// SPDX-FileCopyrightText: 2023 The wlroots contributors
// SPDX-FileCopyrightText: 2025 KylinSoft Co., Ltd.
//
// SPDX-License-Identifier: Expat

#define _POSIX_C_SOURCE 200809L
#include <assert.h>
#include <string.h>

#include <kywc/log.h>

#include "libinput_p.h"
#include "util/time.h"

struct tablet_tool {
    struct wlr_tablet_tool wlr_tool;
    struct libinput_tablet_tool *handle;
    struct wl_list link; // libinput_input_device.tablet_tools
};

const struct wlr_tablet_impl libinput_tablet_impl = {
    .name = "libinput-tablet-tool",
};

void init_device_tablet(struct libinput_input_device *dev)
{
    const char *name = libinput_device_get_name(dev->handle);
    struct wlr_tablet *wlr_tablet = &dev->tablet;
    wlr_tablet_init(wlr_tablet, &libinput_tablet_impl, name);

    libinput_device_get_size(dev->handle, &wlr_tablet->width_mm, &wlr_tablet->height_mm);

    struct udev_device *udev = libinput_device_get_udev_device(dev->handle);
    char **dst = wl_array_add(&wlr_tablet->paths, sizeof(char *));
    *dst = strdup(udev_device_get_syspath(udev));
    udev_device_unref(udev);

    wl_list_init(&dev->tablet_tools);
}

static void tool_destroy(struct tablet_tool *tool)
{
    wl_signal_emit_mutable(&tool->wlr_tool.events.destroy, &tool->wlr_tool);
    libinput_tablet_tool_unref(tool->handle);
    libinput_tablet_tool_set_user_data(tool->handle, NULL);
    wl_list_remove(&tool->link);
    free(tool);
}

void finish_device_tablet(struct libinput_input_device *dev)
{
    struct tablet_tool *tool, *tmp;
    wl_list_for_each_safe(tool, tmp, &dev->tablet_tools, link) {
        tool_destroy(tool);
    }
    wlr_tablet_finish(&dev->tablet);
}

struct libinput_input_device *device_from_tablet(struct wlr_tablet *wlr_tablet)
{
    assert(wlr_tablet->impl == &libinput_tablet_impl);
    struct libinput_input_device *dev = wl_container_of(wlr_tablet, dev, tablet);
    return dev;
}

static enum wlr_tablet_tool_type wlr_type_from_libinput_type(enum libinput_tablet_tool_type value)
{
    switch (value) {
    case LIBINPUT_TABLET_TOOL_TYPE_PEN:
        return WLR_TABLET_TOOL_TYPE_PEN;
    case LIBINPUT_TABLET_TOOL_TYPE_ERASER:
        return WLR_TABLET_TOOL_TYPE_ERASER;
    case LIBINPUT_TABLET_TOOL_TYPE_BRUSH:
        return WLR_TABLET_TOOL_TYPE_BRUSH;
    case LIBINPUT_TABLET_TOOL_TYPE_PENCIL:
        return WLR_TABLET_TOOL_TYPE_PENCIL;
    case LIBINPUT_TABLET_TOOL_TYPE_AIRBRUSH:
        return WLR_TABLET_TOOL_TYPE_AIRBRUSH;
    case LIBINPUT_TABLET_TOOL_TYPE_MOUSE:
        return WLR_TABLET_TOOL_TYPE_MOUSE;
    case LIBINPUT_TABLET_TOOL_TYPE_LENS:
        return WLR_TABLET_TOOL_TYPE_LENS;
    case LIBINPUT_TABLET_TOOL_TYPE_TOTEM:
        return WLR_TABLET_TOOL_TYPE_TOTEM;
    }
    abort(); // unreachable
}

static struct tablet_tool *get_tablet_tool(struct libinput_input_device *dev,
                                           struct libinput_tablet_tool *libinput_tool)
{
    struct tablet_tool *tool = libinput_tablet_tool_get_user_data(libinput_tool);
    if (tool) {
        return tool;
    }

    tool = calloc(1, sizeof(*tool));
    if (!tool) {
        kywc_log_errno(KYWC_ERROR, "failed to allocate libinput_tablet_tool");
        return NULL;
    }

    tool->wlr_tool.type = wlr_type_from_libinput_type(libinput_tablet_tool_get_type(libinput_tool));
    tool->wlr_tool.hardware_serial = libinput_tablet_tool_get_serial(libinput_tool);
    tool->wlr_tool.hardware_wacom = libinput_tablet_tool_get_tool_id(libinput_tool);

