/*
 * This work is licensed under the terms of the GNU GPL, version 2 or
 * (at your option) any later version.  See the COPYING file in the
 * top-level directory.
 */

#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu-common.h"
#include "qemu/config-file.h"
#include "qemu/sockets.h"
#include "sysemu/sysemu.h"
#include "ui/input.h"
#include "qom/object_interfaces.h"

#include <sys/ioctl.h>
#include "standard-headers/linux/input.h"

static int linux_to_qcode[KEY_CNT] = {
    [KEY_ESC]            = Q_KEY_CODE_ESC,
    [KEY_1]              = Q_KEY_CODE_1,
    [KEY_2]              = Q_KEY_CODE_2,
    [KEY_3]              = Q_KEY_CODE_3,
    [KEY_4]              = Q_KEY_CODE_4,
    [KEY_5]              = Q_KEY_CODE_5,
    [KEY_6]              = Q_KEY_CODE_6,
    [KEY_7]              = Q_KEY_CODE_7,
    [KEY_8]              = Q_KEY_CODE_8,
    [KEY_9]              = Q_KEY_CODE_9,
    [KEY_0]              = Q_KEY_CODE_0,
    [KEY_MINUS]          = Q_KEY_CODE_MINUS,
    [KEY_EQUAL]          = Q_KEY_CODE_EQUAL,
    [KEY_BACKSPACE]      = Q_KEY_CODE_BACKSPACE,
    [KEY_TAB]            = Q_KEY_CODE_TAB,
    [KEY_Q]              = Q_KEY_CODE_Q,
    [KEY_W]              = Q_KEY_CODE_W,
    [KEY_E]              = Q_KEY_CODE_E,
    [KEY_R]              = Q_KEY_CODE_R,
    [KEY_T]              = Q_KEY_CODE_T,
    [KEY_Y]              = Q_KEY_CODE_Y,
    [KEY_U]              = Q_KEY_CODE_U,
    [KEY_I]              = Q_KEY_CODE_I,
    [KEY_O]              = Q_KEY_CODE_O,
    [KEY_P]              = Q_KEY_CODE_P,
    [KEY_LEFTBRACE]      = Q_KEY_CODE_BRACKET_LEFT,
    [KEY_RIGHTBRACE]     = Q_KEY_CODE_BRACKET_RIGHT,
    [KEY_ENTER]          = Q_KEY_CODE_RET,
    [KEY_LEFTCTRL]       = Q_KEY_CODE_CTRL,
    [KEY_A]              = Q_KEY_CODE_A,
    [KEY_S]              = Q_KEY_CODE_S,
    [KEY_D]              = Q_KEY_CODE_D,
    [KEY_F]              = Q_KEY_CODE_F,
    [KEY_G]              = Q_KEY_CODE_G,
    [KEY_H]              = Q_KEY_CODE_H,
    [KEY_J]              = Q_KEY_CODE_J,
    [KEY_K]              = Q_KEY_CODE_K,
    [KEY_L]              = Q_KEY_CODE_L,
    [KEY_SEMICOLON]      = Q_KEY_CODE_SEMICOLON,
    [KEY_APOSTROPHE]     = Q_KEY_CODE_APOSTROPHE,
    [KEY_GRAVE]          = Q_KEY_CODE_GRAVE_ACCENT,
    [KEY_LEFTSHIFT]      = Q_KEY_CODE_SHIFT,
    [KEY_BACKSLASH]      = Q_KEY_CODE_BACKSLASH,
    [KEY_102ND]          = Q_KEY_CODE_LESS,
    [KEY_Z]              = Q_KEY_CODE_Z,
    [KEY_X]              = Q_KEY_CODE_X,
    [KEY_C]              = Q_KEY_CODE_C,
    [KEY_V]              = Q_KEY_CODE_V,
    [KEY_B]              = Q_KEY_CODE_B,
    [KEY_N]              = Q_KEY_CODE_N,
    [KEY_M]              = Q_KEY_CODE_M,
