// SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#include <tuple>
#include "common/assert.h"
#include "common/scope_exit.h"
#include "core/core.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_scoped_resource_reservation.h"
#include "core/hle/kernel/k_server_port.h"
#include "core/hle/result.h"
#include "core/hle/service/ipc_helpers.h"
#include "core/hle/service/server_manager.h"
#include "core/hle/service/sm/sm.h"
#include "core/hle/service/sm/sm_controller.h"

namespace Service::SM {

constexpr Result ResultInvalidClient(ErrorModule::SM, 2);
constexpr Result ResultAlreadyRegistered(ErrorModule::SM, 4);
constexpr Result ResultInvalidServiceName(ErrorModule::SM, 6);
constexpr Result ResultNotRegistered(ErrorModule::SM, 7);

ServiceManager::ServiceManager(Kernel::KernelCore& kernel_) : kernel{kernel_} {
    controller_interface = std::make_unique<Controller>(kernel.System());
}

ServiceManager::~ServiceManager() {
    for (auto& [name, port] : service_ports) {
        port->GetClientPort().Close();
        port->GetServerPort().Close();
    }

    if (deferral_event) {
        deferral_event->Close();
    }
}

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

static Result ValidateServiceName(const std::string& name) {
    if (name.empty() || name.size() > 8) {
        LOG_ERROR(Service_SM, "Invalid service name! service={}", name);
        return Service::SM::ResultInvalidServiceName;
    }
    return ResultSuccess;
}

Result ServiceManager::RegisterService(std::string name, u32 max_sessions,
                                       SessionRequestHandlerPtr handler) {
    R_TRY(ValidateServiceName(name));

    std::scoped_lock lk{lock};
    if (registered_services.find(name) != registered_services.end()) {
        LOG_ERROR(Service_SM, "Service is already registered! service={}", name);
        return Service::SM::ResultAlreadyRegistered;
    }

    auto* port = Kernel::KPort::Create(kernel);
    port->Initialize(ServerSessionCountMax, false, 0);

    // Register the port.
    Kernel::KPort::Register(kernel, port);

    service_ports.emplace(name, port);
    registered_services.emplace(name, handler);
    if (deferral_event) {
        deferral_event->Signal();
    }

    return ResultSuccess;
}

Result ServiceManager::UnregisterService(const std::string& name) {
    R_TRY(ValidateServiceName(name));

    std::scoped_lock lk{lock};
    const auto iter = registered_services.find(name);
    if (iter == registered_services.end()) {
        LOG_ERROR(Service_SM, "Server is not registered! service={}", name);
        return Service::SM::ResultNotRegistered;
    }

    registered_services.erase(iter);
    service_ports.erase(name);

    return ResultSuccess;
}

Result ServiceManager::GetServicePort(Kernel::KPort** out_port, const std::string& name) {
    R_TRY(ValidateServiceName(name));

    std::scoped_lock lk{lock};
    auto it = service_ports.find(name);
    if (it == service_ports.end()) {
        LOG_WARNING(Service_SM, "Server is not registered! service={}", name);
        return Service::SM::ResultNotRegistered;
    }

    *out_port = it->second;
    return ResultSuccess;
}

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

    ctx.GetManager()->SetIsInitializedForSm();

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

void SM::GetService(HLERequestContext& ctx) {
    Kernel::KClientSession* client_session{};
    auto result = GetServiceImpl(&client_session, ctx);
    if (ctx.GetIsDeferred()) {
        // Don't overwrite the command buffer.
        return;
    }

    if (result == ResultSuccess) {
        IPC::ResponseBuilder rb{ctx, 2, 0, 1, IPC::ResponseBuilder::Flags::AlwaysMoveHandles};
        rb.Push(result);
        rb.PushMoveObjects(client_session);
    } else {
        IPC::ResponseBuilder rb{ctx, 2};
        rb.Push(result);
    }
}

void SM::GetServiceTipc(HLERequestContext& ctx) {
    Kernel::KClientSession* client_session{};
    auto result = GetServiceImpl(&client_session, ctx);
    if (ctx.GetIsDeferred()) {
        // Don't overwrite the command buffer.
        return;
    }

