#include "libpldm/base.h"

#include "base.hpp"
#include "registration.hpp"

#include <array>
#include <cstring>
#include <map>
#include <stdexcept>
#include <vector>

namespace pldm
{
namespace responder
{

using Cmd = std::vector<uint8_t>;

static const std::map<Type, Cmd> capabilities{
    {PLDM_BASE, {PLDM_GET_PLDM_TYPES, PLDM_GET_PLDM_COMMANDS}}};

static const std::map<Type, ver32_t> versions{
    {PLDM_BASE, {0xF1, 0xF0, 0xF0, 0x00}},
    {PLDM_PLATFORM, {0xF1, 0xF1, 0xF1, 0x00}},
    {PLDM_BIOS, {0xF1, 0xF0, 0xF0, 0x00}},
};

namespace base
{

void registerHandlers()
{
    registerHandler(PLDM_BASE, PLDM_GET_PLDM_TYPES, std::move(getPLDMTypes));
    registerHandler(PLDM_BASE, PLDM_GET_PLDM_COMMANDS,
                    std::move(getPLDMCommands));
    registerHandler(PLDM_BASE, PLDM_GET_PLDM_VERSION,
                    std::move(getPLDMVersion));
}

} // namespace base

Response getPLDMTypes(const pldm_msg* request, size_t payloadLength)
{
    // DSP0240 has this as a bitfield8[N], where N = 0 to 7
    std::array<bitfield8_t, 8> types{};
    for (const auto& type : capabilities)
    {
        auto index = type.first / 8;
        // <Type Number> = <Array Index> * 8 + <bit position>
        auto bit = type.first - (index * 8);
        types[index].byte |= 1 << bit;
    }

    Response response(sizeof(pldm_msg_hdr) + PLDM_GET_TYPES_RESP_BYTES, 0);
    auto responsePtr = reinterpret_cast<pldm_msg*>(response.data());
    encode_get_types_resp(request->hdr.instance_id, PLDM_SUCCESS, types.data(),
                          responsePtr);

    return response;
}

Response getPLDMCommands(const pldm_msg* request, size_t payloadLength)
{
    ver32_t version{};
    Type type;

    Response response(sizeof(pldm_msg_hdr) + PLDM_GET_COMMANDS_RESP_BYTES, 0);
    auto responsePtr = reinterpret_cast<pldm_msg*>(response.data());

    auto rc = decode_get_commands_req(request->payload, payloadLength, &type,
                                      &version);

    if (rc != PLDM_SUCCESS)
    {
        encode_get_commands_resp(request->hdr.instance_id, rc, nullptr,
                                 responsePtr);
        return response;
    }

    // DSP0240 has this as a bitfield8[N], where N = 0 to 31
    std::array<bitfield8_t, 32> cmds{};
    if (capabilities.find(type) == capabilities.end())
    {
        encode_get_commands_resp(request->hdr.instance_id,
                                 PLDM_ERROR_INVALID_PLDM_TYPE, nullptr,
                                 responsePtr);
        return response;
    }

    for (const auto& cmd : capabilities.at(type))
    {
        auto index = cmd / 8;
        // <Type Number> = <Array Index> * 8 + <bit position>
        auto bit = cmd - (index * 8);
        cmds[index].byte |= 1 << bit;
    }

    encode_get_commands_resp(request->hdr.instance_id, PLDM_SUCCESS,
                             cmds.data(), responsePtr);

    return response;
}

Response getPLDMVersion(const pldm_msg* request, size_t payloadLength)
{
    uint32_t transferHandle;
    Type type;
    uint8_t transferFlag;

    Response response(sizeof(pldm_msg_hdr) + PLDM_GET_VERSION_RESP_BYTES, 0);
    auto responsePtr = reinterpret_cast<pldm_msg*>(response.data());

    uint8_t rc = decode_get_version_req(request->payload, payloadLength,
                                        &transferHandle, &transferFlag, &type);

    if (rc != PLDM_SUCCESS)
    {
        encode_get_version_resp(request->hdr.instance_id, rc, 0, 0, nullptr, 4,
                                responsePtr);
        return response;
    }

    ver32_t version{};
    auto search = versions.find(type);

    if (search == versions.end())
    {
        encode_get_version_resp(request->hdr.instance_id,
                                PLDM_ERROR_INVALID_PLDM_TYPE, 0, 0, nullptr, 4,
                                responsePtr);
        return response;
    }

    memcpy(&version, &(search->second), sizeof(version));
    encode_get_version_resp(request->hdr.instance_id, PLDM_SUCCESS, 0,
                            PLDM_START_AND_END, &version, sizeof(pldm_version),
                            responsePtr);

    return response;
}

} // namespace responder
} // namespace pldm