    [KEY_COMMA]          = Q_KEY_CODE_COMMA,
    [KEY_DOT]            = Q_KEY_CODE_DOT,
    [KEY_SLASH]          = Q_KEY_CODE_SLASH,
    [KEY_RIGHTSHIFT]     = Q_KEY_CODE_SHIFT_R,
    [KEY_LEFTALT]        = Q_KEY_CODE_ALT,
    [KEY_SPACE]          = Q_KEY_CODE_SPC,
    [KEY_CAPSLOCK]       = Q_KEY_CODE_CAPS_LOCK,
    [KEY_F1]             = Q_KEY_CODE_F1,
    [KEY_F2]             = Q_KEY_CODE_F2,
    [KEY_F3]             = Q_KEY_CODE_F3,
    [KEY_F4]             = Q_KEY_CODE_F4,
    [KEY_F5]             = Q_KEY_CODE_F5,
    [KEY_F6]             = Q_KEY_CODE_F6,
    [KEY_F7]             = Q_KEY_CODE_F7,
    [KEY_F8]             = Q_KEY_CODE_F8,
    [KEY_F9]             = Q_KEY_CODE_F9,
    [KEY_F10]            = Q_KEY_CODE_F10,
    [KEY_NUMLOCK]        = Q_KEY_CODE_NUM_LOCK,
    [KEY_SCROLLLOCK]     = Q_KEY_CODE_SCROLL_LOCK,
    [KEY_KP0]            = Q_KEY_CODE_KP_0,
    [KEY_KP1]            = Q_KEY_CODE_KP_1,
    [KEY_KP2]            = Q_KEY_CODE_KP_2,
    [KEY_KP3]            = Q_KEY_CODE_KP_3,
    [KEY_KP4]            = Q_KEY_CODE_KP_4,
    [KEY_KP5]            = Q_KEY_CODE_KP_5,
    [KEY_KP6]            = Q_KEY_CODE_KP_6,
    [KEY_KP7]            = Q_KEY_CODE_KP_7,
    [KEY_KP8]            = Q_KEY_CODE_KP_8,
    [KEY_KP9]            = Q_KEY_CODE_KP_9,
    [KEY_KPMINUS]        = Q_KEY_CODE_KP_SUBTRACT,
    [KEY_KPPLUS]         = Q_KEY_CODE_KP_ADD,
    [KEY_KPDOT]          = Q_KEY_CODE_KP_DECIMAL,
    [KEY_KPENTER]        = Q_KEY_CODE_KP_ENTER,
    [KEY_KPSLASH]        = Q_KEY_CODE_KP_DIVIDE,
    [KEY_KPASTERISK]     = Q_KEY_CODE_KP_MULTIPLY,
    [KEY_F11]            = Q_KEY_CODE_F11,
    [KEY_F12]            = Q_KEY_CODE_F12,
    [KEY_RIGHTCTRL]      = Q_KEY_CODE_CTRL_R,
    [KEY_SYSRQ]          = Q_KEY_CODE_SYSRQ,
    [KEY_RIGHTALT]       = Q_KEY_CODE_ALT_R,
    [KEY_HOME]           = Q_KEY_CODE_HOME,
    [KEY_UP]             = Q_KEY_CODE_UP,
    [KEY_PAGEUP]         = Q_KEY_CODE_PGUP,
    [KEY_LEFT]           = Q_KEY_CODE_LEFT,
    [KEY_RIGHT]          = Q_KEY_CODE_RIGHT,
    [KEY_END]            = Q_KEY_CODE_END,
    [KEY_DOWN]           = Q_KEY_CODE_DOWN,
    [KEY_PAGEDOWN]       = Q_KEY_CODE_PGDN,
    [KEY_INSERT]         = Q_KEY_CODE_INSERT,
    [KEY_DELETE]         = Q_KEY_CODE_DELETE,
    [KEY_LEFTMETA]       = Q_KEY_CODE_META_L,
    [KEY_RIGHTMETA]      = Q_KEY_CODE_META_R,
    [KEY_MENU]           = Q_KEY_CODE_MENU,
};

static int qemu_input_linux_to_qcode(unsigned int lnx)
{
    assert(lnx < KEY_CNT);
    return linux_to_qcode[lnx];
}

static bool linux_is_button(unsigned int lnx)
{
    if (lnx < 0x100) {
        return false;
    }
    if (lnx >= 0x160 && lnx < 0x2c0) {
        return false;
    }
    return true;
}

