/*

  Simple DirectMedia Layer

  Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied

  warranty.  In no event will the authors be held liable for any damages

  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,

  including commercial applications, and to alter it and redistribute it

  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not

     claim that you wrote the original software. If you use this software

     in a product, an acknowledgment in the product documentation would be

     appreciated but is not required.

  2. Altered source versions must be plainly marked as such, and must not be

     misrepresented as being the original software.

  3. This notice may not be removed or altered from any source distribution.

*/

#include "../SDL_internal.h"

/* This is the joystick API for Simple DirectMedia Layer */

#include "SDL.h"

#include "SDL_events.h"

#include "SDL_sysjoystick.h"

#include "SDL_assert.h"

#include "SDL_hints.h"

#if !SDL_EVENTS_DISABLED

#include "../events/SDL_events_c.h"

#endif

static SDL_bool SDL_joystick_allows_background_events = SDL_FALSE;

static SDL_Joystick *SDL_joysticks = NULL;

static SDL_Joystick *SDL_updating_joystick = NULL;

static void

SDL_JoystickAllowBackgroundEventsChanged(void *userdata, const char *name, const char *oldValue, const char *hint)

{

    if (hint && *hint == '1') {

        SDL_joystick_allows_background_events = SDL_TRUE;

    } else {

        SDL_joystick_allows_background_events = SDL_FALSE;

    }

}

int

SDL_JoystickInit(void)

{

    int status;

    /* See if we should allow joystick events while in the background */

    SDL_AddHintCallback(SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS,

                        SDL_JoystickAllowBackgroundEventsChanged, NULL);

#if !SDL_EVENTS_DISABLED

    if (SDL_InitSubSystem(SDL_INIT_EVENTS) < 0) {

        return -1;

    }

#endif /* !SDL_EVENTS_DISABLED */

    status = SDL_SYS_JoystickInit();

    if (status >= 0) {

        status = 0;

    }

    return (status);

}

/*

 * Count the number of joysticks attached to the system

 */

int

SDL_NumJoysticks(void)

{

    return SDL_SYS_NumJoysticks();

}

/*

 * Get the implementation dependent name of a joystick

 */

const char *

SDL_JoystickNameForIndex(int device_index)

{

    if ((device_index < 0) || (device_index >= SDL_NumJoysticks())) {

        SDL_SetError("There are %d joysticks available", SDL_NumJoysticks());

        return (NULL);

    }

    return (SDL_SYS_JoystickNameForDeviceIndex(device_index));

}

/*

 * Open a joystick for use - the index passed as an argument refers to

 * the N'th joystick on the system.  This index is the value which will

 * identify this joystick in future joystick events.

 *

 * This function returns a joystick identifier, or NULL if an error occurred.

 */

SDL_Joystick *

SDL_JoystickOpen(int device_index)

{

    SDL_Joystick *joystick;

    SDL_Joystick *joysticklist;

    const char *joystickname = NULL;

    if ((device_index < 0) || (device_index >= SDL_NumJoysticks())) {

        SDL_SetError("There are %d joysticks available", SDL_NumJoysticks());

        return (NULL);

    }

    joysticklist = SDL_joysticks;

    /* If the joystick is already open, return it

    * it is important that we have a single joystick * for each instance id

    */

    while (joysticklist) {

        if (SDL_SYS_GetInstanceIdOfDeviceIndex(device_index) == joysticklist->instance_id) {

                joystick = joysticklist;

                ++joystick->ref_count;

                return (joystick);

        }

        joysticklist = joysticklist->next;

    }

    /* Create and initialize the joystick */

    joystick = (SDL_Joystick *) SDL_malloc((sizeof *joystick));

    if (joystick == NULL) {

        SDL_OutOfMemory();

        return NULL;

    }

    SDL_memset(joystick, 0, (sizeof *joystick));

    if (SDL_SYS_JoystickOpen(joystick, device_index) < 0) {

        SDL_free(joystick);

        return NULL;

    }

    joystickname = SDL_SYS_JoystickNameForDeviceIndex(device_index);

    if (joystickname)

        joystick->name = SDL_strdup(joystickname);

    else

        joystick->name = NULL;

    if (joystick->naxes > 0) {

        joystick->axes = (Sint16 *) SDL_malloc

            (joystick->naxes * sizeof(Sint16));

    }

    if (joystick->nhats > 0) {

        joystick->hats = (Uint8 *) SDL_malloc

            (joystick->nhats * sizeof(Uint8));

