/*
 * QEMU HID devices
 *
 * Copyright (c) 2005 Fabrice Bellard
 * Copyright (c) 2007 OpenMoko, Inc.  (andrew@openedhand.com)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "hw/hw.h"
#include "ui/console.h"
#include "qemu/timer.h"
#include "hw/input/hid.h"

#define HID_USAGE_ERROR_ROLLOVER        0x01
#define HID_USAGE_POSTFAIL              0x02
#define HID_USAGE_ERROR_UNDEFINED       0x03

/* Indices are QEMU keycodes, values are from HID Usage Table.  Indices
 * above 0x80 are for keys that come after 0xe0 or 0xe1+0x1d or 0xe1+0x9d.  */
static const uint8_t hid_usage_keys[0x100] = {
    0x00, 0x29, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23,
    0x24, 0x25, 0x26, 0x27, 0x2d, 0x2e, 0x2a, 0x2b,
    0x14, 0x1a, 0x08, 0x15, 0x17, 0x1c, 0x18, 0x0c,
    0x12, 0x13, 0x2f, 0x30, 0x28, 0xe0, 0x04, 0x16,
    0x07, 0x09, 0x0a, 0x0b, 0x0d, 0x0e, 0x0f, 0x33,
    0x34, 0x35, 0xe1, 0x31, 0x1d, 0x1b, 0x06, 0x19,
    0x05, 0x11, 0x10, 0x36, 0x37, 0x38, 0xe5, 0x55,
    0xe2, 0x2c, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e,
    0x3f, 0x40, 0x41, 0x42, 0x43, 0x53, 0x47, 0x5f,
    0x60, 0x61, 0x56, 0x5c, 0x5d, 0x5e, 0x57, 0x59,
    0x5a, 0x5b, 0x62, 0x63, 0x00, 0x00, 0x00, 0x44,
    0x45, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e,
    0xe8, 0xe9, 0x71, 0x72, 0x73, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x85, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0xe3, 0xe7, 0x65,

    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x58, 0xe4, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x54, 0x00, 0x46,
    0xe6, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x48, 0x00, 0x4a,
    0x52, 0x4b, 0x00, 0x50, 0x00, 0x4f, 0x00, 0x4d,
    0x51, 0x4e, 0x49, 0x4c, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0xe3, 0xe7, 0x65, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
};

bool hid_has_events(HIDState *hs)
{
    return hs->n > 0 || hs->idle_pending;
}

static void hid_idle_timer(void *opaque)
{
    HIDState *hs = opaque;

    hs->idle_pending = true;
    hs->event(hs);
}

static void hid_del_idle_timer(HIDState *hs)
{
    if (hs->idle_timer) {
        timer_del(hs->idle_timer);
        timer_free(hs->idle_timer);
        hs->idle_timer = NULL;
    }
}

void hid_set_next_idle(HIDState *hs)
{
    if (hs->idle) {
        uint64_t expire_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
                               get_ticks_per_sec() * hs->idle * 4 / 1000;
        if (!hs->idle_timer) {
            hs->idle_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, hid_idle_timer, hs);
        }
        timer_mod_ns(hs->idle_timer, expire_time);
    } else {
        hid_del_idle_timer(hs);
    }
}

static void hid_pointer_event(DeviceState *dev, QemuConsole *src,
                              InputEvent *evt)
{
    static const int bmap[INPUT_BUTTON__MAX] = {
        [INPUT_BUTTON_LEFT]   = 0x01,
        [INPUT_BUTTON_RIGHT]  = 0x02,
        [INPUT_BUTTON_MIDDLE] = 0x04,
    };
    HIDState *hs = (HIDState *)dev;
    HIDPointerEvent *e;

    assert(hs->n < QUEUE_LENGTH);
    e = &hs->ptr.queue[(hs->head + hs->n) & QUEUE_MASK];

