacturer = nullptr;
            const std::string* model = nullptr;
            const std::string* partNumber = nullptr;
            const std::string* serialNumber = nullptr;
            const std::string* sparePartNumber = nullptr;

            const bool success = sdbusplus::unpackPropertiesNoThrow(
                dbus_utils::UnpackErrorPrinter(), assetList, "Manufacturer",
                manufacturer, "Model", model, "PartNumber", partNumber,
                "SerialNumber", serialNumber, "SparePartNumber",
                sparePartNumber);

            if (!success)
            {
                messages::internalError(asyncResp->res);
                return;
            }

            if (manufacturer != nullptr)
            {
                asyncResp->res.jsonValue["Manufacturer"] = *manufacturer;
            }
            if (model != nullptr)
            {
                asyncResp->res.jsonValue["Model"] = *model;
            }

            if (partNumber != nullptr)
            {
                asyncResp->res.jsonValue["PartNumber"] = *partNumber;
            }

            if (serialNumber != nullptr)
            {
                asyncResp->res.jsonValue["SerialNumber"] = *serialNumber;
            }

            if (sparePartNumber != nullptr && !sparePartNumber->empty())
            {
                asyncResp->res.jsonValue["SparePartNumber"] = *sparePartNumber;
            }
        });
}

inline void addPCIeDeviceProperties(
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const std::string& pcieDeviceId,
    const dbus::utility::DBusPropertiesMap& pcieDevProperties)
{
    const std::string* generationInUse = nullptr;
    const std::string* generationSupported = nullptr;
    const size_t* lanesInUse = nullptr;
    const size_t* maxLanes = nullptr;

    const bool success = sdbusplus::unpackPropertiesNoThrow(
        dbus_utils::UnpackErrorPrinter(), pcieDevProperties, "GenerationInUse",
        generationInUse, "GenerationSupported", generationSupported,
        "LanesInUse", lanesInUse, "MaxLanes", maxLanes);

    if (!success)
    {
        messages::internalError(asyncResp->res);
        return;
    }

    if (generationInUse != nullptr)
    {
        std::optional<pcie_device::PCIeTypes> redfishGenerationInUse =
            pcie_util::redfishPcieGenerationFromDbus(*generationInUse);

        if (!redfishGenerationInUse)
        {
            BMCWEB_LOG_WARNING("Unknown PCIe Device Generation: {}",
                               *generationInUse);
        }
        else
        {
            if (*redfishGenerationInUse == pcie_device::PCIeTypes::Invalid)
            {
                BMCWEB_LOG_ERROR("Invalid PCIe Device Generation: {}",
                                 *generationInUse);
                messages::internalError(asyncResp->res);
                return;
            }
            asyncResp->res.jsonValue["PCIeInterface"]["PCIeType"] =
                *redfishGenerationInUse;
        }
    }

    if (generationSupported != nullptr)
    {
        std::optional<pcie_device::PCIeTypes> redfishGenerationSupported =
            pcie_util::redfishPcieGenerationFromDbus(*generationSupported);

        if (!redfishGenerationSupported)
        {
            BMCWEB_LOG_WARNING("Unknown PCIe Device Generation: {}",
                               *generationSupported);
        }
        else
        {
            if (*redfishGenerationSupported == pcie_device::PCIeTypes::Invalid)
            {
                BMCWEB_LOG_ERROR("Invalid PCIe Device Generation: {}",
                                 *generationSupported);
                messages::internalError(asyncResp->res);
                return;
            }
            asyncResp->res.jsonValue["PCIeInterface"]["MaxPCIeType"] =
                *redfishGenerationSupported;
        }
    }

    if (lanesInUse != nullptr)
    {
        if (*lanesInUse == std::numeric_limits<size_t>::max())
        {
            // The default value of LanesInUse is "maxint", and the field will
            // be null if it is a default value.
            asyncResp->res.jsonValue["PCIeInterface"]["LanesInUse"] = nullptr;
        }
        else
        {
            asyncResp->res.jsonValue["PCIeInterface"]["LanesInUse"] =
                *lanesInUse;
        }
    }
    // The default value of MaxLanes is 0, and the field will be
    // left as off if it is a default value.
    if (maxLanes != nullptr && *maxLanes != 0)
    {
        asyncResp->res.jsonValue["PCIeInterface"]["MaxLanes"] = *maxLanes;
    }

    asyncResp->res.jsonValue["PCIeFunctions"]["@odata.id"] =
        boost::urls::format(
            "/redfish/v1/Systems/{}/PCIeDevices/{}/PCIeFunctions",
            BMCWEB_REDFISH_SYSTEM_URI_NAME, pcieDeviceId);
}

