#include "bios_parser.hpp"

#include "libpldmresponder/utils.hpp"

#include <filesystem>
#include <fstream>
#include <nlohmann/json.hpp>
#include <optional>
#include <phosphor-logging/log.hpp>

namespace bios_parser
{

using Json = nlohmann::json;
namespace fs = std::filesystem;
using namespace phosphor::logging;

const std::vector<Json> emptyJsonList{};
const Json emptyJson{};

struct DBusMapping
{
    std::string objectPath;   //!< D-Bus object path
    std::string interface;    //!< D-Bus interface
    std::string propertyName; //!< D-Bus property name
};

using AttrName = std::string;
using BIOSJsonName = std::string;
using AttrLookup = std::map<AttrName, std::optional<DBusMapping>>;
using BIOSStringHandler =
    std::function<int(const Json& entry, Strings& strings)>;
using AttrLookupHandler = std::function<int(const Json& entry, AttrLookup)>;
using typeHandler = std::function<int(const Json& entry)>;

Strings BIOSStrings;
AttrLookup BIOSAttrLookup;

const Strings& getStrings()
{
    return BIOSStrings;
}

int parseBiosJsonFile(const fs::path& dirPath, const std::string& fileName,
                      Json& fileData)
{
    int rc = 0;

    fs::path filePath = dirPath / fileName;

    std::ifstream jsonFile(filePath);
    if (!jsonFile.is_open())
    {
        log<level::ERR>("BIOS config file does not exist",
                        entry("FILE=%s", filePath.c_str()));
        rc = -1;
    }
    else
    {
        fileData = Json::parse(jsonFile, nullptr, false);
        if (fileData.is_discarded())
        {
            log<level::ERR>("Parsing config file failed",
                            entry("FILE=%s", filePath.c_str()));
            rc = -1;
        }
    }

    return rc;
}

namespace bios_enum
{

namespace internal
{

using PropertyValue =
    std::variant<bool, uint8_t, int16_t, uint16_t, int32_t, uint32_t, int64_t,
                 uint64_t, double, std::string>;
using Value = std::string;

/** @brief Map of DBus property value to attribute value
 */
using DbusValToValMap = std::map<PropertyValue, Value>;

/** @brief Map containing the DBus property value to attribute value map for the
 * BIOS enumeration type attributes
 */
std::map<AttrName, DbusValToValMap> dbusValToValMaps;

/** @brief Map containing the possible and the default values for the BIOS
 *         enumeration type attributes.
 */
AttrValuesMap valueMap;

/** @brief Populate the mapping between D-Bus property value and attribute value
 *         for the BIOS enumeration attribute.
 *
 *  @param[in] type - type of the D-Bus property
 *  @param[in] dBusValues - json array of D-Bus property values
 *  @param[in] pv - Possible values for the BIOS enumeration attribute
 *
 */
DbusValToValMap populateMapping(const std::string& type, const Json& dBusValues,
                                const PossibleValues& pv)
{
    size_t pos = 0;
    PropertyValue value;
    DbusValToValMap valueMap;
    for (auto it = dBusValues.begin(); it != dBusValues.end(); ++it, ++pos)
    {
        if (type == "uint8_t")
        {
            value = static_cast<uint8_t>(it.value());
        }
        else if (type == "uint16_t")
        {
            value = static_cast<uint16_t>(it.value());
        }
        else if (type == "uint32_t")
        {
            value = static_cast<uint32_t>(it.value());
        }
        else if (type == "uint64_t")
        {
            value = static_cast<uint64_t>(it.value());
        }
        else if (type == "int16_t")
        {
            value = static_cast<int16_t>(it.value());
        }
        else if (type == "int32_t")
        {
            value = static_cast<int32_t>(it.value());
        }
        else if (type == "int64_t")
        {
            value = static_cast<int64_t>(it.value());
        }
        else if (type == "bool")
        {
            value = static_cast<bool>(it.value());
        }
        else if (type == "double")
        {
            value = static_cast<double>(it.value());
        }
        else if (type == "string")
        {
            value = static_cast<std::string>(it.value());
        }
        else
        {
            log<level::ERR>("Unknown D-Bus property type",
                            entry("TYPE=%s", type.c_str()));
        }

        valueMap.emplace(value, pv[pos]);
    }

    return valueMap;
}

} // namespace internal

int setupBIOSStrings(const Json& entry, Strings& strings)
{
    Json pvs = entry.value("possible_values", emptyJsonList);

    for (auto& pv : pvs)
    {
        strings.emplace_back(std::move(pv.get<std::string>()));
    }