#define TYPE_INPUT_LINUX "input-linux"
#define INPUT_LINUX(obj) \
    OBJECT_CHECK(InputLinux, (obj), TYPE_INPUT_LINUX)
#define INPUT_LINUX_GET_CLASS(obj) \
    OBJECT_GET_CLASS(InputLinuxClass, (obj), TYPE_INPUT_LINUX)
#define INPUT_LINUX_CLASS(klass) \
    OBJECT_CLASS_CHECK(InputLinuxClass, (klass), TYPE_INPUT_LINUX)

typedef struct InputLinux InputLinux;
typedef struct InputLinuxClass InputLinuxClass;

struct InputLinux {
    Object parent;

    char        *evdev;
    int         fd;
    bool        repeat;
    bool        grab_request;
    bool        grab_active;
    bool        grab_all;
    bool        keydown[KEY_CNT];
    int         keycount;
    int         wheel;
    bool        initialized;

    bool        has_rel_x;
    bool        has_abs_x;
    int         num_keys;
    int         num_btns;
    struct input_event event;
    int         read_offset;

    QTAILQ_ENTRY(InputLinux) next;
};

struct InputLinuxClass {
    ObjectClass parent_class;
};

static QTAILQ_HEAD(, InputLinux) inputs = QTAILQ_HEAD_INITIALIZER(inputs);

static void input_linux_toggle_grab(InputLinux *il)
{
    intptr_t request = !il->grab_active;
    InputLinux *item;
    int rc;

    rc = ioctl(il->fd, EVIOCGRAB, request);
    if (rc < 0) {
        return;
    }
    il->grab_active = !il->grab_active;

    if (!il->grab_all) {
        return;
    }
    QTAILQ_FOREACH(item, &inputs, next) {
        if (item == il || item->grab_all) {
            /* avoid endless loops */
            continue;
        }
        if (item->grab_active != il->grab_active) {
            input_linux_toggle_grab(item);
        }
    }
}

static void input_linux_handle_keyboard(InputLinux *il,
                                        struct input_event *event)
{
    if (event->type == EV_KEY) {
        if (event->value > 2 || (event->value > 1 && !il->repeat)) {
            /*
             * ignore autorepeat + unknown key events
             * 0 == up, 1 == down, 2 == autorepeat, other == undefined
             */
            return;
        }
        if (event->code >= KEY_CNT) {
            /*
             * Should not happen.  But better safe than sorry,
             * and we make Coverity happy too.
             */
            return;
        }

        /* keep track of key state */
        if (!il->keydown[event->code] && event->value) {
            il->keydown[event->code] = true;
            il->keycount++;
        }
        if (il->keydown[event->code] && !event->value) {
            il->keydown[event->code] = false;
            il->keycount--;
        }

        /* send event to guest when grab is active */
        if (il->grab_active) {
            int qcode = qemu_input_linux_to_qcode(event->code);
            qemu_input_event_send_key_qcode(NULL, qcode, event->value);
        }

        /* hotkey -> record switch request ... */
        if (il->keydown[KEY_LEFTCTRL] &&
            il->keydown[KEY_RIGHTCTRL]) {
            il->grab_request = true;
        }

        /*
         * ... and do the switch when all keys are lifted, so we
         * confuse neither guest nor host with keys which seem to
         * be stuck due to missing key-up events.
         */
        if (il->grab_request && !il->keycount) {
            il->grab_request = false;
            input_linux_toggle_grab(il);
        }
    }
}

static void input_linux_event_mouse_button(int button)
{
    qemu_input_queue_btn(NULL, button, true);
    qemu_input_event_sync();
    qemu_input_queue_btn(NULL, button, false);
    qemu_input_event_sync();
}

static void input_linux_handle_mouse(InputLinux *il, struct input_event *event)
{
    if (!il->grab_active) {
        return;
    }

