/*
 * Copyright (c) Atmosphère-NX
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <mesosphere.hpp>

namespace ams::kern::svc {

    /* =============================    Common    ============================= */

    namespace {

        Result GetInitialProcessIdRange(u64 *out, ams::svc::InitialProcessIdRangeInfo info) {
            switch (info) {
                case ams::svc::InitialProcessIdRangeInfo_Minimum:
                    MESOSPHERE_ABORT_UNLESS(GetInitialProcessIdMin() <= GetInitialProcessIdMax());
                    *out = GetInitialProcessIdMin();
                    break;
                case ams::svc::InitialProcessIdRangeInfo_Maximum:
                    MESOSPHERE_ABORT_UNLESS(GetInitialProcessIdMin() <= GetInitialProcessIdMax());
                    *out = GetInitialProcessIdMax();
                    break;
                default:
                    return svc::ResultInvalidCombination();
            }

            return ResultSuccess();
        }

        Result GetInfoImpl(u64 *out, ams::svc::InfoType info_type, KProcess *process) {
            switch (info_type) {
                case ams::svc::InfoType_CoreMask:
                    *out = process->GetCoreMask();
                    break;
                case ams::svc::InfoType_PriorityMask:
                    *out = process->GetPriorityMask();
                    break;
                case ams::svc::InfoType_AliasRegionAddress:
                    *out = GetInteger(process->GetPageTable().GetAliasRegionStart());
                    break;
                case ams::svc::InfoType_AliasRegionSize:
                    *out = process->GetPageTable().GetAliasRegionSize();
                    break;
                case ams::svc::InfoType_HeapRegionAddress:
                    *out = GetInteger(process->GetPageTable().GetHeapRegionStart());
                    break;
                case ams::svc::InfoType_HeapRegionSize:
                    *out = process->GetPageTable().GetHeapRegionSize();
                    break;
                case ams::svc::InfoType_TotalMemorySize:
                    *out = process->GetTotalUserPhysicalMemorySize();
                    break;
                case ams::svc::InfoType_UsedMemorySize:
                    *out = process->GetUsedUserPhysicalMemorySize();
                    break;
                case ams::svc::InfoType_AslrRegionAddress:
                    *out = GetInteger(process->GetPageTable().GetAliasCodeRegionStart());
                    break;
                case ams::svc::InfoType_AslrRegionSize:
                    *out = process->GetPageTable().GetAliasCodeRegionSize();
                    break;
                case ams::svc::InfoType_StackRegionAddress:
                    *out = GetInteger(process->GetPageTable().GetStackRegionStart());
                    break;
                case ams::svc::InfoType_StackRegionSize:
                    *out = process->GetPageTable().GetStackRegionSize();
                    break;
                case ams::svc::InfoType_SystemResourceSizeTotal:
                    *out = process->GetTotalSystemResourceSize();
                    break;
                case ams::svc::InfoType_SystemResourceSizeUsed:
                    *out = process->GetUsedSystemResourceSize();
                    break;
                case ams::svc::InfoType_ProgramId:
                    *out = process->GetProgramId();
                    break;
                case ams::svc::InfoType_UserExceptionContextAddress:
                    *out = GetInteger(process->GetProcessLocalRegionAddress());
                    break;
                case ams::svc::InfoType_TotalNonSystemMemorySize:
                    *out = process->GetTotalNonSystemUserPhysicalMemorySize();
                    break;
                case ams::svc::InfoType_UsedNonSystemMemorySize:
                    *out = process->GetUsedNonSystemUserPhysicalMemorySize();
                    break;
                case ams::svc::InfoType_IsApplication:
                    *out = process->IsApplication();
                    break;
                case ams::svc::InfoType_FreeThreadCount:
                    if (KResourceLimit *resource_limit = process->GetResourceLimit(); resource_limit != nullptr) {
                        const auto current_value = resource_limit->GetCurrentValue(ams::svc::LimitableResource_ThreadCountMax);
                        const auto limit_value   = resource_limit->GetLimitValue(ams::svc::LimitableResource_ThreadCountMax);
                        *out = limit_value - current_value;
                    } else {
                        *out = 0;
                    }
                    break;
                MESOSPHERE_UNREACHABLE_DEFAULT_CASE();
            }

