/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2015 Tycho Nightingale <tycho.nightingale@pluribusnetworks.com>
 * Copyright (c) 2015 Nahanni Systems Inc.
 * 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 ``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.
 */

#include <sys/types.h>
#include <sys/stat.h>

#include <machine/vmm_snapshot.h>

#include <assert.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <pthread.h>
#include <pthread_np.h>
#include <unistd.h>
#include <fcntl.h>

#include "atkbdc.h"
#include "bhyverun.h"
#include "config.h"
#include "console.h"
#include "debug.h"
#include "ps2kbd.h"

/* keyboard device commands */
#define PS2KC_RESET_DEV         0xff
#define PS2KC_SET_DEFAULTS      0xf6
#define PS2KC_DISABLE           0xf5
#define PS2KC_ENABLE            0xf4
#define PS2KC_SET_TYPEMATIC     0xf3
#define PS2KC_SEND_DEV_ID       0xf2
#define PS2KC_SET_SCANCODE_SET  0xf0
#define PS2KC_ECHO              0xee
#define PS2KC_SET_LEDS          0xed

#define PS2KC_BAT_SUCCESS       0xaa
#define PS2KC_ACK               0xfa

#define PS2KBD_FIFOSZ           16

#define PS2KBD_LAYOUT_BASEDIR   "/usr/share/bhyve/kbdlayout/"

#define MAX_PATHNAME            256

struct fifo {
        uint8_t buf[PS2KBD_FIFOSZ];
        int     rindex;         /* index to read from */
        int     windex;         /* index to write to */
        int     num;            /* number of bytes in the fifo */
        int     size;           /* size of the fifo */
};

struct ps2kbd_softc {
        struct atkbdc_softc     *atkbdc_sc;
        pthread_mutex_t         mtx;

        bool                    enabled;
        struct fifo             fifo;

        uint8_t                 curcmd; /* current command for next byte */
};

#define SCANCODE_E0_PREFIX 1
struct extended_translation {
        uint32_t keysym;
        uint8_t scancode;
        int flags;
};

