// Copyright 2023 Niels Martignène <niels.martignene@protonmail.com>
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files (the “Software”), to deal in 
// the Software without restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
// Software, and to permit persons to whom the Software is furnished to do so,
// subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.

#if defined(__aarch64__) || defined(_M_ARM64)

#include "src/core/libcc/libcc.hh"
#include "ffi.hh"
#include "call.hh"
#include "util.hh"
#ifdef _WIN32
    #include "win32.hh"
#endif

#include <napi.h>

namespace RG {

struct HfaInfo {
    int count;
    bool float32;
};

struct X0X1Ret {
    uint64_t x0;
    uint64_t x1;
};
struct HfaRet {
    double d0;
    double d1;
    double d2;
    double d3;
};

struct BackRegisters {
    uint64_t x0;
    uint64_t x1;
    double d0;
    double d1;
    double d2;
    double d3;
};

extern "C" X0X1Ret ForwardCallGG(const void *func, uint8_t *sp, uint8_t **out_old_sp);
extern "C" float ForwardCallF(const void *func, uint8_t *sp, uint8_t **out_old_sp);
extern "C" HfaRet ForwardCallDDDD(const void *func, uint8_t *sp, uint8_t **out_old_sp);

extern "C" X0X1Ret ForwardCallXGG(const void *func, uint8_t *sp, uint8_t **out_old_sp);
extern "C" float ForwardCallXF(const void *func, uint8_t *sp, uint8_t **out_old_sp);
extern "C" HfaRet ForwardCallXDDDD(const void *func, uint8_t *sp, uint8_t **out_old_sp);

extern "C" napi_value CallSwitchStack(Napi::Function *func, size_t argc, napi_value *argv,
                                      uint8_t *old_sp, Span<uint8_t> *new_stack,
                                      napi_value (*call)(Napi::Function *func, size_t argc, napi_value *argv));

#include "trampolines/prototypes.inc"

static HfaInfo IsHFA(const TypeInfo *type)
{
    bool float32 = false;
    bool float64 = false;
    int count = 0;

    count = AnalyseFlat(type, [&](const TypeInfo *type, int, int) {
        if (type->primitive == PrimitiveKind::Float32) {
            float32 = true;
        } else if (type->primitive == PrimitiveKind::Float64) {
            float64 = true;
        } else {
            float32 = true;
            float64 = true;
        }
    });

    HfaInfo info = {};

    if (count < 1 || count > 4)
        return info;
    if (float32 && float64)
        return info;

    info.count = count;
    info.float32 = float32;

    return info;
}

static inline void ExpandFloats(uint8_t *ptr, Size len, Size bytes)
{
    for (Size i = len - 1; i >= 0; i--) {
        const uint8_t *src = ptr + i * bytes;
        uint8_t *dest = ptr + i * 8;

        memmove(dest, src, bytes);
    }
}

static inline void CompactFloats(uint8_t *ptr, Size len, Size bytes)
{
    for (Size i = 0; i < len; i++) {
        const uint8_t *src = ptr + i * 8;
        uint8_t *dest = ptr + i * bytes;

        memmove(dest, src, bytes);
    }
}

bool AnalyseFunction(Napi::Env, InstanceData *, FunctionInfo *func)
{
    if (HfaInfo hfa = IsHFA(func->ret.type); hfa.count) {
        func->ret.vec_count = (int8_t)hfa.count;
        func->ret.vec_bytes = hfa.float32 ? 4 : 8;
    } else if (func->ret.type->size <= 16) {
        func->ret.gpr_count = (int8_t)((func->ret.type->size + 7) / 8);
    } else {
        func->ret.use_memory = true;
    }

    int gpr_avail = 8;
    int vec_avail = 8;
#ifdef _M_ARM64EC
    if (func->variadic) {
        gpr_avail = 4;
    }
#endif

    for (ParameterInfo &param: func->parameters) {
        switch (param.type->primitive) {
            case PrimitiveKind::Void: { RG_UNREACHABLE(); } break;

            case PrimitiveKind::Bool:
            case PrimitiveKind::Int8:
            case PrimitiveKind::UInt8:
            case PrimitiveKind::Int16:
            case PrimitiveKind::Int16S:
            case PrimitiveKind::UInt16:
            case PrimitiveKind::UInt16S:
            case PrimitiveKind::Int32:
            case PrimitiveKind::Int32S:
            case PrimitiveKind::UInt32:
            case PrimitiveKind::UInt32S:
            case PrimitiveKind::Int64:
            case PrimitiveKind::Int64S:
            case PrimitiveKind::UInt64:
            case PrimitiveKind::UInt64S:
            case PrimitiveKind::String:
            case PrimitiveKind::String16:
            case PrimitiveKind::Pointer:
            case PrimitiveKind::Callback: {
#ifdef __APPLE__
                if (param.variadic)
                    break;
#endif

                if (gpr_avail) {
                    param.gpr_count = 1;
                    gpr_avail--;
                }
            } break;
            case PrimitiveKind::Record:
            case PrimitiveKind::Union: {
                HfaInfo hfa = IsHFA(param.type);

