/* Copyright 2025 Jaakko Keränen <jaakko.keranen@iki.fi>

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 OWNER 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. */

#include "gamepad.h"

#if defined (LAGRANGE_USE_GAMEPAD)

#include "app.h"
#include "command.h"
#include "documentwidget.h"
#include "inputwidget.h"
#include "keyboardwidget.h"
#include "labelwidget.h"
#include "render/paint.h"
#include "resources.h"
#include "util.h"
#include "window.h"

#include <the_Foundation/ptrset.h>
#include <SDL.h>

int actions_Gamepad[max_GamepadAction] = {
    SDL_CONTROLLER_BUTTON_A,
    SDL_CONTROLLER_BUTTON_X,
    SDL_CONTROLLER_BUTTON_B,
    SDL_CONTROLLER_BUTTON_START,
    SDL_CONTROLLER_BUTTON_Y | triggerMod_Gamepad,
    SDL_CONTROLLER_BUTTON_BACK,
    SDL_CONTROLLER_BUTTON_B | triggerMod_Gamepad,
    SDL_CONTROLLER_BUTTON_Y,
};

int findAction_Gamepad(int button, iBool trigger) {
    for (int i = 0; i < max_GamepadAction; i++) {
        if (actions_Gamepad[i] == (button | (trigger ? triggerMod_Gamepad : 0))) {
            return i;
        }
    }
    return unassigned_Gamepad;
}

/*----------------------------------------------------------------------------------------------*/

struct Impl_Gamepad {
    SDL_GameController *ctl;
    int      joyIndex;
    iWindow *window; /* TODO: we assume there is one window and it won't change; must fix! */
    iPtrSet *openMenus;
    float    scrollSpeed;
    float    scrollAccum; /* pixels */
    iBool    isScrollCancelled;
    float    pointerSpeed[2]; /* pixels */
    iAnim    pointerf[2];     /* pixels */
    iInt2    pointer;         /* points (for SDL event) */
    iInt2    lastPointer;     /* points (for SDL event) */
    iAnim    opacity;
    uint32_t buttons; /* currently down; bits */
    iBool    rightTrigger;
    /* Graphics: */
    SDL_Texture *pointerTexture;
};

iDefineTypeConstruction(Gamepad);

static iBool wasInited_;

static void ticker_Gamepad_ (void *);
static void animate_Gamepad_(void *);

static iRoot *root_Gamepad_(const iGamepad *d) {
    return d->window->roots[0];
}

static void open_Gamepad_(iGamepad *d, int index) {
    iAssert(d->joyIndex < 0);
    d->joyIndex = index;
    d->ctl      = SDL_GameControllerOpen(index);
    char guid[64];
    SDL_JoystickGetGUIDString(SDL_JoystickGetDeviceGUID(index), guid, sizeof(guid));
    fprintf(stderr,
            "[Gamepad] using controller: %s (type:%d, GUID:%s)\n",
            SDL_GameControllerNameForIndex(index),
            SDL_GameControllerGetType(d->ctl),
            guid);
    d->isScrollCancelled = iFalse;
}

static void close_Gamepad_(iGamepad *d) {
    if (d->ctl) {
        SDL_GameControllerClose(d->ctl);
        d->ctl      = NULL;
        d->joyIndex = -1;
        fprintf(stderr, "[Gamepad] controller disconnected\n");
    }
}

static void updateHover_Gamepad_(iGamepad *d) {
    const iRoot *root = root_Gamepad_(d);
    iWidget *w = hitChild_Widget(root->widget, coord_Window(d->window, d->pointer.x, d->pointer.y));
    if (isHoverable_Widget(w)) {
        setHover_Widget(w);
    }
}

static void addTicker_Gamepad_(iGamepad *d) {
    addTickerRoot_App(ticker_Gamepad_, root_Gamepad_(d), d);
}