/*
 * FIXME: Pause/break and Print Screen/SysRq require special handling.
 */
static struct extended_translation extended_translations[128] = {
                {0xff08, 0x66, 0},              /* Back space */
                {0xff09, 0x0d, 0},              /* Tab */
                {0xff0d, 0x5a, 0},              /* Return */
                {0xff1b, 0x76, 0},              /* Escape */
                {0xff50, 0x6c, SCANCODE_E0_PREFIX},     /* Home */
                {0xff51, 0x6b, SCANCODE_E0_PREFIX},     /* Left arrow */
                {0xff52, 0x75, SCANCODE_E0_PREFIX},     /* Up arrow */
                {0xff53, 0x74, SCANCODE_E0_PREFIX},     /* Right arrow */
                {0xff54, 0x72, SCANCODE_E0_PREFIX},     /* Down arrow */
                {0xff55, 0x7d, SCANCODE_E0_PREFIX},     /* PgUp */
                {0xff56, 0x7a, SCANCODE_E0_PREFIX},     /* PgDown */
                {0xff57, 0x69, SCANCODE_E0_PREFIX},     /* End */
                {0xff63, 0x70, SCANCODE_E0_PREFIX},     /* Ins */
                {0xff8d, 0x5a, SCANCODE_E0_PREFIX},     /* Keypad Enter */
                {0xffe1, 0x12, 0},              /* Left shift */
                {0xffe2, 0x59, 0},              /* Right shift */
                {0xffe3, 0x14, 0},              /* Left control */
                {0xffe4, 0x14, SCANCODE_E0_PREFIX},     /* Right control */
                /* {0xffe7, XXX}, Left meta */
                /* {0xffe8, XXX}, Right meta */
                {0xffe9, 0x11, 0},              /* Left alt */
                {0xfe03, 0x11, SCANCODE_E0_PREFIX},     /* AltGr */
                {0xffea, 0x11, SCANCODE_E0_PREFIX},     /* Right alt */
                {0xffeb, 0x1f, SCANCODE_E0_PREFIX},     /* Left Windows */
                {0xffec, 0x27, SCANCODE_E0_PREFIX},     /* Right Windows */
                {0xffbe, 0x05, 0},              /* F1 */
                {0xffbf, 0x06, 0},              /* F2 */
                {0xffc0, 0x04, 0},              /* F3 */
                {0xffc1, 0x0c, 0},              /* F4 */
                {0xffc2, 0x03, 0},              /* F5 */
                {0xffc3, 0x0b, 0},              /* F6 */
                {0xffc4, 0x83, 0},              /* F7 */
                {0xffc5, 0x0a, 0},              /* F8 */
                {0xffc6, 0x01, 0},              /* F9 */
                {0xffc7, 0x09, 0},              /* F10 */
                {0xffc8, 0x78, 0},              /* F11 */
                {0xffc9, 0x07, 0},              /* F12 */
                {0xffff, 0x71, SCANCODE_E0_PREFIX},     /* Del */
                {0xff14, 0x7e, 0},              /* ScrollLock */
                /* NumLock and Keypads*/
                {0xff7f, 0x77, 0},      /* NumLock */
                {0xffaf, 0x4a, SCANCODE_E0_PREFIX},     /* Keypad slash */
                {0xffaa, 0x7c, 0},      /* Keypad asterisk */
                {0xffad, 0x7b, 0},      /* Keypad minus */
                {0xffab, 0x79, 0},      /* Keypad plus */
                {0xffb7, 0x6c, 0},      /* Keypad 7 */
                {0xff95, 0x6c, 0},      /* Keypad home */
                {0xffb8, 0x75, 0},      /* Keypad 8 */
                {0xff97, 0x75, 0},      /* Keypad up arrow */
                {0xffb9, 0x7d, 0},      /* Keypad 9 */
                {0xff9a, 0x7d, 0},      /* Keypad PgUp */
                {0xffb4, 0x6b, 0},      /* Keypad 4 */
                {0xff96, 0x6b, 0},      /* Keypad left arrow */
                {0xffb5, 0x73, 0},      /* Keypad 5 */
                {0xff9d, 0x73, 0},      /* Keypad empty */
                {0xffb6, 0x74, 0},      /* Keypad 6 */
                {0xff98, 0x74, 0},      /* Keypad right arrow */
                {0xffb1, 0x69, 0},      /* Keypad 1 */
                {0xff9c, 0x69, 0},      /* Keypad end */
                {0xffb2, 0x72, 0},      /* Keypad 2 */
                {0xff99, 0x72, 0},      /* Keypad down arrow */
                {0xffb3, 0x7a, 0},      /* Keypad 3 */
                {0xff9b, 0x7a, 0},      /* Keypad PgDown */
                {0xffb0, 0x70, 0},      /* Keypad 0 */
                {0xff9e, 0x70, 0},      /* Keypad ins */
                {0xffae, 0x71, 0},      /* Keypad . */
                {0xff9f, 0x71, 0},      /* Keypad del */
                {0, 0, 0}               /* Terminator */
};

/* ASCII to type 2 scancode lookup table */
static uint8_t ascii_translations[128] = {
                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,
                0x29, 0x16, 0x52, 0x26, 0x25, 0x2e, 0x3d, 0x52,
                0x46, 0x45, 0x3e, 0x55, 0x41, 0x4e, 0x49, 0x4a,
                0x45, 0x16, 0x1e, 0x26, 0x25, 0x2e, 0x36, 0x3d,
                0x3e, 0x46, 0x4c, 0x4c, 0x41, 0x55, 0x49, 0x4a,
                0x1e, 0x1c, 0x32, 0x21, 0x23, 0x24, 0x2b, 0x34,
                0x33, 0x43, 0x3b, 0x42, 0x4b, 0x3a, 0x31, 0x44,
                0x4d, 0x15, 0x2d, 0x1b, 0x2c, 0x3c, 0x2a, 0x1d,
                0x22, 0x35, 0x1a, 0x54, 0x5d, 0x5b, 0x36, 0x4e,
                0x0e, 0x1c, 0x32, 0x21, 0x23, 0x24, 0x2b, 0x34,
                0x33, 0x43, 0x3b, 0x42, 0x4b, 0x3a, 0x31, 0x44,
                0x4d, 0x15, 0x2d, 0x1b, 0x2c, 0x3c, 0x2a, 0x1d,
                0x22, 0x35, 0x1a, 0x54, 0x5d, 0x5b, 0x0e, 0x00,
};

