#include "node_usb.h"
#include <string.h>

#define STRUCT_TO_V8(TARGET, STR, NAME) \
    TARGET.DefineProperty(Napi::PropertyDescriptor::Value(#NAME, Napi::Number::New(env, (uint32_t) (STR).NAME), CONST_PROP));

#define CHECK_OPEN() \
    if (!self->device_handle){THROW_ERROR("Device is not opened");}

#define MAX_PORTS 7

Device::Device(const Napi::CallbackInfo& info) : Napi::ObjectWrap<Device>(info), env(0), device_handle(0), refs_(0), completionQueue(handleCompletion) {
    env = info.Env();
    device = info[0].As<Napi::External<libusb_device>>().Data();
    libusb_ref_device(device);

    std::map<libusb_device*, Device*>& byPtr = env.GetInstanceData<ModuleData>()->byPtr;
    byPtr[device] = this;

    DEBUG_LOG("Created device %p", this);
    Constructor(info);
}

Device::~Device() {
    DEBUG_LOG("Freed device %p", this);

    ModuleData* instanceData = env.GetInstanceData<ModuleData>();
    std::map<libusb_device*, Device*>& byPtr = instanceData->byPtr;

    auto it = byPtr.find(device);
    if (it != byPtr.end() && it->second == this)
        byPtr.erase(it);
    libusb_close(device_handle);
    libusb_unref_device(device);
}

// Get a V8 instance for a libusb_device: either the existing one from the map,
// or create a new one and add it to the map.
Napi::Object Device::get(Napi::Env env, libusb_device* dev) {
    ModuleData* instanceData = env.GetInstanceData<ModuleData>();
    std::map<libusb_device*, Device*>& byPtr = instanceData->byPtr;

    auto it = byPtr.find(dev);
    if (it != byPtr.end()) {
        auto value = it->second->Value();
        // JS object may have already been garbage collected
        if (!value.IsEmpty())
            return value;
    }

    Napi::Object obj = instanceData->deviceConstructor.New({ Napi::External<libusb_device>::New(env, dev) });
    return obj;
}

Napi::Value Device::Constructor(const Napi::CallbackInfo& info) {
    Napi::Env env = info.Env();
    ENTER_CONSTRUCTOR_POINTER(Device, 1);
    auto obj = info.This().As<Napi::Object>();
    obj.DefineProperty(Napi::PropertyDescriptor::Value("busNumber", Napi::Number::New(env, libusb_get_bus_number(self->device)), CONST_PROP));
    obj.DefineProperty(Napi::PropertyDescriptor::Value("deviceAddress", Napi::Number::New(env, libusb_get_device_address(self->device)), CONST_PROP));

    Napi::Object v8dd = Napi::Object::New(env);
    obj.DefineProperty(Napi::PropertyDescriptor::Value("deviceDescriptor", v8dd, CONST_PROP));

    struct libusb_device_descriptor dd;
    CHECK_USB(libusb_get_device_descriptor(self->device, &dd));

    STRUCT_TO_V8(v8dd, dd, bLength)
    STRUCT_TO_V8(v8dd, dd, bDescriptorType)
    STRUCT_TO_V8(v8dd, dd, bcdUSB)
    STRUCT_TO_V8(v8dd, dd, bDeviceClass)
    STRUCT_TO_V8(v8dd, dd, bDeviceSubClass)
    STRUCT_TO_V8(v8dd, dd, bDeviceProtocol)
    STRUCT_TO_V8(v8dd, dd, bMaxPacketSize0)
    STRUCT_TO_V8(v8dd, dd, idVendor)
    STRUCT_TO_V8(v8dd, dd, idProduct)
    STRUCT_TO_V8(v8dd, dd, bcdDevice)
    STRUCT_TO_V8(v8dd, dd, iManufacturer)
    STRUCT_TO_V8(v8dd, dd, iProduct)
    STRUCT_TO_V8(v8dd, dd, iSerialNumber)
    STRUCT_TO_V8(v8dd, dd, bNumConfigurations)

    uint8_t port_numbers[MAX_PORTS];
    int ret = libusb_get_port_numbers(self->device, &port_numbers[0], MAX_PORTS);
    if (ret > 0) {
        Napi::Array array = Napi::Array::New(env, ret);
        for (int i = 0; i < ret; ++ i) {
            array.Set(i, Napi::Number::New(env, port_numbers[i]));
        }
        obj.DefineProperty(Napi::PropertyDescriptor::Value("portNumbers", array, CONST_PROP));
    }
    return info.This();
}

Napi::Object Device::cdesc2V8(Napi::Env env, libusb_config_descriptor * cdesc) {
    Napi::Object v8cdesc = Napi::Object::New(env);

