using ChocolArm64.Memory;
using Ryujinx.Core.OsHle.Handles;
using Ryujinx.Core.OsHle.Ipc;
using Ryujinx.Core.OsHle.Utilities;
using Ryujinx.Graphics.Gpu;
using System;
using System.Collections.Generic;

namespace Ryujinx.Core.OsHle.Services
{
    static partial class Service
    {
        private delegate long ServiceProcessRequest(ServiceCtx Context);

        private static Dictionary<(string, int), ServiceProcessRequest> IoctlCmds =
                   new Dictionary<(string, int), ServiceProcessRequest>()
        {
            { ("/dev/nvhost-as-gpu",   0x4101), NvGpuAsIoctlBindChannel           },
            { ("/dev/nvhost-as-gpu",   0x4102), NvGpuAsIoctlAllocSpace            },
            { ("/dev/nvhost-as-gpu",   0x4106), NvGpuAsIoctlMapBufferEx           },
            { ("/dev/nvhost-as-gpu",   0x4108), NvGpuAsIoctlGetVaRegions          },
            { ("/dev/nvhost-as-gpu",   0x4109), NvGpuAsIoctlInitializeEx          },
            { ("/dev/nvhost-ctrl",     0x001b), NvHostIoctlCtrlGetConfig          },
            { ("/dev/nvhost-ctrl",     0x001d), NvHostIoctlCtrlEventWait          },
            { ("/dev/nvhost-ctrl-gpu", 0x4701), NvGpuIoctlZcullGetCtxSize         },
            { ("/dev/nvhost-ctrl-gpu", 0x4702), NvGpuIoctlZcullGetInfo            },
            { ("/dev/nvhost-ctrl-gpu", 0x4705), NvGpuIoctlGetCharacteristics      },
            { ("/dev/nvhost-ctrl-gpu", 0x4706), NvGpuIoctlGetTpcMasks             },
            { ("/dev/nvhost-ctrl-gpu", 0x4714), NvGpuIoctlZbcGetActiveSlotMask    },
            { ("/dev/nvhost-gpu",      0x4714), NvMapIoctlChannelSetUserData      },
            { ("/dev/nvhost-gpu",      0x4801), NvMapIoctlChannelSetNvMap         },
            { ("/dev/nvhost-gpu",      0x4808), NvMapIoctlChannelSubmitGpFifo     },
            { ("/dev/nvhost-gpu",      0x4809), NvMapIoctlChannelAllocObjCtx      },
            { ("/dev/nvhost-gpu",      0x480b), NvMapIoctlChannelZcullBind        },
            { ("/dev/nvhost-gpu",      0x480c), NvMapIoctlChannelSetErrorNotifier },
            { ("/dev/nvhost-gpu",      0x480d), NvMapIoctlChannelSetPriority      },
            { ("/dev/nvhost-gpu",      0x481a), NvMapIoctlChannelAllocGpFifoEx2   },
            { ("/dev/nvmap",           0x0101), NvMapIocCreate                    },
            { ("/dev/nvmap",           0x0103), NvMapIocFromId                    },
            { ("/dev/nvmap",           0x0104), NvMapIocAlloc                     },
            { ("/dev/nvmap",           0x0109), NvMapIocParam                     },
            { ("/dev/nvmap",           0x010e), NvMapIocGetId                     },
        };

        public static long NvDrvOpen(ServiceCtx Context)
        {
            long NamePtr = Context.Request.SendBuff[0].Position;

            string Name = AMemoryHelper.ReadAsciiString(Context.Memory, NamePtr);

            int Fd = Context.Ns.Os.Fds.GenerateId(new FileDesc(Name));

            Context.ResponseData.Write(Fd);
            Context.ResponseData.Write(0);

            return 0;
        }

        public static long NvDrvIoctl(ServiceCtx Context)
        {
            int Fd  = Context.RequestData.ReadInt32();
            int Cmd = Context.RequestData.ReadInt32() & 0xffff;
            