#ifdef _M_ARM64EC
                if (func->variadic) {
                    if (IsRegularSize(param.type->size, 8) && gpr_avail) {
                        param.gpr_count = 1;
                        gpr_avail--;
                    } else {
                        if (gpr_avail) {
                            param.gpr_count = 1;
                            gpr_avail--;
                        }
                        param.use_memory = true;
                    }

                    break;
                }
#endif

#if defined(_WIN32)
                if (param.variadic) {
                    hfa.count = 0;
                }
#elif defined(__APPLE__)
                if (param.variadic) {
                    param.use_memory = (param.type->size > 16);
                    break;
                }
#endif

                if (hfa.count) {
                    if (hfa.count <= vec_avail) {
                        param.vec_count = (int8_t)hfa.count;
                        param.vec_bytes = hfa.float32 ? 4 : 8;
                        vec_avail -= hfa.count;
                    } else {
                        vec_avail = 0;
                    }
                } else if (param.type->size <= 16) {
                    int gpr_count = (param.type->size + 7) / 8;

                    if (gpr_count <= gpr_avail) {
                        param.gpr_count = (int8_t)gpr_count;
                        gpr_avail -= gpr_count;
                    } else {
                        gpr_avail = 0;
                    }
                } else {
                    // Big types (more than 16 bytes) are replaced by a pointer
                    if (gpr_avail) {
                        param.gpr_count = 1;
                        gpr_avail--;
                    }
                    param.use_memory = true;
                }
            } break;
            case PrimitiveKind::Array: { RG_UNREACHABLE(); } break;
            case PrimitiveKind::Float32:
            case PrimitiveKind::Float64: {
#if defined(_WIN32)
                if (param.variadic) {
                    if (gpr_avail) {
                        param.gpr_count = 1;
                        gpr_avail--;
                    }
                    break;
                }
#elif defined(__APPLE__)
                if (param.variadic)
                    break;
#endif

                if (vec_avail) {
                    param.vec_count = 1;
                    vec_avail--;
                }
            } break;

            case PrimitiveKind::Prototype: { RG_UNREACHABLE(); } break;
        }
    }

    func->args_size = 16 * func->parameters.len;
    func->forward_fp = (vec_avail < 8);

    return true;
}

bool CallData::Prepare(const FunctionInfo *func, const Napi::CallbackInfo &info)
{
    uint64_t *args_ptr = nullptr;
    uint64_t *gpr_ptr = nullptr;
    uint64_t *vec_ptr = nullptr;

    // Return through registers unless it's too big
    if (!AllocStack(func->args_size, 16, &args_ptr)) [[unlikely]]
        return false;
    if (!AllocStack(8 * 8, 8, &vec_ptr)) [[unlikely]]
        return false;
    if (!AllocStack(9 * 8, 8, &gpr_ptr)) [[unlikely]]
        return false;
    if (func->ret.use_memory) {
        return_ptr = AllocHeap(func->ret.type->size, 16);
        gpr_ptr[8] = (uint64_t)return_ptr;
    }

#ifdef _M_ARM64EC
    if (func->variadic) {
        gpr_ptr[4] = (uint64_t)args_ptr;
        gpr_ptr[5] = 0;

        for (Size i = 4; i < func->parameters.len; i++) {
            const ParameterInfo &param = func->parameters[i];
            gpr_ptr[5] += std::max((Size)8, param.type->size);
        }
    }
#endif

#ifdef __APPLE__
    #define PUSH_INTEGER(CType) \
        do { \
            if (!value.IsNumber() && !value.IsBigInt()) [[unlikely]] { \
                ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected number", GetValueType(instance, value)); \
                return false; \
            } \
             \
            CType v = GetNumber<CType>(value); \
             \
            if (param.gpr_count) [[likely]] { \
                *(gpr_ptr++) = (uint64_t)v; \
            } else { \
                args_ptr = AlignUp(args_ptr, param.type->align); \
                *args_ptr = (uint64_t)v; \
                args_ptr = (uint64_t *)((uint8_t *)args_ptr + param.type->size); \
            } \
        } while (false)
    #define PUSH_INTEGER_SWAP(CType) \
        do { \
            if (!value.IsNumber() && !value.IsBigInt()) [[unlikely]] { \
                ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected number", GetValueType(instance, value)); \
                return false; \
            } \
             \
            CType v = GetNumber<CType>(value); \
             \
            if (param.gpr_count) [[likely]] { \
                *(gpr_ptr++) = (uint64_t)ReverseBytes(v); \
            } else { \
                args_ptr = AlignUp(args_ptr, param.type->align); \
                *args_ptr = (uint64_t)ReverseBytes(v); \
                args_ptr = (uint64_t *)((uint8_t *)args_ptr + param.type->size); \
            } \
        } while (false)
#else
    #define PUSH_INTEGER(CType) \
        do { \
            if (!value.IsNumber() && !value.IsBigInt()) [[unlikely]] { \
                ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected number", GetValueType(instance, value)); \
                return false; \
            } \
             \
            CType v = GetNumber<CType>(value); \
            *((param.gpr_count ? gpr_ptr : args_ptr)++) = (uint64_t)v; \
        } while (false)
    #define PUSH_INTEGER_SWAP(CType) \
        do { \
            if (!value.IsNumber() && !value.IsBigInt()) [[unlikely]] { \
                ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected number", GetValueType(instance, value)); \
                return false; \
            } \
             \
            CType v = GetNumber<CType>(value); \
            *((param.gpr_count ? gpr_ptr : args_ptr)++) = (uint64_t)ReverseBytes(v); \
        } while (false)
#endif

    // Push arguments
    for (Size i = 0; i < func->parameters.len; i++) {
        const ParameterInfo &param = func->parameters[i];
        RG_ASSERT(param.directions >= 1 && param.directions <= 3);

        Napi::Value value = info[param.offset];

        switch (param.type->primitive) {
            case PrimitiveKind::Void: { RG_UNREACHABLE(); } break;

            case PrimitiveKind::Bool: {
                if (!value.IsBoolean()) [[unlikely]] {
                    ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected boolean", GetValueType(instance, value));
                    return false;
                }

                bool b = value.As<Napi::Boolean>();