    tool->wlr_tool.pressure = libinput_tablet_tool_has_pressure(libinput_tool);
    tool->wlr_tool.distance = libinput_tablet_tool_has_distance(libinput_tool);
    tool->wlr_tool.tilt = libinput_tablet_tool_has_tilt(libinput_tool);
    tool->wlr_tool.rotation = libinput_tablet_tool_has_rotation(libinput_tool);
    tool->wlr_tool.slider = libinput_tablet_tool_has_slider(libinput_tool);
    tool->wlr_tool.wheel = libinput_tablet_tool_has_wheel(libinput_tool);

    wl_signal_init(&tool->wlr_tool.events.destroy);

    tool->handle = libinput_tablet_tool_ref(libinput_tool);
    libinput_tablet_tool_set_user_data(libinput_tool, tool);

    wl_list_insert(&dev->tablet_tools, &tool->link);
    return tool;
}

void handle_tablet_tool_axis(struct libinput_event *event, struct wlr_tablet *wlr_tablet)
{
    struct libinput_event_tablet_tool *tevent = libinput_event_get_tablet_tool_event(event);
    struct libinput_input_device *dev = device_from_tablet(wlr_tablet);
    struct tablet_tool *tool = get_tablet_tool(dev, libinput_event_tablet_tool_get_tool(tevent));

    struct wlr_tablet_tool_axis_event wlr_event = {
        .tablet = wlr_tablet,
        .tool = &tool->wlr_tool,
        .time_msec = usec_to_msec(libinput_event_tablet_tool_get_time_usec(tevent)),
    };
    if (libinput_event_tablet_tool_x_has_changed(tevent)) {
        wlr_event.updated_axes |= WLR_TABLET_TOOL_AXIS_X;
        wlr_event.x = libinput_event_tablet_tool_get_x_transformed(tevent, 1);
        wlr_event.dx = libinput_event_tablet_tool_get_dx(tevent);
    }
    if (libinput_event_tablet_tool_y_has_changed(tevent)) {
        wlr_event.updated_axes |= WLR_TABLET_TOOL_AXIS_Y;
        wlr_event.y = libinput_event_tablet_tool_get_y_transformed(tevent, 1);
        wlr_event.dy = libinput_event_tablet_tool_get_dy(tevent);
    }
    if (libinput_event_tablet_tool_pressure_has_changed(tevent)) {
        wlr_event.updated_axes |= WLR_TABLET_TOOL_AXIS_PRESSURE;
        wlr_event.pressure = libinput_event_tablet_tool_get_pressure(tevent);
    }
    if (libinput_event_tablet_tool_distance_has_changed(tevent)) {
        wlr_event.updated_axes |= WLR_TABLET_TOOL_AXIS_DISTANCE;
        wlr_event.distance = libinput_event_tablet_tool_get_distance(tevent);
    }
    if (libinput_event_tablet_tool_tilt_x_has_changed(tevent)) {
        wlr_event.updated_axes |= WLR_TABLET_TOOL_AXIS_TILT_X;
        wlr_event.tilt_x = libinput_event_tablet_tool_get_tilt_x(tevent);
    }
    if (libinput_event_tablet_tool_tilt_y_has_changed(tevent)) {
        wlr_event.updated_axes |= WLR_TABLET_TOOL_AXIS_TILT_Y;
        wlr_event.tilt_y = libinput_event_tablet_tool_get_tilt_y(tevent);
    }
    if (libinput_event_tablet_tool_rotation_has_changed(tevent)) {
        wlr_event.updated_axes |= WLR_TABLET_TOOL_AXIS_ROTATION;
        wlr_event.rotation = libinput_event_tablet_tool_get_rotation(tevent);
    }
    if (libinput_event_tablet_tool_slider_has_changed(tevent)) {
        wlr_event.updated_axes |= WLR_TABLET_TOOL_AXIS_SLIDER;
        wlr_event.slider = libinput_event_tablet_tool_get_slider_position(tevent);
    }
    if (libinput_event_tablet_tool_wheel_has_changed(tevent)) {
        wlr_event.updated_axes |= WLR_TABLET_TOOL_AXIS_WHEEL;
        wlr_event.wheel_delta = libinput_event_tablet_tool_get_wheel_delta(tevent);
    }
    wl_signal_emit_mutable(&wlr_tablet->events.axis, &wlr_event);
}

