using ARMeilleure.Memory;
using Ryujinx.Common;
using Ryujinx.Common.Logging;
using Ryujinx.HLE.Exceptions;
using Ryujinx.HLE.HOS.Kernel.Common;
using Ryujinx.HLE.HOS.Kernel.Ipc;
using Ryujinx.HLE.HOS.Kernel.Memory;
using Ryujinx.HLE.HOS.Kernel.Process;
using Ryujinx.HLE.HOS.Kernel.Threading;

namespace Ryujinx.HLE.HOS.Kernel.SupervisorCall
{
    partial class SvcHandler
    {
        public void ExitProcess64()
        {
            ExitProcess();
        }

        public void ExitProcess32()
        {
            ExitProcess();
        }

        public KernelResult TerminateProcess64([R(0)] int handle)
        {
            return TerminateProcess(handle);
        }

        public KernelResult TerminateProcess32([R(0)] int handle)
        {
            return TerminateProcess(handle);
        }

        private KernelResult TerminateProcess(int handle)
        {
            KProcess process = _process.HandleTable.GetObject<KProcess>(handle);

            KernelResult result;

            if (process != null)
            {
                if (process == _system.Scheduler.GetCurrentProcess())
                {
                    result = KernelResult.Success;
                    process.DecrementToZeroWhileTerminatingCurrent();
                }
                else
                {
                    result = process.Terminate();
                    process.DecrementReferenceCount();
                }
            }
            else
            {
                result = KernelResult.InvalidHandle;
            }

            return result;
        }

        private void ExitProcess()
        {
            _system.Scheduler.GetCurrentProcess().TerminateCurrentProcess();
        }

        public KernelResult SignalEvent64([R(0)] int handle)
        {
            return SignalEvent(handle);
        }

        public KernelResult SignalEvent32([R(0)] int handle)
        {
            return SignalEvent(handle);
        }

        private KernelResult SignalEvent(int handle)
        {
            KWritableEvent writableEvent = _process.HandleTable.GetObject<KWritableEvent>(handle);

            KernelResult result;

            if (writableEvent != null)
            {
                writableEvent.Signal();

                result = KernelResult.Success;
            }
            else
            {
                result = KernelResult.InvalidHandle;
            }

            return result;
        }

        public KernelResult ClearEvent64([R(0)] int handle)
        {
            return ClearEvent(handle);
        }

        public KernelResult ClearEvent32([R(0)] int handle)
        {
            return ClearEvent(handle);
        }

        private KernelResult ClearEvent(int handle)
        {
            KernelResult result;

            KWritableEvent writableEvent = _process.HandleTable.GetObject<KWritableEvent>(handle);

            if (writableEvent == null)
            {
                KReadableEvent readableEvent = _process.HandleTable.GetObject<KReadableEvent>(handle);

                result = readableEvent?.Clear() ?? KernelResult.InvalidHandle;
            }
            else
            {
                result = writableEvent.Clear();
            }

            return result;
        }

        public KernelResult CloseHandle64([R(0)] int handle)
        {
            return CloseHandle(handle);
        }

        public KernelResult CloseHandle32([R(0)] int handle)
        {
            return CloseHandle(handle);
        }

        private KernelResult CloseHandle(int handle)
        {
            KAutoObject obj = _process.HandleTable.GetObject<KAutoObject>(handle);

            _process.HandleTable.CloseHandle(handle);

            if (obj == null)
            {
                return KernelResult.InvalidHandle;
            }

            if (obj is KSession session)
            {
                session.Dispose();
            }
            else if (obj is KTransferMemory transferMemory)
            {
                _process.MemoryManager.ResetTransferMemory(
                    transferMemory.Address,
                    transferMemory.Size);
            }

            return KernelResult.Success;
        }

        public KernelResult ResetSignal64([R(0)] int handle)
        {
            return ResetSignal(handle);
        }

        public KernelResult ResetSignal32([R(0)] int handle)
        {
            return ResetSignal(handle);
        }

        private KernelResult ResetSignal(int handle)
        {
            KProcess currentProcess = _system.Scheduler.GetCurrentProcess();

            KReadableEvent readableEvent = currentProcess.HandleTable.GetObject<KReadableEvent>(handle);