#ifdef __APPLE__
                if (param.gpr_count) [[likely]] {
                    *(gpr_ptr++) = (uint64_t)b;
                } else {
                    *(uint8_t *)args_ptr = b;
                    args_ptr = (uint64_t *)((uint8_t *)args_ptr + 1);
                }
#else
                *((param.gpr_count ? gpr_ptr : args_ptr)++) = (uint64_t)b;
#endif
            } break;
            case PrimitiveKind::Int8: { PUSH_INTEGER(int8_t); } break;
            case PrimitiveKind::UInt8: { PUSH_INTEGER(uint8_t); } break;
            case PrimitiveKind::Int16: { PUSH_INTEGER(int16_t); } break;
            case PrimitiveKind::Int16S: { PUSH_INTEGER_SWAP(int16_t); } break;
            case PrimitiveKind::UInt16: { PUSH_INTEGER(uint16_t); } break;
            case PrimitiveKind::UInt16S: { PUSH_INTEGER_SWAP(uint16_t); } break;
            case PrimitiveKind::Int32: { PUSH_INTEGER(int32_t); } break;
            case PrimitiveKind::Int32S: { PUSH_INTEGER_SWAP(int32_t); } break;
            case PrimitiveKind::UInt32: { PUSH_INTEGER(uint32_t); } break;
            case PrimitiveKind::UInt32S: { PUSH_INTEGER_SWAP(uint32_t); } break;
            case PrimitiveKind::Int64: { PUSH_INTEGER(int64_t); } break;
            case PrimitiveKind::Int64S: { PUSH_INTEGER_SWAP(int64_t); } break;
            case PrimitiveKind::UInt64: { PUSH_INTEGER(uint64_t); } break;
            case PrimitiveKind::UInt64S: { PUSH_INTEGER_SWAP(uint64_t); } break;
            case PrimitiveKind::String: {
                const char *str;
                if (!PushString(value, param.directions, &str)) [[unlikely]]
                    return false;

#ifdef __APPLE__
                args_ptr = param.gpr_count ? args_ptr : AlignUp(args_ptr, 8);
#endif
                *(const char **)((param.gpr_count ? gpr_ptr : args_ptr)++) = str;
            } break;
            case PrimitiveKind::String16: {
                const char16_t *str16;
                if (!PushString16(value, param.directions, &str16)) [[unlikely]]
                    return false;

#ifdef __APPLE__
                args_ptr = param.gpr_count ? args_ptr : AlignUp(args_ptr, 8);
#endif
                *(const char16_t **)((param.gpr_count ? gpr_ptr : args_ptr)++) = str16;
            } break;
            case PrimitiveKind::Pointer: {
                void *ptr;
                if (!PushPointer(value, param.type, param.directions, &ptr)) [[unlikely]]
                    return false;

#ifdef __APPLE__
                args_ptr = param.gpr_count ? args_ptr : AlignUp(args_ptr, 8);
#endif
                *(void **)((param.gpr_count ? gpr_ptr : args_ptr)++) = ptr;
            } break;
            case PrimitiveKind::Record:
            case PrimitiveKind::Union: {
                if (!IsObject(value)) [[unlikely]] {
                    ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected object", GetValueType(instance, value));
                    return false;
                }

                Napi::Object obj = value.As<Napi::Object>();

                if (param.vec_count) { // HFA
                    uint8_t *ptr = (uint8_t *)vec_ptr;

                    if (!PushObject(obj, param.type, ptr))
                        return false;
                    ExpandFloats(ptr, param.vec_count, param.vec_bytes);

                    vec_ptr += param.vec_count;
                } else if (!param.use_memory) {
                    if (param.gpr_count) {
                        RG_ASSERT(param.type->align <= 8);

                        if (!PushObject(obj, param.type, (uint8_t *)gpr_ptr))
                            return false;
                        gpr_ptr += param.gpr_count;
                    } else if (param.type->size) {
#ifdef __APPLE__
                        args_ptr = AlignUp(args_ptr, 8);
#endif
                        if (!PushObject(obj, param.type, (uint8_t *)args_ptr))
                            return false;
                        args_ptr += (param.type->size + 7) / 8;
                    }
                } else {
                    uint8_t *ptr = AllocHeap(param.type->size, 16);

                    if (param.gpr_count) {
                        RG_ASSERT(param.gpr_count == 1);
                        RG_ASSERT(param.vec_count == 0);

                        *(uint8_t **)(gpr_ptr++) = ptr;
                    } else {
#ifdef __APPLE__
                        args_ptr = AlignUp(args_ptr, 8);
#endif
                        *(uint8_t **)(args_ptr++) = ptr;
                    }

                    if (!PushObject(obj, param.type, ptr))
                        return false;
                }
            } break;
            case PrimitiveKind::Array: { RG_UNREACHABLE(); } break;
            case PrimitiveKind::Float32: {
                if (!value.IsNumber() && !value.IsBigInt()) [[unlikely]] {
                    ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected number", GetValueType(instance, value));
                    return false;
                }

                float f = GetNumber<float>(value);

                if (param.vec_count) [[likely]] {
                    memset((uint8_t *)vec_ptr + 4, 0, 4);
                    *(float *)(vec_ptr++) = f;
#ifdef _WIN32
                } else if (param.gpr_count) {
                    memset((uint8_t *)gpr_ptr + 4, 0, 4);
                    *(float *)(gpr_ptr++) = f;
#endif
                } else {
#ifdef __APPLE__
                    args_ptr = AlignUp(args_ptr, 4);
                    *(float *)args_ptr = f;
                    args_ptr = (uint64_t *)((uint8_t *)args_ptr + 4);
#else
                    memset((uint8_t *)args_ptr + 4, 0, 4);
                    *(float *)(args_ptr++) = f;
#endif
                }
            } break;
            case PrimitiveKind::Float64: {
                if (!value.IsNumber() && !value.IsBigInt()) [[unlikely]] {
                    ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected number", GetValueType(instance, value));
                    return false;
                }

                double d = GetNumber<double>(value);

                if (param.vec_count) [[likely]] {
                    *(double *)(vec_ptr++) = d;
#ifdef _WIN32
                } else if (param.gpr_count) {
                    *(double *)(gpr_ptr++) = d;
#endif
                } else {
#ifdef __APPLE__
                    args_ptr = AlignUp(args_ptr, 8);
#endif
                    *(double *)(args_ptr++) = d;
                }
            } break;
            case PrimitiveKind::Callback: {
                void *ptr;

                if (value.IsFunction()) {
                    Napi::Function func = value.As<Napi::Function>();

                    ptr = ReserveTrampoline(param.type->ref.proto, func);
                    if (!ptr) [[unlikely]]
                        return false;
                } else if (CheckValueTag(instance, value, param.type->ref.marker)) {
                    ptr = value.As<Napi::External<void>>().Data();
                } else if (IsNullOrUndefined(value)) {
                    ptr = nullptr;
                } else {
                    ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected %2", GetValueType(instance, value), param.type->name);
                    return false;
                }