void movePointer_Gamepad(iGamepad *d, iInt2 coord, int span) {
    if (!isConnected_Gamepad(d) || !d->window) return;
    setValue_Anim(&d->pointerf[0], coord.x, span);
    setValue_Anim(&d->pointerf[1], coord.y, span);
    d->pointer = divf_I2(coord, d->window->pixelRatio);
    const iInt2 delta = sub_I2(d->pointer, d->lastPointer);
    SDL_PushEvent((SDL_Event *) &(SDL_MouseMotionEvent) {
        .type      = SDL_MOUSEMOTION,
        .which     = mouseId_Gamepad,
        .windowID  = id_Window(d->window),
        .x         = d->pointer.x,
        .y         = d->pointer.y,
        .xrel      = delta.x,
        .yrel      = delta.y,
    });
    d->lastPointer = d->pointer;
    animate_Gamepad_(d);
}

void movePointerOntoWidget_Gamepad(iGamepad *d, iWidget *widget, int span) {
    if (isConnected_Gamepad(d) && widget) {
        const iInt2 mid = mid_Rect(boundsWithoutVisualOffset_Widget(widget));
        movePointer_Gamepad(d, mid, span);
        setHover_Widget(widget);
    }
}

static void pointerOntoFocus_Gamepad_(iGamepad *d) {
    if (isConnected_Gamepad(d)) {
        movePointerOntoWidget_Gamepad(d, focus_Widget(), 100);
    }
}

static void ticker_Gamepad_(void *context) {
    iGamepad *d = context;
    const float elapsed = elapsedSinceLastTicker_App() / 1000.0f;
    if (d->isScrollCancelled) {
        d->scrollSpeed = 0;
    }
    d->scrollAccum += d->scrollSpeed * 250 * gap_UI * elapsed;
    const float maxPointer[2] = { d->window->size.x, d->window->size.y };
    iForIndices(i, d->pointerf) {
        iAnim *pf = &d->pointerf[i];
        float val = targetValue_Anim(pf);
        val += d->pointerSpeed[i] * 100 * gap_UI * elapsed;
        val = iClamp(val, 0, maxPointer[i]);
        if (isFinished_Anim(pf)) {
            setValue_Anim(pf, val, 0);
        }
        else {
            pf->to = val;
        }
    }
    /* Post a wheel scroll event. */ {
        const int pixels = (int)(fabs(d->scrollAccum)) * iSign(d->scrollAccum);
        if (pixels) {
            updateHover_Gamepad_(d);
            SDL_PushEvent((SDL_Event *) &(SDL_MouseWheelEvent) {
                .type      = SDL_MOUSEWHEEL,
                .which     = mouseId_Gamepad,
                .windowID  = id_Window(d->window),
                .direction = perPixel_MouseWheelFlag,
                .y         = -pixels,
#if SDL_VERSION_ATLEAST(2, 26, 0)
                .mouseX    = d->pointer.x,
                .mouseY    = d->pointer.y,
#endif
            });
            d->scrollAccum -= pixels;
        }
    }
    /* Post pointer movement. */ {
        d->pointer.x = (int) (value_Anim(&d->pointerf[0]) / d->window->pixelRatio);
        d->pointer.y = (int) (value_Anim(&d->pointerf[1]) / d->window->pixelRatio);
        const iInt2 delta = sub_I2(d->lastPointer, d->pointer);
        if (delta.x || delta.y) {
            SDL_PushEvent((SDL_Event *) &(SDL_MouseMotionEvent) {
                .type      = SDL_MOUSEMOTION,
                .which     = mouseId_Gamepad,
                .windowID  = id_Window(d->window),
                .x         = d->pointer.x,
                .y         = d->pointer.y,
                .xrel      = delta.x,
                .yrel      = delta.y,
            });
            d->lastPointer = d->pointer;
            postRefresh_Window(d->window);
        }
    }
    if (d->scrollSpeed || d->pointerSpeed[0] || d->pointerSpeed[1]) {
        /* Keep scrolling. */
        addTicker_Gamepad_(d);
    }
}