            return ResultSuccess();
        }

        Result GetInfo(u64 *out, ams::svc::InfoType info_type, ams::svc::Handle handle, u64 info_subtype) {
            switch (info_type) {
                case ams::svc::InfoType_CoreMask:
                case ams::svc::InfoType_PriorityMask:
                case ams::svc::InfoType_AliasRegionAddress:
                case ams::svc::InfoType_AliasRegionSize:
                case ams::svc::InfoType_HeapRegionAddress:
                case ams::svc::InfoType_HeapRegionSize:
                case ams::svc::InfoType_TotalMemorySize:
                case ams::svc::InfoType_UsedMemorySize:
                case ams::svc::InfoType_AslrRegionAddress:
                case ams::svc::InfoType_AslrRegionSize:
                case ams::svc::InfoType_StackRegionAddress:
                case ams::svc::InfoType_StackRegionSize:
                case ams::svc::InfoType_SystemResourceSizeTotal:
                case ams::svc::InfoType_SystemResourceSizeUsed:
                case ams::svc::InfoType_ProgramId:
                case ams::svc::InfoType_UserExceptionContextAddress:
                case ams::svc::InfoType_TotalNonSystemMemorySize:
                case ams::svc::InfoType_UsedNonSystemMemorySize:
                case ams::svc::InfoType_IsApplication:
                case ams::svc::InfoType_FreeThreadCount:
                    {
                        /* These info types don't support non-zero subtypes. */
                        R_UNLESS(info_subtype == 0,  svc::ResultInvalidCombination());

                        /* Get the process from its handle. */
                        KScopedAutoObject process = GetCurrentProcess().GetHandleTable().GetObject<KProcess>(handle);

                        #if defined(MESOSPHERE_ENABLE_GET_INFO_OF_DEBUG_PROCESS)
                        /* If we the process is valid, use it. */
                        if (process.IsNotNull()) {
                            return GetInfoImpl(out, info_type, process.GetPointerUnsafe());
                        }

                        /* Otherwise, as a mesosphere extension check if we were passed a usable KDebug. */
                        KScopedAutoObject debug = GetCurrentProcess().GetHandleTable().GetObject<KDebug>(handle);
                        R_UNLESS(debug.IsNotNull(), svc::ResultInvalidHandle());

                        /* Get the process from the debug object. */
                        /* TODO: ResultInvalidHandle()? */
                        R_UNLESS(debug->IsAttached(),  svc::ResultProcessTerminated());
                        R_UNLESS(debug->OpenProcess(), svc::ResultProcessTerminated());

                        /* Close the process when we're done. */
                        ON_SCOPE_EXIT { debug->CloseProcess(); };

                        /* Return the info. */
                        return GetInfoImpl(out, info_type, debug->GetProcessUnsafe());
                        #else
                        /* Verify that the process is valid. */
                        R_UNLESS(process.IsNotNull(), svc::ResultInvalidHandle());

                        /* Return the relevant info. */
                        return GetInfoImpl(out, info_type, process.GetPointerUnsafe());
                        #endif
                    }
                    break;
                case ams::svc::InfoType_DebuggerAttached:
                    {
                        /* Verify the input handle is invalid. */
                        R_UNLESS(handle == ams::svc::InvalidHandle, svc::ResultInvalidHandle());

                        /* Verify the sub-type is valid. */
                        R_UNLESS(info_subtype == 0, svc::ResultInvalidCombination());

                        /* Get whether debugger is attached. */
                        *out = GetCurrentProcess().GetDebugObject() != nullptr;
                    }
                    break;
                case ams::svc::InfoType_ResourceLimit:
                    {
                        /* Verify the input handle is invalid. */
                        R_UNLESS(handle == ams::svc::InvalidHandle, svc::ResultInvalidHandle());

                        /* Verify the sub-type is valid. */
                        R_UNLESS(info_subtype == 0, svc::ResultInvalidCombination());

                        /* Get the handle table and resource limit. */
                        KHandleTable &handle_table     = GetCurrentProcess().GetHandleTable();
                        KResourceLimit *resource_limit = GetCurrentProcess().GetResourceLimit();

                        if (resource_limit != nullptr) {
                            /* Get a new handle for the resource limit. */
                            ams::svc::Handle tmp;
                            R_TRY(handle_table.Add(std::addressof(tmp), resource_limit));

                            /* Set the output. */
                            *out = tmp;
                        } else {
                            /* Set the output. */
                            *out = ams::svc::InvalidHandle;
                        }
                    }
                    break;
                case ams::svc::InfoType_IdleTickCount:
                    {
                        /* Verify the input handle is invalid. */
                        R_UNLESS(handle == ams::svc::InvalidHandle, svc::ResultInvalidHandle());

                        /* Disable dispatch while we get the tick count. */
                        KScopedDisableDispatch dd;