            FileDesc FdData = Context.Ns.Os.Fds.GetData<FileDesc>(Fd);

            long Position = Context.Request.PtrBuff[0].Position;

            Context.ResponseData.Write(0);

            if (IoctlCmds.TryGetValue((FdData.Name, Cmd), out ServiceProcessRequest ProcReq))
            {
                return ProcReq(Context);
            }
            else
            {
                throw new NotImplementedException($"{FdData.Name} {Cmd:x4}");
            }
        }

        public static long NvDrvClose(ServiceCtx Context)
        {
            int Fd = Context.RequestData.ReadInt32();

            Context.Ns.Os.Fds.Delete(Fd);

            Context.ResponseData.Write(0);

            return 0;
        }

        public static long NvDrvInitialize(ServiceCtx Context)
        {
            long TransferMemSize   = Context.RequestData.ReadInt64();
            int  TransferMemHandle = Context.Request.HandleDesc.ToCopy[0];

            Context.ResponseData.Write(0);

            return 0;
        }

        public static long NvDrvQueryEvent(ServiceCtx Context)
        {
            int Fd      = Context.RequestData.ReadInt32();
            int EventId = Context.RequestData.ReadInt32();

            Context.Response.HandleDesc = IpcHandleDesc.MakeCopy(0xcafe);

            Context.ResponseData.Write(0);

            return 0;
        }

        public static long NvDrvSetClientPid(ServiceCtx Context)
        {
            long Pid = Context.RequestData.ReadInt64();

            Context.ResponseData.Write(0);

            return 0;
        }

        private static long NvGpuAsIoctlBindChannel(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            int Fd = Context.Memory.ReadInt32(Position);

            return 0;
        }

        private static long NvGpuAsIoctlAllocSpace(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            MemReader Reader = new MemReader(Context.Memory, Position);

            int  Pages    = Reader.ReadInt32();
            int  PageSize = Reader.ReadInt32();
            int  Flags    = Reader.ReadInt32();
            int  Padding  = Reader.ReadInt32();
            long Align    = Reader.ReadInt64();

            if ((Flags & 1) != 0)
            {
                Align = Context.Ns.Gpu.ReserveMemory(Align, (long)Pages * PageSize, 1);
            }
            else
            {
                Align = Context.Ns.Gpu.ReserveMemory((long)Pages * PageSize, Align);
            }

            Context.Memory.WriteInt64(Position + 0x10, Align);

            return 0;
        }

        private static long NvGpuAsIoctlMapBufferEx(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            MemReader Reader = new MemReader(Context.Memory, Position);

            int  Flags    = Reader.ReadInt32();
            int  Kind     = Reader.ReadInt32();
            int  Handle   = Reader.ReadInt32();
            int  PageSize = Reader.ReadInt32();            
            long BuffAddr = Reader.ReadInt64();
            long MapSize  = Reader.ReadInt64();
            long Offset   = Reader.ReadInt64();

            HNvMap NvMap = Context.Ns.Os.Handles.GetData<HNvMap>(Handle);

            if (NvMap != null)
            {
                if ((Flags & 1) != 0)
                {
                    Offset = Context.Ns.Gpu.MapMemory(NvMap.Address, Offset, NvMap.Size);
                }
                else
                {
                    Offset = Context.Ns.Gpu.MapMemory(NvMap.Address, NvMap.Size);
                }
            }

            Context.Memory.WriteInt64(Position + 0x20, Offset);

            return 0;
        }

        private static long NvGpuAsIoctlGetVaRegions(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            MemReader Reader = new MemReader(Context.Memory, Position);
            MemWriter Writer = new MemWriter(Context.Memory, Position);

            long Unused   = Reader.ReadInt64();
            int  BuffSize = Reader.ReadInt32();
            int  Padding  = Reader.ReadInt32();

            BuffSize = 0x30;

            Writer.WriteInt64(Unused);
            Writer.WriteInt32(BuffSize);
            Writer.WriteInt32(Padding);

