/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2010 Hans Petter Selasky. All rights reserved.
 *
 * 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 AUTHOR 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 AUTHOR 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.
 */

/*
 * HID spec: http://www.usb.org/developers/devclass_docs/HID1_11.pdf
 */

#include <sys/param.h>
#include <sys/stdint.h>
#include <sys/stddef.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/linker_set.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/condvar.h>
#include <sys/sysctl.h>
#include <sys/sx.h>
#include <sys/unistd.h>
#include <sys/callout.h>
#include <sys/malloc.h>
#include <sys/priv.h>

#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>
#include <dev/usb/usbdi_util.h>
#include <dev/usb/usbhid.h>
#include "usb_if.h"

#define USB_DEBUG_VAR g_mouse_debug
#include <dev/usb/usb_debug.h>

#include <dev/usb/gadget/g_mouse.h>

static SYSCTL_NODE(_hw_usb, OID_AUTO, g_mouse, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "USB mouse gadget");

#ifdef USB_DEBUG
static int g_mouse_debug = 0;

SYSCTL_INT(_hw_usb_g_mouse, OID_AUTO, debug, CTLFLAG_RWTUN,
    &g_mouse_debug, 0, "Debug level");
#endif

static int g_mouse_mode = 0;

SYSCTL_INT(_hw_usb_g_mouse, OID_AUTO, mode, CTLFLAG_RWTUN,
    &g_mouse_mode, 0, "Mode selection");

static int g_mouse_button_press_interval = 0;

SYSCTL_INT(_hw_usb_g_mouse, OID_AUTO, button_press_interval, CTLFLAG_RWTUN,
    &g_mouse_button_press_interval, 0, "Mouse button update interval in milliseconds");

static int g_mouse_cursor_update_interval = 1023;

SYSCTL_INT(_hw_usb_g_mouse, OID_AUTO, cursor_update_interval, CTLFLAG_RWTUN,
    &g_mouse_cursor_update_interval, 0, "Mouse cursor update interval in milliseconds");

static int g_mouse_cursor_radius = 128;

SYSCTL_INT(_hw_usb_g_mouse, OID_AUTO, cursor_radius, CTLFLAG_RWTUN,
    &g_mouse_cursor_radius, 0, "Mouse cursor radius in pixels");

struct g_mouse_data {
        uint8_t buttons;
#define BUT_0 0x01
#define BUT_1 0x02
#define BUT_2 0x04
        int8_t dx;
        int8_t dy;
        int8_t dz;
};

enum {
        G_MOUSE_INTR_DT,
        G_MOUSE_N_TRANSFER,
};

struct g_mouse_softc {
        struct mtx sc_mtx;
        struct usb_callout sc_button_press_callout;
        struct usb_callout sc_cursor_update_callout;
        struct g_mouse_data sc_data;
        struct usb_xfer *sc_xfer[G_MOUSE_N_TRANSFER];

        int     sc_mode;
        int     sc_radius;
        int     sc_last_x_state;
        int     sc_last_y_state;
        int     sc_curr_x_state;
        int     sc_curr_y_state;
        int     sc_tick;

        uint8_t sc_do_cursor_update;
        uint8_t sc_do_button_update;
};

static device_probe_t g_mouse_probe;
static device_attach_t g_mouse_attach;
static device_detach_t g_mouse_detach;
static usb_handle_request_t g_mouse_handle_request;
static usb_callback_t g_mouse_intr_callback;

static device_method_t g_mouse_methods[] = {
        /* USB interface */
        DEVMETHOD(usb_handle_request, g_mouse_handle_request),

        /* Device interface */
        DEVMETHOD(device_probe, g_mouse_probe),
        DEVMETHOD(device_attach, g_mouse_attach),
        DEVMETHOD(device_detach, g_mouse_detach),

        DEVMETHOD_END
};

static driver_t g_mouse_driver = {
        .name = "g_mouse",
        .methods = g_mouse_methods,
        .size = sizeof(struct g_mouse_softc),
};