static void animate_Gamepad_(void *context) {
    iGamepad *d = context;
    postRefresh_Window(d->window);
    if (!isFinished_Anim(&d->opacity) || !isFinished_Anim(&d->pointerf[0]) ||
        !isFinished_Anim(&d->pointerf[1])) {
        addTickerRoot_App(animate_Gamepad_, root_Gamepad_(d), context);
    }
}

static void showPointer_Gamepad_(iGamepad *d) {
    if (targetValue_Anim(&d->opacity) < 1) {
        setValue_Anim(&d->opacity, 1, 160);
        animate_Gamepad_(d);
    }
    /* TODO: Fade the pointer away after some time .*/
}

static void hidePointer_Gamepad_(iGamepad *d, iBool completely) {
    if (targetValue_Anim(&d->opacity) > 0) {
        setValue_Anim(&d->opacity, completely ? 0.f : 0.25f, 320);
        animate_Gamepad_(d);
    }
}

/*-----------------------------------------------------------------------------------------------*/

static iBool sdlInit_(void) {
    if (!wasInited_) {
        if (SDL_Init(SDL_INIT_GAMECONTROLLER)) {
            fprintf(stderr, "[Gamepad] failed to initialize: %s\n", SDL_GetError());
            return iFalse;
        }
        wasInited_ = iTrue;
    }
    return iTrue;
}

void init_Gamepad(iGamepad *d) {
    d->ctl            = NULL;
    d->joyIndex       = -1;
    d->scrollSpeed    = 0;
    d->scrollAccum    = 0;
    d->rightTrigger   = iFalse;
    d->window         = (iWindow *) constFront_PtrArray(mainWindows_App());
    d->openMenus      = new_PtrSet();
    init_Anim(&d->opacity, 0);
    /* Place the soft pointer at the center of the window. */
    d->pointer     = mid_Rect(initSize_Rect(d->window->size.x / d->window->pixelRatio,
                                            d->window->size.y / d->window->pixelRatio));
    d->lastPointer = d->pointer;
    init_Anim(&d->pointerf[0], d->pointer.x * d->window->pixelRatio);
    init_Anim(&d->pointerf[1], d->pointer.y * d->window->pixelRatio);
    setFlags_Anim(&d->pointerf[0], easeOut_AnimFlag, iTrue);
    setFlags_Anim(&d->pointerf[1], easeOut_AnimFlag, iTrue);
    d->buttons = 0;
    if (!sdlInit_()) {
        d->pointerTexture = NULL;
        return;
    }
    SDL_GameControllerEventState(SDL_ENABLE);
    d->pointerTexture = makeTextureFromImageData_Window(d->window, &imagePointer_Resources);
    /* Look for gamepads. */
    for (int i = 0; i < SDL_NumJoysticks(); i++) {
        if (SDL_IsGameController(i)) {
            open_Gamepad_(d, i);
            break;
        }
    }
}

void deinit_Gamepad(iGamepad *d) {
    close_Gamepad_(d);
    delete_PtrSet(d->openMenus);
    if (wasInited_) {
        SDL_GameControllerEventState(SDL_IGNORE);
        SDL_DestroyTexture(d->pointerTexture);
    }
}

iBool isAvailable_Gamepad(void) {
    if (!sdlInit_()) return iFalse;
    for (int i = 0; i < SDL_NumJoysticks(); i++) {
        if (SDL_IsGameController(i)) {
            return iTrue;
        }
    }
    return iFalse;
}

iBool isConnected_Gamepad(const iGamepad *d) {
    return d && d->ctl != NULL;
}

iBool isPointing_Gamepad(const iGamepad *d) {
    return isConnected_Gamepad(d) && targetValue_Anim(&d->opacity) > 0.5f;
}