            Writer.WriteInt64(0);
            Writer.WriteInt32(0);
            Writer.WriteInt32(0);
            Writer.WriteInt64(0);

            Writer.WriteInt64(0);
            Writer.WriteInt32(0);
            Writer.WriteInt32(0);
            Writer.WriteInt64(0);

            return 0;
        }

        private static long NvGpuAsIoctlInitializeEx(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            MemReader Reader = new MemReader(Context.Memory, Position);

            int  BigPageSize = Reader.ReadInt32();
            int  AsFd        = Reader.ReadInt32();
            int  Flags       = Reader.ReadInt32();
            int  Reserved    = Reader.ReadInt32();
            long Unknown10   = Reader.ReadInt64();
            long Unknown18   = Reader.ReadInt64();
            long Unknown20   = Reader.ReadInt64();

            return 0;
        }

        private static long NvHostIoctlCtrlGetConfig(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            MemReader Reader = new MemReader(Context.Memory, Position);
            MemWriter Writer = new MemWriter(Context.Memory, Position + 0x82);

            for (int Index = 0; Index < 0x101; Index++)
            {
                Writer.WriteByte(0);
            }

            return 0;
        }

        private static long NvHostIoctlCtrlEventWait(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            MemReader Reader = new MemReader(Context.Memory, Position);

            int SyncPtId  = Reader.ReadInt32();
            int Threshold = Reader.ReadInt32();
            int Timeout   = Reader.ReadInt32();
            int Value     = Reader.ReadInt32();

            Context.Memory.WriteInt32(Position + 0xc, 0xcafe);

            return 0;
        }

        private static long NvGpuIoctlZcullGetCtxSize(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            Context.Memory.WriteInt32(Position, 1);

            return 0;
        }

        private static long NvGpuIoctlZcullGetInfo(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            MemWriter Writer = new MemWriter(Context.Memory, Position);

            Writer.WriteInt32(0);
            Writer.WriteInt32(0);
            Writer.WriteInt32(0);
            Writer.WriteInt32(0);
            Writer.WriteInt32(0);
            Writer.WriteInt32(0);
            Writer.WriteInt32(0);
            Writer.WriteInt32(0);
            Writer.WriteInt32(0);
            Writer.WriteInt32(0);

            return 0;
        }

        private static long NvGpuIoctlGetCharacteristics(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            MemReader Reader = new MemReader(Context.Memory, Position);
            MemWriter Writer = new MemWriter(Context.Memory, Position);

            //Note: We should just ignore the BuffAddr, because official code
            //does __memcpy_device from Position + 0x10 to BuffAddr.
            long BuffSize = Reader.ReadInt64();
            long BuffAddr = Reader.ReadInt64();

            BuffSize = 0xa0;

            Writer.WriteInt64(BuffSize);
            Writer.WriteInt64(BuffAddr);
            Writer.WriteInt32(0x120);  //NVGPU_GPU_ARCH_GM200
            Writer.WriteInt32(0xb);    //NVGPU_GPU_IMPL_GM20B
            Writer.WriteInt32(0xa1);
            Writer.WriteInt32(1);
            Writer.WriteInt64(0x40000);
            Writer.WriteInt64(0);
            Writer.WriteInt32(2);
            Writer.WriteInt32(0x20);   //NVGPU_GPU_BUS_TYPE_AXI
            Writer.WriteInt32(0x20000);
            Writer.WriteInt32(0x20000);
            Writer.WriteInt32(0x1b);
            Writer.WriteInt32(0x30000);
            Writer.WriteInt32(1);
            Writer.WriteInt32(0x503);
            Writer.WriteInt32(0x503);
            Writer.WriteInt32(0x80);
            Writer.WriteInt32(0x28);
            Writer.WriteInt32(0);
            Writer.WriteInt64(0x55);
            Writer.WriteInt32(0x902d); //FERMI_TWOD_A
            Writer.WriteInt32(0xb197); //MAXWELL_B
            Writer.WriteInt32(0xb1c0); //MAXWELL_COMPUTE_B
            Writer.WriteInt32(0xb06f); //MAXWELL_CHANNEL_GPFIFO_A
            Writer.WriteInt32(0xa140); //KEPLER_INLINE_TO_MEMORY_B
            Writer.WriteInt32(0xb0b5); //MAXWELL_DMA_COPY_A
            Writer.WriteInt32(1);
            Writer.WriteInt32(0);
            Writer.WriteInt32(2);
            Writer.WriteInt32(1);
            Writer.WriteInt32(0);
            Writer.WriteInt32(1);
            Writer.WriteInt32(0x21d70);
            Writer.WriteInt32(0);
            Writer.WriteByte((byte)'g');
            Writer.WriteByte((byte)'m');
            Writer.WriteByte((byte)'2');
            Writer.WriteByte((byte)'0');
            Writer.WriteByte((byte)'b');
            Writer.WriteByte((byte)'\0');
            Writer.WriteByte((byte)'\0');
            Writer.WriteByte((byte)'\0');
            Writer.WriteInt64(0);