inline void getPCIeDeviceProperties(
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const std::string& pcieDevicePath, const std::string& service,
    const std::function<void(
        const dbus::utility::DBusPropertiesMap& pcieDevProperties)>&& callback)
{
    sdbusplus::asio::getAllProperties(
        *crow::connections::systemBus, service, pcieDevicePath,
        "xyz.openbmc_project.Inventory.Item.PCIeDevice",
        [asyncResp,
         callback](const boost::system::error_code& ec,
                   const dbus::utility::DBusPropertiesMap& pcieDevProperties) {
            if (ec)
            {
                if (ec.value() != EBADR)
                {
                    BMCWEB_LOG_ERROR("DBUS response error for Properties");
                    messages::internalError(asyncResp->res);
                }
                return;
            }
            callback(pcieDevProperties);
        });
}

inline void addPCIeDeviceCommonProperties(
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const std::string& pcieDeviceId)
{
    asyncResp->res.addHeader(
        boost::beast::http::field::link,
        "</redfish/v1/JsonSchemas/PCIeDevice/PCIeDevice.json>; rel=describedby");
    asyncResp->res.jsonValue["@odata.type"] = "#PCIeDevice.v1_9_0.PCIeDevice";
    asyncResp->res.jsonValue["@odata.id"] =
        boost::urls::format("/redfish/v1/Systems/{}/PCIeDevices/{}",
                            BMCWEB_REDFISH_SYSTEM_URI_NAME, pcieDeviceId);
    asyncResp->res.jsonValue["Name"] = "PCIe Device";
    asyncResp->res.jsonValue["Id"] = pcieDeviceId;
    asyncResp->res.jsonValue["Status"]["State"] = resource::State::Enabled;
    asyncResp->res.jsonValue["Status"]["Health"] = resource::Health::OK;
}

inline void afterGetValidPcieDevicePath(
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const std::string& pcieDeviceId, const std::string& pcieDevicePath,
    const std::string& service)
{
    addPCIeDeviceCommonProperties(asyncResp, pcieDeviceId);
    getPCIeDeviceAsset(asyncResp, pcieDevicePath, service);
    getPCIeDeviceState(asyncResp, pcieDevicePath, service);
    getPCIeDeviceHealth(asyncResp, pcieDevicePath, service);
    getPCIeDeviceProperties(
        asyncResp, pcieDevicePath, service,
        std::bind_front(addPCIeDeviceProperties, asyncResp, pcieDeviceId));
    getPCIeDeviceSlotPath(
        pcieDevicePath, asyncResp,
        std::bind_front(afterGetPCIeDeviceSlotPath, asyncResp));
}

inline void handlePCIeDeviceGet(
    App& app, const crow::Request& req,
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const std::string& systemName, const std::string& pcieDeviceId)
{
    if (!redfish::setUpRedfishRoute(app, req, asyncResp))
    {
        return;
    }
    if constexpr (BMCWEB_EXPERIMENTAL_REDFISH_MULTI_COMPUTER_SYSTEM)
    {
        // Option currently returns no systems.  TBD
        messages::resourceNotFound(asyncResp->res, "ComputerSystem",
                                   systemName);
        return;
    }
    if (systemName != BMCWEB_REDFISH_SYSTEM_URI_NAME)
    {
        messages::resourceNotFound(asyncResp->res, "ComputerSystem",
                                   systemName);
        return;
    }

    getValidPCIeDevicePath(
        pcieDeviceId, asyncResp,
        std::bind_front(afterGetValidPcieDevicePath, asyncResp, pcieDeviceId));
}

inline void requestRoutesSystemPCIeDevice(App& app)
{
    BMCWEB_ROUTE(app, "/redfish/v1/Systems/<str>/PCIeDevices/<str>/")
        .privileges(redfish::privileges::getPCIeDevice)
        .methods(boost::beast::http::verb::get)(
            std::bind_front(handlePCIeDeviceGet, std::ref(app)));
}

inline void addPCIeFunctionList(
    crow::Response& res, const std::string& pcieDeviceId,
    const dbus::utility::DBusPropertiesMap& pcieDevProperties)
{
    nlohmann::json& pcieFunctionList = res.jsonValue["Members"];
    pcieFunctionList = nlohmann::json::array();
    static constexpr const int maxPciFunctionNum = 8;

    for (int functionNum = 0; functionNum < maxPciFunctionNum; functionNum++)
    {
        // Check if this function exists by
        // looking for a device ID
        std::string devIDProperty =
            "Function" + std::to_string(functionNum) + "DeviceId";
        const std::string* property = nullptr;
        for (const auto& propEntry : pcieDevProperties)
        {
            if (propEntry.first == devIDProperty)
            {
                property = std::get_if<std::string>(&propEntry.second);
                break;
            }
        }
        if (property == nullptr || property->empty())
        {
            continue;
        }