iInt2 pointerCoord_Gamepad(const iGamepad *d) {
    return isConnected_Gamepad(d) ? coord_Window(d->window, d->pointer.x, d->pointer.y) : zero_I2();
}

int modState_Gamepad(const iGamepad *d) {
    return isConnected_Gamepad(d) && d->rightTrigger ? KMOD_SHIFT : 0;
}

const char *buttonName_Gamepad(const iGamepad *d, int sdlGameControllerButton) {
    iUnused(d);
    iString bstr;
    initCStr_String(&bstr, SDL_GameControllerGetStringForButton(sdlGameControllerButton));
    iString *name = upper_String(&bstr);
    deinit_String(&bstr);
    return cstrCollect_String(name);
}

static iBool moveFocusToDirection_Gamepad_(iGamepad *d, int button) {
    if (focus_Widget() && isInstance_Object(focus_Widget(), &Class_DocumentWidget)) {
        setFocus_Widget(NULL);
    }
    if (!focus_Widget()) {
        /* If a dialog or sidebar is open, place the focus there. */
        iWidget *focusable =
            !isEmpty_PtrSet(d->openMenus) ? front_PtrSet(d->openMenus) : NULL;
        if (focusable) {
            iConstForEach(ObjectList, k, children_Widget(focusable)) {
                if (flags_Widget(k.object) & focusable_WidgetFlag) {
                    setFocus_Widget((iWidget *) k.object);
                    return iTrue;
                }
            }
            return iTrue;
        }
        if (!focusable) {
            iForEach(ObjectList, j, children_Widget(root_Gamepad_(d)->widget)) {
                const iWidget *child = j.object;
                if (isVisible_Widget(child) && flags_Widget(child) & focusRoot_WidgetFlag) {
                    focusable = j.object;
                    break;
                }
            }
        }
        if (focusable) {
            setFocus_Widget(findFocusable_Widget(focusable,
                                                 button == SDL_CONTROLLER_BUTTON_DPAD_DOWN ||
                                                         button == SDL_CONTROLLER_BUTTON_DPAD_RIGHT
                                                     ? forward_WidgetFocusDir
                                                     : backward_WidgetFocusDir));
            return iTrue;
        }
        return iFalse;
    }
    int key   = 0;
    int kmods = d->rightTrigger ? KMOD_SHIFT : 0;
    switch (button) {
        case SDL_CONTROLLER_BUTTON_DPAD_UP:
            key = SDLK_UP;
            break;
        case SDL_CONTROLLER_BUTTON_DPAD_DOWN:
            key = SDLK_DOWN;
            break;
        case SDL_CONTROLLER_BUTTON_DPAD_LEFT:
            key = SDLK_LEFT;
            break;
        case SDL_CONTROLLER_BUTTON_DPAD_RIGHT:
            key = SDLK_RIGHT;
            break;
    }
    if (key) {
        emulateKeyPress_Window(d->window, key, kmods);
        return iTrue;
    }
    return iFalse;
}

static iBool isInputFocused_(void) {
    return focus_Widget() && isInstance_Object(focus_Widget(), &Class_InputWidget);
}

static iBool isPointerOnKeyboard_Gamepad_(const iGamepad *d) {
    if (isInputFocused_() && isHandheld_Platform()) {
        return contains_Widget(
            findWidget_App("keyboard"),
            init_I2(targetValue_Anim(&d->pointerf[0]), targetValue_Anim(&d->pointerf[1])));
    }
    return iFalse;
}