            return 0;
        }

        private static long NvGpuIoctlGetTpcMasks(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            MemReader Reader = new MemReader(Context.Memory, Position);

            int  MaskBuffSize = Reader.ReadInt32();
            int  Reserved     = Reader.ReadInt32();
            long MaskBuffAddr = Reader.ReadInt64();
            long Unknown      = Reader.ReadInt64();

            return 0;
        }

        private static long NvGpuIoctlZbcGetActiveSlotMask(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            Context.Memory.WriteInt32(Position + 0, 7);
            Context.Memory.WriteInt32(Position + 4, 1);

            return 0;
        }

        private static long NvMapIoctlChannelSetUserData(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            return 0;
        }

        private static long NvMapIoctlChannelSetNvMap(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            int Fd = Context.Memory.ReadInt32(Position);

            return 0;
        }

        private static long NvMapIoctlChannelSubmitGpFifo(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            MemReader Reader = new MemReader(Context.Memory, Position);
            MemWriter Writer = new MemWriter(Context.Memory, Position + 0x10);

            long GpFifo   = Reader.ReadInt64();
            int  Count    = Reader.ReadInt32();
            int  Flags    = Reader.ReadInt32();
            int  FenceId  = Reader.ReadInt32();
            int  FenceVal = Reader.ReadInt32();

            for (int Index = 0; Index < Count; Index++)
            {
                long GpFifoHdr = Reader.ReadInt64();

                long GpuAddr = GpFifoHdr & 0xffffffffff;

                int Size = (int)(GpFifoHdr >> 40) & 0x7ffffc;

                long CpuAddr = Context.Ns.Gpu.GetCpuAddr(GpuAddr);

                if (CpuAddr != -1)
                {
                    byte[] Data = AMemoryHelper.ReadBytes(Context.Memory, CpuAddr, Size);

                    NsGpuPBEntry[] PushBuffer = NsGpuPBEntry.DecodePushBuffer(Data);

                    Context.Ns.Gpu.ProcessPushBuffer(PushBuffer, Context.Memory);
                }
            }

            Writer.WriteInt32(0);
            Writer.WriteInt32(0);

            return 0;
        }

        private static long NvMapIoctlChannelAllocObjCtx(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            int ClassNum = Context.Memory.ReadInt32(Position + 0);
            int Flags    = Context.Memory.ReadInt32(Position + 4);

            Context.Memory.WriteInt32(Position + 8, 0);

            return 0;
        }

        private static long NvMapIoctlChannelZcullBind(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            MemReader Reader = new MemReader(Context.Memory, Position);

            long GpuVa   = Reader.ReadInt64();
            int  Mode    = Reader.ReadInt32();
            int  Padding = Reader.ReadInt32();

            return 0;
        }

        private static long NvMapIoctlChannelSetErrorNotifier(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            MemReader Reader = new MemReader(Context.Memory, Position);

            long Offset  = Reader.ReadInt64();
            long Size    = Reader.ReadInt64();
            int  Mem     = Reader.ReadInt32();
            int  Padding = Reader.ReadInt32();

            return 0;
        }

        private static long NvMapIoctlChannelSetPriority(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            int Priority = Context.Memory.ReadInt32(Position);

            return 0;
        }

        private static long NvMapIoctlChannelAllocGpFifoEx2(ServiceCtx Context)
        {
            long Position = Context.Request.PtrBuff[0].Position;