#ifdef __APPLE__
                args_ptr = param.gpr_count ? args_ptr : AlignUp(args_ptr, 8);
#endif
                *(void **)((param.gpr_count ? gpr_ptr : args_ptr)++) = ptr;
            } break;

            case PrimitiveKind::Prototype: { RG_UNREACHABLE(); } break;
        }
    }

#undef PUSH_INTEGER_SWAP
#undef PUSH_INTEGER

    new_sp = mem->stack.end();

    return true;
}

void CallData::Execute(const FunctionInfo *func, void *native)
{
#ifdef _WIN32
    TEB *teb = GetTEB();

    // Restore previous stack limits at the end
    RG_DEFER_C(exception_list = teb->ExceptionList,
               base = teb->StackBase,
               limit = teb->StackLimit,
               dealloc = teb->DeallocationStack,
               guaranteed = teb->GuaranteedStackBytes) {
        teb->ExceptionList = exception_list;
        teb->StackBase = base;
        teb->StackLimit = limit;
        teb->DeallocationStack = dealloc;
        teb->GuaranteedStackBytes = guaranteed;
    };

    // Adjust stack limits so SEH works correctly
    teb->ExceptionList = (void *)-1; // EXCEPTION_CHAIN_END
    teb->StackBase = mem->stack0.end();
    teb->StackLimit = mem->stack0.ptr;
    teb->DeallocationStack = mem->stack0.ptr;
    teb->GuaranteedStackBytes = 0;
#endif

#define PERFORM_CALL(Suffix) \
        ([&]() { \
            auto ret = (func->forward_fp ? ForwardCallX ## Suffix(native, new_sp, &old_sp) \
                                         : ForwardCall ## Suffix(native, new_sp, &old_sp)); \
            return ret; \
        })()

    // Execute and convert return value
    switch (func->ret.type->primitive) {
        case PrimitiveKind::Void:
        case PrimitiveKind::Bool:
        case PrimitiveKind::Int8:
        case PrimitiveKind::UInt8:
        case PrimitiveKind::Int16:
        case PrimitiveKind::Int16S:
        case PrimitiveKind::UInt16:
        case PrimitiveKind::UInt16S:
        case PrimitiveKind::Int32:
        case PrimitiveKind::Int32S:
        case PrimitiveKind::UInt32:
        case PrimitiveKind::UInt32S:
        case PrimitiveKind::Int64:
        case PrimitiveKind::Int64S:
        case PrimitiveKind::UInt64:
        case PrimitiveKind::UInt64S:
        case PrimitiveKind::String:
        case PrimitiveKind::String16:
        case PrimitiveKind::Pointer:
        case PrimitiveKind::Callback: { result.u64 = PERFORM_CALL(GG).x0; } break;
        case PrimitiveKind::Record:
        case PrimitiveKind::Union: {
            if (func->ret.gpr_count) {
                X0X1Ret ret = PERFORM_CALL(GG);
                memcpy(&result.buf, &ret, RG_SIZE(ret));
            } else if (func->ret.vec_count) {
                HfaRet ret = PERFORM_CALL(DDDD);
                memcpy(&result.buf, &ret, RG_SIZE(ret));
            } else {
                PERFORM_CALL(GG);
            }
        } break;
        case PrimitiveKind::Array: { RG_UNREACHABLE(); } break;
        case PrimitiveKind::Float32: { result.f = PERFORM_CALL(F); } break;
        case PrimitiveKind::Float64: { result.d = PERFORM_CALL(DDDD).d0; } break;

        case PrimitiveKind::Prototype: { RG_UNREACHABLE(); } break;
    }

#undef PERFORM_CALL
}

Napi::Value CallData::Complete(const FunctionInfo *func)
{
    RG_DEFER {
       PopOutArguments();

        if (func->ret.type->dispose) {
            func->ret.type->dispose(env, func->ret.type, result.ptr);
        }
    };

    switch (func->ret.type->primitive) {
        case PrimitiveKind::Void: return env.Undefined();
        case PrimitiveKind::Bool: return Napi::Boolean::New(env, result.u32);
        case PrimitiveKind::Int8: return Napi::Number::New(env, (double)result.i8);
        case PrimitiveKind::UInt8: return Napi::Number::New(env, (double)result.u8);
        case PrimitiveKind::Int16: return Napi::Number::New(env, (double)result.i16);
        case PrimitiveKind::Int16S: return Napi::Number::New(env, (double)ReverseBytes(result.i16));
        case PrimitiveKind::UInt16: return Napi::Number::New(env, (double)result.u16);
        case PrimitiveKind::UInt16S: return Napi::Number::New(env, (double)ReverseBytes(result.u16));
        case PrimitiveKind::Int32: return Napi::Number::New(env, (double)result.i32);
        case PrimitiveKind::Int32S: return Napi::Number::New(env, (double)ReverseBytes(result.i32));
        case PrimitiveKind::UInt32: return Napi::Number::New(env, (double)result.u32);
        case PrimitiveKind::UInt32S: return Napi::Number::New(env, (double)ReverseBytes(result.u32));
        case PrimitiveKind::Int64: return NewBigInt(env, result.i64);
        case PrimitiveKind::Int64S: return NewBigInt(env, ReverseBytes(result.i64));
        case PrimitiveKind::UInt64: return NewBigInt(env, result.u64);
        case PrimitiveKind::UInt64S: return NewBigInt(env, ReverseBytes(result.u64));
        case PrimitiveKind::String: return result.ptr ? Napi::String::New(env, (const char *)result.ptr) : env.Null();
        case PrimitiveKind::String16: return result.ptr ? Napi::String::New(env, (const char16_t *)result.ptr) : env.Null();
        case PrimitiveKind::Pointer:
        case PrimitiveKind::Callback: {
            if (result.ptr) {
                Napi::External<void> external = Napi::External<void>::New(env, result.ptr);
                SetValueTag(instance, external, func->ret.type->ref.marker);

                return external;
            } else {
                return env.Null();
            }
        } break;
        case PrimitiveKind::Record:
        case PrimitiveKind::Union: {
            if (func->ret.vec_count) { // HFA
                uint8_t *ptr = (uint8_t *)&result.buf;