    return 0;
}

int setup(const Json& entry)
{
    PossibleValues possibleValues;
    DefaultValues defaultValues;

    std::string attrName = entry.value("attribute_name", "");
    Json pv = entry["possible_values"];
    for (auto& val : pv)
    {
        possibleValues.emplace_back(std::move(val));
    }
    Json dv = entry["default_values"];
    for (auto& val : dv)
    {
        defaultValues.emplace_back(std::move(val));
    }
    if (entry.count("dbus") != 0)
    {
        auto dbusEntry = entry.value("dbus", emptyJson);
        std::string propertyType = dbusEntry.value("property_type", "");
        Json propValues = dbusEntry["property_values"];
        internal::dbusValToValMaps.emplace(
            attrName, internal::populateMapping(propertyType, propValues,
                                                possibleValues));
    }
    // Defaulting all the types of attributes to BIOSEnumeration
    internal::valueMap.emplace(std::move(attrName),
                               std::make_tuple(entry.count("dbus") == 0,
                                               std::move(possibleValues),
                                               std::move(defaultValues)));
    return 0;
}

const AttrValuesMap& getValues()
{
    return internal::valueMap;
}

CurrentValues getAttrValue(const AttrName& attrName)
{
    const auto& dBusMap = BIOSAttrLookup.at(attrName);
    CurrentValues currentValues;
    internal::PropertyValue propValue;

    if (dBusMap == std::nullopt)
    {
        const auto& valueEntry = internal::valueMap.at(attrName);
        const auto& [readOnly, possibleValues, currentValues] = valueEntry;
        return currentValues;
    }

    const auto& dbusValToValMap = internal::dbusValToValMaps.at(attrName);
    auto bus = sdbusplus::bus::new_default();
    auto service = pldm::responder::getService(bus, dBusMap.value().objectPath,
                                               dBusMap.value().interface);
    auto method =
        bus.new_method_call(service.c_str(), dBusMap.value().objectPath.c_str(),
                            "org.freedesktop.DBus.Properties", "Get");
    method.append(dBusMap->interface, dBusMap->propertyName);
    auto reply = bus.call(method);
    reply.read(propValue);

    auto iter = dbusValToValMap.find(propValue);
    if (iter != dbusValToValMap.end())
    {
        currentValues.push_back(iter->second);
    }

    return currentValues;
}

} // namespace bios_enum

namespace bios_string
{

/** @brief BIOS string types
 */
enum BiosStringEncoding
{
    UNKNOWN = 0x00,
    ASCII = 0x01,
    HEX = 0x02,
    UTF_8 = 0x03,
    UTF_16LE = 0x04,
    UTF_16BE = 0x05,
    VENDOR_SPECIFIC = 0xFF
};

const std::map<std::string, uint8_t> strTypeMap{
    {"Unknown", UNKNOWN},
    {"ASCII", ASCII},
    {"Hex", HEX},
    {"UTF-8", UTF_8},
    {"UTF-16LE", UTF_16LE},
    {"UTF-16LE", UTF_16LE},
    {"Vendor Specific", VENDOR_SPECIFIC}};

namespace internal
{

/** @brief Map containing the possible and the default values for the BIOS
 *         string type attributes.
 */
AttrValuesMap valueMap;

} // namespace internal

int setup(const Json& entry)
{

    std::string attr = entry.value("attribute_name", "");
    // Transfer string type from string to enum
    std::string strTypeTmp = entry.value("string_type", "Unknown");
    auto iter = strTypeMap.find(strTypeTmp);
    if (iter == strTypeMap.end())
    {
        log<level::ERR>(
            "Wrong string type",
            phosphor::logging::entry("STRING_TYPE=%s", strTypeTmp.c_str()),
            phosphor::logging::entry("ATTRIBUTE_NAME=%s", attr.c_str()));
        return -1;
    }
    uint8_t strType = iter->second;

    uint16_t minStrLen = entry.value("minimum_string_length", 0);
    uint16_t maxStrLen = entry.value("maximum_string_length", 0);
    if (maxStrLen - minStrLen < 0)
    {
        log<level::ERR>(
            "Maximum string length is smaller than minimum string length",
            phosphor::logging::entry("ATTRIBUTE_NAME=%s", attr.c_str()));
        return -1;
    }
    uint16_t defaultStrLen = entry.value("default_string_length", 0);
    std::string defaultStr = entry.value("default_string", "");
    if ((defaultStrLen == 0) && (defaultStr.size() > 0))
    {
        log<level::ERR>(
            "Default string length is 0, but default string is existing",
            phosphor::logging::entry("ATTRIBUTE_NAME=%s", attr.c_str()));
        return -1;
    }

