// Copyright 2018 yuzu emulator team
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.

#include <tuple>
#include "common/assert.h"
#include "core/core.h"
#include "core/hle/ipc_helpers.h"
#include "core/hle/kernel/k_client_port.h"
#include "core/hle/kernel/k_client_session.h"
#include "core/hle/kernel/k_port.h"
#include "core/hle/kernel/k_server_port.h"
#include "core/hle/kernel/k_server_session.h"
#include "core/hle/kernel/k_session.h"
#include "core/hle/result.h"
#include "core/hle/service/sm/controller.h"
#include "core/hle/service/sm/sm.h"

namespace Service::SM {

constexpr ResultCode ERR_ALREADY_REGISTERED(ErrorModule::SM, 4);
constexpr ResultCode ERR_INVALID_NAME(ErrorModule::SM, 6);
constexpr ResultCode ERR_SERVICE_NOT_REGISTERED(ErrorModule::SM, 7);

ServiceManager::ServiceManager(Kernel::KernelCore& kernel_) : kernel{kernel_} {}
ServiceManager::~ServiceManager() = default;

void ServiceManager::InvokeControlRequest(Kernel::HLERequestContext& context) {
    controller_interface->InvokeRequest(context);
}

static ResultCode ValidateServiceName(const std::string& name) {
    if (name.empty() || name.size() > 8) {
        LOG_ERROR(Service_SM, "Invalid service name! service={}", name);
        return ERR_INVALID_NAME;
    }
    if (name.rfind('\0') != std::string::npos) {
        LOG_ERROR(Service_SM, "A non null terminated service was passed");
        return ERR_INVALID_NAME;
    }
    return RESULT_SUCCESS;
}

void ServiceManager::InstallInterfaces(std::shared_ptr<ServiceManager> self, Core::System& system) {
    ASSERT(self->sm_interface.expired());

    auto sm = std::make_shared<SM>(self, system);
    sm->InstallAsNamedPort(system.Kernel());
    self->sm_interface = sm;
    self->controller_interface = std::make_unique<Controller>(system);
}

ResultVal<Kernel::KServerPort*> ServiceManager::RegisterService(std::string name,
                                                                u32 max_sessions) {

    CASCADE_CODE(ValidateServiceName(name));

    if (registered_services.find(name) != registered_services.end()) {
        LOG_ERROR(Service_SM, "Service is already registered! service={}", name);
        return ERR_ALREADY_REGISTERED;
    }

    auto* port = Kernel::KPort::Create(kernel);
    port->Initialize(max_sessions, false, name);

    registered_services.emplace(std::move(name), port);

    return MakeResult(&port->GetServerPort());
}

ResultCode ServiceManager::UnregisterService(const std::string& name) {
    CASCADE_CODE(ValidateServiceName(name));

    const auto iter = registered_services.find(name);
    if (iter == registered_services.end()) {
        LOG_ERROR(Service_SM, "Server is not registered! service={}", name);
        return ERR_SERVICE_NOT_REGISTERED;
    }

    iter->second->Close();

    registered_services.erase(iter);
    return RESULT_SUCCESS;
}

ResultVal<Kernel::KPort*> ServiceManager::GetServicePort(const std::string& name) {

    CASCADE_CODE(ValidateServiceName(name));
    auto it = registered_services.find(name);
    if (it == registered_services.end()) {
        LOG_ERROR(Service_SM, "Server is not registered! service={}", name);
        return ERR_SERVICE_NOT_REGISTERED;
    }

    return MakeResult(it->second);
}

SM::~SM() = default;

/**
 * SM::Initialize service function
 *  Inputs:
 *      0: 0x00000000
 *  Outputs:
 *      0: ResultCode
 */
void SM::Initialize(Kernel::HLERequestContext& ctx) {
    LOG_DEBUG(Service_SM, "called");

    IPC::ResponseBuilder rb{ctx, 2};
    rb.Push(RESULT_SUCCESS);
}

void SM::GetService(Kernel::HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    auto name_buf = rp.PopRaw<std::array<char, 8>>();
    auto end = std::find(name_buf.begin(), name_buf.end(), '\0');

    std::string name(name_buf.begin(), end);

    auto result = service_manager->GetServicePort(name);
    if (result.Failed()) {
        IPC::ResponseBuilder rb{ctx, 2};
        rb.Push(result.Code());
        LOG_ERROR(Service_SM, "called service={} -> error 0x{:08X}", name, result.Code().raw);
        if (name.length() == 0)
            return; // LibNX Fix
        UNIMPLEMENTED();
        return;
    }

    auto* port = result.Unwrap();

    auto* session = Kernel::KSession::Create(kernel);
    session->Initialize(&port->GetClientPort(), std::move(name));

    if (port->GetServerPort().GetHLEHandler()) {
        port->GetServerPort().GetHLEHandler()->ClientConnected(&session->GetServerSession());
    } else {
        port->EnqueueSession(&session->GetServerSession());
    }

    LOG_DEBUG(Service_SM, "called service={} -> session={}", name, session->GetObjectId());
    IPC::ResponseBuilder rb{ctx, 2, 0, 1, IPC::ResponseBuilder::Flags::AlwaysMoveHandles};
    rb.Push(RESULT_SUCCESS);
    rb.PushMoveObjects(session->GetClientSession());
}

void SM::RegisterService(Kernel::HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};

    const auto name_buf = rp.PopRaw<std::array<char, 8>>();
    const auto end = std::find(name_buf.begin(), name_buf.end(), '\0');

    const std::string name(name_buf.begin(), end);

    const auto is_light = static_cast<bool>(rp.PopRaw<u32>());
    const auto max_session_count = rp.PopRaw<u32>();

    LOG_DEBUG(Service_SM, "called with name={}, max_session_count={}, is_light={}", name,
              max_session_count, is_light);

    auto handle = service_manager->RegisterService(name, max_session_count);
    if (handle.Failed()) {
        LOG_ERROR(Service_SM, "failed to register service with error_code={:08X}",
                  handle.Code().raw);
        IPC::ResponseBuilder rb{ctx, 2};
        rb.Push(handle.Code());
        return;
    }

    IPC::ResponseBuilder rb{ctx, 2, 0, 1, IPC::ResponseBuilder::Flags::AlwaysMoveHandles};
    rb.Push(handle.Code());

    auto server_port = handle.Unwrap();
    rb.PushMoveObjects(server_port);
}

void SM::UnregisterService(Kernel::HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};

    const auto name_buf = rp.PopRaw<std::array<char, 8>>();
    const auto end = std::find(name_buf.begin(), name_buf.end(), '\0');

    const std::string name(name_buf.begin(), end);
    LOG_DEBUG(Service_SM, "called with name={}", name);

    IPC::ResponseBuilder rb{ctx, 2};
    rb.Push(service_manager->UnregisterService(name));
}

SM::SM(std::shared_ptr<ServiceManager> service_manager_, Core::System& system_)
    : ServiceFramework{system_, "sm:", 4},
      service_manager{std::move(service_manager_)}, kernel{system_.Kernel()} {
    static const FunctionInfo functions[] = {
        {0, &SM::Initialize, "Initialize"},
        {1, &SM::GetService, "GetService"},
        {2, &SM::RegisterService, "RegisterService"},
        {3, &SM::UnregisterService, "UnregisterService"},
        {4, nullptr, "DetachClient"},
    };
    RegisterHandlers(functions);
}

} // namespace Service::SM