                CompactFloats(ptr, func->ret.vec_count, func->ret.vec_bytes);

                Napi::Object obj = DecodeObject(env, ptr, func->ret.type);
                return obj;
            } else {
                const uint8_t *ptr = return_ptr ? (const uint8_t *)return_ptr
                                                : (const uint8_t *)&result.buf;

                Napi::Object obj = DecodeObject(env, ptr, func->ret.type);
                return obj;
            }
        } break;
        case PrimitiveKind::Array: { RG_UNREACHABLE(); } break;
        case PrimitiveKind::Float32: return Napi::Number::New(env, (double)result.f);
        case PrimitiveKind::Float64: return Napi::Number::New(env, result.d);

        case PrimitiveKind::Prototype: { RG_UNREACHABLE(); } break;
    }

    RG_UNREACHABLE();
}

void CallData::Relay(Size idx, uint8_t *own_sp, uint8_t *caller_sp, bool async, BackRegisters *out_reg)
{
    if (env.IsExceptionPending()) [[unlikely]]
        return;

#ifdef _WIN32
    TEB *teb = GetTEB();

    // Restore previous stack limits at the end
    RG_DEFER_C(base = teb->StackBase,
               limit = teb->StackLimit,
               dealloc = teb->DeallocationStack) {
        teb->StackBase = base;
        teb->StackLimit = limit;
        teb->DeallocationStack = dealloc;
    };

    // Adjust stack limits so SEH works correctly
    teb->StackBase = instance->main_stack_max;
    teb->StackLimit = instance->main_stack_min;
    teb->DeallocationStack = instance->main_stack_min;
#endif

    const TrampolineInfo &trampoline = shared.trampolines[idx];

    const FunctionInfo *proto = trampoline.proto;
    Napi::Function func = trampoline.func.Value();

    uint64_t *gpr_ptr = (uint64_t *)own_sp;
    uint64_t *vec_ptr = gpr_ptr + 9;
    uint64_t *args_ptr = (uint64_t *)caller_sp;

    uint8_t *return_ptr = proto->ret.use_memory ? (uint8_t *)gpr_ptr[8] : nullptr;

    RG_DEFER_N(err_guard) { memset(out_reg, 0, RG_SIZE(*out_reg)); };

    if (trampoline.generation >= 0 && trampoline.generation != (int32_t)mem->generation) [[unlikely]] {
        ThrowError<Napi::Error>(env, "Cannot use non-registered callback beyond FFI call");
        return;
    }

    LocalArray<napi_value, MaxParameters + 1> arguments;

    arguments.Append(!trampoline.recv.IsEmpty() ? trampoline.recv.Value() : env.Undefined());

    // Convert to JS arguments
    for (Size i = 0; i < proto->parameters.len; i++) {
        const ParameterInfo &param = proto->parameters[i];
        RG_ASSERT(param.directions >= 1 && param.directions <= 3);

        switch (param.type->primitive) {
            case PrimitiveKind::Void: { RG_UNREACHABLE(); } break;

            case PrimitiveKind::Bool: {
#ifdef __APPLE__
                bool b;
                if (param.gpr_count) {
                    b = *(bool *)(gpr_ptr++);
                } else {
                    b = *(bool *)args_ptr;
                    args_ptr = (uint64_t *)((uint8_t *)args_ptr + 1);
                }
#else
                bool b = *(bool *)((param.gpr_count ? gpr_ptr : args_ptr)++);
#endif

                Napi::Value arg = Napi::Boolean::New(env, b);
                arguments.Append(arg);
            } break;
            case PrimitiveKind::Int8: {
#ifdef __APPLE__
                double d;
                if (param.gpr_count) {
                    d = (double)*(int8_t *)(gpr_ptr++);
                } else {
                    d = (double)*(int8_t *)args_ptr;
                    args_ptr = (uint64_t *)((uint8_t *)args_ptr + 1);
                }
#else
                double d = (double)*(int8_t *)((param.gpr_count ? gpr_ptr : args_ptr)++);
#endif

                Napi::Value arg = Napi::Number::New(env, d);
                arguments.Append(arg);
            } break;
            case PrimitiveKind::UInt8: {
#ifdef __APPLE__
                double d;
                if (param.gpr_count) {
                    d = (double)*(uint8_t *)(gpr_ptr++);
                } else {
                    d = (double)*(uint8_t *)args_ptr;
                    args_ptr = (uint64_t *)((uint8_t *)args_ptr + 1);
                }
#else
                double d = (double)*(uint8_t *)((param.gpr_count ? gpr_ptr : args_ptr)++);
#endif

                Napi::Value arg = Napi::Number::New(env, d);
                arguments.Append(arg);
            } break;
            case PrimitiveKind::Int16: {
#ifdef __APPLE__
                double d;
                if (param.gpr_count) {
                    d = (double)*(int16_t *)(gpr_ptr++);
                } else {
                    args_ptr = AlignUp(args_ptr, 2);
                    d = (double)*(int16_t *)args_ptr;
                    args_ptr = (uint64_t *)((uint8_t *)args_ptr + 2);
                }
#else
                double d = (double)*(int16_t *)((param.gpr_count ? gpr_ptr : args_ptr)++);
#endif