    STRUCT_TO_V8(v8cdesc, *cdesc, bLength)
    STRUCT_TO_V8(v8cdesc, *cdesc, bDescriptorType)
    STRUCT_TO_V8(v8cdesc, *cdesc, wTotalLength)
    STRUCT_TO_V8(v8cdesc, *cdesc, bNumInterfaces)
    STRUCT_TO_V8(v8cdesc, *cdesc, bConfigurationValue)
    STRUCT_TO_V8(v8cdesc, *cdesc, iConfiguration)
    STRUCT_TO_V8(v8cdesc, *cdesc, bmAttributes)
    // Libusb 1.0 typo'd bMaxPower as MaxPower
    v8cdesc.DefineProperty(Napi::PropertyDescriptor::Value("bMaxPower", Napi::Number::New(env, (uint32_t)cdesc->MaxPower), CONST_PROP));
    const auto config_extras = (cdesc->extra && cdesc->extra_length)
        ? Napi::Buffer<const char>::Copy(env, (const char*)cdesc->extra, cdesc->extra_length)
        : Napi::Buffer<const char>::New(env, 0);

    v8cdesc.DefineProperty(Napi::PropertyDescriptor::Value("extra", config_extras, CONST_PROP));

    Napi::Array v8interfaces = Napi::Array::New(env, cdesc->bNumInterfaces);
    v8cdesc.DefineProperty(Napi::PropertyDescriptor::Value("interfaces", v8interfaces, CONST_PROP));

    for (int idxInterface = 0; idxInterface < cdesc->bNumInterfaces; idxInterface++) {
        int numAltSettings = cdesc->interface[idxInterface].num_altsetting;

        Napi::Array v8altsettings = Napi::Array::New(env, numAltSettings);
        v8interfaces.Set(idxInterface, v8altsettings);

        for (int idxAltSetting = 0; idxAltSetting < numAltSettings; idxAltSetting++) {
            const libusb_interface_descriptor& idesc =
                cdesc->interface[idxInterface].altsetting[idxAltSetting];

            Napi::Object v8idesc = Napi::Object::New(env);
            v8altsettings.Set(idxAltSetting, v8idesc);

            STRUCT_TO_V8(v8idesc, idesc, bLength)
            STRUCT_TO_V8(v8idesc, idesc, bDescriptorType)
            STRUCT_TO_V8(v8idesc, idesc, bInterfaceNumber)
            STRUCT_TO_V8(v8idesc, idesc, bAlternateSetting)
            STRUCT_TO_V8(v8idesc, idesc, bNumEndpoints)
            STRUCT_TO_V8(v8idesc, idesc, bInterfaceClass)
            STRUCT_TO_V8(v8idesc, idesc, bInterfaceSubClass)
            STRUCT_TO_V8(v8idesc, idesc, bInterfaceProtocol)
            STRUCT_TO_V8(v8idesc, idesc, iInterface)

            auto interface_extras = (idesc.extra && idesc.extra_length)
                ? Napi::Buffer<const char>::Copy(env, (const char*)idesc.extra, idesc.extra_length)
                : Napi::Buffer<const char>::New(env, 0);
            v8idesc.DefineProperty(Napi::PropertyDescriptor::Value("extra", interface_extras, CONST_PROP));

            Napi::Array v8endpoints = Napi::Array::New(env, idesc.bNumEndpoints);
            v8idesc.DefineProperty(Napi::PropertyDescriptor::Value("endpoints", v8endpoints, CONST_PROP));
            for (int idxEndpoint = 0; idxEndpoint < idesc.bNumEndpoints; idxEndpoint++){
                const libusb_endpoint_descriptor& edesc = idesc.endpoint[idxEndpoint];

                Napi::Object v8edesc = Napi::Object::New(env);
                v8endpoints.Set(idxEndpoint, v8edesc);

                STRUCT_TO_V8(v8edesc, edesc, bLength)
                STRUCT_TO_V8(v8edesc, edesc, bDescriptorType)
                STRUCT_TO_V8(v8edesc, edesc, bEndpointAddress)
                STRUCT_TO_V8(v8edesc, edesc, bmAttributes)
                STRUCT_TO_V8(v8edesc, edesc, wMaxPacketSize)
                STRUCT_TO_V8(v8edesc, edesc, bInterval)
                STRUCT_TO_V8(v8edesc, edesc, bRefresh)
                STRUCT_TO_V8(v8edesc, edesc, bSynchAddress)
                auto endpoint_extras = (edesc.extra && edesc.extra_length)
                    ? Napi::Buffer<const char>::Copy(env, (const char*)edesc.extra, edesc.extra_length)
                    : Napi::Buffer<const char>::New(env, 0);
                v8edesc.DefineProperty(Napi::PropertyDescriptor::Value("extra", endpoint_extras, CONST_PROP));
            }
        }
    }
    return v8cdesc;
}