    switch (event->type) {
    case EV_KEY:
        switch (event->code) {
        case BTN_LEFT:
            qemu_input_queue_btn(NULL, INPUT_BUTTON_LEFT, event->value);
            break;
        case BTN_RIGHT:
            qemu_input_queue_btn(NULL, INPUT_BUTTON_RIGHT, event->value);
            break;
        case BTN_MIDDLE:
            qemu_input_queue_btn(NULL, INPUT_BUTTON_MIDDLE, event->value);
            break;
        case BTN_GEAR_UP:
            qemu_input_queue_btn(NULL, INPUT_BUTTON_WHEEL_UP, event->value);
            break;
        case BTN_GEAR_DOWN:
            qemu_input_queue_btn(NULL, INPUT_BUTTON_WHEEL_DOWN,
                                 event->value);
            break;
        case BTN_SIDE:
            qemu_input_queue_btn(NULL, INPUT_BUTTON_SIDE, event->value);
            break;
        case BTN_EXTRA:
            qemu_input_queue_btn(NULL, INPUT_BUTTON_EXTRA, event->value);
            break;
        };
        break;
    case EV_REL:
        switch (event->code) {
        case REL_X:
            qemu_input_queue_rel(NULL, INPUT_AXIS_X, event->value);
            break;
        case REL_Y:
            qemu_input_queue_rel(NULL, INPUT_AXIS_Y, event->value);
            break;
        case REL_WHEEL:
            il->wheel = event->value;
            break;
        }
        break;
    case EV_SYN:
        qemu_input_event_sync();
        if (il->wheel != 0) {
            input_linux_event_mouse_button((il->wheel > 0)
                                           ? INPUT_BUTTON_WHEEL_UP
                                           : INPUT_BUTTON_WHEEL_DOWN);
            il->wheel = 0;
        }
        break;
    }
}

static void input_linux_event(void *opaque)
{
    InputLinux *il = opaque;
    int rc;
    int read_size;
    uint8_t *p = (uint8_t *)&il->event;

    for (;;) {
        read_size = sizeof(il->event) - il->read_offset;
        rc = read(il->fd, &p[il->read_offset], read_size);
        if (rc != read_size) {
            if (rc < 0 && errno != EAGAIN) {
                fprintf(stderr, "%s: read: %s\n", __func__, strerror(errno));
                qemu_set_fd_handler(il->fd, NULL, NULL, NULL);
                close(il->fd);
            } else if (rc > 0) {
                il->read_offset += rc;
            }
            break;
        }
        il->read_offset = 0;

        if (il->num_keys) {
            input_linux_handle_keyboard(il, &il->event);
        }
        if (il->has_rel_x && il->num_btns) {
            input_linux_handle_mouse(il, &il->event);
        }
    }
}

static void input_linux_complete(UserCreatable *uc, Error **errp)
{
    InputLinux *il = INPUT_LINUX(uc);
    uint8_t evtmap, relmap, absmap;
    uint8_t keymap[KEY_CNT / 8], keystate[KEY_CNT / 8];
    unsigned int i;
    int rc, ver;

    if (!il->evdev) {
        error_setg(errp, "no input device specified");
        return;
    }

    il->fd = open(il->evdev, O_RDWR);
    if (il->fd < 0)  {
        error_setg_file_open(errp, errno, il->evdev);
        return;
    }
    qemu_set_nonblock(il->fd);

    rc = ioctl(il->fd, EVIOCGVERSION, &ver);
    if (rc < 0) {
        error_setg(errp, "%s: is not an evdev device", il->evdev);
        goto err_close;
    }

    rc = ioctl(il->fd, EVIOCGBIT(0, sizeof(evtmap)), &evtmap);
    if (rc < 0) {
        error_setg(errp, "%s: failed to read event bits", il->evdev);
        goto err_close;
    }

    if (evtmap & (1 << EV_REL)) {
        relmap = 0;
        rc = ioctl(il->fd, EVIOCGBIT(EV_REL, sizeof(relmap)), &relmap);
        if (relmap & (1 << REL_X)) {
            il->has_rel_x = true;
        }
    }