    switch (evt->type) {
    case INPUT_EVENT_KIND_REL:
        if (evt->u.rel->axis == INPUT_AXIS_X) {
            e->xdx += evt->u.rel->value;
        } else if (evt->u.rel->axis == INPUT_AXIS_Y) {
            e->ydy += evt->u.rel->value;
        }
        break;

    case INPUT_EVENT_KIND_ABS:
        if (evt->u.rel->axis == INPUT_AXIS_X) {
            e->xdx = evt->u.rel->value;
        } else if (evt->u.rel->axis == INPUT_AXIS_Y) {
            e->ydy = evt->u.rel->value;
        }
        break;

    case INPUT_EVENT_KIND_BTN:
        if (evt->u.btn->down) {
            e->buttons_state |= bmap[evt->u.btn->button];
            if (evt->u.btn->button == INPUT_BUTTON_WHEELUP) {
                e->dz--;
            } else if (evt->u.btn->button == INPUT_BUTTON_WHEELDOWN) {
                e->dz++;
            }
        } else {
            e->buttons_state &= ~bmap[evt->u.btn->button];
        }
        break;

    default:
        /* keep gcc happy */
        break;
    }

}

static void hid_pointer_sync(DeviceState *dev)
{
    HIDState *hs = (HIDState *)dev;
    HIDPointerEvent *prev, *curr, *next;
    bool event_compression = false;

    if (hs->n == QUEUE_LENGTH-1) {
        /*
         * Queue full.  We are losing information, but we at least
         * keep track of most recent button state.
         */
        return;
    }

    prev = &hs->ptr.queue[(hs->head + hs->n - 1) & QUEUE_MASK];
    curr = &hs->ptr.queue[(hs->head + hs->n) & QUEUE_MASK];
    next = &hs->ptr.queue[(hs->head + hs->n + 1) & QUEUE_MASK];

    if (hs->n > 0) {
        /*
         * No button state change between previous and current event
         * (and previous wasn't seen by the guest yet), so there is
         * motion information only and we can combine the two event
         * into one.
         */
        if (curr->buttons_state == prev->buttons_state) {
            event_compression = true;
        }
    }

    if (event_compression) {
        /* add current motion to previous, clear current */
        if (hs->kind == HID_MOUSE) {
            prev->xdx += curr->xdx;
            curr->xdx = 0;
            prev->ydy += curr->ydy;
            curr->ydy = 0;
        } else {
            prev->xdx = curr->xdx;
            prev->ydy = curr->ydy;
        }
        prev->dz += curr->dz;
        curr->dz = 0;
    } else {
        /* prepate next (clear rel, copy abs + btns) */
        if (hs->kind == HID_MOUSE) {
            next->xdx = 0;
            next->ydy = 0;
        } else {
            next->xdx = curr->xdx;
            next->ydy = curr->ydy;
        }
        next->dz = 0;
        next->buttons_state = curr->buttons_state;
        /* make current guest visible, notify guest */
        hs->n++;
        hs->event(hs);
    }
}

static void hid_keyboard_event(DeviceState *dev, QemuConsole *src,
                               InputEvent *evt)
{
    HIDState *hs = (HIDState *)dev;
    int scancodes[3], i, count;
    int slot;

    count = qemu_input_key_value_to_scancode(evt->u.key->key,
                                             evt->u.key->down,
                                             scancodes);
    if (hs->n + count > QUEUE_LENGTH) {
        fprintf(stderr, "usb-kbd: warning: key event queue full\n");
        return;
    }
    for (i = 0; i < count; i++) {
        slot = (hs->head + hs->n) & QUEUE_MASK; hs->n++;
        hs->kbd.keycodes[slot] = scancodes[i];
    }
    hs->event(hs);
}

static void hid_keyboard_process_keycode(HIDState *hs)
{
    uint8_t hid_code, index, key;
    int i, keycode, slot;

    if (hs->n == 0) {
        return;
    }
    slot = hs->head & QUEUE_MASK; QUEUE_INCR(hs->head); hs->n--;
    keycode = hs->kbd.keycodes[slot];