iBool processEvent_Gamepad(iGamepad *d, const void *sdlEvent) {
    if (!d) {
        return iFalse;
    }
    const SDL_Event *event = sdlEvent;
    switch (event->type) {
        case SDL_CONTROLLERDEVICEADDED: {
            const SDL_ControllerDeviceEvent *dev = &event->cdevice;
            if (!d->ctl) {
                open_Gamepad_(d, dev->which);
            }
            return iTrue;
        }
        case SDL_CONTROLLERDEVICEREMOVED: {
            const SDL_ControllerDeviceEvent *dev = &event->cdevice;
            if (dev->which == d->joyIndex) {
                close_Gamepad_(d);
            }
            return iTrue;
        }
        default:
            break;
    }
    if (isCommand_UserEvent(sdlEvent, "menu.opened")) {
        insert_PtrSet(d->openMenus, pointer_Command(command_UserEvent(sdlEvent)));
        return iFalse;
    }
    else if (isCommand_UserEvent(sdlEvent, "menu.closed")) {
        remove_PtrSet(d->openMenus, pointer_Command(command_UserEvent(sdlEvent)));
        return iFalse;
    }
    if (!isConnected_Gamepad(d)) {
        return iFalse;
    }
    if (isCommand_UserEvent(sdlEvent, "focus.gained")) {
        pointerOntoFocus_Gamepad_(d);
        return iFalse;
    }
    switch (event->type) {
        case SDL_CONTROLLERAXISMOTION: {
            const SDL_ControllerAxisEvent *axis = &event->caxis;
            // printf("[Gamepad] axis:%d value:%d\n", axis->axis, axis->value);
            if (axis->axis == SDL_CONTROLLER_AXIS_TRIGGERRIGHT) {
                const iBool isDown = axis->value > (SDL_JOYSTICK_AXIS_MAX / 2);
                if (d->rightTrigger != isDown) {
                    d->rightTrigger = isDown;
                    SDL_PushEvent((SDL_Event *) &(SDL_KeyboardEvent) {
                        .type     = isDown ? SDL_KEYDOWN : SDL_KEYUP,
                        .keysym   = { .sym = SDLK_LSHIFT, .mod = 0 },
                        .windowID = id_Window(d->window),
                    });
                }
                return iTrue;
            }
            const float deadZone = 0.1f;
            float norm = axis->value / (float) SDL_JOYSTICK_AXIS_MAX;
            const int pointerAxis = (axis->axis == SDL_CONTROLLER_AXIS_LEFTY ? 1 : 0);
            if (fabs(norm) < deadZone) {
                if (axis->axis == SDL_CONTROLLER_AXIS_RIGHTY &&
                    !(d->buttons & ((1 << SDL_CONTROLLER_BUTTON_DPAD_UP) |
                                    (1 << SDL_CONTROLLER_BUTTON_DPAD_DOWN)))) {
                    d->scrollSpeed = 0;
                    d->isScrollCancelled = iFalse;
                    updateHover_Gamepad_(d);
                }
                else if (axis->axis == SDL_CONTROLLER_AXIS_LEFTX ||
                         axis->axis == SDL_CONTROLLER_AXIS_LEFTY) {
                    d->pointerSpeed[pointerAxis] = 0;
                }
                return iTrue;
            }
            norm = iClamp((norm - iSign(norm) * deadZone) / (1.0f - deadZone), -1.0f, 1.0f);
            if (axis->axis == SDL_CONTROLLER_AXIS_RIGHTY) {
                d->scrollSpeed = norm * norm * iSignf(norm);
                hidePointer_Gamepad_(d, iTrue);
                addTicker_Gamepad_(d);
                updateHover_Gamepad_(d);
            }
            else if (axis->axis == SDL_CONTROLLER_AXIS_LEFTX ||
                     axis->axis == SDL_CONTROLLER_AXIS_LEFTY) {
                d->pointerSpeed[pointerAxis] = norm;
                /* Moving the pointer resets focus unless we're on an input field, in which
                   case the keyboard is visible. */
                if (focus_Widget() && !isInstance_Object(focus_Widget(), &Class_InputWidget)) {
                    setFocus_Widget(NULL);
                }
                showPointer_Gamepad_(d);
                addTicker_Gamepad_(d);
            }
            return iTrue;
        }
        case SDL_CONTROLLERBUTTONDOWN:
        case SDL_CONTROLLERBUTTONUP: {
            const SDL_ControllerButtonEvent *but = &event->cbutton;
            const int   modButton = but->button | (d->rightTrigger ? triggerMod_Gamepad : 0);
            const iBool isPress   = (but->state != 0);
            iChangeFlags(d->buttons, 1 << but->button, isPress);
            if (but->button == SDL_CONTROLLER_BUTTON_DPAD_LEFT && isPress) {
                if (isPointerOnKeyboard_Gamepad_(d)) {
                    if (moveHover_KeyboardWidget(findWidget_App("keyboard"), left_Direction)) {
                        return iTrue;
