// Copyright 2015 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.

#include "input_common/input_common.h"

#ifdef HAS_SDL
    #include "input_common/sdl_input/sdl_input.h"
#endif

#include "core/core_timing.h"
#include "core/settings.h"

namespace InputCommon {

// Set to nullptr until initialized by a backend
InputBase* g_user_input = nullptr;

// Event id for CoreTiming
static int input_event;

// Ticks for CoreTiming event, same as VBlank in GPU
static u64 frame_ticks;

/// Callback for CoreTiming
static void InputCallback(u64 userdata, int cycles_late) {

    // Call user input plugin Poll()
    if (g_user_input != nullptr) g_user_input->Poll();

    // Reschedule recurrent event
    CoreTiming::ScheduleEvent(frame_ticks - cycles_late, input_event);
}

std::string InputBase::GetDeviceName() const {
    return device_name;
}

Service::HID::PadState InputBase::GetPadState() const {
    return controller.pad_state;
}

void Init(ControllerBackends backend) {
    switch (backend) {
        #ifdef HAS_SDL
            // SDL2 backend selected
            case ControllerBackends::SDL2:
                g_user_input = new SDLController();
                break;
        #endif

        // No backend selected
        case ControllerBackends::NONE:
            break;

        // If no backend whatsoever inits, launch a critical log
        default:
            LOG_CRITICAL(Input, "Input backend initialization failed!");
            break;
    }

    // Shutdown immediately if backend failed to initialize
    if (g_user_input != nullptr && !g_user_input->activated) {
        Shutdown();
        return;
    }

    // Setup CoreTiming
    frame_ticks = 268123480 / Settings::values.gpu_refresh_rate / 16;

    input_event = CoreTiming::RegisterEvent("InputCommon::InputCallback", InputCallback);
    CoreTiming::ScheduleEvent(frame_ticks, input_event);
}

void Shutdown() {
    if (g_user_input != nullptr) {
        delete g_user_input;
        g_user_input = nullptr;
    }
}

} // namespace