                Napi::Value arg = Napi::Number::New(env, d);
                arguments.Append(arg);
            } break;
            case PrimitiveKind::Int16S: {
#ifdef __APPLE__
                double d;
                if (param.gpr_count) {
                    int16_t v = *(int16_t *)(gpr_ptr++);
                    d = (double)ReverseBytes(v);
                } else {
                    args_ptr = AlignUp(args_ptr, 2);

                    int16_t v = *(int16_t *)args_ptr;
                    d = (double)ReverseBytes(v);

                    args_ptr = (uint64_t *)((uint8_t *)args_ptr + 2);
                }
#else
                int16_t v = *(int16_t *)((param.gpr_count ? gpr_ptr : args_ptr)++);
                double d = (double)ReverseBytes(v);
#endif

                Napi::Value arg = Napi::Number::New(env, d);
                arguments.Append(arg);
            } break;
            case PrimitiveKind::UInt16: {
#ifdef __APPLE__
                double d;
                if (param.gpr_count) {
                    d = (double)*(uint16_t *)(gpr_ptr++);
                } else {
                    args_ptr = AlignUp(args_ptr, 2);
                    d = (double)*(uint16_t *)args_ptr;
                    args_ptr = (uint64_t *)((uint8_t *)args_ptr + 2);
                }
#else
                double d = (double)*(uint16_t *)((param.gpr_count ? gpr_ptr : args_ptr)++);
#endif

                Napi::Value arg = Napi::Number::New(env, d);
                arguments.Append(arg);
            } break;
            case PrimitiveKind::UInt16S: {
#ifdef __APPLE__
                double d;
                if (param.gpr_count) {
                    uint16_t v = *(uint16_t *)(gpr_ptr++);
                    d = (double)ReverseBytes(v);
                } else {
                    args_ptr = AlignUp(args_ptr, 2);

                    uint16_t v = *(uint16_t *)args_ptr;
                    d = (double)ReverseBytes(v);

                    args_ptr = (uint64_t *)((uint8_t *)args_ptr + 2);
                }
#else
                uint16_t v = *(uint16_t *)((param.gpr_count ? gpr_ptr : args_ptr)++);
                double d = (double)ReverseBytes(v);
#endif

                Napi::Value arg = Napi::Number::New(env, d);
                arguments.Append(arg);
            } break;
            case PrimitiveKind::Int32: {
#ifdef __APPLE__
                double d;
                if (param.gpr_count) {
                    d = (double)*(int32_t *)(gpr_ptr++);
                } else {
                    args_ptr = AlignUp(args_ptr, 4);
                    d = (double)*(int32_t *)args_ptr;
                    args_ptr = (uint64_t *)((uint8_t *)args_ptr + 4);
                }
#else
                double d = (double)*(int32_t *)((param.gpr_count ? gpr_ptr : args_ptr)++);
#endif

                Napi::Value arg = Napi::Number::New(env, d);
                arguments.Append(arg);
            } break;
            case PrimitiveKind::Int32S: {
#ifdef __APPLE__
                double d;
                if (param.gpr_count) {
                    int32_t v = *(int32_t *)(gpr_ptr++);
                    d = (double)ReverseBytes(v);
                } else {
                    args_ptr = AlignUp(args_ptr, 4);

                    int32_t v = *(int32_t *)args_ptr;
                    d = (double)ReverseBytes(v);

                    args_ptr = (uint64_t *)((uint8_t *)args_ptr + 4);
                }
#else
                int32_t v = *(int32_t *)((param.gpr_count ? gpr_ptr : args_ptr)++);
                double d = (double)ReverseBytes(v);
#endif

                Napi::Value arg = Napi::Number::New(env, d);
                arguments.Append(arg);
            } break;
            case PrimitiveKind::UInt32: {
#ifdef __APPLE__
                double d;
                if (param.gpr_count) {
                    d = (double)*(uint32_t *)(gpr_ptr++);
                } else {
                    args_ptr = AlignUp(args_ptr, 4);
                    d = (double)*(uint32_t *)args_ptr;
                    args_ptr = (uint64_t *)((uint8_t *)args_ptr + 4);
                }
#else
                double d = (double)*(uint32_t *)((param.gpr_count ? gpr_ptr : args_ptr)++);
#endif

                Napi::Value arg = Napi::Number::New(env, d);
                arguments.Append(arg);
            } break;
            case PrimitiveKind::UInt32S: {
#ifdef __APPLE__
                double d;
                if (param.gpr_count) {
                    uint32_t v = *(uint32_t *)(gpr_ptr++);
                    d = (double)ReverseBytes(v);
                } else {
                    args_ptr = AlignUp(args_ptr, 4);

                    uint32_t v = *(uint32_t *)args_ptr;
                    d = (double)ReverseBytes(v);

                    args_ptr = (uint64_t *)((uint8_t *)args_ptr + 4);
                }
#else
                uint32_t v = *(uint32_t *)((param.gpr_count ? gpr_ptr : args_ptr)++);
                double d = (double)ReverseBytes(v);
#endif

                Napi::Value arg = Napi::Number::New(env, d);
                arguments.Append(arg);
            } break;
            case PrimitiveKind::Int64: {
#ifdef __APPLE__
                args_ptr = AlignUp(args_ptr, 8);
#endif

                int64_t v = *(int64_t *)((param.gpr_count ? gpr_ptr : args_ptr)++);

                Napi::Value arg = NewBigInt(env, v);
                arguments.Append(arg);
            } break;
            case PrimitiveKind::Int64S: {
#ifdef __APPLE__
                args_ptr = AlignUp(args_ptr, 8);
#endif

                int64_t v = *(int64_t *)((param.gpr_count ? gpr_ptr : args_ptr)++);

                Napi::Value arg = NewBigInt(env, ReverseBytes(v));
                arguments.Append(arg);
            } break;
            case PrimitiveKind::UInt64: {
#ifdef __APPLE__
                args_ptr = AlignUp(args_ptr, 8);
#endif

                uint64_t v = *(uint64_t *)((param.gpr_count ? gpr_ptr : args_ptr)++);