                    }
                }
                if (moveFocusToDirection_Gamepad_(d, but->button)) return iTrue;
                postCommand_Root(root_Gamepad_(d), "navigate.back");
            }
            else if (but->button == SDL_CONTROLLER_BUTTON_DPAD_RIGHT && isPress) {
                if (isPointerOnKeyboard_Gamepad_(d)) {
                    if (moveHover_KeyboardWidget(findWidget_App("keyboard"), right_Direction)) {
                        return iTrue;
                    }
                }
                if (moveFocusToDirection_Gamepad_(d, but->button)) return iTrue;
                postCommand_Root(root_Gamepad_(d), "navigate.forward");
            }
            else if (but->button == SDL_CONTROLLER_BUTTON_DPAD_UP) {
                if (isPress) {
                    if (isInputFocused_()) {
                        if (isPointerOnKeyboard_Gamepad_(d)) {
                            iKeyboardWidget *keyboard = findWidget_App("keyboard");
                            if (keyboard) {
                                const iRect target = keyRectAtX_KeyboardWidget(
                                    keyboard, targetValue_Anim(&d->pointerf[0]), iInvalidPos, -1);
                                if (!isEmpty_Rect(target)) {
                                    movePointer_Gamepad(
                                        d, addY_I2(mid_Rect(target), height_Rect(target) / 4), 100);
                                }
                                else {
                                    movePointerOntoWidget_Gamepad(d, focus_Widget(), 100);
                                }
                            }
                        }
                        return iTrue;
                    }
                    if (d->rightTrigger) {
                        postCommand_Root(root_Gamepad_(d), "zoom.delta arg:10");
                        return iTrue;
                    }
                    if (moveFocusToDirection_Gamepad_(d, but->button)) return iTrue;
                }
                d->scrollSpeed = (isPress ? -0.75f : 0);
                addTicker_Gamepad_(d);
            }
            else if (but->button == SDL_CONTROLLER_BUTTON_DPAD_DOWN) {
                if (isPress) {
                    if (isInputFocused_()) {
                        iKeyboardWidget *keyboard = findWidget_App("keyboard");
                        if (keyboard) {
                            const size_t fromRow =
                                isPointerOnKeyboard_Gamepad_(d) ? iInvalidPos : 0;
                            const int   offset = isPointerOnKeyboard_Gamepad_(d) ? +1 : 0;
                            const iRect target = keyRectAtX_KeyboardWidget(
                                keyboard, targetValue_Anim(&d->pointerf[0]), fromRow, offset);
                            if (!isEmpty_Rect(target)) {
                                movePointer_Gamepad(
                                    d, addY_I2(mid_Rect(target), height_Rect(target) / 4), 100);
                            }
                            return iTrue;
                        }
                    }
                    if (d->rightTrigger) {
                        postCommand_Root(root_Gamepad_(d), "zoom.delta arg:-10");
                        return iTrue;
                    }
                    if (moveFocusToDirection_Gamepad_(d, but->button)) return iTrue;
                }
                d->scrollSpeed = (isPress ? 0.75f : 0);
                addTicker_Gamepad_(d);
            }
            else if (but->button == SDL_CONTROLLER_BUTTON_RIGHTSTICK && isPress) {
                if (d->scrollSpeed < 0) {
                    postCommand_Root(root_Gamepad_(d), "scroll.top smooth:1");
                    d->isScrollCancelled = iTrue;
                }
                else if (d->scrollSpeed > 0) {
                    postCommand_Root(root_Gamepad_(d), "scroll.bottom smooth:1");
                    d->isScrollCancelled = iTrue;
                }
            }
            else if (but->button == SDL_CONTROLLER_BUTTON_Y && isPress && isInputFocused_() &&
                     isPointerOnKeyboard_Gamepad_(d)) {
                SDL_PushEvent((SDL_Event *) &(SDL_TextInputEvent) {
                    .type     = SDL_TEXTINPUT,
                    .windowID = id_Window(d->window),
                    .text     = " ",
                });
                return iTrue;
            }
            else if ((but->button == SDL_CONTROLLER_BUTTON_LEFTSHOULDER ||