DRIVER_MODULE(g_mouse, uhub, g_mouse_driver, 0, 0);
MODULE_DEPEND(g_mouse, usb, 1, 1, 1);

static const struct usb_config g_mouse_config[G_MOUSE_N_TRANSFER] = {
        [G_MOUSE_INTR_DT] = {
                .type = UE_INTERRUPT,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_IN,
                .flags = {.ext_buffer = 1,.pipe_bof = 1,},
                .bufsize = sizeof(struct g_mouse_data),
                .callback = &g_mouse_intr_callback,
                .frames = 1,
                .usb_mode = USB_MODE_DEVICE,
        },
};

static void g_mouse_button_press_timeout(void *arg);
static void g_mouse_cursor_update_timeout(void *arg);

static void
g_mouse_button_press_timeout_reset(struct g_mouse_softc *sc)
{
        int i = g_mouse_button_press_interval;

        if (i <= 0) {
                sc->sc_data.buttons = 0;
                sc->sc_do_button_update = 0;
        } else {
                sc->sc_do_button_update = 1;
        }

        if ((i <= 0) || (i > 1023))
                i = 1023;

        i = USB_MS_TO_TICKS(i);

        usb_callout_reset(&sc->sc_button_press_callout, i, 
            &g_mouse_button_press_timeout, sc);
}

static void
g_mouse_cursor_update_timeout_reset(struct g_mouse_softc *sc)
{
        int i = g_mouse_cursor_update_interval;

        if (i <= 0) {
                sc->sc_data.dx = 0;
                sc->sc_data.dy = 0;
                sc->sc_do_cursor_update = 0;
                sc->sc_tick = 0;
        } else {
                sc->sc_do_cursor_update = 1;
        }

        if ((i <= 0) || (i > 1023))
                i = 1023;

        i = USB_MS_TO_TICKS(i);

        usb_callout_reset(&sc->sc_cursor_update_callout, i, 
            &g_mouse_cursor_update_timeout, sc);
}

static void
g_mouse_update_mode_radius(struct g_mouse_softc *sc)
{
        sc->sc_mode = g_mouse_mode;
        sc->sc_radius = g_mouse_cursor_radius;

        if (sc->sc_radius < 0)
                sc->sc_radius = 0;
        else if (sc->sc_radius > 1023)
                sc->sc_radius = 1023;
}

static void
g_mouse_button_press_timeout(void *arg)
{
        struct g_mouse_softc *sc = arg;

        g_mouse_update_mode_radius(sc);

        DPRINTFN(11, "Timeout %p (button press)\n", sc->sc_xfer[G_MOUSE_INTR_DT]);

        g_mouse_button_press_timeout_reset(sc);

        usbd_transfer_start(sc->sc_xfer[G_MOUSE_INTR_DT]);
}

static void
g_mouse_cursor_update_timeout(void *arg)
{
        struct g_mouse_softc *sc = arg;

        g_mouse_update_mode_radius(sc);

        DPRINTFN(11, "Timeout %p (cursor update)\n", sc->sc_xfer[G_MOUSE_INTR_DT]);

        g_mouse_cursor_update_timeout_reset(sc);

        usbd_transfer_start(sc->sc_xfer[G_MOUSE_INTR_DT]);
}

static int
g_mouse_probe(device_t dev)
{
        struct usb_attach_arg *uaa = device_get_ivars(dev);

        DPRINTFN(11, "\n");

        if (uaa->usb_mode != USB_MODE_DEVICE)
                return (ENXIO);

        if ((uaa->info.bInterfaceClass == UICLASS_HID) &&
            (uaa->info.bInterfaceSubClass == UISUBCLASS_BOOT) &&
            (uaa->info.bInterfaceProtocol == UIPROTO_MOUSE))
                return (0);

        return (ENXIO);
}

static int
g_mouse_attach(device_t dev)
{
        struct g_mouse_softc *sc = device_get_softc(dev);
        struct usb_attach_arg *uaa = device_get_ivars(dev);
        int error;

        DPRINTFN(11, "\n");

        device_set_usb_desc(dev);

        mtx_init(&sc->sc_mtx, "g_mouse", NULL, MTX_DEF);

        usb_callout_init_mtx(&sc->sc_button_press_callout, &sc->sc_mtx, 0);
        usb_callout_init_mtx(&sc->sc_cursor_update_callout, &sc->sc_mtx, 0);

        sc->sc_mode = G_MOUSE_MODE_SILENT;

        error = usbd_transfer_setup(uaa->device,
            &uaa->info.bIfaceIndex, sc->sc_xfer, g_mouse_config,
            G_MOUSE_N_TRANSFER, sc, &sc->sc_mtx);

        if (error) {
                DPRINTF("error=%s\n", usbd_errstr(error));
                goto detach;
        }

        mtx_lock(&sc->sc_mtx);
        g_mouse_button_press_timeout_reset(sc);
        g_mouse_cursor_update_timeout_reset(sc);
        mtx_unlock(&sc->sc_mtx);

        return (0);                     /* success */

detach:
        g_mouse_detach(dev);

        return (ENXIO);                 /* error */
}

static int
g_mouse_detach(device_t dev)
{
        struct g_mouse_softc *sc = device_get_softc(dev);