/* ScanCode set1 to set2 lookup table */
static const uint8_t keyset1to2_translations[128] = {
                   0, 0x76, 0x16, 0x1E, 0x26, 0x25, 0x2e, 0x36,
                0x3d, 0x3e, 0x46, 0x45, 0x4e, 0x55, 0x66, 0x0d,
                0x15, 0x1d, 0x24, 0x2d, 0x2c, 0x35, 0x3c, 0x43,
                0x44, 0x4d, 0x54, 0x5b, 0x5a, 0x14, 0x1c, 0x1b,
                0x23, 0x2b, 0x34, 0x33, 0x3b, 0x42, 0x4b, 0x4c,
                0x52, 0x0e, 0x12, 0x5d, 0x1a, 0x22, 0x21, 0x2a,
                0x32, 0x31, 0x3a, 0x41, 0x49, 0x4a, 0x59, 0x7c,
                0x11, 0x29, 0x58, 0x05, 0x06, 0x04, 0x0c, 0x03,
                0x0b, 0x83, 0x0a, 0x01, 0x09, 0x77, 0x7e, 0x6c,
                0x75, 0x7d, 0x7b, 0x6b, 0x73, 0x74, 0x79, 0x69,
                0x72, 0x7a, 0x70, 0x71, 0x84, 0x60, 0x61, 0x78,
                0x07, 0x0f, 0x17, 0x1f, 0x27, 0x2f, 0x37, 0x3f,
                0x47, 0x4f, 0x56, 0x5e, 0x08, 0x10, 0x18, 0x20,
                0x28, 0x30, 0x38, 0x40, 0x48, 0x50, 0x57, 0x6f,
                0x13, 0x19, 0x39, 0x51, 0x53, 0x5c, 0x5f, 0x62,
                0x63, 0x64, 0x65, 0x67, 0x68, 0x6a, 0x6d, 0x6e,
};

static void
fifo_init(struct ps2kbd_softc *sc)
{
        struct fifo *fifo;

        fifo = &sc->fifo;
        fifo->size = sizeof(((struct fifo *)0)->buf);
}

static void
fifo_reset(struct ps2kbd_softc *sc)
{
        struct fifo *fifo;

        fifo = &sc->fifo;
        bzero(fifo, sizeof(struct fifo));
        fifo->size = sizeof(((struct fifo *)0)->buf);
}

static void
fifo_put(struct ps2kbd_softc *sc, uint8_t val)
{
        struct fifo *fifo;

        fifo = &sc->fifo;
        if (fifo->num < fifo->size) {
                fifo->buf[fifo->windex] = val;
                fifo->windex = (fifo->windex + 1) % fifo->size;
                fifo->num++;
        }
}

static int
fifo_get(struct ps2kbd_softc *sc, uint8_t *val)
{
        struct fifo *fifo;

        fifo = &sc->fifo;
        if (fifo->num > 0) {
                *val = fifo->buf[fifo->rindex];
                fifo->rindex = (fifo->rindex + 1) % fifo->size;
                fifo->num--;
                return (0);
        }

        return (-1);
}

int
ps2kbd_read(struct ps2kbd_softc *sc, uint8_t *val)
{
        int retval;

        pthread_mutex_lock(&sc->mtx);
        retval = fifo_get(sc, val);
        pthread_mutex_unlock(&sc->mtx);