                Napi::Value arg = NewBigInt(env, v);
                arguments.Append(arg);
            } break;
            case PrimitiveKind::UInt64S: {
#ifdef __APPLE__
                args_ptr = AlignUp(args_ptr, 8);
#endif

                uint64_t v = *(uint64_t *)((param.gpr_count ? gpr_ptr : args_ptr)++);

                Napi::Value arg = NewBigInt(env, ReverseBytes(v));
                arguments.Append(arg);
            } break;
            case PrimitiveKind::String: {
#ifdef __APPLE__
                args_ptr = AlignUp(args_ptr, 8);
#endif

                const char *str = *(const char **)((param.gpr_count ? gpr_ptr : args_ptr)++);

                Napi::Value arg = str ? Napi::String::New(env, str) : env.Null();
                arguments.Append(arg);

                if (param.type->dispose) {
                    param.type->dispose(env, param.type, str);
                }
            } break;
            case PrimitiveKind::String16: {
#ifdef __APPLE__
                args_ptr = AlignUp(args_ptr, 8);
#endif

                const char16_t *str16 = *(const char16_t **)((param.gpr_count ? gpr_ptr : args_ptr)++);

                Napi::Value arg = str16 ? Napi::String::New(env, str16) : env.Null();
                arguments.Append(arg);

                if (param.type->dispose) {
                    param.type->dispose(env, param.type, str16);
                }
            } break;
            case PrimitiveKind::Pointer:
            case PrimitiveKind::Callback: {
#ifdef __APPLE__
                args_ptr = AlignUp(args_ptr, 8);
#endif

                void *ptr2 = *(void **)((param.gpr_count ? gpr_ptr : args_ptr)++);

                if (ptr2) {
                    Napi::External<void> external = Napi::External<void>::New(env, ptr2);
                    SetValueTag(instance, external, param.type->ref.marker);

                    arguments.Append(external);
                } else {
                    arguments.Append(env.Null());
                }

                if (param.type->dispose) {
                    param.type->dispose(env, param.type, ptr2);
                }
            } break;
            case PrimitiveKind::Record:
            case PrimitiveKind::Union: {
                if (param.vec_count) { // HFA
                    uint8_t *ptr = (uint8_t *)vec_ptr;

                    CompactFloats(ptr, param.vec_count, param.vec_bytes);

                    Napi::Object obj = DecodeObject(env, ptr, param.type);
                    arguments.Append(obj);

                    vec_ptr += param.vec_count;
                } else if (!param.use_memory) {
                    if (param.gpr_count) {
                        RG_ASSERT(param.type->align <= 8);

                        Napi::Object obj = DecodeObject(env, (uint8_t *)gpr_ptr, param.type);
                        arguments.Append(obj);

                        gpr_ptr += param.gpr_count;
                    } else if (param.type->size) {
                        args_ptr = AlignUp(args_ptr, param.type->align);

                        Napi::Object obj = DecodeObject(env, (uint8_t *)args_ptr, param.type);
                        arguments.Append(obj);

                        args_ptr += (param.type->size + 7) / 8;
                    }
                } else {
#ifdef __APPLE__
                    args_ptr = AlignUp(args_ptr, 8);
#endif

                    void *ptr2 = *(void **)((param.gpr_count ? gpr_ptr : args_ptr)++);

                    Napi::Object obj = DecodeObject(env, (uint8_t *)ptr2, param.type);
                    arguments.Append(obj);
                }
            } break;
            case PrimitiveKind::Array: { RG_UNREACHABLE(); } break;
            case PrimitiveKind::Float32: {
                float f;
                if (param.vec_count) [[likely]] {
                    f = *(float *)(vec_ptr++);
#ifdef _WIN32
                } else if (param.gpr_count) {
                    f = *(float *)(gpr_ptr++);
#endif
                } else {
#ifdef __APPLE__
                    args_ptr = AlignUp(args_ptr, 4);
                    f = *(float *)args_ptr;
                    args_ptr = (uint64_t *)((uint8_t *)args_ptr + 4);
#else
                    f = *(float *)(args_ptr++);
#endif
                }

                Napi::Value arg = Napi::Number::New(env, (double)f);
                arguments.Append(arg);
            } break;
            case PrimitiveKind::Float64: {
                double d;
                if (param.vec_count) [[likely]] {
                    d = *(double *)(vec_ptr++);
#ifdef _WIN32
                } else if (param.gpr_count) {
                    d = *(double *)(gpr_ptr++);
#endif
                } else {
#ifdef __APPLE__
                    args_ptr = AlignUp(args_ptr, 8);
#endif

                    d = *(double *)(args_ptr++);
                }

                Napi::Value arg = Napi::Number::New(env, d);
                arguments.Append(arg);
            } break;

            case PrimitiveKind::Prototype: { RG_UNREACHABLE(); } break;
        }
    }

    const TypeInfo *type = proto->ret.type;

    // Make the call
    napi_value ret;
    if (async) {
        ret = (napi_value)func.Call(arguments[0], arguments.len - 1, arguments.data + 1);
    } else {
        ret = CallSwitchStack(&func, (size_t)arguments.len, arguments.data, old_sp, &mem->stack,
                              [](Napi::Function *func, size_t argc, napi_value *argv) { return (napi_value)func->Call(argv[0], argc - 1, argv + 1); });
    }
    Napi::Value value(env, ret);

    if (env.IsExceptionPending()) [[unlikely]]
        return;

#define RETURN_INTEGER(CType) \
        do { \
            if (!value.IsNumber() && !value.IsBigInt()) [[unlikely]] { \
                ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected number", GetValueType(instance, value)); \
                return; \
            } \
             \
            CType v = GetNumber<CType>(value); \
            out_reg->x0 = (uint64_t)v; \
        } while (false)
#define RETURN_INTEGER_SWAP(CType) \
        do { \
            if (!value.IsNumber() && !value.IsBigInt()) [[unlikely]] { \
                ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected number", GetValueType(instance, value)); \
                return; \
            } \
             \
            CType v = GetNumber<CType>(value); \
            out_reg->x0 = (uint64_t)ReverseBytes(v); \
        } while (false)