Napi::Value Device::GetConfigDescriptor(const Napi::CallbackInfo& info) {
    ENTER_METHOD(Device, 0);
    libusb_config_descriptor* cdesc;
    CHECK_USB(libusb_get_active_config_descriptor(self->device, &cdesc));
    Napi::Object v8cdesc = Device::cdesc2V8(env, cdesc);
    libusb_free_config_descriptor(cdesc);
    return v8cdesc;
}

Napi::Value Device::GetAllConfigDescriptors(const Napi::CallbackInfo& info) {
    ENTER_METHOD(Device, 0);
    libusb_config_descriptor * cdesc;
    struct libusb_device_descriptor dd;
    libusb_get_device_descriptor(self->device, &dd);
    Napi::Array v8cdescriptors = Napi::Array::New(env, dd.bNumConfigurations);
    for(uint8_t i = 0; i < dd.bNumConfigurations; i++){
        // libusb_get_config_descriptor is nonblocking but allocates and those allocates
        // may fail
        CHECK_USB(libusb_get_config_descriptor(device, i, &cdesc));
        v8cdescriptors.Set(i, Device::cdesc2V8(env, cdesc));
        libusb_free_config_descriptor(cdesc);
    }
    return v8cdescriptors;
}

Napi::Value Device::GetParent(const Napi::CallbackInfo& info) {
    ENTER_METHOD(Device, 0);
    libusb_device* dev = libusb_get_parent(self->device);
    if(dev)
        return Device::get(env, dev);
    else
        return env.Null();
}

Napi::Value Device::Open(const Napi::CallbackInfo& info) {
    ENTER_METHOD(Device, 0);
    if (!self->device_handle){
        CHECK_USB(libusb_open(self->device, &self->device_handle));
        completionQueue.start(info.Env());
    }
    return env.Undefined();
}

Napi::Value Device::Close(const Napi::CallbackInfo& info) {
    ENTER_METHOD(Device, 0);
    if (self->canClose()){
        if (self->device_handle){
            libusb_close(self->device_handle);
            self->device_handle = NULL;
            completionQueue.stop();
        }
    }else{
        THROW_ERROR("Can't close device with a pending request");
    }
    return env.Undefined();
}

struct Req: Napi::AsyncWorker {
    Device* device;
    int errcode;

    Req(Device* d, Napi::Function& callback)
        : Napi::AsyncWorker(callback), device(d) {
        device->ref();
    }

    void OnOK() override {
        auto env = Env();
        Napi::HandleScope scope(env);
        device->unref();

        Napi::Value error = env.Undefined();
        if (errcode < 0){
            error = libusbException(env, errcode).Value();
        }
        try {
            Callback().Call(device->Value(), { error });
        }
        catch (const Napi::Error& e) {
            Napi::Error::Fatal("", e.what());
        }
    }
};

struct Device_Reset: Req {
    Device_Reset(Device* d, Napi::Function& callback): Req(d, callback) {}

    virtual void Execute() {
        errcode = libusb_reset_device(device->device_handle);
    }
};

Napi::Value Device::Reset(const Napi::CallbackInfo& info) {
    ENTER_METHOD(Device, 1);
    CHECK_OPEN();
    CALLBACK_ARG(0);
    auto baton = new Device_Reset(self, callback);
    baton->Queue();
    return env.Undefined();
}

struct Device_Clear_Halt: Req {
    Device_Clear_Halt(Device* d, Napi::Function& callback): Req(d, callback) {}

    int endpoint;

    virtual void Execute() {
        errcode = libusb_clear_halt(device->device_handle, endpoint);
    }
};

Napi::Value Device::ClearHalt(const Napi::CallbackInfo& info) {
    ENTER_METHOD(Device, 2);
    int endpoint;
    CHECK_OPEN();
    INT_ARG(endpoint, 0);
    CALLBACK_ARG(1);
    auto baton = new Device_Clear_Halt(self, callback);
    baton->endpoint = endpoint;
    baton->Queue();
    return env.Undefined();
}

Napi::Value Device::IsKernelDriverActive(const Napi::CallbackInfo& info) {
    ENTER_METHOD(Device, 1);
    CHECK_OPEN();
    int interface;
    INT_ARG(interface, 0);
    int r = libusb_kernel_driver_active(self->device_handle, interface);
    CHECK_USB(r);
    return Napi::Boolean::New(env, r);
}