void handle_tablet_tool_proximity(struct libinput_event *event, struct wlr_tablet *wlr_tablet)
{
    struct libinput_event_tablet_tool *tevent = libinput_event_get_tablet_tool_event(event);
    struct libinput_input_device *dev = device_from_tablet(wlr_tablet);
    struct tablet_tool *tool = get_tablet_tool(dev, libinput_event_tablet_tool_get_tool(tevent));

    struct wlr_tablet_tool_proximity_event wlr_event = {
        .tablet = wlr_tablet,
        .tool = &tool->wlr_tool,
        .time_msec = usec_to_msec(libinput_event_tablet_tool_get_time_usec(tevent)),
        .x = libinput_event_tablet_tool_get_x_transformed(tevent, 1),
        .y = libinput_event_tablet_tool_get_y_transformed(tevent, 1),
    };

    switch (libinput_event_tablet_tool_get_proximity_state(tevent)) {
    case LIBINPUT_TABLET_TOOL_PROXIMITY_STATE_OUT:
        wlr_event.state = WLR_TABLET_TOOL_PROXIMITY_OUT;
        break;
    case LIBINPUT_TABLET_TOOL_PROXIMITY_STATE_IN:
        wlr_event.state = WLR_TABLET_TOOL_PROXIMITY_IN;
        break;
    }
    wl_signal_emit_mutable(&wlr_tablet->events.proximity, &wlr_event);

    if (libinput_event_tablet_tool_get_proximity_state(tevent) ==
        LIBINPUT_TABLET_TOOL_PROXIMITY_STATE_IN) {
        handle_tablet_tool_axis(event, wlr_tablet);
    }

    // If the tool is not unique, libinput will not find it again after the
    // proximity out, so we should destroy it
    if (!libinput_tablet_tool_is_unique(tool->handle) &&
        libinput_event_tablet_tool_get_proximity_state(tevent) ==
            LIBINPUT_TABLET_TOOL_PROXIMITY_STATE_OUT) {
        // The tool isn't unique, it can't be on multiple tablets
        tool_destroy(tool);
    }
}

void handle_tablet_tool_tip(struct libinput_event *event, struct wlr_tablet *wlr_tablet)
{
    handle_tablet_tool_axis(event, wlr_tablet);

    struct libinput_event_tablet_tool *tevent = libinput_event_get_tablet_tool_event(event);
    struct libinput_input_device *dev = device_from_tablet(wlr_tablet);
    struct tablet_tool *tool = get_tablet_tool(dev, libinput_event_tablet_tool_get_tool(tevent));

    struct wlr_tablet_tool_tip_event wlr_event = {
        .tablet = wlr_tablet,
        .tool = &tool->wlr_tool,
        .time_msec = usec_to_msec(libinput_event_tablet_tool_get_time_usec(tevent)),
        .x = libinput_event_tablet_tool_get_x_transformed(tevent, 1),
        .y = libinput_event_tablet_tool_get_y_transformed(tevent, 1),
    };

    switch (libinput_event_tablet_tool_get_tip_state(tevent)) {
    case LIBINPUT_TABLET_TOOL_TIP_UP:
        wlr_event.state = WLR_TABLET_TOOL_TIP_UP;
        break;
    case LIBINPUT_TABLET_TOOL_TIP_DOWN:
        wlr_event.state = WLR_TABLET_TOOL_TIP_DOWN;
        break;
    }
    wl_signal_emit_mutable(&wlr_tablet->events.tip, &wlr_event);
}

void handle_tablet_tool_button(struct libinput_event *event, struct wlr_tablet *wlr_tablet)
{
    handle_tablet_tool_axis(event, wlr_tablet);
    struct libinput_event_tablet_tool *tevent = libinput_event_get_tablet_tool_event(event);
    struct libinput_input_device *dev = device_from_tablet(wlr_tablet);
    struct tablet_tool *tool = get_tablet_tool(dev, libinput_event_tablet_tool_get_tool(tevent));

    struct wlr_tablet_tool_button_event wlr_event = {
        .tablet = wlr_tablet,
        .tool = &tool->wlr_tool,
        .time_msec = usec_to_msec(libinput_event_tablet_tool_get_time_usec(tevent)),
        .button = libinput_event_tablet_tool_get_button(tevent),
    };
    switch (libinput_event_tablet_tool_get_button_state(tevent)) {
    case LIBINPUT_BUTTON_STATE_RELEASED:
        wlr_event.state = WLR_BUTTON_RELEASED;
        break;
    case LIBINPUT_BUTTON_STATE_PRESSED:
        wlr_event.state = WLR_BUTTON_PRESSED;
        break;
    }
    wl_signal_emit_mutable(&wlr_tablet->events.button, &wlr_event);
}