    // Defaulting all the types of attributes to BIOSString
    internal::valueMap.emplace(
        std::move(attr),
        std::make_tuple(entry.count("dbus") == 0, strType, minStrLen, maxStrLen,
                        defaultStrLen, std::move(defaultStr)));

    return 0;
}

const AttrValuesMap& getValues()
{
    return internal::valueMap;
}

std::string getAttrValue(const AttrName& attrName)
{
    const auto& dBusMap = BIOSAttrLookup.at(attrName);
    std::variant<std::string> propValue;

    if (dBusMap == std::nullopt)
    { // return default string
        const auto& valueEntry = internal::valueMap.at(attrName);
        return std::get<DefaultStr>(valueEntry);
    }

    auto bus = sdbusplus::bus::new_default();
    auto service = pldm::responder::getService(bus, dBusMap->objectPath,
                                               dBusMap->interface);
    auto method =
        bus.new_method_call(service.c_str(), dBusMap->objectPath.c_str(),
                            "org.freedesktop.DBus.Properties", "Get");
    method.append(dBusMap->interface, dBusMap->propertyName);
    auto reply = bus.call(method);
    reply.read(propValue);

    return std::get<std::string>(propValue);
}

} // namespace bios_string

const std::map<BIOSJsonName, BIOSStringHandler> BIOSStringHandlers = {
    {bIOSEnumJson, bios_enum::setupBIOSStrings},
};

const std::map<BIOSJsonName, typeHandler> BIOSTypeHandlers = {
    {bIOSEnumJson, bios_enum::setup},
    {bIOSStrJson, bios_string::setup},
};

void setupBIOSStrings(const BIOSJsonName& jsonName, const Json& entry,
                      Strings& strings)
{
    strings.emplace_back(entry.value("attribute_name", ""));
    auto iter = BIOSStringHandlers.find(jsonName);
    if (iter != BIOSStringHandlers.end())
    {
        iter->second(entry, strings);
    }
}

void setupBIOSAttrLookup(const Json& entry, AttrLookup& lookup)
{
    std::optional<DBusMapping> dBusMap;
    std::string attrName = entry.value("attribute_name", "");

    if (entry.count("dbus") != 0)
    {
        auto dBusEntry = entry.value("dbus", emptyJson);
        std::string objectPath = dBusEntry.value("object_path", "");
        std::string interface = dBusEntry.value("interface", "");
        std::string propertyName = dBusEntry.value("property_name", "");
        if (!objectPath.empty() && !interface.empty() && !propertyName.empty())
        {
            dBusMap = std::optional<DBusMapping>(
                {objectPath, interface, propertyName});
        }
        else
        {
            log<level::ERR>(
                "Invalid dbus config",
                phosphor::logging::entry("OBJPATH=%s",
                                         dBusMap->objectPath.c_str()),
                phosphor::logging::entry("INTERFACE=%s",
                                         dBusMap->interface.c_str()),
                phosphor::logging::entry("PROPERTY_NAME=%s",
                                         dBusMap->propertyName.c_str()));
        }
    }
    lookup.emplace(attrName, dBusMap);
}

int setupBIOSType(const BIOSJsonName& jsonName, const Json& entry)
{
    auto iter = BIOSTypeHandlers.find(jsonName);
    if (iter != BIOSTypeHandlers.end())
    {
        iter->second(entry);
    }
    return 0;
}

const std::vector<BIOSJsonName> BIOSConfigFiles = {bIOSEnumJson, bIOSStrJson};

int setupConfig(const char* dirPath)
{
    if (!BIOSStrings.empty() && !BIOSAttrLookup.empty())
    {
        return 0;
    }

    fs::path dir(dirPath);
    if (!fs::exists(dir) || fs::is_empty(dir))
    {
        log<level::ERR>("BIOS config directory does not exist or empty",
                        entry("DIR=%s", dirPath));
        return -1;
    }
    for (auto jsonName : BIOSConfigFiles)
    {
        Json json;
        if (parseBiosJsonFile(dir, jsonName, json) < 0)
        {
            continue;
        }
        auto entries = json.value("entries", emptyJsonList);
        for (auto& entry : entries)
        {
            setupBIOSStrings(jsonName, entry, BIOSStrings);
            setupBIOSAttrLookup(entry, BIOSAttrLookup);
            setupBIOSType(jsonName, entry);
        }
    }
    if (BIOSStrings.empty())
    { // means there is no attribute
        log<level::ERR>("No attribute is found in the config directory",
                        entry("DIR=%s", dirPath));
        return -1;
    }
    return 0;
}

} // namespace bios_parser