        DPRINTF("\n");

        mtx_lock(&sc->sc_mtx);
        usb_callout_stop(&sc->sc_button_press_callout);
        usb_callout_stop(&sc->sc_cursor_update_callout);
        mtx_unlock(&sc->sc_mtx);

        usbd_transfer_unsetup(sc->sc_xfer, G_MOUSE_N_TRANSFER);

        usb_callout_drain(&sc->sc_button_press_callout);
        usb_callout_drain(&sc->sc_cursor_update_callout);

        mtx_destroy(&sc->sc_mtx);

        return (0);
}

static void
g_mouse_intr_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct g_mouse_softc *sc = usbd_xfer_softc(xfer);
        int actlen;
        int aframes;
        int dx;
        int dy;
        int radius;

        usbd_xfer_status(xfer, &actlen, NULL, &aframes, NULL);

        DPRINTF("st=%d aframes=%d actlen=%d bytes\n",
            USB_GET_STATE(xfer), aframes, actlen);

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                if (!(sc->sc_do_cursor_update || sc->sc_do_button_update))
                        break;

        case USB_ST_SETUP:
tr_setup:

          if (sc->sc_do_cursor_update) {
                sc->sc_do_cursor_update = 0;
                sc->sc_tick += 80;
                if ((sc->sc_tick < 0) || (sc->sc_tick > 7999))
                        sc->sc_tick = 0;
          }

          if (sc->sc_do_button_update) {
                        sc->sc_do_button_update = 0;
                        sc->sc_data.buttons ^= BUT_0;
          }

          radius = sc->sc_radius;

                switch (sc->sc_mode) {
                case G_MOUSE_MODE_SILENT:
                        sc->sc_data.buttons = 0;
                        break;
                case G_MOUSE_MODE_SPIRAL:
                        radius = (radius * (8000-sc->sc_tick)) / 8000;
                case G_MOUSE_MODE_CIRCLE:
                        /* TODO */
                        sc->sc_curr_y_state = 0;
                        sc->sc_curr_x_state = 0;
                        break;
                case G_MOUSE_MODE_BOX:
                        if (sc->sc_tick < 2000) {
                                sc->sc_curr_x_state = (sc->sc_tick * radius) / 2000;
                                sc->sc_curr_y_state = 0;
                        } else if (sc->sc_tick < 4000) {
                                sc->sc_curr_x_state = radius;
                                sc->sc_curr_y_state = -(((sc->sc_tick - 2000) * radius) / 2000);
                        } else if (sc->sc_tick < 6000) {
                                sc->sc_curr_x_state = radius - (((sc->sc_tick - 4000) * radius) / 2000);
                                sc->sc_curr_y_state = -radius;
                        } else {
                                sc->sc_curr_x_state = 0;
                                sc->sc_curr_y_state = -radius + (((sc->sc_tick - 6000) * radius) / 2000);
                        }
                        break;
                default:
                        break;
                }

                dx = sc->sc_curr_x_state - sc->sc_last_x_state;
                dy = sc->sc_curr_y_state - sc->sc_last_y_state;

                if (dx < -63)
                  dx = -63;
                else if (dx > 63)
                  dx = 63;

                if (dy < -63)
                  dy = -63;
                else if (dy > 63)
                  dy = 63;

                sc->sc_last_x_state += dx;
                sc->sc_last_y_state += dy;

                sc->sc_data.dx = dx;
                sc->sc_data.dy = dy;

                usbd_xfer_set_frame_data(xfer, 0, &sc->sc_data, sizeof(sc->sc_data));
                usbd_xfer_set_frames(xfer, 1);
                usbd_transfer_submit(xfer);
                break;

        default:                        /* Error */
                DPRINTF("error=%s\n", usbd_errstr(error));

                if (error != USB_ERR_CANCELLED) {
                        /* try to clear stall first */
                        usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                break;
        }
}

static int
g_mouse_handle_request(device_t dev,
    const void *preq, void **pptr, uint16_t *plen,
    uint16_t offset, uint8_t *pstate)
{
        const struct usb_device_request *req = preq;
        uint8_t is_complete = *pstate;

        if (!is_complete) {
                if ((req->bmRequestType == UT_WRITE_CLASS_INTERFACE) &&
                    (req->bRequest == UR_SET_PROTOCOL) &&
                    (req->wValue[0] == 0x00) &&
                    (req->wValue[1] == 0x00)) {
                        *plen = 0;
                        return (0);
                }
        }
        return (ENXIO);                 /* use builtin handler */
}