                        /* Verify the requested core is valid. */
                        const bool core_valid = (info_subtype == static_cast<u64>(-1ul)) || (info_subtype == static_cast<u64>(GetCurrentCoreId()));
                        R_UNLESS(core_valid, svc::ResultInvalidCombination());

                        /* Get the idle tick count. */
                        *out = Kernel::GetScheduler().GetIdleThread()->GetCpuTime() - Kernel::GetInterruptTaskManager().GetCpuTime();
                    }
                    break;
                case ams::svc::InfoType_RandomEntropy:
                    {
                        /* Verify the input handle is invalid. */
                        R_UNLESS(handle == ams::svc::InvalidHandle, svc::ResultInvalidHandle());

                        /* Verify the requested entropy is valid. */
                        R_UNLESS(info_subtype < 4, svc::ResultInvalidCombination());

                        /* Get the entropy. */
                        *out = GetCurrentProcess().GetRandomEntropy(info_subtype);
                    }
                    break;
                case ams::svc::InfoType_InitialProcessIdRange:
                    {
                        /* NOTE: This info type was added in 4.0.0, and removed in 5.0.0. */
                        R_UNLESS(GetTargetFirmware() < TargetFirmware_5_0_0, svc::ResultInvalidEnumValue());

                        /* Verify the input handle is invalid. */
                        R_UNLESS(handle == ams::svc::InvalidHandle, svc::ResultInvalidHandle());

                        /* Get the process id range. */
                        R_TRY(GetInitialProcessIdRange(out, static_cast<ams::svc::InitialProcessIdRangeInfo>(info_subtype)));
                    }
                    break;
                case ams::svc::InfoType_ThreadTickCount:
                    {
                        /* Verify the requested core is valid. */
                        const bool core_valid = (info_subtype == static_cast<u64>(-1ul)) || (info_subtype < cpu::NumVirtualCores);
                        R_UNLESS(core_valid, svc::ResultInvalidCombination());

                        /* Get the thread from its handle. */
                        KScopedAutoObject thread = GetCurrentProcess().GetHandleTable().GetObject<KThread>(handle);
                        R_UNLESS(thread.IsNotNull(), svc::ResultInvalidHandle());

                        /* Disable dispatch while we get the tick count. */
                        KScopedDisableDispatch dd;

                        /* Determine the tick count. */
                        s64 tick_count;
                        if (info_subtype == static_cast<u64>(-1ul)) {
                            tick_count = thread->GetCpuTime();
                            if (GetCurrentThreadPointer() == thread.GetPointerUnsafe()) {
                                const s64 cur_tick    = KHardwareTimer::GetTick();
                                const s64 prev_switch = Kernel::GetScheduler().GetLastContextSwitchTime();
                                tick_count += (cur_tick - prev_switch);
                            }
                        } else {
                            const s32 phys_core = cpu::VirtualToPhysicalCoreMap[info_subtype];
                            MESOSPHERE_ABORT_UNLESS(phys_core < static_cast<s32>(cpu::NumCores));

                            tick_count = thread->GetCpuTime(phys_core);
                            if (GetCurrentThreadPointer() == thread.GetPointerUnsafe() && phys_core == GetCurrentCoreId()) {
                                const s64 cur_tick    = KHardwareTimer::GetTick();
                                const s64 prev_switch = Kernel::GetScheduler().GetLastContextSwitchTime();
                                tick_count += (cur_tick - prev_switch);
                            }
                        }

                        /* Set the output. */
                        *out = tick_count;
                    }
                    break;
                case ams::svc::InfoType_MesosphereMeta:
                    {
                        /* Verify the handle is invalid. */
                        R_UNLESS(handle == ams::svc::InvalidHandle, svc::ResultInvalidHandle());

                        switch (static_cast<ams::svc::MesosphereMetaInfo>(info_subtype)) {
                            case ams::svc::MesosphereMetaInfo_KernelVersion:
                                {
                                    /* Return the supported kernel version. */
                                    *out = ams::svc::SupportedKernelVersion;
                                }
                                break;
                            case ams::svc::MesosphereMetaInfo_IsKTraceEnabled:
                                {
                                    /* Return whether the kernel supports tracing. */
                                    constexpr u64 KTraceValue = ams::kern::IsKTraceEnabled ? 1 : 0;
                                    *out = KTraceValue;
                                }
                                break;
                            case ams::svc::MesosphereMetaInfo_IsSingleStepEnabled:
                                {
                                    /* Return whether the kernel supports hardware single step. */
                                    #if defined(MESOSPHERE_ENABLE_HARDWARE_SINGLE_STEP)
                                    *out = 1;
                                    #else
                                    *out = 0;
                                    #endif
                                }
                                break;
                            default:
                                return svc::ResultInvalidCombination();
                        }
                    }
                    break;
                case ams::svc::InfoType_MesosphereCurrentProcess:
                    {
                        /* Verify the input handle is invalid. */
                        R_UNLESS(handle == ams::svc::InvalidHandle, svc::ResultInvalidHandle());