    }

    if (joystick->nballs > 0) {

        joystick->balls = (struct balldelta *) SDL_malloc

            (joystick->nballs * sizeof(*joystick->balls));

    }

    if (joystick->nbuttons > 0) {

        joystick->buttons = (Uint8 *) SDL_malloc

            (joystick->nbuttons * sizeof(Uint8));

    }

    if (((joystick->naxes > 0) && !joystick->axes)

        || ((joystick->nhats > 0) && !joystick->hats)

        || ((joystick->nballs > 0) && !joystick->balls)

        || ((joystick->nbuttons > 0) && !joystick->buttons)) {

        SDL_OutOfMemory();

        SDL_JoystickClose(joystick);

        return NULL;

    }

    if (joystick->axes) {

        SDL_memset(joystick->axes, 0, joystick->naxes * sizeof(Sint16));

    }

    if (joystick->hats) {

        SDL_memset(joystick->hats, 0, joystick->nhats * sizeof(Uint8));

    }

    if (joystick->balls) {

        SDL_memset(joystick->balls, 0,

            joystick->nballs * sizeof(*joystick->balls));

    }

    if (joystick->buttons) {

        SDL_memset(joystick->buttons, 0, joystick->nbuttons * sizeof(Uint8));

    }

    joystick->epowerlevel = SDL_JOYSTICK_POWER_UNKNOWN;

    /* Add joystick to list */

    ++joystick->ref_count;

    /* Link the joystick in the list */

    joystick->next = SDL_joysticks;

    SDL_joysticks = joystick;

    SDL_SYS_JoystickUpdate(joystick);

    return (joystick);

}

/*

 * Checks to make sure the joystick is valid.

 */

int

SDL_PrivateJoystickValid(SDL_Joystick * joystick)

{

    int valid;

    if (joystick == NULL) {

        SDL_SetError("Joystick hasn't been opened yet");

        valid = 0;

    } else {

        valid = 1;

    }

    return valid;

}

/*

 * Get the number of multi-dimensional axis controls on a joystick

 */

int

SDL_JoystickNumAxes(SDL_Joystick * joystick)

{

    if (!SDL_PrivateJoystickValid(joystick)) {

        return (-1);

    }

    return (joystick->naxes);

}

/*

 * Get the number of hats on a joystick

 */

int

SDL_JoystickNumHats(SDL_Joystick * joystick)

{

    if (!SDL_PrivateJoystickValid(joystick)) {

        return (-1);

    }

    return (joystick->nhats);

}

/*

 * Get the number of trackballs on a joystick

 */

int

SDL_JoystickNumBalls(SDL_Joystick * joystick)

{

    if (!SDL_PrivateJoystickValid(joystick)) {

        return (-1);

    }

    return (joystick->nballs);

}

/*

 * Get the number of buttons on a joystick

 */

int

SDL_JoystickNumButtons(SDL_Joystick * joystick)

{

    if (!SDL_PrivateJoystickValid(joystick)) {

        return (-1);

    }

    return (joystick->nbuttons);

}

/*

 * Get the current state of an axis control on a joystick

 */

Sint16

SDL_JoystickGetAxis(SDL_Joystick * joystick, int axis)

{

    Sint16 state;

    if (!SDL_PrivateJoystickValid(joystick)) {

        return (0);

    }

    if (axis < joystick->naxes) {

        state = joystick->axes[axis];

    } else {

        SDL_SetError("Joystick only has %d axes", joystick->naxes);

        state = 0;

    }

    return (state);

}

/*

 * Get the current state of a hat on a joystick

 */

Uint8

SDL_JoystickGetHat(SDL_Joystick * joystick, int hat)

{

    Uint8 state;

    if (!SDL_PrivateJoystickValid(joystick)) {

        return (0);

    }

    if (hat < joystick->nhats) {

        state = joystick->hats[hat];

    } else {

        SDL_SetError("Joystick only has %d hats", joystick->nhats);

        state = 0;

    }

    return (state);

}

/*

 * Get the ball axis change since the last poll

 */

int

SDL_JoystickGetBall(SDL_Joystick * joystick, int ball, int *dx, int *dy)

{

    int retval;

    if (!SDL_PrivateJoystickValid(joystick)) {

        return (-1);

    }

    retval = 0;

    if (ball < joystick->nballs) {

        if (dx) {

            *dx = joystick->balls[ball].dx;