        nlohmann::json::object_t pcieFunction;
        pcieFunction["@odata.id"] = boost::urls::format(
            "/redfish/v1/Systems/{}/PCIeDevices/{}/PCIeFunctions/{}",
            BMCWEB_REDFISH_SYSTEM_URI_NAME, pcieDeviceId,
            std::to_string(functionNum));
        pcieFunctionList.emplace_back(std::move(pcieFunction));
    }
    res.jsonValue["PCIeFunctions@odata.count"] = pcieFunctionList.size();
}

inline void handlePCIeFunctionCollectionGet(
    App& app, const crow::Request& req,
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const std::string& systemName, const std::string& pcieDeviceId)
{
    if (!redfish::setUpRedfishRoute(app, req, asyncResp))
    {
        return;
    }
    if constexpr (BMCWEB_EXPERIMENTAL_REDFISH_MULTI_COMPUTER_SYSTEM)
    {
        // Option currently returns no systems.  TBD
        messages::resourceNotFound(asyncResp->res, "ComputerSystem",
                                   systemName);
        return;
    }

    getValidPCIeDevicePath(
        pcieDeviceId, asyncResp,
        [asyncResp, pcieDeviceId](const std::string& pcieDevicePath,
                                  const std::string& service) {
            asyncResp->res.addHeader(
                boost::beast::http::field::link,
                "</redfish/v1/JsonSchemas/PCIeFunctionCollection/PCIeFunctionCollection.json>; rel=describedby");
            asyncResp->res.jsonValue["@odata.type"] =
                "#PCIeFunctionCollection.PCIeFunctionCollection";
            asyncResp->res.jsonValue["@odata.id"] = boost::urls::format(
                "/redfish/v1/Systems/{}/PCIeDevices/{}/PCIeFunctions",
                BMCWEB_REDFISH_SYSTEM_URI_NAME, pcieDeviceId);
            asyncResp->res.jsonValue["Name"] = "PCIe Function Collection";
            asyncResp->res.jsonValue["Description"] =
                "Collection of PCIe Functions for PCIe Device " + pcieDeviceId;
            getPCIeDeviceProperties(
                asyncResp, pcieDevicePath, service,
                [asyncResp, pcieDeviceId](
                    const dbus::utility::DBusPropertiesMap& pcieDevProperties) {
                    addPCIeFunctionList(asyncResp->res, pcieDeviceId,
                                        pcieDevProperties);
                });
        });
}

inline void requestRoutesSystemPCIeFunctionCollection(App& app)
{
    /**
     * Functions triggers appropriate requests on DBus
     */
    BMCWEB_ROUTE(app,
                 "/redfish/v1/Systems/<str>/PCIeDevices/<str>/PCIeFunctions/")
        .privileges(redfish::privileges::getPCIeFunctionCollection)
        .methods(boost::beast::http::verb::get)(
            std::bind_front(handlePCIeFunctionCollectionGet, std::ref(app)));
}

inline bool validatePCIeFunctionId(
    uint64_t pcieFunctionId,
    const dbus::utility::DBusPropertiesMap& pcieDevProperties)
{
    std::string functionName = "Function" + std::to_string(pcieFunctionId);
    std::string devIDProperty = functionName + "DeviceId";

    const std::string* devIdProperty = nullptr;
    for (const auto& property : pcieDevProperties)
    {
        if (property.first == devIDProperty)
        {
            devIdProperty = std::get_if<std::string>(&property.second);
            break;
        }
    }
    return (devIdProperty != nullptr && !devIdProperty->empty());
}