            KernelResult result;

            if (readableEvent != null)
            {
                result = readableEvent.ClearIfSignaled();
            }
            else
            {
                KProcess process = currentProcess.HandleTable.GetKProcess(handle);

                if (process != null)
                {
                    result = process.ClearIfNotExited();
                }
                else
                {
                    result = KernelResult.InvalidHandle;
                }
            }

            return result;
        }

        public ulong GetSystemTick64()
        {
            return _system.Scheduler.GetCurrentThread().Context.CntpctEl0;
        }

        public void GetSystemTick32([R(0)] out uint resultLow, [R(1)] out uint resultHigh)
        {
            ulong result = _system.Scheduler.GetCurrentThread().Context.CntpctEl0;

            resultLow  = (uint)(result & uint.MaxValue);
            resultHigh = (uint)(result >> 32);
        }

        public KernelResult GetProcessId64([R(1)] int handle, [R(1)] out long pid)
        {
            return GetProcessId(handle, out pid);
        }

        public KernelResult GetProcessId32([R(1)] int handle, [R(1)] out int pidLow, [R(2)] out int pidHigh)
        {
            KernelResult result = GetProcessId(handle, out long pid);

            pidLow  = (int)(pid & uint.MaxValue);
            pidHigh = (int)(pid >> 32);

            return result;
        }

        private KernelResult GetProcessId(int handle, out long pid)
        {
            KProcess currentProcess = _system.Scheduler.GetCurrentProcess();

            KProcess process = currentProcess.HandleTable.GetKProcess(handle);

            if (process == null)
            {
                KThread thread = currentProcess.HandleTable.GetKThread(handle);

                if (thread != null)
                {
                    process = thread.Owner;
                }

                // TODO: KDebugEvent.
            }

            pid = process?.Pid ?? 0;

            return process != null
                ? KernelResult.Success
                : KernelResult.InvalidHandle;
        }

        public void Break64([R(0)] ulong reason, [R(1)] ulong x1, [R(2)] ulong info)
        {
            Break(reason);
        }

        public void Break32([R(0)] uint reason, [R(1)] uint r1, [R(2)] uint info)
        {
            Break(reason);
        }

        private void Break(ulong reason)
        {
            KThread currentThread = _system.Scheduler.GetCurrentThread();

            if ((reason & (1UL << 31)) == 0)
            {
                currentThread.PrintGuestStackTrace();

                // As the process is exiting, this is probably caused by emulation termination.
                if (currentThread.Owner.State == ProcessState.Exiting)
                {
                    return;
                }

                // TODO: Debug events.
                currentThread.Owner.TerminateCurrentProcess();

                throw new GuestBrokeExecutionException();
            }
            else
            {
                Logger.PrintInfo(LogClass.KernelSvc, "Debugger triggered.");

                currentThread.PrintGuestStackTrace();
            }
        }

        public void OutputDebugString64([R(0)] ulong strPtr, [R(1)] ulong size)
        {
            OutputDebugString(strPtr, size);
        }

        public void OutputDebugString32([R(0)] uint strPtr, [R(1)] uint size)
        {
            OutputDebugString(strPtr, size);
        }

        private void OutputDebugString(ulong strPtr, ulong size)
        {
            string str = MemoryHelper.ReadAsciiString(_process.CpuMemory, (long)strPtr, (long)size);

            Logger.PrintWarning(LogClass.KernelSvc, str);
        }

        public KernelResult GetInfo64([R(1)] uint id, [R(2)] int handle, [R(3)] long subId, [R(1)] out long value)
        {
            return GetInfo(id, handle, subId, out value);
        }

        public KernelResult GetInfo32(
            [R(0)] uint     subIdLow,
            [R(1)] uint     id,
            [R(2)] int      handle,
            [R(3)] uint     subIdHigh,
            [R(1)] out uint valueLow,
            [R(2)] out uint valueHigh)
        {
            long subId = (long)(subIdLow | ((ulong)subIdHigh << 32));

            KernelResult result = GetInfo(id, handle, subId, out long value);
            valueHigh = (uint)(value >> 32);
            valueLow  = (uint)(value & uint.MaxValue);

            return result;
        }

        private KernelResult GetInfo(uint id, int handle, long subId, out long value)
        {
            value = 0;

            switch (id)
            {
                case 0:
                case 1:
                case 2:
                case 3:
                case 4:
                case 5:
                case 6:
                case 7:
                case 12:
                case 13:
                case 14:
                case 15:
                case 16:
                case 17:
                case 18:
                case 20:
                case 21:
                case 22:
                {
                    if (subId != 0)
                    {
                        return KernelResult.InvalidCombination;
                    }

                    KProcess currentProcess = _system.Scheduler.GetCurrentProcess();

                    KProcess process = currentProcess.HandleTable.GetKProcess(handle);

                    if (process == null)
                    {
                        return KernelResult.InvalidHandle;
                    }

                    switch (id)
                    {
                        case 0: value = process.Capabilities.AllowedCpuCoresMask;    break;
                        case 1: value = process.Capabilities.AllowedThreadPriosMask; break;

                        case 2: value = (long)process.MemoryManager.AliasRegionStart; break;
                        case 3: value = (long)(process.MemoryManager.AliasRegionEnd -
                                               process.MemoryManager.AliasRegionStart); break;