    IPC::ResponseBuilder rb{ctx, 2, 0, 1, IPC::ResponseBuilder::Flags::AlwaysMoveHandles};
    rb.Push(result);
    rb.PushMoveObjects(result == ResultSuccess ? client_session : nullptr);
}

static std::string PopServiceName(IPC::RequestParser& rp) {
    auto name_buf = rp.PopRaw<std::array<char, 8>>();
    std::string result;
    for (const auto& c : name_buf) {
        if (c >= ' ' && c <= '~') {
            result.push_back(c);
        }
    }
    return result;
}

Result SM::GetServiceImpl(Kernel::KClientSession** out_client_session, HLERequestContext& ctx) {
    if (!ctx.GetManager()->GetIsInitializedForSm()) {
        return Service::SM::ResultInvalidClient;
    }

    IPC::RequestParser rp{ctx};
    std::string name(PopServiceName(rp));

    // Find the named port.
    Kernel::KPort* port{};
    auto port_result = service_manager.GetServicePort(&port, name);
    if (port_result == Service::SM::ResultInvalidServiceName) {
        LOG_ERROR(Service_SM, "Invalid service name '{}'", name);
        return Service::SM::ResultInvalidServiceName;
    }

    if (port_result != ResultSuccess) {
        LOG_INFO(Service_SM, "Waiting for service {} to become available", name);
        ctx.SetIsDeferred();
        return Service::SM::ResultNotRegistered;
    }

    // Create a new session.
    Kernel::KClientSession* session{};
    if (const auto result = port->GetClientPort().CreateSession(&session); result.IsError()) {
        LOG_ERROR(Service_SM, "called service={} -> error 0x{:08X}", name, result.raw);
        return result;
    }

    LOG_DEBUG(Service_SM, "called service={} -> session={}", name, session->GetId());

    *out_client_session = session;
    return ResultSuccess;
}

void SM::RegisterService(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    std::string name(PopServiceName(rp));

    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);

    if (const auto result = service_manager.RegisterService(name, max_session_count, nullptr);
        result.IsError()) {
        LOG_ERROR(Service_SM, "failed to register service with error_code={:08X}", result.raw);
        IPC::ResponseBuilder rb{ctx, 2};
        rb.Push(result);
        return;
    }

    auto* port = Kernel::KPort::Create(kernel);
    port->Initialize(ServerSessionCountMax, is_light, 0);
    SCOPE_EXIT({ port->GetClientPort().Close(); });

    IPC::ResponseBuilder rb{ctx, 2, 0, 1, IPC::ResponseBuilder::Flags::AlwaysMoveHandles};
    rb.Push(ResultSuccess);
    rb.PushMoveObjects(port->GetServerPort());
}

void SM::UnregisterService(HLERequestContext& ctx) {
    IPC::RequestParser rp{ctx};
    std::string name(PopServiceName(rp));

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

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

SM::SM(ServiceManager& service_manager_, Core::System& system_)
    : ServiceFramework{system_, "sm:", 4},
      service_manager{service_manager_}, kernel{system_.Kernel()} {
    RegisterHandlers({
        {0, &SM::Initialize, "Initialize"},
        {1, &SM::GetService, "GetService"},
        {2, &SM::RegisterService, "RegisterService"},
        {3, &SM::UnregisterService, "UnregisterService"},
        {4, nullptr, "DetachClient"},
    });
    RegisterHandlersTipc({
        {0, &SM::Initialize, "Initialize"},
        {1, &SM::GetServiceTipc, "GetService"},
        {2, &SM::RegisterService, "RegisterService"},
        {3, &SM::UnregisterService, "UnregisterService"},
        {4, nullptr, "DetachClient"},
    });
}

SM::~SM() = default;

void LoopProcess(Core::System& system) {
    auto& service_manager = system.ServiceManager();
    auto server_manager = std::make_unique<ServerManager>(system);

    Kernel::KEvent* deferral_event{};
    server_manager->ManageDeferral(&deferral_event);
    service_manager.SetDeferralEvent(deferral_event);

    server_manager->ManageNamedPort("sm:", std::make_shared<SM>(system.ServiceManager(), system));
    ServerManager::RunServer(std::move(server_manager));
}

} // namespace Service::SM
