/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include <AK/CircularQueue.h>
#include <Kernel/Devices/CharacterDevice.h>
#include <Kernel/IRQHandler.h>
#include <Kernel/MousePacket.h>

class PS2MouseDevice final : public IRQHandler
    , public CharacterDevice {
public:
    PS2MouseDevice();
    virtual ~PS2MouseDevice() override;

    static PS2MouseDevice& the();

    // ^CharacterDevice
    virtual bool can_read(const FileDescription&) const override;
    virtual ssize_t read(FileDescription&, u8*, ssize_t) override;
    virtual ssize_t write(FileDescription&, const u8*, ssize_t) override;
    virtual bool can_write(const FileDescription&) const override { return true; }

private:
    // ^IRQHandler
    virtual void handle_irq() override;

    // ^CharacterDevice
    virtual const char* class_name() const override { return "PS2MouseDevice"; }

    void initialize();
    void check_device_presence();
    void initialize_device();
    void prepare_for_input();
    void prepare_for_output();
    void mouse_write(u8);
    u8 mouse_read();
    void wait_then_write(u8 port, u8 data);
    u8 wait_then_read(u8 port);
    void parse_data_packet();
    void expect_ack();

    bool m_device_present { false };
    CircularQueue<MousePacket, 100> m_queue;
    u8 m_data_state { 0 };
    u8 m_data[4];
    bool m_has_wheel { false };
};