/* Copyright (c) 2014-2015, Stanislaw Halik <sthalik@misaki.pl>

 * Permission to use, copy, modify, and/or distribute this
 * software for any purpose with or without fee is hereby granted,
 * provided that the above copyright notice and this permission
 * notice appear in all copies.
 */

#ifdef _WIN32

#include "keybinding-worker.hpp"
#include "compat/macros.hpp"
#include "compat/thread-name.hpp"

#include <QDebug>
#include <QMutexLocker>

#include <windows.h>

Key::Key() = default;

bool Key::should_process()
{
    if (!enabled || (keycode == 0 && guid == ""))
        return false;
    bool ret = !held || timer.elapsed_ms() > 100;
    timer.start();
    return ret;
}

KeybindingWorker::~KeybindingWorker()
{
    qDebug() << "exit: keybinding worker";

    requestInterruption();
    wait();

    if (dinkeyboard)
    {
        dinkeyboard->Unacquire();
        dinkeyboard->Release();
    }
}

bool KeybindingWorker::init()
{
    if (dinkeyboard)
        return true;

    if (!din)
    {
        qDebug() << "can't create dinput handle";
        goto fail;
    }

    if (din->CreateDevice(GUID_SysKeyboard, &dinkeyboard, nullptr) != DI_OK)
    {
        qDebug() << "dinput: create keyboard failed" << GetLastError();
        goto fail;
    }

    if (dinkeyboard->SetDataFormat(&c_dfDIKeyboard) != DI_OK)
    {
        qDebug() << "dinput: keyboard SetDataFormat" << GetLastError();
        goto fail;
    }

    if (dinkeyboard->SetCooperativeLevel((HWND) fake_main_window.winId(), DISCL_NONEXCLUSIVE | DISCL_BACKGROUND) != DI_OK)
    {
        qDebug() << "dinput: keyboard SetCooperativeLevel" << GetLastError();
        goto fail;
    }

    {
        DIPROPDWORD dipdw;
        dipdw.dwData = num_keyboard_states;
        dipdw.diph.dwHeaderSize = sizeof(dipdw.diph);
        dipdw.diph.dwHow = DIPH_DEVICE;
        dipdw.diph.dwObj = 0;
        dipdw.diph.dwSize = sizeof(dipdw);

        if (dinkeyboard->SetProperty(DIPROP_BUFFERSIZE, &dipdw.diph) != DI_OK)
        {
            qDebug() << "dinput: DIPROP_BUFFERSIZE";
            goto fail;
        }
    }

    return true;

fail:
    if (dinkeyboard)
    {
        dinkeyboard->Release();
        dinkeyboard = nullptr;
    }
    return false;
}

KeybindingWorker::KeybindingWorker()
{
    fake_main_window.setAttribute(Qt::WA_NativeWindow);

    if (init())
        start(QThread::HighPriority);
}

KeybindingWorker& KeybindingWorker::make()
{
    static KeybindingWorker k;
    return k;
}

void KeybindingWorker::run()
{
    portable::set_curthread_name("keybinding worker");

    while (!isInterruptionRequested())
    {
        {
            QMutexLocker l(&mtx);

            if (!receivers.empty())
            {
                bool ok = true;

                ok &= run_keyboard_nolock();
                ok &= run_joystick_nolock();

                if (!ok)
                    Sleep(500);
            }
        }

        Sleep(25);
    }
}

bool KeybindingWorker::run_keyboard_nolock()
{
    /* There are some problems reported on various forums
     * with regard to key-up events. But that's what I dug up:
     *
     * https://www.gamedev.net/forums/topic/633011-keyboard-getdevicedata-buffered-never-releases-keys/
     *
     * "Over in the xna forums (http://xboxforums.create.msdn.com/forums/p/108722/642144.aspx#642144)
     *  we discovered this behavior is caused by calling Unacquire in your event processing loop.
     *  Funnily enough only the keyboard seems to be affected."
     *
     * Key-up events work on my end.
     */

    if (!di_t::poll_device(dinkeyboard))
        eval_once(qDebug() << "dinput: keyboard poll failed");

    DWORD sz = num_keyboard_states;
    HRESULT hr = dinkeyboard->GetDeviceData(sizeof(*keyboard_states), keyboard_states, &sz, 0);

    if (FAILED(hr))
    {
        eval_once(qDebug() << "dinput: keyboard GetDeviceData failed" << (void*)hr);
        return false;
    }

    for (unsigned k = 0; k < sz; k++)
    {
        const unsigned idx = keyboard_states[k].dwOfs & 0xff; // defensive programming
        const bool held = !!(keyboard_states[k].dwData & 0x80);

        switch (idx)
        {
        case DIK_LCONTROL:
        case DIK_LSHIFT:
        case DIK_LALT:
        case DIK_RCONTROL:
        case DIK_RSHIFT:
        case DIK_RALT:
        case DIK_LWIN:
        case DIK_RWIN:
            break;
        default:
        {
            Key k;
            k.shift = keystate[DIK_LSHIFT] | keystate[DIK_RSHIFT];
            k.alt = keystate[DIK_LALT] | keystate[DIK_RALT];
            k.ctrl = keystate[DIK_LCONTROL] | keystate[DIK_RCONTROL];
            k.keycode = idx;
            k.held = held;

            for (auto& r : receivers)
                (*r)(k);
        }
            break;
        }

        keystate[idx] = held;
    }

    return true;
}

bool KeybindingWorker::run_joystick_nolock()
{
    using joy_fn = std::function<void(const QString& guid, int idx, bool held)>;

    joy_fn f = [&](const QString& guid, int idx, bool held) {
        Key k;
        k.keycode = idx;
        k.shift = keystate[DIK_LSHIFT] | keystate[DIK_RSHIFT];
        k.alt = keystate[DIK_LALT] | keystate[DIK_RALT];
        k.ctrl = keystate[DIK_LCONTROL] | keystate[DIK_RCONTROL];
        k.guid = guid;
        k.held = held;

        for (auto& r : receivers)
            (*r)(k);
    };

    joy_ctx.poll(f);

    return true;
}

KeybindingWorker::fun* KeybindingWorker::add_receiver(fun& receiver)
{
    QMutexLocker l(&mtx);
    receivers.push_back(std::make_unique<fun>(receiver));
    fun* f = &*receivers[receivers.size() - 1];
    //qDebug() << "add receiver" << (long) f;
    joy_ctx.refresh();
    return f;
}

void KeybindingWorker::remove_receiver(KeybindingWorker::fun* pos)
{
    QMutexLocker l(&mtx);
    bool ok = false;

    using s = int;

    for (int i = s(receivers.size()) - 1; i >= 0; i--)
    {
        using u = unsigned;
        if (&*receivers[u(i)] == pos)
        {
            ok = true;
            //qDebug() << "remove receiver" << (long) pos;
            receivers.erase(receivers.begin() + i);
            break;
        }
    }
    if (!ok)
    {
        qDebug() << "bad remove receiver" << (void*) pos;
    }
}

#endif