    if (evtmap & (1 << EV_ABS)) {
        absmap = 0;
        rc = ioctl(il->fd, EVIOCGBIT(EV_ABS, sizeof(absmap)), &absmap);
        if (absmap & (1 << ABS_X)) {
            il->has_abs_x = true;
        }
    }

    if (evtmap & (1 << EV_KEY)) {
        memset(keymap, 0, sizeof(keymap));
        rc = ioctl(il->fd, EVIOCGBIT(EV_KEY, sizeof(keymap)), keymap);
        rc = ioctl(il->fd, EVIOCGKEY(sizeof(keystate)), keystate);
        for (i = 0; i < KEY_CNT; i++) {
            if (keymap[i / 8] & (1 << (i % 8))) {
                if (linux_is_button(i)) {
                    il->num_btns++;
                } else {
                    il->num_keys++;
                }
                if (keystate[i / 8] & (1 << (i % 8))) {
                    il->keydown[i] = true;
                    il->keycount++;
                }
            }
        }
    }

    qemu_set_fd_handler(il->fd, input_linux_event, NULL, il);
    if (il->keycount) {
        /* delay grab until all keys are released */
        il->grab_request = true;
    } else {
        input_linux_toggle_grab(il);
    }
    QTAILQ_INSERT_TAIL(&inputs, il, next);
    il->initialized = true;
    return;

err_close:
    close(il->fd);
    return;
}

static void input_linux_instance_finalize(Object *obj)
{
    InputLinux *il = INPUT_LINUX(obj);

    if (il->initialized) {
        QTAILQ_REMOVE(&inputs, il, next);
        close(il->fd);
    }
    g_free(il->evdev);
}

static char *input_linux_get_evdev(Object *obj, Error **errp)
{
    InputLinux *il = INPUT_LINUX(obj);

    return g_strdup(il->evdev);
}

static void input_linux_set_evdev(Object *obj, const char *value,
                                  Error **errp)
{
    InputLinux *il = INPUT_LINUX(obj);

    if (il->evdev) {
        error_setg(errp, "evdev property already set");
        return;
    }
    il->evdev = g_strdup(value);
}

static bool input_linux_get_grab_all(Object *obj, Error **errp)
{
    InputLinux *il = INPUT_LINUX(obj);

    return il->grab_all;
}

static void input_linux_set_grab_all(Object *obj, bool value,
                                   Error **errp)
{
    InputLinux *il = INPUT_LINUX(obj);

    il->grab_all = value;
}

static bool input_linux_get_repeat(Object *obj, Error **errp)
{
    InputLinux *il = INPUT_LINUX(obj);

    return il->repeat;
}

static void input_linux_set_repeat(Object *obj, bool value,
                                   Error **errp)
{
    InputLinux *il = INPUT_LINUX(obj);

    il->repeat = value;
}

static void input_linux_instance_init(Object *obj)
{
    object_property_add_str(obj, "evdev",
                            input_linux_get_evdev,
                            input_linux_set_evdev, NULL);
    object_property_add_bool(obj, "grab_all",
                             input_linux_get_grab_all,
                             input_linux_set_grab_all, NULL);
    object_property_add_bool(obj, "repeat",
                             input_linux_get_repeat,
                             input_linux_set_repeat, NULL);
}

static void input_linux_class_init(ObjectClass *oc, void *data)
{
    UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);

    ucc->complete = input_linux_complete;
}

static const TypeInfo input_linux_info = {
    .name = TYPE_INPUT_LINUX,
    .parent = TYPE_OBJECT,
    .class_size = sizeof(InputLinuxClass),
    .class_init = input_linux_class_init,
    .instance_size = sizeof(InputLinux),
    .instance_init = input_linux_instance_init,
    .instance_finalize = input_linux_instance_finalize,
    .interfaces = (InterfaceInfo[]) {
        { TYPE_USER_CREATABLE },
        { }
    }
};

static void register_types(void)
{
    type_register_static(&input_linux_info);
}

type_init(register_types);