/*
 * Copyright (c) 2021, Jesse Buhagiar <jooster669@gmail.com>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <AK/Badge.h>
#include <AK/OwnPtr.h>
#include <AK/SetOnce.h>
#include <AK/Types.h>
#include <AK/Vector.h>
#include <Kernel/Bus/USB/Drivers/USBDriver.h>
#include <Kernel/Bus/USB/USBConfiguration.h>
#include <Kernel/Bus/USB/USBPipe.h>
#include <Kernel/Locking/SpinlockProtected.h>

namespace Kernel {
class SysFSUSBDeviceInformation;
}

namespace Kernel::USB {

class USBController;
class USBConfiguration;

//
// Some nice info from FTDI on device enumeration and how some of this
// glues together:
//
// https://www.ftdichip.com/Support/Documents/TechnicalNotes/TN_113_Simplified%20Description%20of%20USB%20Device%20Enumeration.pdf
class Hub;
class Device : public AtomicRefCounted<Device> {
    friend class Hub;
    // Note: This constructor is only used by the USB::Hub class
    //       As that class inherits from Device, but is usually initialized with a Device object
    //       needing a copy constructor,
    // FIXME: Ideally Hub should not inherit from Device, but instead have a Device member
    Device(Device const& device);

public:
    enum class DeviceSpeed : u8 {
        LowSpeed = 0,
        FullSpeed,
        HighSpeed,
        SuperSpeed,
    };

    static ErrorOr<NonnullLockRefPtr<Device>> try_create(USBController&, Hub const&, u8, DeviceSpeed);

    Device(USBController const&, Hub const*, u8 port, DeviceSpeed);
    Device(USBController const&, Hub const*, u8 port, DeviceSpeed, u8 address, USBDeviceDescriptor const& descriptor);
    virtual ~Device();

    u8 port() const { return m_device_port; }
    DeviceSpeed speed() const { return m_device_speed; }

    u8 address() const { return m_address; }

    USBDeviceDescriptor const& device_descriptor() const { return m_device_descriptor; }

    USBController& controller() { return *m_controller; }
    USBController const& controller() const { return *m_controller; }

    Hub const* hub() const { return m_hub; }

    ErrorOr<size_t> control_transfer(u8 request_type, u8 request, u16 value, u16 index, u16 length, void* data);

    Vector<USBConfiguration> const& configurations() const { return m_configurations; }

    void set_driver(Driver& driver) { m_driver = driver; }
    void detach()
    {
        if (m_driver)
            m_driver->detach(*this);
        m_driver = nullptr;
    }

    ErrorOr<void> set_configuration_and_interface(USBInterface const& interface);

    SpinlockProtected<RefPtr<SysFSUSBDeviceInformation>, LockRank::None>& sysfs_device_info_node(Badge<USB::Hub>) { return m_sysfs_device_info_node; }

    template<DerivedFrom<USBController> Controller>
    void set_max_packet_size(Badge<Controller>, u8 max_packet_size)
    {
        m_default_pipe->set_max_packet_size(max_packet_size);
    }
    template<DerivedFrom<USBController> Controller>
    void set_address(Badge<Controller>, u8 address)
    {
        VERIFY(m_address == 0); // Device can only transition once
        m_address = address;
    }
    template<DerivedFrom<USBController> Controller>
    void set_descriptor(Badge<Controller>, USBDeviceDescriptor const& descriptor)
    {
        memcpy(&m_device_descriptor, &descriptor, sizeof(USBDeviceDescriptor));
    }
    template<DerivedFrom<USBController> Controller>
    Vector<USBConfiguration>& configurations(Badge<Controller>) { return m_configurations; }
    template<DerivedFrom<USBController> Controller>
    void set_controller_identifier(Badge<Controller>, size_t identifier)
    {
        m_controller_identifier = identifier;
    }
    size_t controller_identifier() const { return m_controller_identifier; }

protected:
    void set_default_pipe(NonnullOwnPtr<ControlPipe> pipe);
    ErrorOr<void> set_configuration(USBConfiguration const& configuration);

    u8 m_device_port { 0 };     // What port is this device attached to. NOTE: This is 1-based.
    DeviceSpeed m_device_speed; // What speed is this device running at
    u8 m_address { 0 };         // USB address assigned to this device
    size_t m_controller_identifier { 0 };

    // Device description
    u16 m_vendor_id { 0 };                      // This device's vendor ID assigned by the USB group
    u16 m_product_id { 0 };                     // This device's product ID assigned by the USB group
    USBDeviceDescriptor m_device_descriptor {}; // Device Descriptor obtained from USB Device
    Vector<USBConfiguration> m_configurations;  // Configurations for this device

    NonnullLockRefPtr<USBController> m_controller;
    Hub const* m_hub { nullptr };
    OwnPtr<ControlPipe> m_default_pipe; // Default communication pipe (endpoint0) used during enumeration

    // The current configuration is behind a SetOnce, this is the easiest way to
    // guarantee that when a driver is attached, another driver cannot choose a different configuration
    // using a different interface in the same configuration is fine, though
    SetOnce m_was_configured;
    u8 m_current_configuration { 0 };

    LockRefPtr<Driver> m_driver;

private:
    IntrusiveListNode<Device, NonnullLockRefPtr<Device>> m_hub_child_node;

protected:
    SpinlockProtected<RefPtr<SysFSUSBDeviceInformation>, LockRank::None> m_sysfs_device_info_node;

public:
    using List = IntrusiveList<&Device::m_hub_child_node>;
};
}