    // Convert the result
    switch (type->primitive) {
        case PrimitiveKind::Void: {} break;
        case PrimitiveKind::Bool: {
            if (!value.IsBoolean()) [[unlikely]] {
                ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected boolean", GetValueType(instance, value));
                return;
            }

            bool b = value.As<Napi::Boolean>();
            out_reg->x0 = (uint64_t)b;
        } break;
        case PrimitiveKind::Int8: { RETURN_INTEGER(int8_t); } break;
        case PrimitiveKind::UInt8: { RETURN_INTEGER(uint8_t); } break;
        case PrimitiveKind::Int16: { RETURN_INTEGER(int16_t); } break;
        case PrimitiveKind::Int16S: { RETURN_INTEGER_SWAP(int16_t); } break;
        case PrimitiveKind::UInt16: { RETURN_INTEGER(uint16_t); } break;
        case PrimitiveKind::UInt16S: { RETURN_INTEGER_SWAP(uint16_t); } break;
        case PrimitiveKind::Int32: { RETURN_INTEGER(int32_t); } break;
        case PrimitiveKind::Int32S: { RETURN_INTEGER_SWAP(int32_t); } break;
        case PrimitiveKind::UInt32: { RETURN_INTEGER(uint32_t); } break;
        case PrimitiveKind::UInt32S: { RETURN_INTEGER_SWAP(uint32_t); } break;
        case PrimitiveKind::Int64: { RETURN_INTEGER(int64_t); } break;
        case PrimitiveKind::Int64S: { RETURN_INTEGER_SWAP(int64_t); } break;
        case PrimitiveKind::UInt64: { RETURN_INTEGER(uint64_t); } break;
        case PrimitiveKind::UInt64S: { RETURN_INTEGER_SWAP(uint64_t); } break;
        case PrimitiveKind::String: {
            const char *str;
            if (!PushString(value, 1, &str)) [[unlikely]]
                return;

            out_reg->x0 = (uint64_t)str;
        } break;
        case PrimitiveKind::String16: {
            const char16_t *str16;
            if (!PushString16(value, 1, &str16)) [[unlikely]]
                return;

            out_reg->x0 = (uint64_t)str16;
        } break;
        case PrimitiveKind::Pointer: {
            uint8_t *ptr;

            if (CheckValueTag(instance, value, type->ref.marker)) {
                ptr = value.As<Napi::External<uint8_t>>().Data();
            } else if (IsObject(value) && (type->ref.type->primitive == PrimitiveKind::Record ||
                                           type->ref.type->primitive == PrimitiveKind::Union)) {
                Napi::Object obj = value.As<Napi::Object>();

                ptr = AllocHeap(type->ref.type->size, 16);

                if (!PushObject(obj, type->ref.type, ptr))
                    return;
            } else if (IsNullOrUndefined(value)) {
                ptr = nullptr;
            } else {
                ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected %2", GetValueType(instance, value), type->name);
                return;
            }

            out_reg->x0 = (uint64_t)ptr;
        } break;
        case PrimitiveKind::Record:
        case PrimitiveKind::Union: {
            if (!IsObject(value)) [[unlikely]] {
                ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected object", GetValueType(instance, value));
                return;
            }

            Napi::Object obj = value.As<Napi::Object>();

            if (return_ptr) {
                if (!PushObject(obj, type, return_ptr))
                    return;
                out_reg->x0 = (uint64_t)return_ptr;
            } else if (proto->ret.vec_count) { // HFA
                uint8_t *ptr = (uint8_t *)&out_reg->d0;

                ExpandFloats(ptr, proto->ret.vec_count, proto->ret.vec_bytes);
                PushObject(obj, type, ptr);
            } else {
                PushObject(obj, type, (uint8_t *)&out_reg->x0);
            }
        } break;
        case PrimitiveKind::Array: { RG_UNREACHABLE(); } break;
        case PrimitiveKind::Float32: {
            if (!value.IsNumber() && !value.IsBigInt()) [[unlikely]] {
                ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected number", GetValueType(instance, value));
                return;
            }

            float f = GetNumber<float>(value);

            memset((uint8_t *)&out_reg->d0 + 4, 0, 4);
            memcpy(&out_reg->d0, &f, 4);
        } break;
        case PrimitiveKind::Float64: {
            if (!value.IsNumber() && !value.IsBigInt()) [[unlikely]] {
                ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected number", GetValueType(instance, value));
                return;
            }

            double d = GetNumber<double>(value);
            out_reg->d0 = d;
        } break;
        case PrimitiveKind::Callback: {
            void *ptr;

            if (value.IsFunction()) {
                Napi::Function func2 = value.As<Napi::Function>();

                ptr = ReserveTrampoline(type->ref.proto, func2);
                if (!ptr) [[unlikely]]
                    return;
            } else if (CheckValueTag(instance, value, type->ref.marker)) {
                ptr = value.As<Napi::External<void>>().Data();
            } else if (IsNullOrUndefined(value)) {
                ptr = nullptr;
            } else {
                ThrowError<Napi::TypeError>(env, "Unexpected %1 value, expected %2", GetValueType(instance, value), type->name);
                return;
            }

            out_reg->x0 = (uint64_t)ptr;
        } break;

        case PrimitiveKind::Prototype: { RG_UNREACHABLE(); } break;
    }

#undef RETURN_INTEGER_SWAP
#undef RETURN_INTEGER

    err_guard.Disable();
}

void *GetTrampoline(int16_t idx, const FunctionInfo *proto)
{
    bool vec = proto->forward_fp || IsFloat(proto->ret.type);
    return Trampolines[idx][vec];
}

}

#endif