                        /* Verify the sub-type is valid. */
                        R_UNLESS(info_subtype == 0, svc::ResultInvalidCombination());

                        /* Get the handle table. */
                        KHandleTable &handle_table = GetCurrentProcess().GetHandleTable();

                        /* Get a new handle for the current process. */
                        ams::svc::Handle tmp;
                        R_TRY(handle_table.Add(std::addressof(tmp), GetCurrentProcessPointer()));

                        /* Set the output. */
                        *out = tmp;
                    }
                    break;
                default:
                    {
                        /* For debug, log the invalid info call. */
                        MESOSPHERE_LOG("GetInfo(%p, %u, %08x, %lu) was called\n", out, static_cast<u32>(info_type), static_cast<u32>(handle), info_subtype);
                    }
                    return svc::ResultInvalidEnumValue();
            }

            return ResultSuccess();
        }

        constexpr bool IsValidMemoryPool(u64 pool) {
            switch (static_cast<KMemoryManager::Pool>(pool)) {
                case KMemoryManager::Pool_Application:
                case KMemoryManager::Pool_Applet:
                case KMemoryManager::Pool_System:
                case KMemoryManager::Pool_SystemNonSecure:
                    return true;
                default:
                    return false;
            }
        }

        Result GetSystemInfo(u64 *out, ams::svc::SystemInfoType info_type, ams::svc::Handle handle, u64 info_subtype) {
            switch (info_type) {
                case ams::svc::SystemInfoType_TotalPhysicalMemorySize:
                case ams::svc::SystemInfoType_UsedPhysicalMemorySize:
                    {
                        /* Verify the input handle is invalid. */
                        R_UNLESS(handle == ams::svc::InvalidHandle, svc::ResultInvalidHandle());

                        /* Verify the sub-type is valid. */
                        R_UNLESS(IsValidMemoryPool(info_subtype), svc::ResultInvalidCombination());

                        /* Convert to pool. */
                        const auto pool = static_cast<KMemoryManager::Pool>(info_subtype);

                        /* Get the memory size. */
                        auto &mm = Kernel::GetMemoryManager();
                        switch (info_type) {
                            case ams::svc::SystemInfoType_TotalPhysicalMemorySize:
                                *out = mm.GetSize(pool);
                                break;
                            case ams::svc::SystemInfoType_UsedPhysicalMemorySize:
                                *out = mm.GetSize(pool) - mm.GetFreeSize(pool);
                                break;
                            MESOSPHERE_UNREACHABLE_DEFAULT_CASE();
                        }
                    }
                    break;
                case ams::svc::SystemInfoType_InitialProcessIdRange:
                    {
                        /* Verify the handle is invalid. */
                        R_UNLESS(handle == ams::svc::InvalidHandle, svc::ResultInvalidHandle());

                        /* Get the process id range. */
                        R_TRY(GetInitialProcessIdRange(out, static_cast<ams::svc::InitialProcessIdRangeInfo>(info_subtype)));
                    }
                    break;
                default:
                    return svc::ResultInvalidEnumValue();
            }

            return ResultSuccess();
        }

    }

    /* =============================    64 ABI    ============================= */

    Result GetInfo64(uint64_t *out, ams::svc::InfoType info_type, ams::svc::Handle handle, uint64_t info_subtype) {
        return GetInfo(out, info_type, handle, info_subtype);
    }

    Result GetSystemInfo64(uint64_t *out, ams::svc::SystemInfoType info_type, ams::svc::Handle handle, uint64_t info_subtype) {
        return GetSystemInfo(out, info_type, handle, info_subtype);
    }

    /* ============================= 64From32 ABI ============================= */

    Result GetInfo64From32(uint64_t *out, ams::svc::InfoType info_type, ams::svc::Handle handle, uint64_t info_subtype) {
        return GetInfo(out, info_type, handle, info_subtype);
    }

    Result GetSystemInfo64From32(uint64_t *out, ams::svc::SystemInfoType info_type, ams::svc::Handle handle, uint64_t info_subtype) {
        return GetSystemInfo(out, info_type, handle, info_subtype);
    }

}