inline void addPCIeFunctionProperties(
    crow::Response& resp, uint64_t pcieFunctionId,
    const dbus::utility::DBusPropertiesMap& pcieDevProperties)
{
    std::string functionName = "Function" + std::to_string(pcieFunctionId);
    for (const auto& property : pcieDevProperties)
    {
        const std::string* strProperty =
            std::get_if<std::string>(&property.second);
        if (strProperty == nullptr)
        {
            continue;
        }
        if (property.first == functionName + "DeviceId")
        {
            resp.jsonValue["DeviceId"] = *strProperty;
        }
        if (property.first == functionName + "VendorId")
        {
            resp.jsonValue["VendorId"] = *strProperty;
        }
        // TODO: FunctionType and DeviceClass are Redfish enums. The D-Bus
        // property strings should be mapped correctly to ensure these
        // strings are Redfish enum values. For now just check for empty.
        if (property.first == functionName + "FunctionType")
        {
            if (!strProperty->empty())
            {
                resp.jsonValue["FunctionType"] = *strProperty;
            }
        }
        if (property.first == functionName + "DeviceClass")
        {
            if (!strProperty->empty())
            {
                resp.jsonValue["DeviceClass"] = *strProperty;
            }
        }
        if (property.first == functionName + "ClassCode")
        {
            resp.jsonValue["ClassCode"] = *strProperty;
        }
        if (property.first == functionName + "RevisionId")
        {
            resp.jsonValue["RevisionId"] = *strProperty;
        }
        if (property.first == functionName + "SubsystemId")
        {
            resp.jsonValue["SubsystemId"] = *strProperty;
        }
        if (property.first == functionName + "SubsystemVendorId")
        {
            resp.jsonValue["SubsystemVendorId"] = *strProperty;
        }
    }
}

inline void addPCIeFunctionCommonProperties(crow::Response& resp,
                                            const std::string& pcieDeviceId,
                                            uint64_t pcieFunctionId)
{
    resp.addHeader(
        boost::beast::http::field::link,
        "</redfish/v1/JsonSchemas/PCIeFunction/PCIeFunction.json>; rel=describedby");
    resp.jsonValue["@odata.type"] = "#PCIeFunction.v1_2_3.PCIeFunction";
    resp.jsonValue["@odata.id"] = boost::urls::format(
        "/redfish/v1/Systems/{}/PCIeDevices/{}/PCIeFunctions/{}",
        BMCWEB_REDFISH_SYSTEM_URI_NAME, pcieDeviceId,
        std::to_string(pcieFunctionId));
    resp.jsonValue["Name"] = "PCIe Function";
    resp.jsonValue["Id"] = std::to_string(pcieFunctionId);
    resp.jsonValue["FunctionId"] = pcieFunctionId;
    resp.jsonValue["Links"]["PCIeDevice"]["@odata.id"] =
        boost::urls::format("/redfish/v1/Systems/{}/PCIeDevices/{}",
                            BMCWEB_REDFISH_SYSTEM_URI_NAME, pcieDeviceId);
}

inline void handlePCIeFunctionGet(
    App& app, const crow::Request& req,
    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
    const std::string& systemName, const std::string& pcieDeviceId,
    const std::string& pcieFunctionIdStr)
{
    if (!redfish::setUpRedfishRoute(app, req, asyncResp))
    {
        return;
    }
    if constexpr (BMCWEB_EXPERIMENTAL_REDFISH_MULTI_COMPUTER_SYSTEM)
    {
        // Option currently returns no systems.  TBD
        messages::resourceNotFound(asyncResp->res, "ComputerSystem",
                                   systemName);
        return;
    }
    if (systemName != BMCWEB_REDFISH_SYSTEM_URI_NAME)
    {
        messages::resourceNotFound(asyncResp->res, "ComputerSystem",
                                   systemName);
        return;
    }
    std::string_view pcieFunctionIdView = pcieFunctionIdStr;

    uint64_t pcieFunctionId = 0;
    std::from_chars_result result = std::from_chars(
        pcieFunctionIdView.begin(), pcieFunctionIdView.end(), pcieFunctionId);
    if (result.ec != std::errc{} || result.ptr != pcieFunctionIdView.end())
    {
        messages::resourceNotFound(asyncResp->res, "PCIeFunction",
                                   pcieFunctionIdStr);
        return;
    }

    getValidPCIeDevicePath(
        pcieDeviceId, asyncResp,
        [asyncResp, pcieDeviceId, pcieFunctionId](
            const std::string& pcieDevicePath, const std::string& service) {
            getPCIeDeviceProperties(
                asyncResp, pcieDevicePath, service,
                [asyncResp, pcieDeviceId, pcieFunctionId](
                    const dbus::utility::DBusPropertiesMap& pcieDevProperties) {
                    addPCIeFunctionCommonProperties(
                        asyncResp->res, pcieDeviceId, pcieFunctionId);
                    addPCIeFunctionProperties(asyncResp->res, pcieFunctionId,
                                              pcieDevProperties);
                });
        });
}

inline void requestRoutesSystemPCIeFunction(App& app)
{
    BMCWEB_ROUTE(
        app, "/redfish/v1/Systems/<str>/PCIeDevices/<str>/PCIeFunctions/<str>/")
        .privileges(redfish::privileges::getPCIeFunction)
        .methods(boost::beast::http::verb::get)(
            std::bind_front(handlePCIeFunctionGet, std::ref(app)));
}

} // namespace redfish