            MemReader Reader = new MemReader(Context.Memory, Position);
            MemWriter Writer = new MemWriter(Context.Memory, Position + 0xc);

            int  Count     = Reader.ReadInt32();
            int  Flags     = Reader.ReadInt32();
            int  Unknown8  = Reader.ReadInt32();
            long Fence     = Reader.ReadInt64();
            int  Unknown14 = Reader.ReadInt32();
            int  Unknown18 = Reader.ReadInt32();

            Writer.WriteInt32(0);
            Writer.WriteInt32(0);

            return 0;
        }

        private static long NvMapIocCreate(ServiceCtx Context)
        {
            long Position = Context.Request.GetSendBuffPtr();

            int Size = Context.Memory.ReadInt32(Position);

            int Id = Context.Ns.Os.NvMapIds.GenerateId();

            int Handle = Context.Ns.Os.Handles.GenerateId(new HNvMap(Id, Size));

            Context.Memory.WriteInt32(Position + 4, Handle);

            return 0;
        }

        private static long NvMapIocFromId(ServiceCtx Context)
        {
            long Position = Context.Request.GetSendBuffPtr();

            int Id = Context.Memory.ReadInt32(Position);

            int Handle = -1;

            foreach (KeyValuePair<int, object> KV in Context.Ns.Os.Handles)
            {
                if (KV.Value is HNvMap NvMap && NvMap.Id == Id)
                {
                    Handle = KV.Key;

                    break;
                }
            }

            Context.Memory.WriteInt32(Position + 4, Handle);

            return 0;
        }

        private static long NvMapIocAlloc(ServiceCtx Context)
        {
            long Position = Context.Request.GetSendBuffPtr();

            MemReader Reader = new MemReader(Context.Memory, Position);

            int  Handle   =       Reader.ReadInt32();
            int  HeapMask =       Reader.ReadInt32();
            int  Flags    =       Reader.ReadInt32();
            int  Align    =       Reader.ReadInt32();
            byte Kind     = (byte)Reader.ReadInt64();
            long Addr     =       Reader.ReadInt64();

            HNvMap NvMap = Context.Ns.Os.Handles.GetData<HNvMap>(Handle);

            if (NvMap != null)
            {
                NvMap.Address = Addr;
                NvMap.Align   = Align;
                NvMap.Kind    = Kind;
            }

            Logging.Debug($"NvMapIocAlloc at {NvMap.Address:x16}");

            return 0;
        }

        private static long NvMapIocParam(ServiceCtx Context)
        {
            long Position = Context.Request.GetSendBuffPtr();

            MemReader Reader = new MemReader(Context.Memory, Position);

            int Handle = Reader.ReadInt32();
            int Param  = Reader.ReadInt32();

            HNvMap NvMap = Context.Ns.Os.Handles.GetData<HNvMap>(Handle);

            int Response = 0;
            
            switch (Param)
            {
                case 1: Response = NvMap.Size;  break;
                case 2: Response = NvMap.Align; break;
                case 4: Response = 0x40000000;  break;
                case 5: Response = NvMap.Kind;  break;
            }

            Context.Memory.WriteInt32(Position + 8, Response);

            return 0;
        }

        private static long NvMapIocGetId(ServiceCtx Context)
        {
            long Position = Context.Request.GetSendBuffPtr();

            int Handle = Context.Memory.ReadInt32(Position + 4);

            HNvMap NvMap = Context.Ns.Os.Handles.GetData<HNvMap>(Handle);

            Context.Memory.WriteInt32(Position, NvMap.Id);

            return 0;
        }
    }
}