    key = keycode & 0x7f;
    index = key | ((hs->kbd.modifiers & (1 << 8)) >> 1);
    hid_code = hid_usage_keys[index];
    hs->kbd.modifiers &= ~(1 << 8);

    switch (hid_code) {
    case 0x00:
        return;

    case 0xe0:
        assert(key == 0x1d);
        if (hs->kbd.modifiers & (1 << 9)) {
            /* The hid_codes for the 0xe1/0x1d scancode sequence are 0xe9/0xe0.
             * Here we're processing the second hid_code.  By dropping bit 9
             * and setting bit 8, the scancode after 0x1d will access the
             * second half of the table.
             */
            hs->kbd.modifiers ^= (1 << 8) | (1 << 9);
            return;
        }
        /* fall through to process Ctrl_L */
    case 0xe1 ... 0xe7:
        /* Ctrl_L/Ctrl_R, Shift_L/Shift_R, Alt_L/Alt_R, Win_L/Win_R.
         * Handle releases here, or fall through to process presses.
         */
        if (keycode & (1 << 7)) {
            hs->kbd.modifiers &= ~(1 << (hid_code & 0x0f));
            return;
        }
        /* fall through */
    case 0xe8 ... 0xe9:
        /* USB modifiers are just 1 byte long.  Bits 8 and 9 of
         * hs->kbd.modifiers implement a state machine that detects the
         * 0xe0 and 0xe1/0x1d sequences.  These bits do not follow the
         * usual rules where bit 7 marks released keys; they are cleared
         * elsewhere in the function as the state machine dictates.
         */
        hs->kbd.modifiers |= 1 << (hid_code & 0x0f);
        return;

    case 0xea ... 0xef:
        abort();

    default:
        break;
    }

    if (keycode & (1 << 7)) {
        for (i = hs->kbd.keys - 1; i >= 0; i--) {
            if (hs->kbd.key[i] == hid_code) {
                hs->kbd.key[i] = hs->kbd.key[-- hs->kbd.keys];
                hs->kbd.key[hs->kbd.keys] = 0x00;
                break;
            }
        }
        if (i < 0) {
            return;
        }
    } else {
        for (i = hs->kbd.keys - 1; i >= 0; i--) {
            if (hs->kbd.key[i] == hid_code) {
                break;
            }
        }
        if (i < 0) {
            if (hs->kbd.keys < sizeof(hs->kbd.key)) {
                hs->kbd.key[hs->kbd.keys++] = hid_code;
            }
        } else {
            return;
        }
    }
}

static inline int int_clamp(int val, int vmin, int vmax)
{
    if (val < vmin) {
        return vmin;
    } else if (val > vmax) {
        return vmax;
    } else {
        return val;
    }
}

void hid_pointer_activate(HIDState *hs)
{
    if (!hs->ptr.mouse_grabbed) {
        qemu_input_handler_activate(hs->s);
        hs->ptr.mouse_grabbed = 1;
    }
}

int hid_pointer_poll(HIDState *hs, uint8_t *buf, int len)
{
    int dx, dy, dz, l;
    int index;
    HIDPointerEvent *e;

    hs->idle_pending = false;

    hid_pointer_activate(hs);

    /* When the buffer is empty, return the last event.  Relative
       movements will all be zero.  */
    index = (hs->n ? hs->head : hs->head - 1);
    e = &hs->ptr.queue[index & QUEUE_MASK];

    if (hs->kind == HID_MOUSE) {
        dx = int_clamp(e->xdx, -127, 127);
        dy = int_clamp(e->ydy, -127, 127);
        e->xdx -= dx;
        e->ydy -= dy;
    } else {
        dx = e->xdx;
        dy = e->ydy;
    }
    dz = int_clamp(e->dz, -127, 127);
    e->dz -= dz;

    if (hs->n &&
        !e->dz &&
        (hs->kind == HID_TABLET || (!e->xdx && !e->ydy))) {
        /* that deals with this event */
        QUEUE_INCR(hs->head);
        hs->n--;
    }