                      but->button == SDL_CONTROLLER_BUTTON_RIGHTSHOULDER) &&
                     isPress) {
                iKeyboardWidget *keyboard = findWidget_App("keyboard");
                if (isVisible_Widget(keyboard)) {
                    cyclePage_KeyboardWidget(
                        keyboard, but->button == SDL_CONTROLLER_BUTTON_LEFTSHOULDER ? -1 : +1);
                }
                else if (isVisible_Widget(findWidget_App("sidebar"))) {
                    postCommandf_Root(root_Gamepad_(d),
                                      "sidebar.cycle arg:%d",
                                      but->button == SDL_CONTROLLER_BUTTON_LEFTSHOULDER ? -1 : +1);
                }
                else {
                    postCommand_Root(root_Gamepad_(d),
                                     but->button == SDL_CONTROLLER_BUTTON_LEFTSHOULDER
                                         ? "tabs.prev"
                                         : "tabs.next");
                }
            }
            else if (modButton == actions_Gamepad[primary_GamepadAction] ||
                     modButton == actions_Gamepad[secondary_GamepadAction]) {
                if (value_Anim(&d->opacity) < 0.5f) {
                    /* If the pointer is invisible, it must appear first. */
                    if (!focus_Widget()) {
                        showPointer_Gamepad_(d);
                        return iTrue;
                    }
                }
                d->isScrollCancelled = iFalse;
                const int mouseButton =
                    (modButton == actions_Gamepad[primary_GamepadAction] ? SDL_BUTTON_LEFT
                                                                         : SDL_BUTTON_RIGHT);
                SDL_PushEvent((SDL_Event *) &(SDL_MouseButtonEvent) {
                    .type     = (isPress ? SDL_MOUSEBUTTONDOWN : SDL_MOUSEBUTTONUP),
                    .which    = mouseId_Gamepad,
                    .windowID = id_Window(d->window),
                    .button   = mouseButton,
                    .state    = (isPress ? SDL_PRESSED : SDL_RELEASED),
                    .clicks   = 1,
                    .x        = d->pointer.x,
                    .y        = d->pointer.y,
                });
                updateHover_Gamepad_(d);
            }
            else if (modButton == actions_Gamepad[openNavMenu_GamepadAction] && isPress) {
                iRoot *root = root_Gamepad_(d);
                setValue_Anim(&d->opacity, 0.25f, 0);
                showToolbar_Root(root, iTrue);
                iWidget *nav = findChild_Widget(root->widget, "toolbar.navmenu");
                if (nav) {
                    emulateMouseClick_Widget(nav, SDL_BUTTON_LEFT);
                }
                else {
                    /* Show the desktop main menu? */
                }
            }
            else if (modButton == actions_Gamepad[openSidebar_GamepadAction] && isPress) {
                hidePointer_Gamepad_(d, iFalse);
                postCommand_Root(root_Gamepad_(d), "sidebar.toggle");
            }
            else if (modButton == actions_Gamepad[reloadPage_GamepadAction] && isPress) {
                postCommand_Root(root_Gamepad_(d), "document.reload");
            }
            else if (modButton == actions_Gamepad[cancel_GamepadAction] && isPress) {
                emulateKeyPress_Window(d->window, SDLK_ESCAPE, 0);
            }
            else if (modButton == actions_Gamepad[openPageMenu_GamepadAction] && isPress) {
                iRoot *root = root_Gamepad_(d);
                showToolbar_Root(root, iTrue);
                iWidget *button = findChild_Widget(root->widget, "pagemenubutton");
                if (button) {
                    emulateMouseClick_Widget(button, SDL_BUTTON_LEFT);
                }
            }
            else if (modButton == actions_Gamepad[focusUrl_GamepadAction] && isPress) {
                postCommand_Root(root_Gamepad_(d), "navigate.focus");
            }
            return iTrue;
        }
        case SDL_CONTROLLERTOUCHPADDOWN:
        case SDL_CONTROLLERTOUCHPADUP:
        case SDL_CONTROLLERTOUCHPADMOTION: {
            /* Touchpad can be used to move cursor and perform clicks. */
            const SDL_ControllerTouchpadEvent *pad = &event->ctouchpad;
            fprintf(stderr, "[Gamepad] touchpad type:%d x:%f y:%f\n", pad->type, pad->x, pad->y);
            return iTrue;
        }
    }
    return iFalse;
}