                        case 4: value = (long)process.MemoryManager.HeapRegionStart; break;
                        case 5: value = (long)(process.MemoryManager.HeapRegionEnd -
                                               process.MemoryManager.HeapRegionStart); break;

                        case 6: value = (long)process.GetMemoryCapacity(); break;

                        case 7: value = (long)process.GetMemoryUsage(); break;

                        case 12: value = (long)process.MemoryManager.GetAddrSpaceBaseAddr(); break;

                        case 13: value = (long)process.MemoryManager.GetAddrSpaceSize(); break;

                        case 14: value = (long)process.MemoryManager.StackRegionStart; break;
                        case 15: value = (long)(process.MemoryManager.StackRegionEnd -
                                                process.MemoryManager.StackRegionStart); break;

                        case 16: value = (long)process.PersonalMmHeapPagesCount * KMemoryManager.PageSize; break;

                        case 17:
                            if (process.PersonalMmHeapPagesCount != 0)
                            {
                                value = process.MemoryManager.GetMmUsedPages() * KMemoryManager.PageSize;
                            }

                            break;

                        case 18: value = (long)process.TitleId; break;

                        case 20: value = (long)process.UserExceptionContextAddress; break;

                        case 21: value = (long)process.GetMemoryCapacityWithoutPersonalMmHeap(); break;

                        case 22: value = (long)process.GetMemoryUsageWithoutPersonalMmHeap(); break;
                    }

                    break;
                }

                case 8:
                {
                    if (handle != 0)
                    {
                        return KernelResult.InvalidHandle;
                    }

                    if (subId != 0)
                    {
                        return KernelResult.InvalidCombination;
                    }

                    value = _system.Scheduler.GetCurrentProcess().Debug ? 1 : 0;

                    break;
                }

                case 9:
                {
                    if (handle != 0)
                    {
                        return KernelResult.InvalidHandle;
                    }

                    if (subId != 0)
                    {
                        return KernelResult.InvalidCombination;
                    }

                    KProcess currentProcess = _system.Scheduler.GetCurrentProcess();

                    if (currentProcess.ResourceLimit != null)
                    {
                        KHandleTable   handleTable   = currentProcess.HandleTable;
                        KResourceLimit resourceLimit = currentProcess.ResourceLimit;

                        KernelResult result = handleTable.GenerateHandle(resourceLimit, out int resLimHandle);

                        if (result != KernelResult.Success)
                        {
                            return result;
                        }

                        value = (uint)resLimHandle;
                    }

                    break;
                }

                case 10:
                {
                    if (handle != 0)
                    {
                        return KernelResult.InvalidHandle;
                    }

                    int currentCore = _system.Scheduler.GetCurrentThread().CurrentCore;

                    if (subId != -1 && subId != currentCore)
                    {
                        return KernelResult.InvalidCombination;
                    }

                    value = _system.Scheduler.CoreContexts[currentCore].TotalIdleTimeTicks;

                    break;
                }

                case 11:
                {
                    if (handle != 0)
                    {
                        return KernelResult.InvalidHandle;
                    }

                    if ((ulong)subId > 3)
                    {
                        return KernelResult.InvalidCombination;
                    }

                    KProcess currentProcess = _system.Scheduler.GetCurrentProcess();


                    value = currentProcess.RandomEntropy[subId];

                    break;
                }

                case 0xf0000002u:
                {
                    if (subId < -1 || subId > 3)
                    {
                        return KernelResult.InvalidCombination;
                    }

                    KThread thread = _system.Scheduler.GetCurrentProcess().HandleTable.GetKThread(handle);

                    if (thread == null)
                    {
                        return KernelResult.InvalidHandle;
                    }

                    KThread currentThread = _system.Scheduler.GetCurrentThread();

                    int currentCore = currentThread.CurrentCore;

                    if (subId != -1 && subId != currentCore)
                    {
                        return KernelResult.Success;
                    }

                    KCoreContext coreContext = _system.Scheduler.CoreContexts[currentCore];

                    long timeDelta = PerformanceCounter.ElapsedMilliseconds - coreContext.LastContextSwitchTime;

                    if (subId != -1)
                    {
                        value = KTimeManager.ConvertMillisecondsToTicks(timeDelta);
                    }
                    else
                    {
                        long totalTimeRunning = thread.TotalTimeRunning;

                        if (thread == currentThread)
                        {
                            totalTimeRunning += timeDelta;
                        }