    /* Appears we have to invert the wheel direction */
    dz = 0 - dz;
    l = 0;
    switch (hs->kind) {
    case HID_MOUSE:
        if (len > l) {
            buf[l++] = e->buttons_state;
        }
        if (len > l) {
            buf[l++] = dx;
        }
        if (len > l) {
            buf[l++] = dy;
        }
        if (len > l) {
            buf[l++] = dz;
        }
        break;

    case HID_TABLET:
        if (len > l) {
            buf[l++] = e->buttons_state;
        }
        if (len > l) {
            buf[l++] = dx & 0xff;
        }
        if (len > l) {
            buf[l++] = dx >> 8;
        }
        if (len > l) {
            buf[l++] = dy & 0xff;
        }
        if (len > l) {
            buf[l++] = dy >> 8;
        }
        if (len > l) {
            buf[l++] = dz;
        }
        break;

    default:
        abort();
    }

    return l;
}

int hid_keyboard_poll(HIDState *hs, uint8_t *buf, int len)
{
    hs->idle_pending = false;

    if (len < 2) {
        return 0;
    }

    hid_keyboard_process_keycode(hs);

    buf[0] = hs->kbd.modifiers & 0xff;
    buf[1] = 0;
    if (hs->kbd.keys > 6) {
        memset(buf + 2, HID_USAGE_ERROR_ROLLOVER, MIN(8, len) - 2);
    } else {
        memcpy(buf + 2, hs->kbd.key, MIN(8, len) - 2);
    }

    return MIN(8, len);
}

int hid_keyboard_write(HIDState *hs, uint8_t *buf, int len)
{
    if (len > 0) {
        int ledstate = 0;
        /* 0x01: Num Lock LED
         * 0x02: Caps Lock LED
         * 0x04: Scroll Lock LED
         * 0x08: Compose LED
         * 0x10: Kana LED */
        hs->kbd.leds = buf[0];
        if (hs->kbd.leds & 0x04) {
            ledstate |= QEMU_SCROLL_LOCK_LED;
        }
        if (hs->kbd.leds & 0x01) {
            ledstate |= QEMU_NUM_LOCK_LED;
        }
        if (hs->kbd.leds & 0x02) {
            ledstate |= QEMU_CAPS_LOCK_LED;
        }
        kbd_put_ledstate(ledstate);
    }
    return 0;
}

void hid_reset(HIDState *hs)
{
    switch (hs->kind) {
    case HID_KEYBOARD:
        memset(hs->kbd.keycodes, 0, sizeof(hs->kbd.keycodes));
        memset(hs->kbd.key, 0, sizeof(hs->kbd.key));
        hs->kbd.keys = 0;
        break;
    case HID_MOUSE:
    case HID_TABLET:
        memset(hs->ptr.queue, 0, sizeof(hs->ptr.queue));
        break;
    }
    hs->head = 0;
    hs->n = 0;
    hs->protocol = 1;
    hs->idle = 0;
    hs->idle_pending = false;
    hid_del_idle_timer(hs);
}

void hid_free(HIDState *hs)
{
    qemu_input_handler_unregister(hs->s);
    hid_del_idle_timer(hs);
}

static QemuInputHandler hid_keyboard_handler = {
    .name  = "QEMU HID Keyboard",
    .mask  = INPUT_EVENT_MASK_KEY,
    .event = hid_keyboard_event,
};

static QemuInputHandler hid_mouse_handler = {
    .name  = "QEMU HID Mouse",
    .mask  = INPUT_EVENT_MASK_BTN | INPUT_EVENT_MASK_REL,
    .event = hid_pointer_event,
    .sync  = hid_pointer_sync,
};