Napi::Value Device::DetachKernelDriver(const Napi::CallbackInfo& info) {
    ENTER_METHOD(Device, 1);
    CHECK_OPEN();
    int interface;
    INT_ARG(interface, 0);
    CHECK_USB(libusb_detach_kernel_driver(self->device_handle, interface));
    return env.Undefined();
}

Napi::Value Device::AttachKernelDriver(const Napi::CallbackInfo& info) {
    ENTER_METHOD(Device, 1);
    CHECK_OPEN();
    int interface;
    INT_ARG(interface, 0);
    CHECK_USB(libusb_attach_kernel_driver(self->device_handle, interface));
    return env.Undefined();
}

Napi::Value Device::ClaimInterface(const Napi::CallbackInfo& info) {
    ENTER_METHOD(Device, 1);
    CHECK_OPEN();
    int interface;
    INT_ARG(interface, 0);
    CHECK_USB(libusb_claim_interface(self->device_handle, interface));
    return env.Undefined();
}

struct Device_ReleaseInterface: Req {
    Device_ReleaseInterface(Device* d, Napi::Function& callback): Req(d, callback) {}

    int interface;

    virtual void Execute() {
        errcode = libusb_release_interface(device->device_handle, interface);
    }
};

Napi::Value Device::ReleaseInterface(const Napi::CallbackInfo& info) {
    ENTER_METHOD(Device, 2);
    CHECK_OPEN();
    int interface;
    INT_ARG(interface, 0);
    CALLBACK_ARG(1);
    auto baton = new Device_ReleaseInterface(self, callback);
    baton->interface = interface;
    baton->Queue();
    return env.Undefined();
}

struct Device_SetInterface: Req {
    Device_SetInterface(Device* d, Napi::Function& callback): Req(d, callback) {}

    int interface;
    int altsetting;

    virtual void Execute() {
        errcode = libusb_set_interface_alt_setting(
            device->device_handle, interface, altsetting);
    }
};

Napi::Value Device::SetInterface(const Napi::CallbackInfo& info) {
    ENTER_METHOD(Device, 3);
    CHECK_OPEN();
    int interface, altsetting;
    INT_ARG(interface, 0);
    INT_ARG(altsetting, 1);
    CALLBACK_ARG(2);
    auto baton = new Device_SetInterface(self, callback);
    baton->interface = interface;
    baton->altsetting = altsetting;
    baton->Queue();
    return env.Undefined();
}

struct Device_SetConfiguration: Req {
    Device_SetConfiguration(Device* d, Napi::Function& callback): Req(d, callback) {}

    int desired;

    virtual void Execute() {
        errcode = libusb_set_configuration(
            device->device_handle, desired);
    }
};

Napi::Value Device::SetConfiguration(const Napi::CallbackInfo& info) {
    ENTER_METHOD(Device, 2);
    CHECK_OPEN();
    int desired;
    INT_ARG(desired, 0);
    CALLBACK_ARG(1);
    auto baton = new Device_SetConfiguration(self, callback);
    baton->desired = desired;
    baton->Queue();
    return env.Undefined();
}

Napi::Object Device::Init(Napi::Env env, Napi::Object exports) {
    auto func = Device::DefineClass(
        env,
        "Device",
        {
            Device::InstanceMethod("__getParent", &Device::GetParent),
            Device::InstanceMethod("__getConfigDescriptor", &Device::GetConfigDescriptor),
            Device::InstanceMethod("__getAllConfigDescriptors", &Device::GetAllConfigDescriptors),
            Device::InstanceMethod("__open", &Device::Open),
            Device::InstanceMethod("__close", &Device::Close),
            Device::InstanceMethod("__clearHalt", &Device::ClearHalt),
            Device::InstanceMethod("reset", &Device::Reset),
            Device::InstanceMethod("__claimInterface", &Device::ClaimInterface),
            Device::InstanceMethod("__releaseInterface", &Device::ReleaseInterface),
            Device::InstanceMethod("__setInterface", &Device::SetInterface),
            Device::InstanceMethod("__setConfiguration", &Device::SetConfiguration),
            Device::InstanceMethod("__isKernelDriverActive", &Device::IsKernelDriverActive),
            Device::InstanceMethod("__detachKernelDriver", &Device::DetachKernelDriver),
            Device::InstanceMethod("__attachKernelDriver", &Device::AttachKernelDriver),
        });
    exports.Set("Device", func);

    ModuleData* instanceData = env.GetInstanceData<ModuleData>();
    instanceData->deviceConstructor = Napi::Persistent(func);

    return exports;
}