void draw_Gamepad(const iGamepad *d) {
    if (!isConnected_Gamepad(d)) {
        return;
    }
    /* Draw the pointer. */
    iPaint p;
    init_Paint(&p);
    SDL_Renderer *render = renderer_Window(get_Window());
    uint8_t       alpha  = value_Anim(&d->opacity) * 255;
    const iInt2   pos    = init_I2(value_Anim(&d->pointerf[0]), value_Anim(&d->pointerf[1]));
    const iInt2   size = mulf_I2(size_SDLTexture(d->pointerTexture), 0.5f * d->window->pixelRatio);
    SDL_SetTextureAlphaMod(d->pointerTexture, alpha);
    SDL_RenderCopy(render, d->pointerTexture, NULL, &(SDL_Rect) { pos.x, pos.y, size.x, size.y });
    /* TODO: Draw button help overlay? */
}

#else

/*- Dummy --------------------------------------------------------------------------------------*/

struct Impl_Gamepad {};

iDefineTypeConstruction(Gamepad);

iBool isAvailable_Gamepad(void) {
    return iFalse;
}

void init_Gamepad   (iGamepad *d) { iUnused(d); }
void deinit_Gamepad (iGamepad *d) { iUnused(d); }
void draw_Gamepad   (const iGamepad *d) { iUnused(d); }

void movePointerOntoWidget_Gamepad(iGamepad *d, iWidget *widget, int span) {
    iUnused(d, widget, span);
}

void movePointer_Gamepad(iGamepad *d, iInt2 coord, int span) {
    iUnused(d, coord, span);
}

iBool isConnected_Gamepad(const iGamepad *d) {
    iUnused(d);
    return iFalse;
}

iBool isPointing_Gamepad(const iGamepad *d) {
    iUnused(d);
    return iFalse;
}

iInt2 pointerCoord_Gamepad(const iGamepad *d) {
    iUnused(d);
    return zero_I2();
}

int modState_Gamepad(const iGamepad *d) {
    iUnused(d);
    return 0;
}

const char *buttonName_Gamepad(const iGamepad *d, int sdlGameControllerButton) {
    iUnused(d, sdlGameControllerButton);
    return "";
}

iBool processEvent_Gamepad(iGamepad *d, const void *event) {
    iUnused(d, event);
    return iFalse;
}

#endif /* LAGRANGE_USE_GAMEPAD */