        return (retval);
}

void
ps2kbd_write(struct ps2kbd_softc *sc, uint8_t val)
{
        pthread_mutex_lock(&sc->mtx);
        if (sc->curcmd) {
                switch (sc->curcmd) {
                case PS2KC_SET_TYPEMATIC:
                        fifo_put(sc, PS2KC_ACK);
                        break;
                case PS2KC_SET_SCANCODE_SET:
                        fifo_put(sc, PS2KC_ACK);
                        break;
                case PS2KC_SET_LEDS:
                        fifo_put(sc, PS2KC_ACK);
                        break;
                default:
                        EPRINTLN("Unhandled ps2 keyboard current "
                            "command byte 0x%02x", val);
                        break;
                }
                sc->curcmd = 0;
        } else {
                switch (val) {
                case 0x00:
                        fifo_put(sc, PS2KC_ACK);
                        break;
                case PS2KC_RESET_DEV:
                        fifo_reset(sc);
                        fifo_put(sc, PS2KC_ACK);
                        fifo_put(sc, PS2KC_BAT_SUCCESS);
                        break;
                case PS2KC_SET_DEFAULTS:
                        fifo_reset(sc);
                        fifo_put(sc, PS2KC_ACK);
                        break;
                case PS2KC_DISABLE:
                        sc->enabled = false;
                        fifo_put(sc, PS2KC_ACK);
                        break;
                case PS2KC_ENABLE:
                        sc->enabled = true;
                        fifo_reset(sc);
                        fifo_put(sc, PS2KC_ACK);
                        break;
                case PS2KC_SET_TYPEMATIC:
                        sc->curcmd = val;
                        fifo_put(sc, PS2KC_ACK);
                        break;
                case PS2KC_SEND_DEV_ID:
                        fifo_put(sc, PS2KC_ACK);
                        fifo_put(sc, 0xab);
                        fifo_put(sc, 0x83);
                        break;
                case PS2KC_SET_SCANCODE_SET:
                        sc->curcmd = val;
                        fifo_put(sc, PS2KC_ACK);
                        break;
                case PS2KC_ECHO:
                        fifo_put(sc, PS2KC_ECHO);
                        break;
                case PS2KC_SET_LEDS:
                        sc->curcmd = val;
                        fifo_put(sc, PS2KC_ACK);
                        break;
                default:
                        EPRINTLN("Unhandled ps2 keyboard command "
                            "0x%02x", val);
                        break;
                }
        }
        pthread_mutex_unlock(&sc->mtx);
}

/*
 * Translate keysym to type 2 scancode and insert into keyboard buffer.
 */
static void
ps2kbd_keysym_queue(struct ps2kbd_softc *sc,
    int down, uint32_t keysym, uint32_t keycode)
{
        const struct extended_translation *trans;
        int e0_prefix, found;
        uint8_t code;

        assert(pthread_mutex_isowned_np(&sc->mtx));

        if (keycode) {
                code =  keyset1to2_translations[(uint8_t)(keycode & 0x7f)];
                e0_prefix = ((keycode & 0x80) ?  SCANCODE_E0_PREFIX : 0);
                found = 1;
        } else {
                found = 0;
                if (keysym < 0x80) {
                        code = ascii_translations[keysym];
                        e0_prefix = 0;
                        found = 1;
                } else {
                        for (trans = &extended_translations[0];
                            trans->keysym != 0; trans++) {
                                if (keysym == trans->keysym) {
                                        code = trans->scancode;
                                        e0_prefix = trans->flags & SCANCODE_E0_PREFIX;
                                        found = 1;
                                        break;
                                }
                        }
                }
        }

        if (!found) {
                EPRINTLN("Unhandled ps2 keyboard keysym 0x%x", keysym);
                return;
        }

        if (e0_prefix)
                fifo_put(sc, 0xe0);
        if (!down)
                fifo_put(sc, 0xf0);
        fifo_put(sc, code);
}

static void
ps2kbd_event(int down, uint32_t keysym, uint32_t keycode, void *arg)
{
        struct ps2kbd_softc *sc = arg;
        int fifo_full;