        }

        if (dy) {

            *dy = joystick->balls[ball].dy;

        }

        joystick->balls[ball].dx = 0;

        joystick->balls[ball].dy = 0;

    } else {

        return SDL_SetError("Joystick only has %d balls", joystick->nballs);

    }

    return (retval);

}

/*

 * Get the current state of a button on a joystick

 */

Uint8

SDL_JoystickGetButton(SDL_Joystick * joystick, int button)

{

    Uint8 state;

    if (!SDL_PrivateJoystickValid(joystick)) {

        return (0);

    }

    if (button < joystick->nbuttons) {

        state = joystick->buttons[button];

    } else {

        SDL_SetError("Joystick only has %d buttons", joystick->nbuttons);

        state = 0;

    }

    return (state);

}

/*

 * Return if the joystick in question is currently attached to the system,

 *  \return SDL_FALSE if not plugged in, SDL_TRUE if still present.

 */

SDL_bool

SDL_JoystickGetAttached(SDL_Joystick * joystick)

{

    if (!SDL_PrivateJoystickValid(joystick)) {

        return SDL_FALSE;

    }

    return SDL_SYS_JoystickAttached(joystick);

}

/*

 * Get the instance id for this opened joystick

 */

SDL_JoystickID

SDL_JoystickInstanceID(SDL_Joystick * joystick)

{

    if (!SDL_PrivateJoystickValid(joystick)) {

        return (-1);

    }

    return (joystick->instance_id);

}

/*

 * Find the SDL_Joystick that owns this instance id

 */

SDL_Joystick *

SDL_JoystickFromInstanceID(SDL_JoystickID joyid)

{

    SDL_Joystick *joystick = SDL_joysticks;

    while (joystick) {

        if (joystick->instance_id == joyid) {

            return joystick;

        }

        joystick = joystick->next;

    }

    return NULL;

}

/*

 * Get the friendly name of this joystick

 */

const char *

SDL_JoystickName(SDL_Joystick * joystick)

{

    if (!SDL_PrivateJoystickValid(joystick)) {

        return (NULL);

    }

    return (joystick->name);

}

/*

 * Close a joystick previously opened with SDL_JoystickOpen()

 */

void

SDL_JoystickClose(SDL_Joystick * joystick)

{

    SDL_Joystick *joysticklist;

    SDL_Joystick *joysticklistprev;

    if (!joystick) {

        return;

    }

    /* First decrement ref count */

    if (--joystick->ref_count > 0) {

        return;

    }

    if (joystick == SDL_updating_joystick) {

        return;

    }

    SDL_SYS_JoystickClose(joystick);

    joystick->hwdata = NULL;

    joysticklist = SDL_joysticks;

    joysticklistprev = NULL;

    while (joysticklist) {

        if (joystick == joysticklist) {

            if (joysticklistprev) {

                /* unlink this entry */

                joysticklistprev->next = joysticklist->next;

            } else {

                SDL_joysticks = joystick->next;

            }

            break;

        }

        joysticklistprev = joysticklist;

        joysticklist = joysticklist->next;

    }

    SDL_free(joystick->name);

    /* Free the data associated with this joystick */

    SDL_free(joystick->axes);

    SDL_free(joystick->hats);

    SDL_free(joystick->balls);

    SDL_free(joystick->buttons);

    SDL_free(joystick);

}

void

SDL_JoystickQuit(void)

{

    /* Make sure we're not getting called in the middle of updating joysticks */

    SDL_assert(!SDL_updating_joystick);

    /* Stop the event polling */

    while (SDL_joysticks) {

        SDL_joysticks->ref_count = 1;

        SDL_JoystickClose(SDL_joysticks);

    }

    /* Quit the joystick setup */

    SDL_SYS_JoystickQuit();

#if !SDL_EVENTS_DISABLED

    SDL_QuitSubSystem(SDL_INIT_EVENTS);

#endif

}

static SDL_bool

SDL_PrivateJoystickShouldIgnoreEvent()

{

    if (SDL_joystick_allows_background_events) {

        return SDL_FALSE;

    }

    if (SDL_WasInit(SDL_INIT_VIDEO)) {

        if (SDL_GetKeyboardFocus() == NULL) {

            /* Video is initialized and we don't have focus, ignore the event. */

            return SDL_TRUE;

        } else {

            return SDL_FALSE;