static QemuInputHandler hid_tablet_handler = {
    .name  = "QEMU HID Tablet",
    .mask  = INPUT_EVENT_MASK_BTN | INPUT_EVENT_MASK_ABS,
    .event = hid_pointer_event,
    .sync  = hid_pointer_sync,
};

void hid_init(HIDState *hs, int kind, HIDEventFunc event)
{
    hs->kind = kind;
    hs->event = event;

    if (hs->kind == HID_KEYBOARD) {
        hs->s = qemu_input_handler_register((DeviceState *)hs,
                                            &hid_keyboard_handler);
        qemu_input_handler_activate(hs->s);
    } else if (hs->kind == HID_MOUSE) {
        hs->s = qemu_input_handler_register((DeviceState *)hs,
                                            &hid_mouse_handler);
    } else if (hs->kind == HID_TABLET) {
        hs->s = qemu_input_handler_register((DeviceState *)hs,
                                            &hid_tablet_handler);
    }
}

static int hid_post_load(void *opaque, int version_id)
{
    HIDState *s = opaque;

    hid_set_next_idle(s);

    if (s->n == QUEUE_LENGTH && (s->kind == HID_TABLET ||
                                 s->kind == HID_MOUSE)) {
        /*
         * Handle ptr device migration from old qemu with full queue.
         *
         * Throw away everything but the last event, so we propagate
         * at least the current button state to the guest.  Also keep
         * current position for the tablet, signal "no motion" for the
         * mouse.
         */
        HIDPointerEvent evt;
        evt = s->ptr.queue[(s->head+s->n) & QUEUE_MASK];
        if (s->kind == HID_MOUSE) {
            evt.xdx = 0;
            evt.ydy = 0;
        }
        s->ptr.queue[0] = evt;
        s->head = 0;
        s->n = 1;
    }
    return 0;
}

static const VMStateDescription vmstate_hid_ptr_queue = {
    .name = "HIDPointerEventQueue",
    .version_id = 1,
    .minimum_version_id = 1,
    .fields = (VMStateField[]) {
        VMSTATE_INT32(xdx, HIDPointerEvent),
        VMSTATE_INT32(ydy, HIDPointerEvent),
        VMSTATE_INT32(dz, HIDPointerEvent),
        VMSTATE_INT32(buttons_state, HIDPointerEvent),
        VMSTATE_END_OF_LIST()
    }
};

const VMStateDescription vmstate_hid_ptr_device = {
    .name = "HIDPointerDevice",
    .version_id = 1,
    .minimum_version_id = 1,
    .post_load = hid_post_load,
    .fields = (VMStateField[]) {
        VMSTATE_STRUCT_ARRAY(ptr.queue, HIDState, QUEUE_LENGTH, 0,
                             vmstate_hid_ptr_queue, HIDPointerEvent),
        VMSTATE_UINT32(head, HIDState),
        VMSTATE_UINT32(n, HIDState),
        VMSTATE_INT32(protocol, HIDState),
        VMSTATE_UINT8(idle, HIDState),
        VMSTATE_END_OF_LIST(),
    }
};

const VMStateDescription vmstate_hid_keyboard_device = {
    .name = "HIDKeyboardDevice",
    .version_id = 1,
    .minimum_version_id = 1,
    .post_load = hid_post_load,
    .fields = (VMStateField[]) {
        VMSTATE_UINT32_ARRAY(kbd.keycodes, HIDState, QUEUE_LENGTH),
        VMSTATE_UINT32(head, HIDState),
        VMSTATE_UINT32(n, HIDState),
        VMSTATE_UINT16(kbd.modifiers, HIDState),
        VMSTATE_UINT8(kbd.leds, HIDState),
        VMSTATE_UINT8_ARRAY(kbd.key, HIDState, 16),
        VMSTATE_INT32(kbd.keys, HIDState),
        VMSTATE_INT32(protocol, HIDState),
        VMSTATE_UINT8(idle, HIDState),
        VMSTATE_END_OF_LIST(),
    }
};