        pthread_mutex_lock(&sc->mtx);
        if (!sc->enabled) {
                pthread_mutex_unlock(&sc->mtx);
                return;
        }
        fifo_full = sc->fifo.num == PS2KBD_FIFOSZ;
        ps2kbd_keysym_queue(sc, down, keysym, keycode);
        pthread_mutex_unlock(&sc->mtx);

        if (!fifo_full)
                atkbdc_event(sc->atkbdc_sc, 1);
}

static void
ps2kbd_update_extended_translation(uint32_t keycode, uint32_t scancode, uint32_t prefix)
{
        int i = 0;

        do {
                if (extended_translations[i].keysym == keycode)
                        break;
        } while (extended_translations[++i].keysym);

        if (i == (sizeof(extended_translations) / sizeof(struct extended_translation) - 1))
                return;

        if (!extended_translations[i].keysym)   {
                extended_translations[i].keysym = keycode;

                extended_translations[i+1].keysym = 0;
                extended_translations[i+1].scancode = 0;
                extended_translations[i+1].flags = 0;
        }

        extended_translations[i].scancode = (uint8_t)(scancode & 0xff);
        extended_translations[i].flags = (prefix ? SCANCODE_E0_PREFIX : 0);
}

static void
ps2kbd_setkbdlayout(void)
{
        int err;
        int fd;
        char path[MAX_PATHNAME];
        char *buf, *next, *line;
        struct stat sb;
        ssize_t sz;
        uint8_t ascii;
        uint32_t keycode, scancode, prefix;

        snprintf(path, MAX_PATHNAME, PS2KBD_LAYOUT_BASEDIR"%s", get_config_value("keyboard.layout") );

        err = stat(path, &sb);
        if (err)
                return;

        buf = (char *)malloc(sizeof(char) * sb.st_size);
        if (buf == NULL)
                return;

        fd = open(path, O_RDONLY);
        if (fd == -1)
                goto out;

        sz = read(fd, buf, sb.st_size);

        close(fd);

        if (sz < 0 || sz != sb.st_size)
                goto out;

        next = buf;
        while ((line = strsep(&next, "\n")) != NULL)    {
                if (sscanf(line, "'%c',%x;", &ascii, &scancode) == 2)   {
                        if (ascii < 0x80)
                                ascii_translations[ascii] = (uint8_t)(scancode & 0xff);
                } else if (sscanf(line, "%x,%x,%x;", &keycode, &scancode, &prefix) == 3 )       {
                        ps2kbd_update_extended_translation(keycode, scancode, prefix);
                } else if (sscanf(line, "%x,%x;", &keycode, &scancode) == 2)    {
                        if (keycode < 0x80)
                                ascii_translations[(uint8_t)(keycode & 0xff)] = (uint8_t)(scancode & 0xff);
                        else
                                ps2kbd_update_extended_translation(keycode, scancode, 0);
                }
        }

out:
        free(buf);
}

struct ps2kbd_softc *
ps2kbd_init(struct atkbdc_softc *atkbdc_sc)
{
        struct ps2kbd_softc *sc;

        if (get_config_value("keyboard.layout") != NULL)
                ps2kbd_setkbdlayout();

        sc = calloc(1, sizeof (struct ps2kbd_softc));
        pthread_mutex_init(&sc->mtx, NULL);
        fifo_init(sc);
        sc->atkbdc_sc = atkbdc_sc;

        console_kbd_register(ps2kbd_event, sc, 1);

        return (sc);
}

#ifdef BHYVE_SNAPSHOT
int
ps2kbd_snapshot(struct ps2kbd_softc *sc, struct vm_snapshot_meta *meta)
{
        int ret;

        SNAPSHOT_VAR_OR_LEAVE(sc->enabled, meta, ret, done);
        SNAPSHOT_VAR_OR_LEAVE(sc->curcmd, meta, ret, done);

done:
        return (ret);
}
#endif