                        value = KTimeManager.ConvertMillisecondsToTicks(totalTimeRunning);
                    }

                    break;
                }

                default: return KernelResult.InvalidEnumValue;
            }

            return KernelResult.Success;
        }

        public KernelResult CreateEvent64([R(1)] out int wEventHandle, [R(2)] out int rEventHandle)
        {
            return CreateEvent(out wEventHandle, out rEventHandle);
        }

        public KernelResult CreateEvent32([R(1)] out int wEventHandle, [R(2)] out int rEventHandle)
        {
            return CreateEvent(out wEventHandle, out rEventHandle);
        }

        private KernelResult CreateEvent(out int wEventHandle, out int rEventHandle)
        {
            KEvent Event = new KEvent(_system);

            KernelResult result = _process.HandleTable.GenerateHandle(Event.WritableEvent, out wEventHandle);

            if (result == KernelResult.Success)
            {
                result = _process.HandleTable.GenerateHandle(Event.ReadableEvent, out rEventHandle);

                if (result != KernelResult.Success)
                {
                    _process.HandleTable.CloseHandle(wEventHandle);
                }
            }
            else
            {
                rEventHandle = 0;
            }

            return result;
        }

        public KernelResult GetProcessList64([R(1)] ulong address, [R(2)] int maxCount, [R(1)] out int count)
        {
            return GetProcessList(address, maxCount, out count);
        }

        public KernelResult GetProcessList32([R(1)] ulong address, [R(2)] int maxCount, [R(1)] out int count)
        {
            return GetProcessList(address, maxCount, out count);
        }

        private KernelResult GetProcessList(ulong address, int maxCount, out int count)
        {
            count = 0;

            if ((maxCount >> 28) != 0)
            {
                return KernelResult.MaximumExceeded;
            }

            if (maxCount != 0)
            {
                KProcess currentProcess = _system.Scheduler.GetCurrentProcess();

                ulong copySize = (ulong)maxCount * 8;

                if (address + copySize <= address)
                {
                    return KernelResult.InvalidMemState;
                }

                if (currentProcess.MemoryManager.OutsideAddrSpace(address, copySize))
                {
                    return KernelResult.InvalidMemState;
                }
            }

            int copyCount = 0;

            lock (_system.Processes)
            {
                foreach (KProcess process in _system.Processes.Values)
                {
                    if (copyCount < maxCount)
                    {
                        if (!KernelTransfer.KernelToUserInt64(_system, address + (ulong)copyCount * 8, process.Pid))
                        {
                            return KernelResult.UserCopyFailed;
                        }
                    }

                    copyCount++;
                }
            }

            count = copyCount;

            return KernelResult.Success;
        }

        public KernelResult GetSystemInfo64([R(1)] uint id, [R(2)] int handle, [R(3)] long subId, [R(1)] out long value)
        {
            return GetSystemInfo(id, handle, subId, out value);
        }

        public KernelResult GetSystemInfo32([R(1)] uint subIdLow, [R(2)] uint id, [R(3)] int handle, [R(3)] uint subIdHigh, [R(1)] out int valueLow, [R(2)] out int valueHigh)
        {
            long subId = (long)(subIdLow | ((ulong)subIdHigh << 32));

            KernelResult result = GetSystemInfo(id, handle, subId, out long value);

            valueHigh = (int)(value >> 32);
            valueLow  = (int)(value & uint.MaxValue);

            return result;
        }

        private KernelResult GetSystemInfo(uint id, int handle, long subId, out long value)
        {
            value = 0;

            if (id > 2)
            {
                return KernelResult.InvalidEnumValue;
            }

            if (handle != 0)
            {
                return KernelResult.InvalidHandle;
            }

            if (id < 2)
            {
                if ((ulong)subId > 3)
                {
                    return KernelResult.InvalidCombination;
                }

                KMemoryRegionManager region = _system.MemoryRegions[subId];

                switch (id)
                {
                    // Memory region capacity.
                    case 0: value = (long)region.Size; break;

                    // Memory region free space.
                    case 1:
                    {
                        ulong freePagesCount = region.GetFreePages();

                        value = (long)(freePagesCount * KMemoryManager.PageSize);

                        break;
                    }
                }
            }
            else /* if (Id == 2) */
            {
                if ((ulong)subId > 1)
                {
                    return KernelResult.InvalidCombination;
                }

                switch (subId)
                {
                    case 0: value = _system.PrivilegedProcessLowestId;  break;
                    case 1: value = _system.PrivilegedProcessHighestId; break;
                }
            }

            return KernelResult.Success;
        }

        public KernelResult FlushProcessDataCache32(
            [R(0)] uint processHandle,
            [R(2)] uint addressLow,
            [R(3)] uint addressHigh,
            [R(1)] uint sizeLow,
            [R(4)] uint sizeHigh)
        {
            // FIXME: This needs to be implemented as ARMv7 doesn't have any way to do cache maintenance operations on EL0. As we don't support (and don't actually need) to flush the cache, this is stubbed.
            return KernelResult.Success;
        }
    }
}